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[Display omitted] • A mathematical model for the influence of the transition layer on metal-polymer film adhesion. • The growth of a transition layer featuring metal nanoparticles between Ni and PI has been proposed for the first time. • The film with a transition layer can withstand more than twice the maximum tensile force of untreated Ni-PI films when the resistance change reaches 10%. The shear strength between Ni and PI has increased by more than 50%. • This research provides a fine application prospect in flexible electronics, facilitating the application of these types of sensors in harsh environments. Metal-polymer films are widely used for flexible sensors and actuators, enduring various mechanical loads and facing the risk of structural damage. In this work, a method of manipulating the metal-polymer interface characteristics by metal nanoparticles in the transition layer is presented to prevent film fracture and restrain electrical failures. A transition layer with nickel (Ni) nanoparticles is grown on the surface of polyimide (PI) film through the stages of ring cleavage, ion exchange, and reduction. Further, the research investigates the influence of three parameters — the concentration of ring cleavage solution, the time of ring cleavage, and the concentration of reductant — on the thickness and particle morphology of the transition layer. After depositing ∼ 200 nm Ni film by magnetron sputtering, the film with a transition layer can withstand twice more than the maximum tensile force of untreated Ni-PI films when the resistance change reaches 10 %. The transition layer featuring metal nanoparticles increases the shear strength between Ni and PI by over 50 %. This method has been proposed for the first time, which considerably improves the adhesion properties of these two widely used materials, which provides a fine application prospect in flexible electronics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hot carrier behavior at the interface between plasmonic nanoparticles (NPs) and semiconductors with opposite doping types is elucidated. • More efficient hot-carrier separation and injection when Au NPs are attached p-doped GaN (Au/p-GaN) compared to n-doped GaN (Au/n-GaN). • A higher enhancement (approximately 8 times) in photoelectrochemical reactions for Au/n-GaN compared to Au/p-GaN is observed. • The difference in the band alignment between the Au/GaN junction systems is responsible for the superior photoelectrochemical performance of Au/n-GaN. In junctions with semiconductors, plasmonic metal nanoparticles (NPs) can be utilized to efficiently harness solar energy by collecting hot carriers. However, the behavior of hot carriers at the interfaces between semiconductors with opposite doping types is not fully elucidated. Here, Au NPs are attached to n-doped (Au/ n -GaN) or p-doped gallium nitrides (Au/ p -GaN) to examine the photoelectrochemical performance regarding hot carrier behavior. Direct surface potential measurements revealed that electrons are collected in n-type GaN (n -GaN) when illuminated, while hot holes remain in Au NPs for oxidation reactions via the plasmonic process. Conversely, holes are collected in p -type GaN (p -GaN), thereby promoting the reduction reaction by the electrons left in Au NPs. Specifically, the change in surface potential difference induced by green light illumination in Au/ p -GaN is four times greater than that observed in Au/ n -GaN. Conversely, the changes in open - circuit potential and photocurrent density under light illumination are approximately six times more significant in Au/ n -GaN compared to Au/ p -GaN. This difference in efficiency can be attributed to the more favorable oxidation reaction occurring in Au NPs at the interface with GaN materials, as opposed to the reduction reaction, due to the difference in band alignment between the Au/GaN junction systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • Simultaneous improvement of H 2 O 2 production and selectivity using NiO nanoparticles. • The presence of NiO nanoparticles promotes CN charge separation and adsorption strength for oxygen. • The loading of NiO nanoparticles greatly reduces the energy barrier for the activation of *O 2 to *OOH. The use of solar photocatalysis to produce H 2 O 2 as a new strategy alternative to the anthraquinone method, is less resource intensive and more environmentally friendly. In this study, carbon nitride (CN) loaded with NiO nanoparticles (CN-NiO) was used as photocatalyst for the generation of H 2 O 2 through two electron oxygen reduction reactions (ORR). The existence of NiO nanoparticles improves both the photoactivity and selectivity of the carbon nitride towards two electron ORR. CN-NiO photocatalyst reaches 86 % selectivity for 2e− ORR, and a yield of 4054.1 μmol g−1h−1 for H 2 O 2 generation under simulated sunlight, which is 2.7 times of that for bare CN. NiO nanoparticles promote the separation efficiency of photogenerated electrons and holes in photocatalysts, and also serve as adsorption sites for O 2 , enhancing the adsorption of O 2. Additionally, DFT calculations show that the loading of NiO nanoparticles greatly reduces the energy barrier for the activation of *O 2 to *OOH, which facilitates the efficient 2e− ORR photocatalysis. This study may advance knowledge regarding the function of metal oxide nanoparticles in the photocatalytic synthesis of H 2 O 2. [ABSTRACT FROM AUTHOR]

[Display omitted] • An efficient 3D SERS substrate was fabricated using Ag nanoparticles decorated ZnO nanorods on textured Silicon Micropyramids, enhancing SERS capability through synergistic effect of the heterostructure. • Our heterostructure demonstrates a significant improvement in the detection limit of 10-13 M for Rhodamine 6G with an enhanced factor of 1.3 × 1012 and a detection limit of 10-10 M for Rhodamine B. • The heterostructure showed a remarkable photocatalytic dye degradation under UV irradiation in open air conditions. • The work exploited the excellent plasmonic enhancement properties of Ag nanoparticles decorated on ZnO nanorods and the light trapping mechanism of the Si Micropyramids that manifests the synergistic performance of the heterostructure. • Our 3D heterostructure substrate paves way for promising applications in reusable SERS sensors. 3D hybrid heterostructure have been fabricated using Ag Nanoparticles decorated ZnO nanorods over textured Silicon Micropyramid for Surface Enhanced Raman Scattering (SERS) applications. Silicon texturing was performed using facile Alkaline texturing route followed by the growth of ZnO nanorods (ZnONR) array on the micropyramids over which, the Ag nanoparticles (AgNPs) were decorated. The phase and the surface of the heterostructure was studied by XRD and Field Emission Scanning Electron Microscope (FESEM), respectively. The SERS performance of the 3D heterostructure was evaluated using Rhodamine 6G (R6G) at various concentrations with a detection limit of 0.1 pM. The superior properties of SiMP/ZnONR/AgNP over ZnONR/AgND heterostructure has also been presented to understand the effect of the 3D pyramidal substrate for superior SERS performance. The recovery of the prepared heterostructure has also been demonstrated by photocatalytic degradation of Rhodamine 6G and Methylene Blue. Our work demonstrates a facile synthesis of 3D SERS heterostructure and sheds light on its superior SERS properties paving ways for wide range of applications in bio-sensors, detection of harmful chemicals, food adulterations, narcotic detection and many more. [ABSTRACT FROM AUTHOR]

The Ag nanoparticles deposited on the surface of Mn 3 O 4 can effectively hinder the Jahn-Teller effect, inhibit the dissolution of Mn2+, improve electronic conductivity, and significantly improve the zinc ion storage performance. [Display omitted] • Composite materials with Ag nanoparticles deposited on the surface of Mn 3 O 4 can be prepared using a simple aqueous solution precipitation method. • During the charging and discharging process, Mn 3 O 4 is first oxidized to the intermediate product Mn 5 O 8 , and then converted to R-MnO 2 , and then reversible H+ and Zn2+ insertion/removal. • The surface deposition of Ag can block the Jahn-Teller effect; inhibit the dissolution of Mn2+ and gas generation, thereby achieving excellent electrochemical performance. Manganese-based compounds, as the most widely used among aqueous zinc-ion batteries cathode materials, have the advantages of high theoretical specific capacity and high voltage. However, their low electrical conductivity and poor cycling stability make them unsuitable for practical applications. Surface modification with metal ions is the most effective and convenient method for improving the situation. Composites deposited with Ag on the surface of Mn 3 O 4 (referred to as AMO) are prepared by the aqueous solution precipitation method. The specific capacity of the AMO-0.5 composite is 423.1 mAh/g at a current density of 0.1 A g−1, and the capacity retention is 87.7% after 1000 cycles at 1.5 A g−1. The surface interaction of AMO improves the intrinsic defects of the material, enhances the electrical conductivity, stabilizes the crystalline structure of the material, and hinders the Jahn-Teller effect. Ag nanoparticles can also inhibit the gas bubbles generated by water decomposition during the cycling process and prevent the dissolution of Mn2+, thus improving the cycling stability. The study on the synergistic mechanism of surface-modified metal nanoparticles can provide inspirations for the development of other similar new materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hollow TiO 2 @Fe 2 O 3 Nanofiber were prepared by a simple electrospinning technique. • TiO 2 @Fe 2 O 3 nanofibers were used as functional additive in Lithium sulfur cell. • The Lithium sulfur cell with TiO 2 @Fe 2 O 3 nanofibers demonstrated excellent electrochemical performance. • TiO 2 @Fe 2 O 3 nanofibers promotes capture conversion of polysulfides. High theoretical capacity (1675 mA h g−1) and energy density (2600 Wh kg−1) in addition to low cost, non-toxicity and natural abundance stimulates the exploration of sulfur as a potential cathode material. However, serious capacity fade and poor reaction kinetics leads to untimely failure which prevents the practical commodification of these batteries. Here, a simple and versatile electrospinning technique has been employed to prepare a polymeric template to fabricate hollow metal oxide@metal oxide nanofibers. The hollow fibrous shell with large specific surface area is incorporated as an anchoring material comprising of distinct crystalline phases separated by amorphous domains. Meanwhile, the encapsulated metal oxide nanoparticles ensure efficient conversion of soluble polysulfides thereby, promoting the reaction kinetics and avoiding any surface passivation of anchoring material. The LSB cell with 5 % TiO 2 @Fe 2 O 3 nanofiber additives delivers impressively in the rate capability test with stable capacities of 620 and 480 mA h g−1 at 1C and 2C rate, respectively. Moreover, an excellent cycling performance is attained with a fade rate of 0.092 % per cycle over 500 cycles at 0.5C-rate. The findings of this work shall provide a pathway for facile preparation of functional metal oxide composites for simultaneous trapping and conversion of polysulfide species in sulfur batteries. [ABSTRACT FROM AUTHOR]

The Pd/HS-1 catalyst with hollow hexagonal prism structure was prepared and applied to Suzuki coupling reaction, achieving over 99% conversion of bromobenzene in a short period of time. [Display omitted] • Hierarchical porous zeolites were prepared by dissolution recrystallization and then loaded with Pd nanoparticles by impregnation. • The proper acid sites as well as metal-zeolite interactions can modulate the electronic state of Pd, and thus improve the conversion of bromobenzene. • The size of metal nanoparticles plays a decisive role in metal-catalyzed heterogeneous reactions, due to Pd binding energy varied with changed sizes. • 2.0Pd/HS-1 provides excellent catalytic performance in non-toxic reaction media, mild reaction conditions, and short reaction times while achieving recyclability. The Suzuki-Miyaura reaction is one of the most effective routes for the construction of carbon–carbon bonds, due to the obvious advantages of mild reaction conditions, wide range of functional group tolerance, simplicity of operation, and environmental friendliness. However, these reactions highly depend on the development of the active and stable catalysts. Herein, the hollow hexagonal prismatic silicalite-1 (HS-1) zeolite-supported palladium nanoparticles (Pd NPs) were synthesized and applied as a catalyst in Suzuki-Miyaura reaction. The experimental results show that 2.0Pd/HS-1 is an efficient and stable catalyst, which can achieve a high conversion rate (>99.9 %) in a short time (45 min) and can be recycled. Further studies show that 2.0Pd/HS-1 has abundant mesopores, which are favorable for exposing more active sites and promoting the transfer of reactants around the catalysts, thus improving the contact opportunities between the catalysts and the feedstock. Moreover, its proper acid sites as well as metal-zeolite interactions can modulate the electronic state of Pd, and thus improve the conversion of bromobenzene. This work provides new insights into the design, synthesis and applications of highly efficient hollow silicalite-1 zeolite loaded metal catalysts. [ABSTRACT FROM AUTHOR]

Nanoconfinement effect allows precise tuning of catalyst performance by providing a spatially confined (sub)nanoscale environment for reaction systems. For the confined catalysts constructed from two-dimensional materials and transition metals, it can be achieved experimentally by wrapping metal nanoparticles in layers of carbon or other similar materials. Here, we propose a new type of confined catalyst composed of iron clusters sandwiched between graphitic carbon nitride and black phosphorus monolayers, and investigate its performance in the nitrogen reduction reaction by first-principles simulations. It is found that the overpotential at the Fe active site exhibits a significant decrease from 0.82 V to 0.49 V after the formation of the confined interfacial microenvironment, which is attributed to the spatial confinement by the two-dimensional monolayers and the change in binding patterns between the adsorbed species and the iron cluster. The corresponding selectivity in competition with the hydrogen evolution reaction is also improved to a certain extent. Moreover, the appearance of electronic states of the black phosphorus overlayer at the Fermi level further promotes the carrier transport in the electrochemical processes. Our work demonstrates the role of the nanoconfinement effect in enhancing the electrocatalytic performance and may shed new light on the rational design of electrocatalysts. • A catalyst of Fe clusters confined between g-C 3 N 4 and black phosphorus is proposed. • The electrocatalytic performance in the nitrogen reduction reaction is investigated. • The overpotential exhibits a significant decrease upon the confinement. • Spatial confinement and binding pattern change cause the overpotential reduction. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Thermal dewetting technique is used to optimize the self-assembling of Ag NPs. • Integration of Ag nanoparticles in proximity to the InGaN/GaN-based nano-LEDs. • It exhibits LSP energy coupling efficiency (70 %) and fast decay lifetime (2.04 ns). • Nearly 130% and 290% enhancement in EL and CL compared with reference nanorod LEDs. • Numerical simulation is performed to correlate the degree of LSP coupling effect. Integration of metal nanoparticles (NPs) in proximity to the InGaN/GaN-based individual nanorod light-emitting diodes (nano-LEDs) can provide a platform to improve the emission efficiency through localized surface plasmon (LSP) coupling effect. This work evaluates an optimizing process for fabricating self-assembled Ag NPs on the surface of horizontally aligned individual nano-LEDs via thermal evaporation/dewetting techniques. The closely integrated Ag NPs on each nano-LED accelerate a strong LSP energy coupling efficiency of 70 % with a fast decay lifetime of 2.04 ns. The self-assembled Ag NPs/nano-LEDs exhibit nearly 130 % and 290 % enhancement in electroluminescent and cathodoluminescent performance compared with reference nanorod LEDs. Furthermore, numerical simulation is performed to correlate the degree of LSP coupling effect concerning changes in particle size and inter-particle distance between the Ag NPs. Thus, the realization of self-assembled Ag NPs/nano-LEDs can prove the concept of the idea to enhance emission efficiency suitable for next-generation display technology. [ABSTRACT FROM AUTHOR]

The hybrid material composed of PtNPs and self-sensitized MOF (PCN-222(Pd)) was obtained by ultrasonic mixing method. The photocatalytic hydrogen production rate the hybrid material was up to 3932 μmol g-1h−1, and it had sufficient stability. [Display omitted] • The Pt/PCN-222(Pd) material was used to increase the H 2 production rate of MOFs. • The synergistic effect of Pd-porphyrin and PtNPs reduced electron-hole recombination. • The 3%Pt/PCN-222(Pd) was repeatedly used for producing H 2 under visible light. • The 3%Pt/PCN-222(Pd) material remains the structural integrity after reaction. Recently, there has been significant interest in the investigation of high-efficiency photocatalysts utilizing metal–organic frameworks (MOFs). The combination of metal nanoparticles (MNPs) into MOFs to form composites, such as platinum NPs (PtNPs)/MOFs, has become a prevalent and widely employed method in the field of photocatalysis. In this investigation, a simple method was employed to distribute PtNPs uniformly across the surface of a self-sensitized palladium porphyrin MOF (PCN-222(Pd)). When subjected to irradiation by visible light, the hybrid material 3%Pt/PCN-222(Pd) demonstrated a notably effective rate of 3932 μmol g-1 h-1 photocatalytic H 2 generation from the water, which is 2.2 times greater than a single PCN-222(Pd). This improvement may be related to the coordination of polyvinylpyrrolidone (PVP) between C=O and Zr4+, which enhances the interaction of PtNPs with PCN-222(Pd) nanorods. Consequently, the long-life electrons from Pd-metalized tetrakis(4-carboxyphenyl)porphyrin (PdTCPP) photosensitizers rapidly shift towards the electron capture site of PtNPs, significantly reducing the occurrence of recombination between photogenerated electron-hole pairs. The utilization of the synergistic effect of Pd-porphyrin photosensitizers and PtNPs co-catalyst in this technique efficiently enhances electron transport between Pd-porphyrin and PtNPs units, hence promoting the rate of H 2 evolution. [ABSTRACT FROM AUTHOR]

[Display omitted] • Copper a promising candidate for plasmonic application due to its earth-abundant nature, significant low cost and a localized surface plasmon resonance in visible range. • Metallic copper nanoparticles are produced by nanosecond pulsed laser ablation in acetone and methanol. • Cu nanoparticles are embedded between two transparent electrodes to synthesize and optimize a plasmonic and conductive structure for photovoltaic applications. • Aluminum-doped zinc oxide and Zirconium- doped Indium Oxide have proven to be excellent indium-free (or very low indium content) alternative for transparent electrodes. • The internal quantum efficiency of a tandem solar cell, on which this plasmonic and conductive structure was integrated, achieved values as high as 89%. We report on copper nanoparticles produced by laser ablation, in acetone and methanol, from a Cu target using a 1064 nm nanosecond pulsed laser. The morphology, size, structure and chemical composition of the nanoparticles are investigated as a function of the solvent employed. Different analyses confirm the metallic nature of the nanoparticles, without amorphous carbon or copper oxides shells. Then, the nanoparticles are embedded between two transparent electrodes, aluminium-doped zinc oxide (AZO) and zirconium-doped indium oxide (IZrO) as top and bottom layers, respectively. The Glass/IZrO bott /Cu nanoparticles/AZO top structures are synthesized and optimized as plasmonic and conductive structure for photovoltaic applications. Optical properties show a strong dependence on the thermal annealing at 200 °C and type of copper nanoparticles embedded in transparent electrodes. The transparent electrode with the lowest E gap limits the E gap to the whole structure. The best structure shows a mean value of transmittance in the visible-NIR range of ∼79% with an E gap of 3.43 eV and, moreover, it shows diffused transmittance between 2.5 and 6% in VIS-NIR range and a sheet resistance of 79 Ω/sq. The performances of the best structure are tested measuring the internal quantum efficiency of a tandem solar cell, getting values as high as 89%. [ABSTRACT FROM AUTHOR]

Figures (a) and (b) demonstrate that the Pt NPs were successfully modified on the MCNO-based detector after annealing at 750 °C. The Pt NPs had a diameter of 5–10 nm, which is within the typical size range of quantum dots, thus allowing them to be considered as quantum dots. Pt NPs modification of MCNO film resulted in a remarkable ratio of 73, which is approximately 4.1 times higher than the ratio without Pt NPs modification. This excellent result can be attributed to three factors. Firstly, the barrier created between the NPs and the film reduces the dark current by blocking the transport of carriers. Secondly, the plasma resonance effect of the Pt NPs increases the incident light intensity. Lastly, the extinction of the NPs enhances the absorption of incident light and reduces the surface resistance, leading to a high photocurrent enhancement. These results demonstrate that Pt NPs modification plays a critical role in improving the photoproperties of MCNO-based detectors. [Display omitted] • High quality MCNO films had been deposited on Si substrates by RF magnetron sputtering. • High vacuum in situ annealing plays a critical role in the properties of MCNO-based detectors. • High vacuum in situ 750 °C annealing resulted in a 7.61 on/off ratio for MCNO-based detectors. • Pt nanoparticles modification significantly improved on/off ratio of the device to 38.51. The work developed a series of infrared detectors based on the Mn-Co-Ni-O (MCNO) films, which were grown using a radio frequency (RF) magnetron sputtering technique. It was observed that the characteristics of MCNO films were significantly impacted by the annealing temperature. Elevating the in-situ annealing temperature from 550 to 750 °C improved the performances of MCNO films. Additionally, it was found that in situ annealing was more advantageous than ex-situ annealing of 750 °C for the properties of MCNO films. The response value (light to dark) increased from 2.5 to 17.7 at 15 V bias, representing a 6.08-fold enhancement, and the response time decreased to 11.8 ms from 19.9 ms. Furthermore, sputtering Pt nanoparticles on the surface of the MCNO film further improved the I-V characteristics in the dark, resulting in a high on/off ratio of 38.15, which is five times higher than that without the Pt nanoparticles modification. This impressive improvement in photoproperties can be attributed to the Pt nanoparticles/MCNO film barrier, plasma resonance effect generated by the Pt nanoparticles, the extinction of the Pt nanoparticles, and the reduction of surface resistance caused by the Pt nanoparticles. This highlights the potential of metal nanoparticles in the development of infrared detectors. [ABSTRACT FROM AUTHOR]

[Display omitted] • Full control of density and average distances on the deposition of metal nanoparticles on a surface. • Deposition and growth of engineered nanostructured gold surfaces. • Tailoring the gold nanostructured surface by design. • Realization of uniform SERS substrates with gold nanostructured surfaces and hormones' detection down to part-per-trillion. Surface-enhanced Raman spectroscopy (SERS) sensors are commonly based on metal nanoparticles in colloidal suspension followed by deposition on a substrate. Despite its simplicity, this approach leads to non-uniform SERS substrates that are hampered by features such as coffee rings. Seed-mediated growth starting from nanoparticles already deposited on a flat substrate potentially allows for creating more uniform and reliable sensors. However, the deposition process, the control of the distribution of the seed nanoparticles, and their optimal growth have not been thoroughly explored. In this work, we present a systematic approach to designing and fabricating gold nanostructured surfaces, tailoring their SERS responses on demand. By controlling and tuning the deposition of nanoparticles, assisted by an experimental and theoretical investigation, we achieved good control over the spatial distribution of the deposited seeds. After enlarging such seeds through chemical reduction, the optimized SERS substrates show great uniformity in their hotspots, a critical feature for sensors. The so-fabricated substrates were used for detecting Skatole in water, achieving a detection limit of 42.2 ppt. The developed methodology has significant implications for the advancement of several fields, particularly SERS-based sensing, enabling the design and targeting of specific excitation wavelengths and Raman bands while obtaining uniform and reliable substrates. [ABSTRACT FROM AUTHOR]

[Display omitted] • A facile method was used to synthesize surface autocatalytic growth of 1D carbon nanotubes and Co, N-doped 3D carbon polyhedra serve as PMS activation catalysts. • NaCl served as the constraining template in preparation, which prevents nitrogen loss and promotes graphitization simultaneously. • The OTC enhanced degradation surely because nonradical mechanisms (1O 2 , surface electron transfer) interact with radical routes (OH, SO 4 −, O 2 −) in the CNT@CoNC-5 + PMS system. Despite attempts made to use carbon nanotubes (CNTs) as metal-free catalysts for peroxymonosulfate (PMS) activation recently, the challenge remains in the preparation of carbon nanotubes by an in-situ method. In this paper, basing a novel molten salt-assisted method with heat treatment, cobalt (Co) and nitrogen (N) co-doped carbonaceous polyhedrons with self-catalyzed-grown CNTs on the surface (CNT@CoNC-x) were synthesized and employed to activate PMS to degradation oxytetracycline (OTC) in the aqueous phase. Such a unique structure, the three-dimensional carbon matrix with Co and N co-doped in the CNT@CoNC-x, not only confirmed the control of the active sites by the simple method, but also promoted the interaction between metal nanoparticles and CNTs. It is beneficial to accelerate the decomposition of PMS, which in turn improves the degradation efficiency of OTC. A two-stage kinetics of OTC degradation was studied and the apparent rate constant (k 0∼5min) of the CNT@CoNC-5 catalyst is 66.97 L/g min−1, which increased 25.46 times greater than that of the CoNC catalyst obtained by calcining ZIF-67 directly. CNT@CoNC-5 catalysts exhibited good environmental resistance and recyclability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Alkali-promoted Pt/ATO catalysts exhibit superior performance in benzene combustion. • Addition of alkali metals enhances combustion activity by transforming less active Pt atoms into active Pt nanoparticles. • Kinetic studies and the Langmuir-Hinshelwood model elucidate the reaction mechanism on metallic Pt sites. • Strong interaction between alkali ions and the ATO support prevents blockage of active sites on Pt nanoparticles, promoting enhanced catalytic activity. Pt-based catalysts play a crucial role in the catalytic combustion of benzene. Previous studies have highlighted the significance of metal Pt atoms as the active phase in benzene combustion, while oxidized Pt sites exhibit lower activity. In practical catalysts synthesized through wet chemical methods, a range of metal species is present, including highly dispersed oxidized metal atoms, small oxidized metal clusters, and metal nanoparticles. This paper explores an effective strategy to enhance metal utilization and develop high-performance platinum-based catalysts for benzene catalytic combustion by introducing alkali metals. This approach transforms low-activity oxidized metal atoms and small oxidized metal clusters into active small metal nanoparticles. The introduction of K-O groups displaces Pt from oxygen vacancy trapping sites on antimony-doped tin oxide (ATO) support, enhancing Pt mobility and converting them into active metallic Pt nanoparticles, ultimately improving benzene combustion. These findings highlight the role of alkali metals in promoting catalytic activity and provide insights for designing high-performance noble-metal-based catalysts. [ABSTRACT FROM AUTHOR]

In this study, CoMnFeO 4 ternary metal oxide nanoparticles are prepared via hydrothermal and sol-gel ignition methods. Their structures are investigated and characterized by FT-IR, XRD, XPS, BET, SEM, EDX and HR-TEM analysis. Also, magnetic properties of nanoparticles synthesized by two methods are compared on a vibrant sample magnetometer (VSM) with maximum saturation magnetization values found to be 28.83 emu g−1 and 23.17 emu g−1, respectively. SEM and HR-TEM results reveal that the mean particles size of hydrothermally synthesized (about 25 nm) nanoparticles is smaller and more uniform than that of their counterparts synthesized by sol-gel ignition method (about 65 nm). Their supercapacitor behaviors are studied and compared by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) methods. The hydrothermally synthesized sample shows higher specific capacitance of about 770 F g−1 (at 1 A g−1) in 3 M KOH while this value for the sample synthesized by sol-gel ignition approach is about 150 F g−1. The higher specific capacitance can be attributed to smaller particle size, more electroactive sites due to higher specific surface area, and quantum size effects. Also, some initial mechanistic studies are performed to achieve a deeper insight into the electrochemical behavior of the nanoparticles implying that the oxidation-reduction process of nanoparticles is generally quasi-reversible and diffusion-controlled. So, by considering the higher performance, the hydrothermal approach developed here is beneficial from cost, time and environmental points of view. Scheme 1: Electrochemical behavior comparison of CoMnFeO 4 -H and CoMnFeO 4 -I electrode materials. Unlabelled Image • CoMnFeO 4 as a novel electroactive supercapacitor material. • Suitable synthesis route without further modification an of CoMnFeO 4 nanoparticles. • Control of electrochemical behavior of CoMnFeO 4 through synthesis route. • Quasi-reversible and diffusion-controlled oxidation-reduction process of nanoparticles. • Higher specific capacitance of hydrothermally synthesized CoMnFeO 4. [ABSTRACT FROM AUTHOR]

The advances in surface-enhanced Raman scattering (SERS) have resulted in significant improvements for sensing glucose, achieving a highly detecting sensitivity of the order of μM. Highly sensitive glucose detection, however, is still a challenge due to extremely small Raman scattering cross section of glucose molecules and weak interaction between the molecules and the metal nanoparticles. Here, we designed a novel homogeneous SERS-based nanoplatform composing of the SERS tags and glucose oxidase in aqueous solution for a highly sensitive glucose detection. Adding glucose caused enzymatic oxidation reaction to etch the tip electric field (E) of silver nanotriangle. Thus, the decreased intensity of E was greatly amplified by the change of SERS signal (E 4 dependent), which resulted in an excellent glucose detection limit of 0.4 nM was firstly achieved. Furthermore, the nonlinear relationship between the decreased SERS intensity and the glucose concentrations was reasonably revealed based on theoretical calculations and deeply understanding of the enhancement mechanism, which is very useful in improving the sensitivity and accuracy of trace glucose detection. The as-prepared nanoplatform showed good sensitivity and high selectivity only through observing the SERS intensity change, which is potential for highly sensitive and practical glucose detection for clinical trace analyses. Unlabelled Image • SNTs/ p -ATP-GOx homogeneous nanoplatform showed perfect SERS sensing behaviors of glucose. • The huge decay degree of the SERS signal caused by etching the tips of SNTs • Good selectivity to glucose and high sensitivity to 0.1 nM [ABSTRACT FROM AUTHOR]

The facile synthesis of a new class of reactive hydrogen polysilsesquioxane (HPSQ, (HSiO 1.5) n ,) hollow spheres is reported in this work. HPSQ hollow spheres can be controllably fabricated from triethoxysilane (TES, HSi(OEt) 3) as a sole precursor through a polystyrene template-directed sol–gel process under aqueous acid-catalyzed conditions followed by template removal. The particle size and shell thickness of the spheres could be fine-tuned by utilizing different amounts of TES. Total preservation of Si H bonds and formation of a Si-O-Si framework in the HPSQ hollow spheres are confirmed by FTIR and 29Si NMR. Reactive Si H moieties combined with a hollow structure make HPSQs suitable as carriers for noble metal nanoparticles. HPSQ hollow spheres function not only as a host that can adsorb Ag ions but also as a mild reducing agent for these ions. TEM studies show that the synthesized AgNPs are dispersed well on the HPSQ hollow spheres with an average particle size of 2–10 nm. XRD studies indicate that the resulting AgNPs are highly crystalline with a face-centered cubic geometry. SEM-EDS shows that the Ag content on the selected surface is 4.76 wt%. HPSQ hollow spheres loaded with AgNPs exhibit high performance when utilized as a catalyst to reduce methylene blue. Unlabelled Image • Hollow spheres from hydrogen polysilsesquioxane were controllably fabricated. • Silane precursor content determined the shell thickness of the hollow spheres. • Reactive Si H groups on HPSQs could reduce Ag ions directly. • Ag/HPSQ hollow spheres for rapid reduction of methylene blue • The uniform and reactive HPSQ materials may open new uses in catalysts and such. [ABSTRACT FROM AUTHOR]

A rapid, facile and label-free sensing strategy is developed for the detection of dopamine (DA) in the real samples by exploiting nitrogen-doped graphene quantum dots (N-GQDs) decorated on Au nanoparticles (Au@N-GQD). The as-grown Au@N-GQD exhibits strong blue fluorescence at room temperature and the fluorescence intensity is drastically quenched in presence of DA in neutral medium. The mechanistic insight into the DA sensing by Au@N-GQDs is explored here by careful monitoring of the evolution of the interaction of Au NPs and N-GQDs with DA under different conditions through electron microscopic and spectroscopic studies. The highly sensitive and selective detection of DA over a wide range is attributed to the unique core-shell structure formation with Au@N-GQD hybrids. The quenching mechanism involves the ground state complex formation as well as electron transfer from N-GQDs. The presence of Au NPs in Au@N-GQD hybrids accelerates the quenching process (~14 fold higher than bare N-GQDs) by the formation of stable dopamine-o-quinone (DQ) in the present detection scheme. The fluorescence quenching follows the linear Stern-Volmer plot in the range 0–100 μM, establishing its efficacy as a fluorescence-based DA sensor with a limit of detection (LOD) 430 nM. Further, based on the systematic change in the intensity of absorption peak of Au@N-GQD with DA concentration, the well-known Hill equation is introduced for the sensing of DA in the range 0–10 μM with detection limit 40 nM. The proposed sensing method has a high selectivity towards DA over a wide range of common biological molecules as well as metal ions. The quenching in Au@N-GQD fluorescence intensity makes it possible to determine the spiked DA in human serum in the linear range from 0.0 to 80.0 μM with the limit of detection (LOD) 590 nM, which is ~27 fold lower than the lowest abnormal concentration of DA in serum (16 μM). This sensing scheme is also successively applied to trace DA in Brahmaputra river water sample with LOD 480 nM including its satisfactory recovery (95–112%). Our studies reveal a novel sensing pathway for DA through the core-shell structure formation and it is highly promising for the design of efficient biological and environmental sensor. Unlabelled Image • Level free detection of dopamine (DA) in human serum and river water based on N-GQD decorated on Au NP. • Highly selective detection of DA by colorimetric and fluorescence methods with LOD 0.04 M and 0.43 M, respectively. • The calorimetric sensing of DA follows Hill equation, while the fluorescence sensing follows linear Stern-Volmer equation. • Sensing mechanism revealed by microscopic evidence of core-shell structure formation. [ABSTRACT FROM AUTHOR]

Size-controlled growth of PdNPs mediated by Sb-cage was demonstrated in this work. During the Suzuki-Miyaura coupling, the average diameter of PdNPs changed from 0.70 to 1.71 nm, exhibiting enhanced catalytic performance and excellent stability. [Display omitted] • A thiphenylstibane-based cage (Sb-cage) has been synthesized in high yield. • Sb-cage could mediate the size-controlled preparation of ultrafine PdNPs. • As-prepared PdNPs exhibited high catalytic activity for Suzuki–Miyaura coupling. • The encapsulated PdNPs could grow up in situ to a stable particle size. Group 15 triphenyl compounds with coordination ability such as triphenylamine (NPh 3) and triphenylphosphine (PPh 3) have been widely investigated for the construction of functional porous organic materials. In this work, a SbPh 3 -based organic molecular cage (Sb-cage) was unprecedently synthesized. The spatial configuration of Sb-cage was precisely analyzed by single crystal X-ray diffraction, showing a trigonal–bipyramidal [2 + 3] assembly. Sb-cage was employed to the mediated growth of palladium nanoparticles (PdNPs) with an average diameter of 0.70 nm. As-synthesized utrafine PdNPs exhibits good catalytic activity in Suzuki-Miyaura coupling reaction between aryl halides and phenylboronic acid, where the PdNPs could grow up in situ to a stable size distribution of 1.71 ± 0.30 nm. Furthermore, the advantages of the trigonal bipyramidal configuration in the stabilization of metal nanoparticles during the catalytic reaction cycles were demonstrated via the control experiments on SbPh 3 -based unclosed semicage. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrostatic manipulation of charged nanoparticles produced by gas aggregation. • Simulation-guided tailoring of highly designed nanostructured surfaces. • The concept for defined and controllable nanoparticle surface coverage. • Nanoparticle diffusion in the substrate vicinity affected by localized fields. This study combines numerical simulation with an experimental investigation of high-level designed nanostructured surfaces built from metal nanoparticles (NPs). The ultimate goal of this research is to prepare highly designed isotropic surfaces with high purity, defined size, homogeneous surface coverage, and high deposition rate, i.e., the properties appreciated e.g., in precise nanoengineering of microsensors and/or nanoelectronics, etc. The approach is based on manipulation of electrically charged nanoparticles, produced by a gas aggregation cluster source (GAS), in the electrostatic field propagated by two parallel electrodes mounted at the GAS output orifice. The model derived by numerical simulation enables prediction of the distribution and properties of the NPs across the (x, y) substrate plane as a function of the electrical potential superimposed by the charged NPs in the volume and the external electrical field. A good qualitative agreement was found between the model and the properties of GAS-deposited NPs onto the Si substrate (the deposited surface was analyzed by the atomic force microscopy (AFM) imaging), which reveals the electrostatic manipulation of the charged NPs beam as a promising tool for deposition of highly tailored nanostructures. [ABSTRACT FROM AUTHOR]

[Display omitted] • B-doping induces rich surface groups, defect sites, mesopores and hydrophilic surface. • Ultra-small Ru NPs with high dispersion are stabilized on BVC without capping agents. • Copious surface-exposed sites and electronic metal-support interaction facilitate ABH. • A high TOF of 1577 min−1 and an ultra-low E a of 11.86 kJ·mol−1 were achieved for ABH. Owing to the lack of adequate nucleation sites for metal nanoparticles (NPs) and weak metal-support interaction, pristine carbon materials supported metal NPs suffer from limited surface-exposed active sites and thereby low catalytic activity. Herein, we report a sodium borohydride-mediated modification of commercial Valcan carbon (VC) to produce B-doped VC (BVC) as a useful support to deposit Ru NPs (Ru/BVC) for hydrogen production from ammonia borane hydrolysis (ABH). The B-doping endows BVC with not only more surface functional groups and defect sites but also abundant meso/macroporous structure and hydrophilic surface, facilitating the generation of uniformly dispersed ultra-small Ru NPs (d = 1.42 nm) with strong electronic metal-support interaction. The optimal Ru/BVC catalyst exhibits an excellent activity with a turnover frequency of 1577.0 min−1 (depending on Ru dispersion). Isotopic and alkali promotion experiments unveil the rate-determining step (RDS) for ABH is the oxidative cleavage of the O H bond in water. The copious surface-exposed active sites and the regulated electron distribution between Ru NPs and BVC efficiently reduce the energy barrier for RDS, thereby promoting catalytic performance of hydrogen evolution from ABH. This simple and efficient heteroatom-doping strategy is easily extended to fabricate efficient catalysts with promoted performance for catalytic applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Different ZIF-67 pyrolysis processes were investigated for H 2 storage by spillover. • Well-dispersed Co and ZIF structure can be kept in a fast-ramping pyrolysis. • Much lower ZIF pyrolysis temperature is needed when pyrolyzed in H 2. • Co dispersion and carbon matrix defect structure are critical in H 2 spillover. Hydrogen spillover involves the dissociation of H 2 on transition metal nanoparticles and further atomic hydrogen surface migration on catalyst supports. Hence, the spillover phenomenon has been reported in applications of heterogeneous catalysis in hydrogenation and room-temperature hydrogen storage. However, a proper catalyst design is requisite to initiate hydrogen spillover, considering the transition metal particle dispersion, sorbent surface modification, porosity, etc. In this report, we pyrolyzed the zeolitic imidazolate framework ZIF-67 for residual Co metal nanoparticles and N-dopant on ZIF-derived carbon (ZDC) for hydrogen adsorption via spillover effect. Catalyst optimization by proper ZIF carbonization process regarding manipulated pyrolytic temperatures, atmospheres, and ramping rates, results in different properties in ZDCs. Well-distributed Co nanoparticles can be obtained on N-rich graphitic sorbent ZDCs with retained high specific surface area. The Co on ZDC exhibits improved room-temperature hydrogen capacity of 0.77 wt% than neat ZIF-67 of 0.09 wt% at 30 bar, 300 K. The adsorption sites were examined experimentally by nitrogen hydrogenation, and possible atomic hydrogen diffusion was evaluated theoretically showing energy barrier reduced by over 0.1 eV. It demonstrates that cobalt nanoparticles can successfully initiate hydrogen spillover on ZIF-derived carbon with nitrogen functionality, even without noble metals. [ABSTRACT FROM AUTHOR]

[Display omitted] • Origin of Cl and CA tuned Pd particle shape is revealed by DFT + Wulff construction. • High chemical potential of adsorbate favors the particle formation with same facet. • Adsorbate number per unit area affect surface stability more than adsorption energy. • Adsorbate rigidity/flexibility affects its number per unit area and particle shape. • The insights can guide particle synthesis in desired shape for various application. Capping agents such as halide and citrate (CA) are crucial in the colloidal synthesis of noble metal nanoparticles (NPs) with desirable shape for specific catalytic reaction. Halide ions have been shown to stabilize the cubic NP while CA ions favor the octahedral NP regardless of the noble metals, but the mechanism remains unclear. We combine DFT calculations and Wulff construction to understand how the morphology of Pd particle changes with Cl and CA chemical potential (μ). Three main factors are identified to affect the morphology of Pd particle: μ of adsorbate, its number per unit area (N AS /S), and rigidity or flexibility. Increasing μ of adsorbate or its N AS /S causes decreased surface free energy and increased exposed surface area. Moreover, rigid adsorbates (PdCl x) occupy a larger surface area for surfaces with high atomic density such as Pd(1 1 1), leading to cubic Pd particle at high μ Cl. Conversely, flexible adsorbates (CA) that can adjust their structure based on the surface occupy smaller surface area on Pd(1 1 1), favoring octahedral Pd particle. This work reveals the origin for capping agent tuned morphology of Pd NP, and the insights can be used to guide metal NP synthesis with desired morphology for catalytic reactions of technological interest. [ABSTRACT FROM AUTHOR]

[Display omitted] • SERS substrate of patterned silicon decorated with Au-nanoparticles (NPs) fabricated by combining femtosecond (fs) laser direct writing with solid state dewetting of Au nanofilm. • Fs laser can induce composite structure of nanopores, nanogrooves and nanoislands on silicon wafer surface in one step. • The composite structure on silicon not only serves as a template to control the solid state dewetting of Au nanofilm but also provides a larger surface area as a carrier for Au plasma "hot spots". • Fs laser-patterned silicon surface decorated with dense Au-NPs constructs multiple coupling modes of LSPR to enhance local electric field. Noble metal nanoparticles (NPs) are frequently utilized in surface-enhanced Raman scattering (SERS) due to their localized surface plasmon resonance (LSPR) effect, whose preparation in high density and suitable size is a prerequisite for high enhancement factors and homogeneity of SERS substrates. Here, a method combining femtosecond (fs) laser direct writing silicon with solid-state dewetting of Au nanofilm was proposed. Patterned silicon with nanostructures modulates the solid-state dewetting of Au nanofilm deposited on its surface by structural curvature, resulting in the formation of patterned silicon decorated with Au-NPs (Au-NPs/PSi). The Au-NPs formed on the patterned silicon are denser and have a 72 nm average diameter better suited to SERS compared to the flat silicon. By the simulation of finite-difference time-domain (FDTD) method, we found the significantly enhanced local electric field in the nanogaps between Au-NPs and between Au-NPs and silicon. Furthermore, the substrate shows excellent SERS ability in detecting R6G molecules, with detection limit as low as 10−10 M and an enhancement factor (EF) of 2.68 × 107. The results indicate that Au-NPs/PSi substrate is a promising candidate for obtaining reliable and high-quality SERS, promoting the application of SERS in trace molecules detection in solution. [ABSTRACT FROM AUTHOR]

Ir-Ni 3 N heterogeneous interfaces are engineered for overall water splitting in which Ir plays the dominant role in improving OER while Ni 3 N plays the dominant role in boosting HER. [Display omitted] • One-step ammonia nitridation enables direct preparation of Ni 3 N nanosheets on nickel foam. • Embedding Ir nanoparticles into Ni 3 N nanosheets builts Ir-Ni 3 N heterogeneous interfaces. • Heterogeneous interfaces play an important role in promoting the oxygen evolution reaction. • Ir-Ni 3 N outperforms most of the HER/OER bi-functional electrocatalysts reported recently. The development of efficient and stable electrocatalysts is a necessary way to overcome the huge overpotential of hydrogen production from water splitting. In this work, a one-step ammonia nitridation process was proposed, in which noble metal Ir nanoparticles were directly embedded into the Ni 3 N nanosheet structure, and the Ir-Ni 3 N heterogeneous interface was established on the surface of the nickel foam substrate. X-ray photoelectron spectroscopy showed that the IrO x /NiOOH heterogeneous interfaces formed after the surface self-reconstruction played an important role in promoting the oxygen evolution reaction, and its over-potential was only 273.3 mV at the current density of 10 mA cm−2. Impressively, the nanosheet structure of Ir-Ni 3 N remained stable after 10 h of constant current oxidation. In addition, when Ir-Ni 3 N was used as the electrocatalyst for hydrogen evolution reaction at the current density of 10 mA cm−2, the overpotential was only 66.7 mV. As expected, when it was examined for overall water splitting, the Ir-Ni 3 N demonstrated a low voltage (1.49 V), outperforming most of the HER/OER bi-functional catalysts reported recently. This work will provide an important basis for the study of transition metal nitrides, especially in improving the stability of oxygen evolution reaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pd-nanoparticles (Pd-NPs) were successfully anchored on the surface of porous ZIF-8 material by chemical reduction method. • Anchored Pd-NPs can lower operating temperature of ZIF-8 and enhance its gas responsiveness to SO 2 gas. • Pd-NPs/ZIF-8 composite material shows excellent sensing properties to 200 ppm of SO 2 at 300 °C. Enhancing the electron transport capability of metal–organic framework (MOF) materials, which are novel gas sensing materials, remains a formidable challenge. In this study, palladium metal nanoparticles (Pd-NPs) were successfully anchored on the surface of ZIF-8, a porous material, by using chemical reduction to improve the gas sensing performance of ZIF-8 significantly. The active catalytic sites of Pd-NPs are stimulated by the porous structure of ZIF-8 and are uniformly dispersed on the surface of the porous ZIF-8 material. The Pd-NPs/ZIF-8 composite material has good response and selectivity for up to 200 ppm SO 2 at 300 °C (gas sensing response of 86.61%), a fast response time (approximately 24 s), low detection limit (4.0 ppb) and excellent stability and anti-interference ability. These outcomes can be attributed to the fact that anchoring Pd-NPs on the surface of the porous ZIF-8 material can effectively improve gas sensing performance by exploiting the high conductivity and catalytic activity of Pd-NPs through electron and chemical sensitisation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Composite of MOF and Ag explored firstly for visible-light-mediated CDC. • Photoactive MOF generates simultaneously singlet oxygen and superoxide radical. • Ultrasmall Ag NPs enhance photocatalytic reaction via Schottky barrier. • Direct interaction between Ag NPs and substrate of tertiary amine. The application of heterogeneous photocatalyst to conduct organic transformation is attractive in sustainable chemistry. Metal-organic frameworks (MOFs) are crystalline materials with diverse structures and rich components, which exhibit great potential to achieve heterogeneous photocatalysis. Herein, we report the synthesis of new photocatalysts of MOF-based nanocomposites to achieve cross-dehydrogenation coupling (CDC). A series of nanocomposites of Ag/MOF were prepared by simple photoreduction method. The resulting nanocomposites exhibit efficient and recyclable photocatalytic performance for CDC reactions under visible light. Experiments show that the photocatalytic activity of the MOF was promoted significantly upon the decoration of ultrasmall Ag nanoparticles (NPs), where the particle size and loading amount of Ag NPs play an important role to improve the photocatalytic performance. Ultrasmall Ag NPs not only boost the photoinduced charge generation by Schottky junction in the nanocomposite, but also promote the reaction by direct interaction with amine substrate. Reactive oxygen species (ROS) of singlet oxygen and superoxide radical were simultaneously generated from molecular oxygen in the photocatalytic reaction, owing to the photoinduced energy and electron transfer of the MOF. The study presents a rare example of photocatalytic CDC using MOF-based nanocomposite, providing more insights into the synergy effect of MOFs and metal nanoparticles for organic transformation. [ABSTRACT FROM AUTHOR]

The study of the effect of particle size and low coordination sites in metal nanoparticles (Cu n , Ag n and Au n with n = 19, 38, 55, 79 and 116) on the reduction of NO 2 to NO + O, was carried out using density functional theory (DFT) calculations. All metal nanoparticles have shown to be more favorable for the NO 2 adsorption than the (111) extended surfaces. The adsorption energy order of NO 2 found for both configurations, O-down (most stable) and N-down, was Cu > Ag > Au. The dissociation energy values of NO 2 on Cu and Ag nanoparticles decrease with the increment of the particle size, however, considering the activation barrier values, the most reactive substrates evaluated were Cu(111) surface, and the Cu 19, Cu 116. The activation barriers (E act) for the larger nanoparticles, were obtained using a non-traditional relationship of Brönsted Evans Polanyi (BEP), from the E act calculated on the smaller ones. The BEP relations highly depend on the reaction product configurations and also on the structure of the active site. Notwithstanding that the nanoparticles improve the NO 2 adsorption and the dissociation energies are lower than those corresponding to the extended surfaces, the activation barriers are higher. Unlabelled Image • NO 2 is preferably adsorbed with O-down configuration on Cu, Ag and Au substrates. • Increase in Cu and Ag particle sizes leads to a decrease in NO 2 dissociation energy. • Activation barriers of largest nanoparticles were obtained using a non-traditional BEP relationship. • Low coordination sites in nanoparticles improve NO 2 adsorption but not its dissociation. [ABSTRACT FROM AUTHOR]

Sulfur-bearing species have received a great deal of interest due to their potential risks and applications as well as their specific interaction with metal nanoparticles. This interaction influenced greatly the properties and functionality of nanoparticles, but is still poorly understood. In this paper, the sulfidation reaction between sulfur species (S, SH−, S2−) and Ag were investigated by using plasmonic Au@Ag as model. We report here that sulfide and bisulfides can cause the rapid transformation of Au@Ag 2 S with varying degree accompanying tunable surface plasmonic resonance and color production. The SPR evolution reflected the much slower reaction kinetic between S and Au@Ag than that of sulfide. The linear relationship was found between SPR maximum or absorption and the concentration of sulfide and sulfides, making it applicable to detect them by using spectroscopy or with naked eyes. This method exhibits high sensitivity and selectivity to bisulfide and sulfide against a variety of metal ions and anions. Since sulfur species and Ag NPs are wide used in biological and environmental system, these results may provide insights for finding new applications in combination of metal NPs and sulfur containing molecules. Unlabelled Image • The chemical interaction between sulfur species and Ag was investigated. • The controllable formation of Au@Ag 2 S resulted in tunable SPR property. • A simple method to detect sulfide and bisulfides has been developed. [ABSTRACT FROM AUTHOR]

Supported noble metal nanoparticles (NPs) are widely applied as heterogeneous catalysts in numerous reactions, in which the morphology of metal clusters is of crucial to the catalytic performance. In this study, the multiscale simulations concerned with the adsorption and morphological behavior of Pd, Au clusters and NPs on Mo 2 C, Mo 2 CO 2 and Mo 2 CF 2 have been performed systematically by density functional theory (DFT) and molecular dynamics (MD). There is an obvious morphological tendency of two-dimension (2D) to three-dimension (3D) for supported Pd n /Au n (n = 4–6) clusters from bare to O, F-terminated Mo 2 C. The electronic properties analysis shows that more charge transfer occurred on clusters leads to the stronger interaction between clusters and Mo 2 C MXene. The plots of projected density of states (PDOS) describe that the O, F groups weaken the strong interaction between clusters and bare Mo 2 C, showing that the nature of the change of morphology is the modification of d states of Pd, Au NPs by the introduction of O, F groups. The MD simulations of large supported Pd n /Au n NPs on bare and functionalized Mo 2 C are corresponded to the 2D-3D growth of DFT result, which shows that for metal NPs, the average coordination number as well as the interaction of Pd/Au NPs and support varies with the order of bare-O-F. Based on the multiscale simulations, the morphology ranges from Pd/Au clusters to NPs have been governed efficiently by surface groups, which may enlighten the design of metal-supported catalysts. Unlabelled Image • Functionalized Mo 2 C can be served as an excellent support. • Functionalized Mo 2 C induces 2D to 3D change for Pd and Au clusters by DFT. • The conclusions from DFT confirmed by MD simulation for large nanoparticles. [ABSTRACT FROM AUTHOR]

Abstract Metal nanoparticles synthesized using the green methods are essential for utilization of the nanoparticles in diagnostic and therapeutic applications. The usual syntheses of the metallic nanoparticles often involve toxic chemicals, which limit the use of metal nanoparticles in biochemical applications. An in-situ synthesis of gold nanoparticles (AuNPs) on the rice grain surfaces using the phenolic acid content of rice as the reducing agent, and utilization of the AuNPs-decorated rice (Au-rice) as a surface-enhanced Raman scattering (SERS) substrate are demonstrated. An increase in the HAuCl 4 concentration of the reaction mixture was shown to cause almost a linear increase in the size of AuNPs on the rice grains. By varying the HAuCl 4 concentration, the size of the synthesized AuNPs can be adjusted between 41 ± 13 nm and 177 ± 38 nm. Among the as-produced Au-rice samples, rice grains with the AuNP size of 131 ± 30 nm were found to be the most effective in the SERS analysis of 4-aminothiophenol (4-ATP). The effectiveness of the Au-rice samples as SERS substrates was demonstrated with a 4-ATP detection limit of 10−6 M and an analytical enhancement factor (AEF) of 1.5 × 105. Graphical abstract Unlabelled Image Highlights • A green method to prepare gold nanoparticles-based SERS substrates presented. • Rice grains serve as a reducing agent and as a support in preparation of Au-rice. • Phenolic acids of rice have dual functions: reducing agent and stabilizer of AuNPs. • The SERS activity of Au-rice depends on the gold nanoparticle size on rice. • The AuNP size on rice can be adjusted with the gold concentration in the synthesis. [ABSTRACT FROM AUTHOR]

Abstract P-type tin monoxide (SnO) decorated TiO 2 nanoparticles have been synthesized by the powder atomic layer deposition (p-ALD) method in a fluidized bed reactor at 150–250 °C. Successful deposition of SnO on a TiO 2 surface was realized using a precursor combination of Sn(dmamp) 2 and H 2 O as Sn source and reactant, respectively. Prepared SnO/TiO 2 nanoparticles were characterized by XRF, XPS, XRD, and TEM-EDS. Formation of a p-SnO/n-TiO 2 heterojunction resulted in improved photocatalytic methylene blue degradation performance compared to using a TiO 2 photocatalyst, which might be attributed to facile separation of photo-induced electron-hole pairs as well as to increased UV/visible light absorption by adopting a narrow bandgap SnO. Highlights • SnO-decorated TiO 2 nanoparticle was synthesized by powder atomic layer deposition. • SnO/TiO 2 showed enhanced methylene blue degradation performance compared to TiO 2 catalyst. • Photocatalytic methylene blue degradation mechanism of SnO/TiO 2 was proposed. [ABSTRACT FROM AUTHOR]

Abstract Gold (Au), silver (Ag), and palladium (Pd) nanoparticles (NPs) dispersed amorphous carbon composites have been prepared successfully by Green synthesis method using the reducing agent extracted from Cissus quadrangularis stem (CQS). The presence of antioxidant compounds in CQS extract is responsible for reducing and capping metal nanoparticles. The synthesized nanocomposites exhibit excellent antibacterial activity against gram-negative bacterial strains. Electrochemical performance of the composites is evaluated in symmetric two-electrode configuration. At a power density of 1 kW kg−1, the symmetric supercapacitor based on Au nanoparticle dispersed carbon electrodes exhibits an energy density of 7.1 Wh kg−1. Graphical abstract Unlabelled Image Highlights • Synthesis of Au, Ag and Pd nanoparticles dispersed amorphous carbon composites by green synthesis method. • The antibacterial tests revealed the ability of nanocomposites to inhibit the growth of E.coli. • The as-prepared materials can be useful in water purification for inhibiting the growth of pathogenic bacteria. • The nanomaterials are used as effective electrode materials in symmetric supercapacitors. • At a constant power density of 1 kW kg−1, the symmetric supercapacitor exhibited an energy density value of 7.1 Wh kg−1. [ABSTRACT FROM AUTHOR]

Abstract Silver and gold nanoparticles-decorated cotton fiber substrates constitute an important group of the simple, inexpensive and versatile platforms for a SERS-based detection of biomolecules. However, the fibrous cotton embedded with metal nanoparticles is yet to be explored as a filter-like substrate for isolation and detection of pathogens from fluid. In this study, we present a straightforward approach based on hydraulic pressing to make a silver nanowire-decorated cotton fibers substrate a realistic platform for effective filtering and detection of bacteria from urine. Silver nanowires were anchored on cotton fibers using an aminopropyltrimethoxysilane as a linker. The obtained silver nanowire-cotton fiber material was compressed with a hydraulic press to substantially reduce the free spaces between the individual fibers. As a proof-of-concept, the prepared substrate was employed to effectively filter Escherichia coli bacteria from phosphate-buffered saline solution and urine. The silver nanowire-cotton SERS substrate thus serves as a low-cost and active platform for an effective detection of bacteria from fluids. Graphical abstract Unlabelled Image Highlights • Silver nanowires decorated cotton fiber SERS substrate is reported. • The substrate can be compressed into a filter-like material using a hydraulic press. • The substrate can be used to trap and detect bacteria from water and urine. [ABSTRACT FROM AUTHOR]

Abstract A novel hollow magnetic nanoreactor with Pd support has been successfully prepared for catalytic reduction of methylene blue and p -nitrophenol. The nanocatalyst perfectly combines the advantages of various structures, so large specific surface area and satisfactory catalytic activity can be acquired. The hollow structure, which can be considered as a nanoreactor, improves the mass transfer and the rate of reaction under the micro-power generated by concentration difference. In addition, given its satisfactory stability and paramagnetic property, the nanospheres can be reused for a minimum of 10 times, separated rapidly, and recovered conveniently using a magnet. Graphical abstract In present work, a novel highly efficient magnetic nanoreactor has been constructed through a simple route for rapid catalytic reduction of methylene blue (MB) and p -nitrophenol (4-NP), combining the hollow structure and MOFs with Pd nanoparticles together. The catalyst makes full use of advantages of various structures, so larger specific surface area is obtained and the common problem of aggregation of metal nanoparticles is solved. In addition, the cavity can form a nanoreactor, with the assistance of concentration difference, rapid reaction rate is acquired. Based on the magnetic core, the nano-catalyst is convenient to recycle. Unlabelled Image Highlights • A simple route was designed to prepare the core-shell hollow magnetic nanospheres. • The catalyst has a high reduction efficiency, contributed by cavities, porous MOFs and loaded metal nanoparticles. • The nanoreactor has a cavity that can make full use of concentration difference to obtain rapid reaction rate. • The magnetic part gives the nanoparticles convenient recycle property. • The mixture substrate was studied in this work. [ABSTRACT FROM AUTHOR]

Abstract Two-dimensional (2D) metal nanoparticle platforms hold great potential in high-throughput point-of-care testing on basis of their excellent fluorescence enhancement effect. Self-assembly of metal nanoparticles (NPs) is versatile but simple for the preparation of 2D platforms; however, the surface charges on NPs would repel each other and induce large gaps on platforms, which hinder the generation of intense hotspots in electromagnetic fields and thus weaken the fluorescence enhancement effect. Here, we presented the hierarchical assembly of large-sized silver (Ag) NPs and small-sized gold (Au) NPs for constructing fluorescence enhanced platforms. The small Au NPs with weak fluorescence were chosen to complementarily fill into the larger gaps of the pre-assembled Ag platforms for increasing the electromagnetic hotspots. The resulting Ag/Au hybrid platforms (1-, 3- and 6-Ag/Au) exhibited growing fluorescence enhancement effects and the maximum enhanced factor reached 3.6-fold. The inserting of small Au NPs enhanced the fluorescence emission of fluorescent dye (cyanine-5) on the Ag platforms, especially on the monolayer 1-Ag platform, which increased by 161.6%. Moreover, the finite-difference time-domain (FDTD) calculations revealed the underlying cause of the improved electromagnetic fields in the Ag/Au hierarchical architecture in comparison to the Ag or Au NP. This work presents the hierarchical assembly is expected to be a powerful tool in the large-scale fabrication of fluorescence enhanced detection platforms. Graphical abstract The hierarchical assembly of silver and gold NPs toward constructing 2D fluorescence enhanced detection platforms. Unlabelled Image Highlights • The 2D metal NP platforms were constructed through the hierarchical assembly of different-sized Ag and Au NPs. • The small Au NPs were complementarily inserted into the large interspace of Ag platforms to induce additional hotspots. • The 2D hierarchical nanostructures achieved stronger fluorescence enhanced effect in fluorescence biodetection. • Fluorescence enhanced mechanism was mainly the improved electromagnetic fields rather than the weak fluorescence of Au NPs. [ABSTRACT FROM AUTHOR]

Highlights • Noble metal NPs are formed in SiO 2 matrix by PLD growth from a mosaic target. • The as-grown sample of Ag/SiO 2 exhibit SPR properties, unlike the Au/SiO 2. • The laser and thermal annealing induce SPR properties of the Au/SiO 2 samples. • The SPR absorption red shifts with the laser and thermal annealing of Ag/SiO 2. • The laser annealing significantly changes the surface morphology of the samples. Abstract The present study focuses on the synthesis of noble metal (Au, Ag) nanoparticles and their incorporation and manipulation in thin film oxide matrix. The structural and functional properties of the nanoparticles embedded in a host matrix of fused SiO 2 films are covered by this research. The effect of post-deposition laser or thermal annealing procedures on the behaviour of laser fabricated composite nanostructures is investigated. The coloration of samples is determined by the nano-sized metal particles in a dielectric matrix, due to a surface plasmon resonance effect of the conductive electrons and respective selective absorption. The laser deposition and annealing are performed by a nanosecond Nd:YAG laser at fourth and third harmonics, respectively. The estimation of the temperature and the heating and cooling rates due to the laser annealing is performed. The influence of the nanosecond UV-laser annealing on the optical spectra and plasmon resonance properties of the samples is investigated. The experimental results indicate that the annealing induces plasmon resonance absorption in Ag/SiO 2 nanocomposite and a red-shift of the existing resonance absorption of Au/SiO 2. The tuning of the optical properties of the samples was interpreted as a function of their morphology and structure, formed at certain parameters in the processing stages of laser deposition and annealing. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Environment-friendly process to obtain Ag nanoplates. • New process combining light irradiation and H 2 O 2. • Very high plasmon sensitivity of 374 nm/RIU. • High SERS enhancement factor of 1.2 * 104. Abstract Sensing properties of noble metal colloids are strongly dependent on their size, shape, composition and distribution so that the individuation of suitable strategies for synthesis and modification is one of the facts in experimental designing. In this paper we show that silver nanoplates can be obtained through a simple two-step process, involving the formation of seeds generated by laser ablation of a metal target in an aqueous solution, followed by addition of H 2 O 2 under light irradiation without additional silver ions. These experiments open up the possibility to obtain metal nanoparticles of different shapes directly in a colloidal state without the action of polluting agents. Nanoplates show excellent plasmon sensitivity and SERS enhancement factor. [ABSTRACT FROM AUTHOR]

Graphical abstract The nitrogen-doped graphene (NG) in-situ modification of MnO nanoparticles (MnO/NG) can largely improve the electrochemistry performance for lithium storage. Highlights • The nitrogen-doped graphene (NG) in-situ modifying MnO nanoparticles (MnO/NG) • NG promoting the electron transfer and improving the reaction activity. • NG alleviating the MnO agglomeration during the reaction. • NG accommodating the volume change of MnO during the cycling process. • MnO/NG exhibiting highly enhanced reversible capacity and cycling capability. Abstract We report the nitrogen-doped graphene (NG) in-situ modifying MnO nanoparticles (MnO/NG) to improve the electrochemistry performance for lithium storage. The NG in-situ modification not only improves the electrical conductivity but also alleviates the agglomeration and accommodates the volume change of MnO nanoparticles during the cycling process. More importantly, the non-heat treatment is beneficial to maintain the original structure and crystal shape of MnO. As a results, the MnO/NG exhibits a high reversible capacity of 1005 mAh/g after 100 cycles at 100 mA/g, four times that of pure MnO nanoparticles (209 mAh/g) and almost twice that of in-situ carbonization of MnO nanoparticles (MnO/C) (490 mAh/g). Particularly, the MnO/NG demonstrates a stable cycling capacity of 549 mAh/g after 1000 cycles at 1000 mA/g without pulverization. This work confirms that nitrogen-doped graphene in-situ modification is a more efficient strategy comparing to carbon modification for transition metal oxides as anode materials for highly improved lithium storage. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Co 2 N-x-T@NC electrocatalyst was prepared via in situ polymerization and pyrolysis under NH 3 atmosphere. • Co 2 N-2-700@NC exhibited excellent electrocatalytic activity towards ORR. • Co 2 N-2-700@NC showed better long-term stability and tolerance to methanol than Pt/C catalyst. Abstract Co-N-C electrocatalysts have attracted great attention in electrocatalytic ORR (oxygen reduction reaction) field. In this work, we propose to prepare Co 2 N nanoparticles embedded N-doped mesoporous carbon by a facile method including in situ copolymerization and pyrolysis under NH 3 atmosphere. The results show that more N atoms can be doped in carbon framework by NH 3 pyrolysis, it is also found that pyrolysis temperature and Co content can influence the ORR performance of samples. The sample prepared by adding Co precursor and pyrolysis at 700 °C has high N content (11.86 at.%) and relative large specific surface area (362 m2 g−1), and it also exhibited superior electrocatalytic ORR performance in terms of E onset (−0.038 V vs. SCE), E 1/2 (−0.126 V vs. SCE) and large current density (5.22 mA cm−2). Additionally, the sample also shows better stability and resistance to methanol poisoning than Pt/C catalyst. The synergistic effect of Co-N active centers and hierarchical porous structures contribute the excellent electrocatalytic activity, which are considering as alternative catalysts for ORR in full cells. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Trace gases causes formation of cuprous carbonate surface contaminant. • Oxidation to cupric carbonate-containing contaminants on atmospheric exposure. • The contaminant is reduced by X rays to elemental copper. • Antimicrobial action in body fluids, is not due to the presence of copper ions. Abstract We have used X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, transmission electron microscopy and reconstructed electron diffraction patterns, to study the contamination of the Cu nanoparticle surface on atmospheric exposure, as would occur on using such nanoparticles as antimicrobials deposited onto bandages intended for use as wound dressings. Our study suggests that the surface contaminant initially formed by residual gases in vacuum is Cu 2 CO 3. On atmospheric exposure, this is oxidized to CuCO 3 , combined with Cu(OH) 2 , as found in azurite and malachite; pure CuO is not found in nature. On subsequent exposure to high energy irradiation, which might occur in the bandage packaging process, the azurite/malachite contaminant breaks down, forming CuO, which is reduced by reaction with carbon, forming Cu0, before ultimately re-oxidizing to reform the surface contaminants. We discuss the implications of these results on possible mechanisms of the antimicrobial action of such nanoparticles when deposited onto bandages. [ABSTRACT FROM AUTHOR]

Highlights • ZnS nanoparticles were synthesized by low-temperature precipitation method. • ZnS nanoparticles were deposited on PVDF pellets by phase inversion method. • PVDF-ZnS pellets showed high photocatalytic activity for removal of organic dye. • PVDF-ZnS pellets were dispersed easily in photocatalytic reactor treating organic dye. • PVDF-ZnS pellets had a mechanical strength without losing ZnS nanoparticles. Abstract ZnS nanoparticles with 90 nm diameter were synthesized by low-temperature method and immobilized onto the surface of polyvinylidene fluoride (PVDF) pellets prepared by phase inversion method. Results by FTIR and X-ray photoelectron spectroscopy revealed that the ZnS nanoparticles were immobilized tightly on the PVDF surface without their release and losing photocatalytic activity. The UV-absorption spectra showed that the PVDF matrix had no adverse effect on the optical properties of ZnS nanoparticles. Due to large size (5 mm) and excellent mechanical stability, the PVDF-ZnS pellets could be easily dispersed in the photocatalytic reactor treating methylene blue solution. The removal efficiency of the methylene blue with the PVDF-ZnS pellets was higher (more than 95%) than that observed by the control PVDF pellets or ZnS nanoparticles tested. No change in the removal efficiency was observed as the PVDF-ZnS pellets were reused by performing photocatalytic tests at the same experimental conditions repeatedly. [ABSTRACT FROM AUTHOR]

Highlights • Synthesis of energetic Al/C nanocomposites via laser ablation synthesis in solution. • Controlling the size and energetic properties by variation of synthesis parameters. • Enhanced energetic properties in comparison to commercial Al nanoparticles. Abstract The large heat release predicted in the early investigations of energetic aluminum nanoparticles (Al NPs) used in solid-state propulsion and pyrotechnics has been offset by hindered diffusion-limited detonation rates due to excess oxide shell formations and surface area loss from aggregations. We address these challenges by manufacturing graphitic shell coated Al NPs (<20 nm sizes) via laser ablation synthesis in solution (LASiS) to preserve high surface areas and interfacial properties of Al NPs. Specifically, we use a high-energy laser to ablate Al pellets confined in either acetone or toluene to coat the laser-ablated Al NPs with graphitic shells generated from the thermal pyrolysis of the organic solvents. Energetic activities of the C/Al NPs were tested via the laser-induced air shock from energetic materials (LASEM) technique. We demonstrate that synthesis parameters such as organic solvents, laser flux and ablation times can be tuned to provide superior control of NP sizes/aggregation with the aid of the C shell formations and, in turn, their energetic behavior. This study unveils the synthesis-structure-property relations in LASiS-based manufacturing of energetic nanocapsules within graphitic shells that are safe to handle and can undergo kinetically controlled spontaneous energy release under desired conditions. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • New method of synthesizing of bifunctional magnetic conglomerates is proposed. • Obtained conglomerates were tested as SERS substrates and catalysts. • Homogeneous SERS substrates were produced from magnetic-plasmonic conglomerates. Abstract Bifunctional conglomerates made of magnetic and noble metal nanoparticles have many applications in the fields of catalysis, chemical analysis, biology, and medicine. Therefore, it is very important to find a way to synthesize such conglomerates that makes it possible to easily control the size and shape of the attached noble metal nanoparticles. In this contribution, we propose a method of synthesizing such conglomerates in which the noble metal nanoparticles are prepared before being bound to the magnetic nanostructures, and in which the initial size and shape of the noble metal nanoparticles does not change during the process of the formation of the conglomerates with magnetic γ-Fe 2 O 3 nanoparticles. The proposed synthesis is based on directly binding the metal and γ-Fe 2 O 3 nanoparticles by means of molecules of (3-aminopropyl)trimethoxysilane (APTMS). Functionalization with APTMS leads to the formation of nanostructures (methoxy groups of APTMS react with the surface of the Fe 2 O 3 nanoparticles, forming strong Fe O Si bonds) with a terminal amine group. The noble metal nanoparticles are then attached to the amine-terminated γ-Fe 2 O 3 nanoparticles. This binding process has been successfully tested for decahedral Ag, cubic Ag, hollow Au, and hollow Pt nanoparticles. As far as we know synthesized composites are the first examples of magnetic composites containing such anisotropic metallic nanostructures. The magnetic-plasmonic conglomerates obtained have been used as materials for easily producing very homogeneous substrates for surface-enhanced Raman scattering (SERS) measurements. Conglomerates with Pt nanoparticles have been tested as catalysts for reducing 2-nitrophenol. We found that, after a relatively quick decomposition of the weakly bonded γ-Fe 2 O 3 -Pt nanostructures in the reaction mixture, the stability of the remaining conglomerates was large enough for them to be recycled in a magnetic field after the reaction and reused. This process may be repeated effectively many times. [ABSTRACT FROM AUTHOR]

Highlights • Adsorption of acetone to (MO) 12 (M = Be, Mg, Zn) and their graphene composites. • (ZnO) 12 and its graphene composite are not sensitive to acetone, and the others are. • (MgO) 12 could be an excellent acetone sensor for the sensitivity and recovery time. Abstract Acetone, one of the most common VOCs, could cause serious air pollution and threat the human health when someone is exposed to certain concentration of acetone. Thereof, acetone detection and elimination in the air was significant to prohibit the hazard of acetone. Acetone adsorbed to (BeO) 12 , (MgO) 12 and (ZnO) 12 nanoparticles and their graphene composites was detailed studied by density functional theory. The adsorption energy of acetone to (MO) 12 (M = Be, Mg, Zn) nanoparticles and their graphene composites were high, which means that all the adsorbents are eligible for acetone adsorption. The variation of band gap was utilized to describe the sensibility to acetone. It was found that the (ZnO) 12 nanoparticle and its graphene composite were not sensitive to the acetone, while the (BeO) 12 and (MgO) 12 , as well as their graphene composites, were sensitive to acetone. Among the (BeO) 12 -graphene and (MgO) 12 -graphene, the latter exhibits more sensitive than the former. The conventional transition state theory was been took to estimate the recovery time. According to our calculation, (BeO) 12 and (ZnO) 12 nanoparticles and all (MO) 12 graphene composites have too long recovery time for the high adsorption energy hampering the recovery of the adsorbents. Contrastingly, (MgO) 12 nanoparticle is sensitive to acetone and has receivable recovery time. Therefore, (BeO) 12 , (MgO) 12 and (ZnO) 12 nanoparticles and their graphene composites may be potential adsorbents for acetone adsorption for their relatively high adsorption energy. The (MgO) 12 nanoparticle could be an excellent gas sensor for detecting acetone due to the sensitivity acetone and receivable recovery time. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • ZnO NPs were synthesized by the precipitation method using conventional high-temperature dyeing equipment. • In situ functionalization of cotton textiles with ZnO NPs was carried out via the exhaust dyeing method. • The ZnO NPs enhanced the ability of the cotton fabric to block erythemally weighted UVR. Abstract Zinc oxide nanoparticles (ZnO NPs) were synthesized by a precipitation method from zinc nitrate hexahydrate and sodium hydroxide using high-temperature dyeing equipment. This synthesis was studied within the framework of the percent yield to determine the most favorable concentrations of the chemical reagents. The in situ functionalization of cotton textiles with ZnO NPs was carried out via an exhaust dyeing method using the previously determined favorable concentrations of zinc nitrate (2, 5, 8 and 10% on-weight-fabric) and sodium hydroxide (0.7, 1.7, 2.5 and 3.0 g/L). The results demonstrated that the ZnO NPs in powder form and those synthesized in situ on the fabric exhibited a wurtzite hexagonal crystalline structure. The powder displayed a star-like morphology with very pronounced sharp points, whereas the NPs grown on the fabric showed a similar morphology but with not very pronounced sharp points. For all concentrations of zinc nitrate studied, before and after 20 washing cycles, the cotton fabric functionalized with the ZnO NPs exhibited a UV protection factor between very good and excellent. [ABSTRACT FROM AUTHOR]

Graphical abstract CoPd nanoparticles supported on covalent triazine frameworks (CoPd/CTF) were fabricated for the first time. The prepared Co 5 Pd 5 /CTF-600 catalyst exhibited 100% H 2 selectivity and excellent catalytic activity toward the dehydrogenation of formic acid at 50 °C. Highlights • CoPd nanoparticles supported on covalent triazine frameworks were fabricated. • Co 5 Pd 5 /CTF-600 exhibits high activity for the dehydrogenation of formic acid. • The TOF value of the catalyst is 2129 mol H 2 mol catalyst−1 h−1. Abstract Dehydrogenation of formic acid to yield molecular H 2 is a sustainable and promising route in hydrogen energy supply. Rational design of high-performance catalytic system for it remains a challenging task. Herein, CoPd nanoparticles supported on covalent triazine frameworks (CoPd/CTF) were fabricated for the first time. The prepared Co 5 Pd 5 /CTF-600 catalyst exhibited 100% H 2 selectivity and excellent catalytic activity (TOF = 2129 h−1, n Pd /n HCOOH = 0.007) toward the dehydrogenation of formic acid at 50 °C. Our study further demonstrated that not only the synergetic effect between CoPd nanoparticles and nitrogen-rich CTF support, but also the ultrafine sizes of CoPd play a key role for the efficient catalytic dehydrogenation from formic acid. This work provides a feasible strategy to design high-performance CTF-based heterogeneous catalyst for catalyzing different reactions. [ABSTRACT FROM AUTHOR]

Highlights • MoS 2 nanoparticles were synthesized via simple hydrothermal approach. • As additive, the molecular weight PEG has a significant effect on the Sheet-thickness of MoS 2 nanoparticles. • Photocatalytic performance of MoS 2 nanoparticles is closely related to their Sheet-thickness. • Kinetic analysis revealed the differences in the catalytic performance of as-prepared samples. Abstract Molybdenum disulfide (MoS 2) nanomaterials have attracted considerable attention recently owing to its unique photoelectrochemistry property and promising applications in the conversion of solar energy to chemical energy and environmental purification. Flower-like MoS 2 photocatalyst was synthesised via hydrothermal method in this work. To achieve the MoS 2 nanoparticles with various sheet-thickness, polyethylene glycols (PEG) with deferent molecular mass were employed as additives in the preparation process. The effects of the molecular weight of PEG on the micro structure and crystal structure of MoS 2 nanoparticles were characterized by field emission scanning electron microscopy (FESEM), high resolution transmission electron microscope (HRTEM) and X-ray diffraction (XRD). The photocatalytic properties of as-synthesized products were evaluated by the degradation of methylene blue (MB) under ultraviolet irradiation. The results suggest that the molecular weight of PEG could affect the sheet thickness of the MoS 2 particles. In addition, the degradation rate of MB show that the photocatalytic performance of MoS 2 nanoparticles is closely related to their sheet thickness, the photocatalytic activity reduced with the decrease of sheet thickness of MoS 2 nanoparticles which is mainly attributed to the reduction of the active sites. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Nanoparticles of silicon and selenium were obtained and characterized by nanosecond laser ablation in water. • Their surface coatings demonstrated strong antibacterial effect. • The presence of singlet oxygen is a possible cause of antibacterial properties of nanoparticles. Abstract Selenium and silicon nanoparticles were obtained by nanosecond laser ablation in distilled water and characterized by scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy. The antibacterial properties of their coatings regarding Gram-positive and Gram-negative bacteria were demonstrated. The presence of singlet oxygen and other reactive oxygen species on the surface of the silicon nanoparticles, leading to oxidative damage to bacterial membranes and further death of the bacteria, was considered a possible mechanism of their antibacterial modality. [ABSTRACT FROM AUTHOR]