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The sluggish kinetics and thermodynamic stability associated with LiAlH 4 have posed significant obstacles to its practical application. Herein, we have designed a general method for preparing a series of hollow 3D flower-like composite, denoted as M-NC@TiO 2 (M = Ni, Co, Fe, Cu), which serve as highly efficient catalysts for the dehydrogenation of LiAlH 4. These composites feature TiO 2 hollow spheres as substrates to induce the growth of MOF nanosheets, leading to the regular arrangement of carbon nanosheets anchored with metal nanoparticles M on the TiO 2 sphere surface after calcination treatment. Evidently, M-NC@TiO 2 exerts a discernible enhancement on the dehydrogenation kinetics of LiAlH 4. LiAlH 4 -7wt% Ni-NC@TiO 2 system begins to release hydrogen at a notably lowered temperature of 56.3 °C, with a total amount of hydrogen released of 7.19 wt% before reaching 300 °C. Subsequent investigations showed that the enhanced hydrogen storage performance can be attributable to the in-situ formation of the metal compounds, the fine size and high dispersion of metallic nanoparticles, and the synergistic effect between TiO 2 and M nanoparticles. This work not only provides an effective general way to synthesize catalysts for improving the hydrogen storage performance of aluminum-based hydrogen storage materials, but also augments our understanding of hydrogen storage mechanisms. [ABSTRACT FROM AUTHOR]

Ta 2 O 5 /Pd hybrid microspheres were readily synthesized via a one-step thermal solution process employing a template composed of glucose carbon spheres, yielding a structure characterized by a rough and porous surface. This morphology offers an expanded contact area and increased sites for ethanol reactions of Ta 2 O 5 /Pd hybrid microspheres. At room temperature (25 °C), the Ta 2 O 5 /Pd hybrid microspheres exhibited responsiveness to ethanol concentrations ranging from 50 to 700 ppm, displaying a linear response pattern to a narrow concentration gradient of 90–120 ppm. The hybrid exhibited notable sensitivity, manifesting a response value of 5.1–100 ppm ethanol. In addition, they displayed less responsiveness to other VOCs gases, were minimally affected by humidity, and maintained gas-sensitive stability for 30 days, demonstrating excellent selectivity and long-term stability. Based on the fitting curve analysis, the material theoretically demonstrated the ability to detect ethanol at concentrations as low as 101 ppb. Ta 2 O 5 /Pd hybrid microspheres modified by glucose carbon sphere templates and noble metal nanoparticles are promising candidates for ethanol room temperature sensing, providing new insights into the development of room temperature sensing. [ABSTRACT FROM AUTHOR]

In recent years, magnetic metal nanoparticles (NPs)/carbon nanofibers (CNFs) composites have become very promising electromagnetic waves (EMWs) absorbers. However, how to achieve controllable growth of magnetic metals in CNFs is still an urgent problem to be solved. Herein, we reported a pore-confined strategy for constructing the porous Co/CoO/CNFs. By introducing different amounts of acetone (0.20 g, 0.30 g and 0.40 g) into the aqueous phase spinning solution to construct the porous structure, we achieved uniform distribution of Co/CoO NPs and ultimately obtained the porous Co/CoO/CNFs microwave absorbers (MAs) with excellent microwave absorption performance. Thanks to the excellent impedance matching and enhanced polarization loss, the porous Co/CoO/CNFs obtained the minimum reflection loss (RL) of −52.2 dB with a thickness of 3.0 mm, and the effective bandwidth (EBW) was 3.02 GHz when the acetone addition in the spinning solution was 0.30 g. Therefore, the pore-confined strategy proposed herein is conducive to the design of the MAs with excellent performance and low infilling rates based on CNFs. Furthermore, the porous structure of CNFs also improves the lightweight performance of the MAs. [ABSTRACT FROM AUTHOR]

Gram-negative bacteria Pseudomonas putida , Gram-positive Bacillus subtilis, and Staphylococcus aureus were utilized as test samples to evaluate the antibacterial characteristics of DD3-clay/MgO and DD3+38 wt% ZrO 2 -clay/MgO nanoparticles. The ceramic powders prepared by a thermal autoclave method are characterized before and after Mg addition by SEM, EDX, XRD, IR, UV–visible, and TEM in order to investigate microstructure, phase, and surface morphology. The results showed that after adding Mg, it led to the deformation of the crystal lattices of (mullite, zirconium silicate, and zirconium oxide) together with a decrease in particle size (75–103 nm) and a complete change in its shape from nanotube to nanospherical, as observed by SEM and TEM analyses. It also confirmed by UV–visible spectroscopy that the addition of Mg increases the absorbance accompanying a decrease in the energy gap of 1.91, 1.74, 1.73, and 1.43 eV corresponding to DD3, DD3Z, DD3/30 wt% Mg and DD3Z/30 wt% Mg respectively. The antibacterial mechanism is related to the size of the particles, the solvent used for powder dissolution, the nanoparticle's size when they come into touch with bacteria, and the generation of reactive oxygen species (ROS: ˙O 2 −, ˙OH, and H 2 O 2). It was observed that the anti-bacterial activity is enhanced with 10 wt% and 30 wt% of Mg added to a modified ceramic powder. Also, more O 2 − is formed on the surface of the prepared powder, which penetrates the bacterial cell and destroys it. The nanocomposite particles showed remarkable antibacterial activity when they were dissolved in DMSO compared to methanol and chloroform as organic solvents. The aim is to enrich knowledge on the antibacterial activities of metal nanoparticles (ZrSiO 4 and MgO) on three bacterial strains with different Grams due to their extensive involvement in the phenomena of contamination and infection encountered in the medical field. The synthesized nanoparticles have good antimicrobial activity against all strains tested. A maximum inhibition zone of 35 ± 0.2 mm was obtained with S. aureus , a zone of 23 ± 0.46 mm with P. putida and a zone of 27 ± 0.46 nm with B. subtilis for DD3/30 wt% Mg and an inhibition zone of 38 ± 0.93 mm, 26 ± 0.24 nm and 17 ± 0.33 nm was obtained with same strains for DD3Z/30 wt% Mg, respectively. [ABSTRACT FROM AUTHOR]

Biogenic combustion with Mellifera (Honey) capping produced ZnO, Ag-doped ZnO, and Fe-doped ZnO nanoparticles. The phase and crystal structure of metal oxide nanoparticles (MONPs) have been recorded through XRD spectrum. It confirms that the prepared metal oxides are within the nanoscale range. The average crystallite size of Fe-doped ZnO is 8.8 nm, smaller than ZnO and Ag-doped nanoparticles. The vibrational spectra of ZnO, Ag-doped ZnO, and Fe-doped ZnO nanoparticles confirm functional group stretching vibrational modes. The exterior surface morphology of all metal oxide nanoparticles was captured by FESEM. Metal oxide nanoparticle compositional analysis shows elemental presence, atomic, and weight %. The optical properties of metal oxide nanoparticles have been examined using UV–vis spectroscopy. The band gap energy of ZnO nanoparticles reduced from 2.68 eV to 1.74 eV under Fe doing and increased to 2.9 eV under Ag doing. Metal oxide thermal stability is also being investigated to determine how it affects ZnO nanoparticles. Fe-doped ZnO nanoparticles have greater sensor properties than other metal oxides due to their tiny size, band gap, and stability. Gas sensor behaviour of three metal oxide nanoparticles was examined in various accepts. It proves Fe-doped ZnO is a promising gas sensor material. [ABSTRACT FROM AUTHOR]

Here in, a novel ternary manganese monoxide@nitrogen-doped carbon nanotube@cobalt composite was obtained via a scalable multistep reaction pathway. Mnganese monoxide (MnO) is adopted as the microwave transparent substrate to couple dielectric and magnetic components. The abundant internal voids of MnO and numerous interfaces between MnO and carbon can increase the dielectric loss to improve the microwave absorption (MA) performance, metal cobalt is employed as the magnetic component to enhance the magnetic loss. Benefiting from the synergistic effect of heterostructures, the ternary absorber exhibits the minimum reflection loss (RLmin) of −48.65 dB@8.1 GHz@2.8 mm and the effective absorption band (EAB) of 5.8 GHz with the thickness of 1.7 mm. Furthermore, the crystal structure, material components, surface element distribution and magnetic properties of the absorbers are characterized, the structure-performance correlation between "Physical properties" and "Electromagnetic performance" is established. Finally, the reliable MA mechanism based on "hierarchical component modulation" is summarized to guide the design of MnO-based absorbers. [ABSTRACT FROM AUTHOR]

Green synthesis of metal oxide nanoparticles is a cost-effective and sustainable approach that allows tailoring of the size and shape of the nanostructures for versatile applications. In this study, aloe vera extract-assisted sol-gel synthesis of nickel oxide nanoparticles (NiO x NPs) was explored for supercapacitor application. The NiO x NPs were synthesized at different aloe vera concentrations (2.5 and 5 wt%) and calcination temperatures (300, 400 and 500 °C). The phytochemical-assisted synthesis yielded NiO x nanopyramids with pores on their surface which widens as calcination temperature increases. As confirmed by XRD analysis, NiO x crystallite size also increased at higher calcination temperatures. Upon electrochemical characterization, NiO x -400B which was synthesized with 5 wt% aloe vera extract at 400 °C recorded the highest specific capacitance of 721 F g−1 at 1 A g-1 current density with the energy and power density of 10.38 Whkg−1 and 241.08 W kg-1 respectively. The charge storage mechanisms in the samples were gauged using Dunn's method which revealed that NiO x synthesized at higher calcination temperatures exhibited a greater contribution of the diffusion-controlled process. The optimized composition, NiO x -400B, also demonstrated excellent cycle stability by retaining up to 90.4 % of its original capacitance over 1500 cycles. This work is an attempt to investigate the viability of green synthesized nanoparticles in energy storage applications and the novel NiO x nanopyramid substantiates its prospect as a good electrode material for supercapacitors. [ABSTRACT FROM AUTHOR]

As tribo-catalysis gains increasing attention to harness mechanical energy for environmental remediation, it is time to explore its application to those organic pollutants that have been challenging to degrade. In this study, four commercial metal oxide nanoparticles, BaTiO 3 , ZnO, P25 TiO 2 , and DXN-RT30 TiO 2 nanoparticles, were stimulated through magnetic stirring to degrade 20 mg/L methyl orange (MO) and 30 mg/L methylene blue (MB) solutions. While all the other nanoparticles showed rather poor performance, DXN-RT30 TiO 2 nanoparticles performed exceptionally well: With Teflon magnetic disks rotating at 400 rpm, 98.2% of MO and 100% of MB were degraded within 330 and 420 min, respectively. DXN-RT30 TiO 2 nanoparticles demonstrated a unique absorption for MB molecules, yielding significantly different outcomes in active species trapping experiments between degradation of MO and MB solutions by DXN-RT30 TiO 2. Complemented by electron paramagnetic resonance analysis, our findings suggest that for DXN-RT30 TiO 2 nanoparticles under magnetic stirring, MO molecules are degraded by h+, ·OH, and e− in solution, while MB molecules are absorbed and degraded via h+ and e− on the surface of DXN-RT30 TiO 2 nanoparticles. This study identifies DXN-RT30 TiO 2 nanoparticles as a cost-effective, high-performance, and environmentally friendly tribo-catalyst for environmental remediation, stimulating further exploration for more excellent tribo-catalysts. [ABSTRACT FROM AUTHOR]

The specific behaviour of kaolinites heated between 600 and 800 °C (metakaolinite) makes this material very appropriate to be used as: i) ecological pozzolanic additive to ordinary Portland cement (OPC), ii) precursor of geopolymers, iii) carrier/supplier of metal nanoparticles with bactericidal/virucidal activity, and iv) catalytic reactions. The strong reactivity of the metakaolinite (mixed 2SiO 2.Al 2 O 3 oxide) is mainly associated with the presence of a large fraction (>50 %) of five-coordinated aluminum in its disordered structure. The thermal treatment of the metakaolinite favours the formation of the stable mullite below 1250 °C. The alkaline activation of metakaolinite produces geopolymers with remarkable mechanical properties, which reduce the CO 2 emission associated to the OPC cement manufacture. This metakaolinite-derived geopolymers also permit the homogeneous and safe stockage of contaminants radioactive Cs and Sr cations. Finally, the retention of Ag and Cu nanoparticles at the metakaolin surface has been successfully used as support as well as dispenser of antimicrobial/virucidal agents. This fact opens the possibility to use metakaolinite as support for another kind of metal nanoparticle (i.e. Pt, Rd, Au, Pd, etc) in catalytic applications as well as in health. This critical review provides an overview of the importance of the metakaolin structure in its main applications. [ABSTRACT FROM AUTHOR]

Combustible dust may result in a catastrophic dust explosion with much larger accident consequences than gas explosions. In this study, porous materials are explored as a promising solution for mitigating explosions. This study focussed on the investigation of aluminium powder explosion in the influence of ceramic foam, with and without coating with non-precious nickel nanopowders. The microscopic properties and structural characteristics of the ceramic foam were analyzed using X-ray spectroscopy, X-ray diffractometry, and scanning electron microscopy. The findings revealed that the nickel-coated ceramic foams are non-uniform and almost spherical in shape, with obvious agglomerations of metallic-silica present on the strut structure. Compared to non-coated ceramic, it can be said that nickel-coated ceramic foams demonstrate a significant reduction in maximum overpressure by approximately 10%. This suggests that the interconnected micro-network structure of the nickel-ceramic walls aids in quenching the flame of the aluminium dust explosion and hence, suppressing the overpressure. [ABSTRACT FROM AUTHOR]

Significant optical nonlinearities in amorphous nanocomposites are essential for developing advanced communications and photonic devices. In this regard, the borate glasses are considered substantial and readily available commercial hosts. The present work demonstrates the white light emission and decay properties in lithium bismuth boro-phosphate glasses reinforced with gold nanoparticles (AuNPs) prepared via melting and quenching technique. Also, their non-linear optical properties are evaluated in the present study. Numerous characterization methods were used to extensively examine the produced glasses, including XRD, HR-TEM, FTIR, XPS, MAS-NMR, DSC, UV–Visible, Photoluminescence, and Z-scan techniques. Following the addition of AuNPs into the glass matrix, an increase in the refractive index and density of the glasses was observed. The amorphous features of the glass sample are disclosed by XRD examination, and DSC research demonstrates the thermal stability of the glasses after the addition of AuNPs, as shown by the rise in T g values from 459 °C to 486 °C. HR-TEM results reveal the presence of Au metal nanoparticles having a cubic crystal structure with an average size of 14 nm, while XPS analysis shows that the valence of Au is 0, i.e. Au0 or, in other words, the metallic nature of gold in glasses. FTIR, MAS-NMR, and UV–Visible spectral studies demonstrate the substantial modifications in the physical, structural, and optical properties brought about by incorporating AuNPs into the glass matrix. The PL spectra of glasses containing AuNPs show three distinct, sharp emissions at 494, 611, and 738 nm, out of which the blue emission (494 nm) is found to be predominant and has an overall emission in the region of yellow on the CIE diagram with an average lifetime of 12.23 μs. Glasses containing AuNPs have a white light correlated colour temperature (CCT) of 5129 K and CIE chromaticity (x, y) coordinates of (0.346, 0.413). Additionally, we utilized a Z-scan technique to measure the nonlinear absorption coefficient and nonlinear refractive index. Our experimental data show that the values obtained are consistent with the theoretical closed and open aperture values. Based on our findings, it appears that the glasses we prepared have the potential to be utilized in optical switching applications. [ABSTRACT FROM AUTHOR]

An advanced version of the solution combustion synthesis (SCS) method was developed to prepare iron oxide (IO) nanoparticles, through controlling the agglomeration, size and shape of nanoparticles by assisting a cationic surfactant, "cetyltrimethylammonium bromide (CTAB)" and ethanol. Various IO nanoparticles were prepared in the presence of different CTAB:ethanol molar compositions of 0:0, 0.27:0, 0.55:0, 0.27:17.1, 0.55:17.1 and 0.82:17.1. The morphological evolution from agglomerated-shape particles to the well-dispersed as well as the size- and shape-controlled particles depended directly on the CTAB:ethanol molar composition. A shift from ferromagnetic behavior to superparamagnetic was observed by the application of CTAB along with ethanol, where the lowest blocking temperature (T b , 60 K), highest saturation magnetization (M s , 83.5 emu g−1), zero coercivity and remanance magnetization were revealed for the particles prepared by CTAB:ethanol molar compositions of 0.55:17.1. These particles showed an acceptable specific absorption rate (SAR) value (320 W g−1) as well as no obvious hemolytic and cytotoxic effects. This work provides new insights into advancing the SCS method and thus controlling the morphology, size and shape of metal oxide nanoparticles. [Display omitted] • Controlling the agglomeration, size and shape of nanoparticles in SCS method. • Structural and magnetic properties of particles depended on the CTAB:ethanol ratio. • The agglomerated-free, size- and shape-controlled IO-EC2 structure was developed. • IO-EC2 represented an acceptable SAR value, and no hemolytic and cytotoxic effects. [ABSTRACT FROM AUTHOR]

In the current work, an investigation of the influence of Zn ion doping on the structural, vibrational, colloidal stability, and morphological features of NiO nanoparticles was carried out. XRD was used to record the change in crystal properties with respect to doping concentration, which confirmed that the crystallite size decreases as the doping concentration rises. SEM was used to investigate the extreme morphology of each and every sample, and it was found that there was a predictable shift in both size and morphology as a result of the varying doping doses. Images taken with a TEM microscope show that the produced samples have a spherical form. The particle distribution curve, also known as a histogram, provides evidence that the predicted crystallite size and the average particle size are very close to being identical. The gas sensor behavior of Zn-doped NiO nanoparticles is performed under various sensor parameters, which confirms the higher sensor response of 15% Zn-doped NiO nanoparticles with the impact of fewer particles size. The response-recovery time confirms that the prepared metal oxide nanoparticles are suitable materials for the CO 2 gas sensor. [ABSTRACT FROM AUTHOR]

WO 3 nanocomposite thin films, in which metal nanoparticles are incorporated into a WO 3 matrix, offer an enhanced electrochromic response speed with color neutrality. This article reports the structural, optical, and electrochemical properties of Ag nanoparticle-incorporated electrochromic WO 3 thin films with different concentrations. Room-temperature-sputtered thin films using composite targets with a low Ag concentration exhibited a random distribution of small nanoparticles. In contrast, in the film with a higher Ag concentration, the particles were merged, resulting in a single or polycrystalline phase. Surface plasmon resonance peaks were observed in the absorption spectra of the Ag–WO 3 composite films, indicating the formation of metallic nanoparticles, which was also confirmed via high-resolution transmission electron microscopy. The optical bandgaps decreased gradually from 3.15 eV for WO 3-δ to 3.02 and 2.99 eV for W 0.97 Ag 0.03 O 3-δ and W 0.91 Ag 0.09 O 3-δ thin films, respectively. The W 0.91 Ag 0.09 O 3-δ thin film showed a faster switching time of 2.6 s for coloring and 4.8 s for bleaching with a higher coloration efficiency of 66.52 cm2/C than those of the WO 3-δ thin film, which were 3.8 s, 6.8 s, and 58.68 cm2/C, respectively. However, transmittance modulation in the W 0.91 Ag 0.09 O 3-δ thin film was inferior to that in the other films. Furthermore, the W 0.91 Ag 0.09 O 3-δ thin films were black in the colored state, whereas the bare WO 3-δ and W 0.97 Ag 0.03 O 3-δ thin films were Prussian blue, suggesting the realization of color neutrality through the incorporation of Ag nanoparticles. [ABSTRACT FROM AUTHOR]

The solar energy conversion through the photocatalyst for the pollutant degradation is important effort for development of the visible light photocatalysts for the practical application in various filed. In this work, elemental semiconductor red phosphorus/ZnO nanohybrid (Z-Rp) through simple, cost-effective, and sustainable ball milling approach and further studied its visible light driven-photocatalytic activity towards the pollutant degradation under visible irradiation. The prepared Z-Rp were characterized by the various stereoscopic and microscopic technique which shows improvement of the structural, optical, and physical properties of the zinc oxide after addition of the elemental red phosphorous. The Diffuse reflectance spectroscopy and valence band spectra shows the shifting of the energy band towards the visible light region after incorporating of the red phosphorus which are father supported by the visible light degradation process. The optimized Z-Rp nanohybrids displayed the excellent visible light driven photocatalytic activity toward the methyl orange dye degradation as compared to the bare materials, which further prove the optimal reaction parameter could effectively enhanced visible light photocatalytic activity. This easy fabrication process and inexpensive earth abundant Rp compared to the silver and gold-based plasmonic metal, which are also used to enhance the photocatalytic performance of the metal oxide nanoparticles, can be a good and sustainable approach for the solar energy conversion for various application. [ABSTRACT FROM AUTHOR]

Silver nanowire (AgNW) transparent conductive films (TCFs) are expected to replace ITO films due to their high transmissivity, conductivity, and flexibility. However, there are high junction resistance and poor inoxidizability of AgNW-TCFs. Instead of sputtering a metal oxide film on the surface of AgNW-TCFs, we apply metal oxide nanoparticles (MONPs) via magnetron sputtering to modify the AgNWs network. The goal is to reduce junction resistance of wire-wire junctions while wrapping AgNWs in a manner that improves the stability of AgNWs-TCFs. SnO 2 , ZnO, Al 2 O 3 , and TiO 2 are used as modification materials, and the AgNWs@MONPs-TCF with like-core–shell structures are obtained via magnetron sputtering. The resistance of AgNWs@MONPs-TCFs is lower by about 50% than that of the reference (AgNW-TCFs). The resistance nonuniformities of the AgNWs, AgNWs@SnO 2 , AgNWs@ZnO, AgNWs@Al 2 O 3 , and AgNWs@TiO 2 TCFs are 12%–13.2%, 6.9%, 9.8%, 10.3%, and 11.1%, respectively. After 28 days, their resistance has been increased 328.2%, 18.4%, 24.3%, 24.1%, and 35.7%, respectively. At 155 °C, their non-uniformity of temperature is 35.6%, 17.7%, 16.9%, 24.8%, and 23.2%, respectively. Comparing with the reference, their failure voltage and their electric-heating efficiency have been significantly improved by MONPs modification. Using the AgNWs@SnO 2 -TCFs as a transparent heating film in electric ceramic teacups, a good electric heating effect and stable performance have presented. [ABSTRACT FROM AUTHOR]

For electrospinning of MgO nanoparticle-based fiber architectures, we exploit the intermediate formation of layered Mg(OH) 2 nanosheets that form inside polyvinylalcohol (PVA) based fibers during nanoparticle-polymer formulation. Upon calcination, Mg(OH) 2 nanosheets undergo a topotactic dehydration reaction. In conjunction with polymer removal, these sheets generate staggered MgO nanoparticle ensembles that comprise flat ribbons. With methanol as a solvent and in polyvinylpyrrolidone (PVP) fibers, the MgO nanoparticles retain their crystallinity and structure inside the electrospun fibers. After calcination, they form nanoparticle threads with a cylindrical profile and particle size gradient. [ABSTRACT FROM AUTHOR]

Herein, low-threshold green and red random lasing actions were investigated in inorganic caesium lead bromide (CsPbBr 3) and caesium lead iodide (CsPbI 3) perovskite microcrystals, which were grown using metal organic chemical vapor deposition. Sharp random lasing emission peaks were visible on the right side of the broad photoluminescence emission spectra. Interferential patterned sapphire substrates and novel metal nanoparticles were used to enhance the lasing emission intensity and reduce the lasing emission thresholds. Fast-decayed random lasing oscillation dynamics and backscattering angular distribution of light confirmed that the multi-scattering of light was important in the reduction of the threshold in thin films on patterned sapphire substrates. Plasmonic enhancement between gold or silver nanoparticles and the perovskite microcrystals contributed similarly to low threshold random lasing emission, which was verified using the simulation result from the finite difference time domain (FDTD) method. This work has a wide range of applications in sensing, speckle-free imaging, illumination, and medical diagnosis. [ABSTRACT FROM AUTHOR]

The extensive application of a multifunctional composite film of metal nanoparticles embedded in a dielectric matrix is remarkable. Due to the oxidation susceptibility of atomic iron, it is difficult to directly fabricate embedded Fe nanoparticles in an oxide dielectric matrix with a Fe target. Because La 0.5 Sr 0.5 FeO 3 can be decomposed into LaSrFeO 4 and α -Fe, ferromagnetic and optical absorption FePt:LaSrFeO 4 composite films were successfully fabricated at room temperature using Pt and La 0.5 Sr 0.5 FeO 3 as targets via magnetron and pulsed laser co-deposition. Further annealing was performed on the FePt:LaSrFeO 4 composite films. FePt is chemically disordered face-centered cubic phase (A1 structure) below 600 oC annealing and chemically ordered face-centered tetragonal phase (L 1 0 structure) above 600 oC annealing. With increasing the annealing temperature, a redshift of the absorption peak from 256 to 285 nm is seen, which can be attributed to the size growth of the LaSrFeO 4 and FePt nanoparticles in the composite films. The strongest absorption peak at around 269 nm for the 600 oC annealed sample can be attributed to the high crystallographic quality and relatively tiny grain size of FePt particles with uniform distribution. FePt:LaSrFeO 4 composite films are ferromagnetic and optically absorbent, making them suited for multifunctional applications. Furthermore, magnetron and pulsed laser co-deposition techniques have the potential to produce multiferroic oxides, in which the coupling of different ordering processes e. g. ferroelectricity and ferromagnetism provides the potential for a new breed of multifunctional devices. [ABSTRACT FROM AUTHOR]

A series of MXene/MnCo 2 O 4.5 nanocomposites was successfully prepared by hydrothermal, ice crystal template and physical blend methods, respectively. Various characterizations indicated that hydrothermal method could successfully loaded MnCo 2 O 4.5 nanoparticles on the surface of MXene nanosheets to obtain MMC-W nanocomposites with 3D flower-like structure, which could give MMC-W large specific surface area. The HTD temperature and decomposition heat of AP with adding 2.0 wt% MMC-W could significantly decrease to 304.7 °C and increase to 1310.9 J g-1, respectively. The lowest decomposition temperature (286.1 °C) and the highest heat release (1427.6 J g-1) of AP could be obtained by adding 8.0 wt% and 4.0 wt% of MMC-W, respectively. Moreover, MMC-W (2.0 wt%) could also significantly reduce the E a of pure AP by 118.3 kJ mol-1 and increase the k value for AP by 11.2 times. The excellent catalytic performance of MMC-W was owing to the synergistic effect of nano-sized MnCo 2 O 4.5 and MXene nanosheets. Owing to its high catalytic activity, MMC-W would be used as an excellent catalyst for ameliorating AP decomposition and supply an idea for the preparation of novel metal oxide nanoparticles. [Display omitted] • Three methods were used to prepare MXene/MnCo 2 O 4.5 nanocomposites as catalysts. • MMC-W with flower-like structure exhibited high specific surface area. • MMC-W exhibited an excellent catalytic performance for AP decomposition. • MMC-W reduced the activation energy of AP decomposition by 118.3 kJ mol-1. • The synergistic effect of nano-sized MnCo 2 O 4.5 and MXene promoted AP decomposition. [ABSTRACT FROM AUTHOR]

Considering the significant role of metal nanoparticles in the detection and removal of pollutants from the environment, metal oxides stand as inexpensive materials at the scale of nanometers that are capable of participating in photocatalytic and decontamination procedures. Meanwhile, nickel nanoparticles have been applied as a new approach for removing the existing pollution from the environment. In this paper, we have synthesized copper doping nickel oxide nanoparticles (Cu-doped NiO-NPs) by a sol-gel method that involved the application of okra plant extract and had investigated their photocatalytic properties and cytotoxicity effects. The obtained Cu-doped NiO-NPs have been characterized through FT-IR, UV–Vis, XRD, FESEM/EDAX/PSA, and VSM analyses in different concentrations (1, 3, and 5%) of copper at an optimum temperature of 400 °C. According to the XRD results, the size of nanoparticles under optimal conditions (at the temperature of 400 °C and % 3 Cu-doped) has been observed to be 10.66 nm while containing a face-centered cubic (fcc) structure. Furthermore, the obtained FESEM outcomes have been indicative of the good dispersion of these nanoparticles. Also, photocatalytic activity of Cu-doped NiO-NPs through the degradation of methylene blue (MB) pigment studied under UV-A light and had detected 78% of degradation throughout 105 min. To complete the characterization process, the cytotoxicity of nanoparticles in inhibiting the cancer CT26 cells has been determined using of MTT assay. [Display omitted] [ABSTRACT FROM AUTHOR]

The large-scale synthesis and the stabilization of noble metal nanocatalysts with ultrasmall sizes are crucial to their practical application. Herein, Pd, Au, and Pt nanoparticles (NPs) are in situ embedded on boron nitride nanosheets (BNNSs) via the reduction of precursor salts induced by 60Co γ-irradiation, which is a mature technique widely used in industry. The reduction mechanism was elucidated by pulse radiolysis experiments. In comparison with other BN substrates like hexagonal BN (h -BN), BNNSs had not only large surface area of 263 m2 g−1, but also abundant hydroxyl groups produced during the sonicated exfoliation, resulting in ultrasmall sizes, large loading amounts, and uniform distribution of the anchored NPs. The particle sizes of the loaded Pd, Au, and Pt NPs were measured to be 2.9, 3.1, and 3.0 nm, respectively. As a consequence, in the model reaction of 2-nitroaniline reduction, the Pd-, Au- and Pt-BNNSs composite nanocatalysts showed much higher catalytic activities than those composites loading the corresponding NPs on other BN substrates. Particularly, most of the 2-nitroaniline could be reduced within merely 40 s when using Pd-BNNSs as catalysts, performing a rate constant of 1.1 × 10−1 s−1. The number of hydroxyl groups on BNNSs support as well as the catalytic performance of the corresponding NPs-loaded BNNSs composites could be improved by extending the sonicated exfoliation time, because more NPs were loaded and the hydroxyl groups were also proved to play an important role in enhancing the catalytic activity. Moreover, Pd-BNNSs catalysts still displayed prominent activity even after five cycles owing to the high stability of BNNSs and their strong affinity for PdNPs. This work not only demonstrates BNNSs as ideal supports to load noble metal NPs for catalysis, but also reveals the feasibility to synthesize and in situ embed ultrasmall noble metal NPs on BNNSs via γ-irradiation. γ-Radiation-induced reduction achieved facile loading of noble-metal nanoparticles on BNNSs as ideal supports for extraordinary catalytic activity and excellent reusability. [Display omitted] • BNNSs with hydroxyl groups, prepared from sonicated exfoliation, were suitable to load noble metal nanoparticles (NPs). • Noble metal NPs of Pd (Au or Pt) were in situ embedded on BNNSs by facile γ-radiation-induced reduction. • The reduction mechanism was elucidated by pulse radiolysis experiments. • NPs loaded on BNNSs possessed the smaller sizes and higher loading amounts, compared with those on other BN substrates. • NPs-loaded BNNSs showed excellent catalytic activity and reusability for 2-nitroaniline reduction. [ABSTRACT FROM AUTHOR]

In this study, we report a method to enhance the performance of environmentally friendly cerium oxide (CeO 2) based pseudocapacitive electrode materials synthesized by a facile and safe co-precipitation method. Although co-precipitation can be considered as one of the most safe and facile procedures for the preparation of metal oxide nanoparticles, co-precipitated CeO 2 often exhibits substantially reduced specific capacitance. However, by simply doping Fe into CeO 2 , we observed a notable enhancement in the performance of the CeO 2 electrode. Although co-precipitated CeO 2 demonstrates a specific capacitance of 121.0 F g-1 at 1 A g-1, the performance of the CeO 2 electrode increased by 4.6 times to 559.0 F g-1 after 10 at.% Fe doping (10FDC). The specific capacitance of 10FDC at a high rate (10 A g-1) significantly increased by 8.9 times compared to that of CeO 2 (21.6 F g-1 for CeO 2 and 192.7 F g-1 for 10FDC). In addition, 10FDC exhibited excellent cycling stability, and less than 5% decrease in its specific capacitance was observed even after 7,300 charging and discharging cycles. The mechanism behind the capacitance enhancement was investigated via electrochemical analysis, which suggested that the contribution of the surface-capacitive limited process and the electrical conductivity of the electrode enhanced after Fe doping. Our study proposes a new possibility for the development of high-performance eco-friendly energy storage materials via the modification of electrical properties and introduction of defects by facile acceptor doping. [ABSTRACT FROM AUTHOR]

Novel mesoporous ferrite nanoparticles of ruthenium (RuFeO 3) and cerium (CeFeO 3) with large surface area were successfully fabricated by hydrothermal method and applied for the removal of fluoxetine from aqueous solution. The morphology and physicochemical properties of meso-porous metal ferrites were characterized by different analytical techniques. The obtained results showed that the particle size of 20–30 nm for meso -CeFeO 3 , and 80–100 nm for meso -RuFeO 3 respectively. Study of the adsorption of fluoxetine over metal ferrite nanoparticles was explored using UV–vis spectroscopy at different experimental conditions such as temperature, pH, initial fluoxetine concentration and time. The adsorption data were fitted and analyzed with kinetic and different adsorption isotherm models, and the results showed that both the metal ferrites effectively adsorbed fluoxetine (>99%). The maximum adsorption capacity of 729.6 mg g−1 for CeFeO 3 , and 683.5 mg g−1 for RuFeO 3 at neutral pH and at 25 °C were observed. The amount adsorbed over the surface of metal ferrite nanoparticles increased with increasing initial fluoxetine concentration, reaction time, and temperature, and the adsorption performance improved under neutral conditions (pH 7 and 8). The pseudo-second order kinetic and Langmuir isotherm models satisfactorily fitted the adsorption data, showing that the adsorption of fluoxetine involved physical adsorption through intermolecular electrostatic force between the metal ferrites and fluoxetine which is further confirmed by intra-particle diffusion model. The observed wide band/gap, 3.815eV for CeFeO 3 , and 3.360eV for RuFeO 3 respectively showed their stability towards visible light suggesting their real sample applicability, recovery and reuse capability involving physisorption with fluoxetine molecules. In addition, the feasible adsorption process of fluoxetine is analyzed with its geometry that is determined by theoretical energy calculations using DFT. • Ease method of synthesis is described for metal ferrites leading their applicability in real samples. • High adsorption capability of metal ferrites towards fluoxetine at room temperature and neutral pH may translate well to industrial scales. • Since the adsorption of fluoxetine is influenced by its geometry, this may consider as a promised method of its removal from aquatic system. [ABSTRACT FROM AUTHOR]

Over the past decade, the subject of "greener chemistry" and chemical processes has been emphasized. The "greener chemistry" improves environmental efficiency in reducing the consumption of resources and energy and achieving a stable economic development of the environment. Nanotechnology is investigating nanoscale materials that have applications in the area of biotechnology and nanomedicine alongside several other significant applications such as cosmetics, drug delivery, and biosensors. The different shapes and sizes of nanoparticles can be synthesized with physical, chemical, or biological methods. The tendency to produce nanomaterials, especially metal oxides, and use them, is increasing because of their exciting properties in the nanoscale. However, metal oxide nanoparticles produced by chemical methods have significant concerns due to hazardous and toxic chemicals and their environmental damage. The production of metal oxide nanoparticles using the principles of greener chemistry has found a special place in research. Increased awareness of greener chemistry and biological processes has necessitated using environmentally friendly methods for the production of non-toxic nanomaterials. Plants and polymeric materials as renewable and inexpensive sources have received particular attention to prepare nano biomaterials. The use of plants to synthesize metal oxide nanoparticles because of the non-use toxic pollutants is one of the environmentally friendly methods, and that's why this type of synthesis is called greener synthesis. In this review, we exhibit a total sight of greener synthesis methods for producing metal oxide nanoparticles and their medical applications. [ABSTRACT FROM AUTHOR]

Metal oxide nanoparticles and their composites with conducting polymers, specifically Polyaniline (PANI) were utilized for fabricating nanoscale supercapacitor (SC) electrode materials. In the present study, we have synthesized pristine Pr 2 O 3 , NiO, Co 3 O 4 nanoparticles, binary PANI-Pr 2 O 3 , PANI-NiO, PANI-Co 3 O 4 , ternary Pr 2 O 3 –NiO–Co 3 O 4 , and quaternary PANI-Pr 2 O 3 –NiO–Co 3 O 4 spherical core-shell nanocomposite using co-precipitation and ultra-sonication methods. The grown samples were characterized with different analytical techniques. The XRD pattern revealed that the as-synthesized products were crystalline with Pr 2 O 3 hexagonal phase, NiO cubic phase, and Co 3 O 4 cubic phase in pure and nanocomposites. The Williamson-Hall, Scherrer, and size-strain plot methods were employed to study the crystalline development and contribution of micro-strain. FTIR pattern exhibited the metal-oxygen and PANI bond vibrations. FE-SEM images shown the spherical core-shell shape morphology of quaternary nanocomposite. EDX evident the presence of praseodymium, cobalt, and nickel in synthesized samples. UV–vis spectroscopy confirmed the absorption in the visible region. The IV graphs showed a higher conductivity of quaternary nanocomposite. The cyclic voltammetry results revealed that the quaternary nanocomposite has a higher specific capacitance 500 Fg-1 as compared to binary nanocomposites 134 F g−1 (PANI-Pr 2 O 3), 143 F g−1 (PANI-Co 3 O 4), 256 F g−1 (PANI-NiO), and PANI (90.8 F g−1) at a scan rate of 5 m Vs−1. The GCD results also showed that the quaternary nanocomposite has a higher specific capacitance of 905 F g−1 at current density 1 A g−1 with maximum energy density and power density of 87.99 kWhkg-1 and 2.6 k W kg−1 , respectively. The EIS curve also confirmed that the quaternary nanocomposite has a lower polarization resistance (R p) and solution resistance (R s). The higher capacitance of quaternary nanocomposite can facilitate ion transfer, and the formation of its core-shell structure flourish to enhance surface-dependent electrochemical properties. Furthermore, this study gives a novel research idea to manufacture electrode materials for supercapacitors. [ABSTRACT FROM AUTHOR]

The environmental–friendly synthesis of nanostructural aluminium nitride with high purity and good dispersity properites is regarded as a technical issue. In this paper, an arc discharge with assistance of direct nitridation has been put forward to synthesize aluminium nitride nanoparticles that simultaneously possess the high purity of more than 97%, the average particle size of 99.1 nm, and the specific surface area of 60.8 m2 g−1. Compared with the aluminium nitride prepared by direct nitridation of aluminium nanoparticles, the unique framework of the satellite structural and small-sized aluminium nanoparticles attached on larger-sized aluminium nitride nanoparticles is prepared by arc discharge, which can prevent effectively agglomeration and coalescence of aluminium nitride nanoparticles in the next nitridation process. In addition, the direct nitridation process requires a low temperature of 600 °C for 2 h, because the nonstructural aluminum particles are evenly distributed on the surface of aluminum nitride and process the low average diameter of 40 nm. The work provides an efficient technique to open up the possibility of technological advancement for preparing metal nitride nanoparticles with high purity and good dispersity. [ABSTRACT FROM AUTHOR]

The use of superhydrophobic metal oxide nanoparticles has been considered for the construction of self-cleaning, anti-corrosion, anti-icing, anti-fogging, and oil/water separation surfaces, but the low chemical and thermal stabilities of applied organic modifiers restrict their wide applications. In this study, the superhydrophobic copper oxide nanoparticles with the hierarchical urchin, flower and spherical-like architectures were fabricated via a simple and facile single-step hydrothermal method without any post chemical modification. Taguchi experimental design was used to evaluate and optimize the synthesis parameters such as structure-directing agent concentration and its type, synthesis temperature, and the molar ratio of the complexing agent to the initial copper (II) ions. The wettability characteristics of synthesized samples were assessed based on the chemical composition of powders and their morphological structures. The scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) analyses were used to characterize the resultant samples. The wettability properties of samples were determined by measuring the water contact angle (WCA) and contact angle hysteresis (CAH). The results confirmed that the synthesized sample under the optimum condition had an excellent superhydrophobic property with a WCA of 158.4⁰±2⁰ and CAH of 1.5⁰. The surface wettability evaluations also revealed that the morphology and surface free energy of the powders could be controlled simultaneously by alterations of type and concentration of the structure-directing agent, in order to enhance the anti-wetteing characteristics. [ABSTRACT FROM AUTHOR]

In order to enhance the photocatalytic activity of TiO 2 under visible light, Ag nanoparticles were introduced into tridoped B–C–N–TiO 2 (TT) catalyst by photoreduction deposition. Ag/B–C–N–TiO 2 (ATT) catalysts with the functions of reducing band gap and carrier recombination were prepared. At the same time, the effect of the amount of Ag on the photocatalytic performance of ATT catalyst was investigated. Through XRD, XPS, PL and other characterization methods, the (211)/(101)/Ag interface heterojunction mechanism similar to the traditional Z-scheme heterojunction was proposed. The intervention of Ag nanoparticles changed the P–N interface heterojunction between (211)/(101) to the (211)/(101)/Ag Z-scheme interface heterojunction. The results show that ATT catalyst exhibits the highest photocatalytic activity when the molar amount of Ag is 0.005% with the MB degradation rate of the ATT catalyst (0.01707 min−1), which is 14.59 times of TiO 2 (0.00117 min−1) and 2.02 times of TT (0.00847 min−1). In addition, the four cycles efficiencies of ATT for MB degradation were all above 94.00%.This study reveals the possibility of construction of Z-scheme heterojunctions between precious metal nanoparticles and different interfaces of TiO 2 , and provides a reference for the construction of Z-scheme interface heterojunctions. [ABSTRACT FROM AUTHOR]

The major issue of consumable water shortage in different parts of the world has piqued the interest of researchers around the globe towards finding out novel, efficient and cost-effective means and techniques for treatment of contaminated water. Towards such efforts, researchers are experimenting with various types of nanoparticles for observing their abilities to treat polluted and/or wastewater. Numerous types of nanoparticles such as carbon-based nanoparticles, semiconductor nanoparticles, ceramic nanoparticles, polymeric nanoparticles, metal nanoparticles, magnetic nanoparticles, etc. are widely tested to confirm their applicability as potential candidates for contaminated as well as wastewater treatment. Different types of nanoparticles offer specific advantages depending on their composition, physical, chemical, electrical, magnetic and structural characteristics. Nanoparticles such as nanoferrites are reported to be easily separated, regenerated and reused up to several runs without incurring any loss in their properties which tend to significantly reduce operations costs. The present study provides a detailed review of the various synthesis and characterization techniques for the production of the nanoparticles. The present study also reviews the current progress, made particularly during the last two decades, in the application of nanoparticles for successful removal of organic, metallic as well as pathogenic pollutants from the water. This review aims to highlight the unlimited potential of nanoparticles and their derivatives in the domain of contaminated and wastewater treatment. [ABSTRACT FROM AUTHOR]

Ceramic-magnetic nanoparticles (CMNPs) are attracting attention due to their various applications, especially in biomedical industries. Among them, spinel ferrite CMNPs have received considerable deliberations among different spinel metal oxides due to their fascinating characteristics. Spinel ferrite CMNPs are used for enhancement of the applicability of CMNPs without affecting the intrinsic advantages of iron oxide CMNPs. Spinel ferrites with doping agents have useful electrical and magnetic properties in various fields. Moreover, the replacement of metallic atoms in ferrites is promising to manipulate physical characteristics and improve their performance. Among different spinel ferrites, CoFe 2 O 4 nanoparticles are the most investigated CMNPs. Furthermore, they are used as permanent magnets, magnetic recorders in high-density and micro-wave devices, and magnetic fluids. This study reviews the CoFe 2 O 4 nanoparticles doped with various elements and their applications in various fields. [ABSTRACT FROM AUTHOR]

In this study, Zn(Al)O thin films were produced using colloidal solution of Zn(Al)O nanoparticles dispersed in polyethylene glycol (PEG). Zn(Al)O mixed metal oxides were obtained by a simple pyrolysis of Zn–Al containing layered double hydroxide materials with different Al content. Survey of textural analysis of Zn(Al)O mixed oxides displayed characteristic peaks of ZnO structure. The calculated ratios of lattice parameters c/a were found to be 1.61 and 1.60 for 3-ZAO and 5-ZAO, respectively. The optical transmittance of the prepared thin films was not significantly affected by the increase in Al content; however, this increase changed the optical band gap from 3.27 eV to 3.33 eV. ZAO thin films, which are both cost-effective with good optical properties, have the potential to be an alternative to those used in many optical devices lately. [ABSTRACT FROM AUTHOR]

The challenge to obtain stable glasses containing monodisperse magnetic nanoparticles with controlled size and shape is an exciting and almost unexplored field of research. Such new materials can be used in magneto-photonics or ultra-sensitive magnetic sensors. In this work, for the first time, colorless and transparent bulk glasses containing monodisperse 20 nm Fe 3−δ O 4 nanoparticles were prepared by a melt-quenching route. Magnetic nanoparticles were synthesized by thermal decomposition and covered with a stellate mesoporous silica shell in order to protect them against dissolution during the glass melting process. The incorporation of nanoparticles into glasses and the ideal parameters obtained for this system are discussed. The new nanocomposite materials were characterized in order to investigate the structure, thermal, and magnetic properties. Such an original approach is a very promising way to incorporate a wide panel of nanoparticles, including metallic, bimetallic and metal oxide nanoparticles, into a variety of glasses providing new properties to these materials. Image 1 [ABSTRACT FROM AUTHOR]

Herein, we present a high-performance NO 2 sensor operating at room temperature based on ZnO nanorods functionalized by nonplasmonic Pd nanoparticles. Optoelectronic measurements revealed that the ZnO/Pd hybrids exhibited high photocurrent with ultrafast rise/decay rates under visible light with optimal wavelength (λ = 475 nm), which was related to the photoexcited nonplasmonic electron injection from Pd nanoparticles to ZnO nanorods. Characterization of the visible-light-activated gas sensing performance is pursued at ppb-level of NO 2 resulting in high responses, fast response/recovery rate, low detection limit as well as full reversibility. The enhanced optoelectronic NO 2 sensing performance of the ZnO/Pd hybrid was attributed to the photoexcited nonplasmonic electrons. Here, we designed and demonstrated a high-performance NO 2 sensing material utilizing the photoexcited nonplasmonic electrons from transition metal nanoparticles. This concept can also be extended to other metal oxide/transition metal nanoparticle heterostructures for optoelectronic devices. [ABSTRACT FROM AUTHOR]

2D heterojunction based on g-C 3 N 4 nanosheets with other semiconductor nanosheets is a promising way to improve photocatalytic hydrogen evolution (PHE) activity over g-C 3 N 4. However, current 2D heterojunction based on g-C 3 N 4 are unsatisfactory due to their insufficient absorption of visible light and inefficient charge separation. In this work, Ag/TiO 2 /g-C 3 N 4 nanocomposites based on 2D heterojunction coupling with Ag surface plasmon resonance (SPR) were synthesized by a method combining facile wetness impregnation calcination. The PHE activity of Ag/TiO 2 /g-C 3 N 4 nanocomposites is attributed to the TiO 2 /g-C 3 N 4 2D heterojunction and bare g-C 3 N 4 nanosheet under visible light irradiation, indicating a cooperative effect between Ag and TiO 2 /g-C 3 N 4 2D heterojunction. As a result of SPR effect, the composites strongly absorb visible light. In addition, the oscillating hot electrons from Ag can easily transfer to 2D heterojunction. This synergistic effect lead to sufficient visible light absorption and efficient charge separation of 2D heterojunction, which improved the PHE activity of g-C 3 N 4. This work indicates that loading metal nanoparticles on 2D heterojunction as metal SPR-2D heterojunction nanocomposites may be a potential method for harvesting visible light for PHE. [ABSTRACT FROM AUTHOR]

A simple organic-phase synthesis process was used to produce bare NiFe 2 O 4 and ZnFe 2 O 4 and core-shell ZnFe 2 O 4 @NiFe 2 O 4 ferrite nanoparticles. X-ray powder diffractograms for all investigated powders show characteristic peaks of a spinel cubic structure without a secondary phase. Transmission electron microscopy (TEM) indicated the presence of nanoparticles that are smaller than 20 nm. The release of divalent ions (Ni2+ and Zn2+) from synthesized nanoparticles that were dispersed in saline solution, phosphate-buffered saline (PBS) and human serum, as determined by the inductively coupled plasma mass spectrometry (ICP-MS) method, was lower than 2 wt %. These results demonstrate the stability of the investigated nanoparticles in biologically relevant media and exclude the toxicity of Ni2+ and Zn2+ due to metal ion release, thereby opening a broad range of (bio)medical applications. [ABSTRACT FROM AUTHOR]

Effects of SiC nanoparticles addition on synthesis and antibacterial properties of TiCu nanocrystalline powder prepared through high energy mechanical milling were studied. The results showed that the synthesis of TiCu powder in the presence of the nanoparticles was accelerated and after mechanical alloying for 20 h, a TiCu/SiC nanocrystalline powder with the crystallite size <5 nm, and 3.3% lattice micro-strain obtained. Further milling resulted in fully amorphous TiCu intermetallic alloy with more uniform distribution of SiC nanoparticles. The antibacterial activity of the synthesized powders was investigated by disk diffusion test. The TiCu/SiC nanocomposites showed enhanced antibacterial effect against S. aureus and E. coli, and with increasing SiC content, the antibacterial behaviour was improved. This behaviour is attributed to high Cu2+ ion release as a result of particle size refinement with increasing SiC nanoparticles. [ABSTRACT FROM AUTHOR]

Egg white (EW) has long been a high-quality source of protein for human beings and has also been widely used in food processing and biomedical engineering. Surprisingly, however, given that EW is a sustainable, environment-friendly, low-cost, versatile, readily available, and highly effective functional additive, it has seen relatively little use in the preparation of inorganic functional materials (IFMs). Fortunately, since 2000, and especially since 2010, this situation has been rapidly changing. This perspective article begins by briefly describing EW's protein composition and its functions as a foaming, gelling, reduction, binding and doping agent. It continues with a comprehensive discussion of the strategies for synthesis, mechanisms of formation, and applications for seven IFMs prepared with EW in the last twenty years, including metallic oxides, ferrites, ceramic foams, carbon materials and their composites, metal nanoclusters and metal nanoparticles, biomimetic mineralization of CaCO 3 , and miscellaneous other IFMs. The article concludes with a summary of the advantages of EW-assisted preparation of IFMs and the bottlenecks that may stand in the way of its rapid development. This case study will provide a reference and guidance for the future use and development of EW in the preparation of IFMs. [ABSTRACT FROM AUTHOR]

Bi 2 Mo 2 O 9 nanoparticles were introduced into bismuth antimony tellurium (BST) alloys by ball milling, and the composite particles were then fabricated into pellets by hot press for thermoelectric property measurement. Both elemental mapping and TEM image confirmed that Bi 2 Mo 2 O 9 nanoparticles were evenly distributed among BST matrix. The impacts of Bi 2 Mo 2 O 9 volume percentage on the electrical resistivity, Seebeck coefficient, thermal conductivity, and thermoelectric figure of merit (ZT) of BST/Bi 2 Mo 2 O 9 composites were investigated. The results told that the composite presented the highest thermoelectric ZT when Bi 2 Mo 2 O 9 was 0.3 vol%, which was increased by 12.15% from the ZT of pure BST at room temperature. This could be attributed to the balance between the decreased thermal conductivity and increased electrical resistivity, and phonons could are blocked when charge carriers passing through the dispersed Bi 2 Mo 2 O 9 nanoparticles. [ABSTRACT FROM AUTHOR]

Herein, novel Ag-doped PbS (Ag:PbS) nanoparticles (NPs) were synthesized via a facile and rapid microwave route. Field emission scanning electron microscopy (FESEM)/energy-dispersive X-ray (EDX) spectroscopy were employed to confirm the homogeneous doping of Ag in PbS. The transmission electron microscopy (TEM) exposed that the PbS NPs were fully encapsulated with Ag. X-ray diffraction (XRD) analysis revealed that all the samples possessed cubic crystal structures whereas the peak positions for the Ag:PbS were slightly shifted towards lower angle compared to pure PbS, further confirm the Ag doping in NPs. Fourier-transform Raman (FT-Raman) spectra also confirmed the phase and doping of Ag in PbS NPs. The grain sizes of the synthesized NPs were found to be in the range of 15–40 nm while calculated crystallite sizes of these samples were in the range of 18–26 nm. The zeta potential for 5.0 wt% Ag:PbS NPs was found to be approximately 10 times higher than that for pure PbS NPs, signifying the high stability of the doped NPs in aqueous media. The optical band gap of Ag:PbS NPs were evaluated from diffused reflectance spectra and found to be in range of 1.95–2.51 eV; increases with Ag doping. The quenching in photoluminescence (PL) intensity was observed with the increase of Ag doping concentration attributed to the charge transfer between Ag and PbS. Moreover, Ag doping also improve the electrical and dielectric properties of PbS NPs. Finally, optoelectrical properties of synthesized materials were investigated under 633 nm laser-light illumination to determine their applicability as visible-light photodetectors. It was found that the Ag doped PbS NPs exhibited enhanced photodetector figures of merit compared to the pure PbS NPs. [ABSTRACT FROM AUTHOR]

The nanoparticles of Ytterbium oxide (Yb 2 O 3) with spherical architectures have been synthesized by using hydrothermal procedure. The prepared Yb 2 O 3 nanoparticles were further doped with Gd3+ ions for exploring the potential of the nanoparticles in terms of tuning the optical properties such as band gap. Here, we demonstrated that the dopant inside the nanoparticles affects the optical properties and show how it has a relevant consequence on the overall peak position of Yb 2 O 3 as a function of dopant concentrations. We have also examined the crystallite changes in Yb 2 O 3 nanoparticles by employing the X-ray peak profile analysis. The respective Williamson–Hall studies and size–strain plot were employed to study the individual roles of crystallite sizes and lattice strain over Yb 2 O 3 nanoparticles as a function of Gd3+ ion doping. The factors including strain, stress and energy density value were computed for both bare and Gd3+ ion doped Yb 2 O 3 nanoparticles. The toxicological profiling of bare and Gd3+ doped Yb 2 O 3 nanoparticles were carried out by multiple assays including antibacterial, antifungal, seed germination assay and A. Cepa genotoxic studies. The results have demonstrated the excellent biocompatibility of prepared nanoparticles and signifying their potential applications in biomedical field. [ABSTRACT FROM AUTHOR]

Pure and Co-doped CeO 2 nanoparticles were synthesized successfully by the solvothermal method. The effect of Co substitution and external magnetic field on the morphologies and magnetic properties of nanoparticles was investigated. Results showed that synthesized Co-doped CeO 2 had the face-centered cubic structure and no other impurities existed in the samples with the increase of Co concentration from 5 to 75 wt%. The increasing Co concentration made the morphologies of Co-doped CeO 2 nanoparticles vary from the hollow sphere, solid sphere to rod-like shape. The applied external magnetic field of 5T decreased the nanoparticle size effectively including the diameter of hollow sphere with low Co concentration and rod-like particles with high Co concentration. Moreover, the wall thickness of hollow sphere particles was also decreased from 35 nm to 18 nm for pure CeO 2. The Co-doped CeO 2 nanoparticles showed the weak ferromagnetic behavior. With the increase of Co concentration, the saturation magnetization (M s) value increased first and then decreased. The Co-doped CeO 2 with 30 wt% showed the highest value of 3.65 × 10−2 emu/g (M s). The M s value of Co-doped CeO 2 prepared in 5T showed an increasing trend with the Co concentration. The highest value (M s) reached 4.21 × 10−2 emu/g for doped CeO 2 with 75 wt% Co. [ABSTRACT FROM AUTHOR]

Abstract Goals of this work lye in attempts to fabricate Ag 2 O–TeO 2 –V 2 O 5 glasses (Gs) and glass-ceramics (GCs), determination of the mean square lattice strain and dislocation density by using Williamson–Smallman method and specially detection of their antibacterial activity against two gram-negative bacteria of Escherichia coli and Kelbesiella pneumoniae and also two gram-positive bacteria of Staphylococcus aureus and Bacillus cereus. The xAg 2 O–40TeO 2 –(60-x)V 2 O 5 (0 ≤ x ≤ 50 mol%) ternary glasses, were obtained using the melt quenching method and so, resulted glasses were annealed at their specified crystallization temperature (T cr) to achieve the glass-ceramics. Then, the Williamson–Smallman method was used to determine the mean square lattice strain and dislocation density. Further structural investigations were done by FESEM, EDX and TEM. Also, serial dilution bioassay was performed against both before-mentioned gram positive and gram negative bacteria (as test strains) to assess their antibacterial activity. Results show that the highest antibacterial and bactericidal potential is devoted to G and GCs sample with x = 30, as the optimal Ag 2 O content. Moreover, the antibacterial activity of the Gs and GCs on Staphylococcus aureus bacteria is higher than Bacillus cereus bacteria and in the case of gram negative's, Escherichia coli exhibit a more inhibition and bactericidal effect at x = 30%; in brief, the studied samples are good candidates in biological applications. [ABSTRACT FROM AUTHOR]

Abstract Aiming at improving the dispersibility of NiO nanoparticles, an in-situ precipitation strategy was developed for constructing MXene/NiO composites, which meanwhile could address the possible oxidation of MXene with traditional high temperature method. This strategy involves electrostatic absorption of Ni2+ cations by MXene, in-situ precipitation of Ni(OH) 2 under room temperature (RT), and calcination under N 2. NiO nanoparticles (~25 nm) were uniformly dispersed on the surface of MXene, and the catalytic effect of NiO on the thermal decomposition of ammonium perchlorate (AP) was enhanced. This method can be generalized to prepare other transition metal oxide (TMO) and MXene composites for dispersibility improvement of TMO nanoparticles for various applications. [ABSTRACT FROM AUTHOR]

Abstract An innovative and environmentally-friendly procedure has been developed for the successful preparation of Ta 2 O 5 nanoparticles (NPs). This method includes mechanical milling and a subsequent calcination step. The in-situ formation of LiCl/KCl and the partial crystallization of Ta 2 O 5 at low-temperature were observed after milling, confirming the existence of chemical reaction between TaCl 5 and LiOH/KOH reagents, and also the mechanochemical synthesis of Ta 2 O 5. By heating at 700 °C during 2 h, complete crystallization of Ta 2 O 5 was achieved. The synthesized Ta 2 O 5 NPs showed flake shape with sizes below 20 nm and S BET of 17 m2 g−1. Furthermore, the proposed method represents an alternative for the straightforward and large-scale production of crystalline Ta 2 O 5 NPs. Moreover, the as-prepared Ta 2 O 5 NPs showed high photocatalytic activity for degrading methylene blue (MB) dye. The Ta 2 O 5 NPs enhanced the degradation rate of MB attaining a degradation percentage of about ⁓ 81% within 180 min under UV–vis irradiation. Herein, trapping experiments demonstrated that holes are the main oxidative species in the MB photodegradation process. After recycling tests, the Ta 2 O 5 NPs showed high stability which demonstrates that this photocatalyst is suitable for use in wastewater treatment. Highlights • Ta 2 O 5 nanoparticles were synthesized by an innovative and green route. • The crystallization of Ta 2 O 5 was achieved at low-temperature during milling. • Ta 2 O 5 nanoparticles showed flake shapes with sizes below 20 nm. • Ta 2 O 5 enhanced the MB photodegradation efficiency achieving ⁓ 81% within 180 min. • The two-step route is an alternative for the easy and large-scale production of Ta 2 O 5. [ABSTRACT FROM AUTHOR]

Abstract Nanoparticles (NPs) of calcium and magnesium co-substituted nickel ferrite with the chemical composition Ca x Mg x Ni 1–2× Fe 2 O 4 (0.00 ≤ x ≤ 0.05) NPs were prepared hydrothermally. The (Ca, Mg) co-substitution effect on morphological, structural, optical and magnetic properties of NiFe 2 O 4 NPs was analyzed via FT-IR, XRD, TEM, SEM, DRS and VSM techniques. The magnetization of Ca x Mg x Ni 1–2× Fe 2 O 4 (0.00 ≤ x ≤ 0.05) NPs were examined and analyzed at room temperature (300 K; RT) and low temperature (10 K). The specific magnetic parameters such as saturation magnetization M s , remanence M r , coercivity H c , squareness ratio (SQR=M r /M s) and magnetic moment n B of Ni 1–2× Mg x Ca x Fe 2 O 4 (0.00 ≤ x ≤ 0.05) NPs were determined and evaluated. The M(H) curves exhibit superparamagnetic behavior at RT and ferrimagnetic nature at 10 K. The substitution significantly changes the magnetizations and coercivity data. An increase in the M s , M r , H c and n B values was observed in substituted products compared to pristine one. The highest values were obtained for x = 0.05 product. The SQR values are found to be below than 0.5, which can be attributed to surface spin disorder effects. The obtained magnetic results are primarily derived from the substitution with Mg and Ca that will strengthen the super exchange interactions. [ABSTRACT FROM AUTHOR]

Abstract This article describes synthesis of superparamagnetic fcc-CaFe 2 O 4 nanoparticles by a metal nitrate-citrate monohydrate sol–gel route and characterization using X-ray diffractometry, Raman spectroscopic, UV–Vis–NIR optical absorption spectroscopic, Mössbauer spectroscopy, dielectric and SQUID magnetometry measurements. Rietveld refinement of the X-ray diffraction pattern and observation of active A 1 g , T 2 g & E g modes in the Raman spectrum confirmed formation of single phase CaFe 2 O 4 nanoparticles in the spinel ferrite type fcc structure without impurity. Mössbauer and Rietveld data analysis revealed that nanocrystalline CaFe 2 O 4 is dominantly an inverse ferrite in which 85% Ca atoms preferentially occupy the octahedral site in the fcc symmetry and the Fe ions are in high spin Fe+3 state. Nanocrystalline CaFe 2 O 4 significantly absorbs optical light below 500 nm and the direct band gap energy is estimated to ~1.83 eV, which is higher than 1.26 eV reported for orthorhombic CaFe 2 O 4. Temperature and field dependent magnetic studies showed that fcc-CaFe 2 O 4 nanoparticles exhibit superparamagnetism at room temperature with high saturation magnetization of 1.07μ B. The blocking temperature is ~53 K at 1000 Oe and ~72 K at 500 Oe clearly shows lowering of blocking temperature at higher magnetic field. Interestingly below the blocking temperature at 20 K, CaFe 2 O 4 nanoparticles behave as non collinear soft-ferrimagnetic material with a saturation magnetization of 1.16 μ B , coercivity of 150 Oe and remanence of 4.45 emu/g. The magnetic momenta of Fe+3 ions residing at the octahedral sub-lattice are canted at ~25 °. [ABSTRACT FROM AUTHOR]

Abstract Diluted magnetic semiconductors (DMSs) have been providing a wide research area with various conflicting results of magnetic properties which are generally originated from structural characteristics due to fabrication process. We focused on the size dependent magnetic behavior of Zn 0.95−x Mg x Ni 0.05 O nanoparticles as a promising novae material introducing room temperature ferromagnetism (FM) at low doping concentrations of Mg+2 and Ni+2 ions. Markov Chain Monte Carlo method based on Metropolis algorithm is used to simulate the system, constructed on experimental parameters such as particle size (D), lattice constants (a and c), uniaxial anisotropy constant (K), applied field (H) herewith doping concentrations of Ni (5%) and Mg (1%). However, we described the system with the Heisenberg Hamiltonian to represent the exotic nature of the DMS type materials since determining the J ij constants by tracing the type of the exchange relation between different types of atoms as reported in former studies. In the light of hysteresis measurements, nanoparticles generated between 5 < D < 15 nm showed strong FM among others. An exciting result is that D = 5 nm, 10 nm and 15 nm curves are so close to be overlapped. Saturation magnetization (Ms) and coercive field (H c) had peaks of; D = 15 nm remnant magnetization (Mr) increased with increasing D up to 50 nm. Furthermore, D < 5 nm and D > 15 nm sized particles started to lose FM behavior. In addition, magnetic features of Zn 0.95−x Mg x Ni 0.05 O nanoparticles can be controlled via picking a fabrication method to tune the particle size. [ABSTRACT FROM AUTHOR]

In this study, we focused on the influence of structural order-disorder effects on the magnetic and optical properties of single-phase nickel ferrite (NiFe 2 O 4 ) nanoparticles that, were synthesized by the co-precipitation method and subsequently calcined at 700, 800, 900 and 1000 °C for 120 min in ambient atmosphere. These results from X-ray diffraction and transmission electron microscopy confirm that the NiFe 2 O 4 nanoparticles have an inverse spinel structure with high purity and crystallinity. The average particle size range between 12 nm and 42 nm depending on the calcination temperature. An analysis of the hysteresis loops revealed a ferromagnetic behavior with an increase in saturation magnetization to 13.2 emu/g from 8.2 emu/g at room temperature. At 7 K, the nanoparticles exhibited saturation magnetization of about 18.1–19.8 emu/g and change in crystallite size, as the calcination temperature increased. UV–vis diffuse spectra results showed an increase in the direct band gap in the range 1.35–1.43 eV, likely due to the increased crystallinity of the NiFe 2 O 4 nanoparticles. Photoluminescence spectroscopy revealed a strong emission in the visible region, which can easily be attributed to the presence of structural disorders in the [FeO 6 ], [FeO 4 ], and [NiO 6 ] clusters of the NiFe 2 O 4 powders. Finally, it was found that these NiFe 2 O 4 powders as-prepared have oxygen atoms that occupy different positions and are highly disturbed in the NiFe 2 O 4 lattice. These findings provide insights into the magnetic and optical behavior of NiFe 2 O 4 spinel nanocrystals, with a significant emphasis on structural order-disorder effects, and help reveal the relationship between structure and properties at the atomic level. [ABSTRACT FROM AUTHOR]