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In this paper, we propose a series of two-dimensional asymmetric Janus γ-Sn2OX (X = S, Se, Te) monolayers and systematically calculate the electronic structure, piezoelectricity, and mobility of carriers by using the first-principles method. It is predicted that while γ-Sn2OS and γ-Sn2OSe monolayers are structurally stable, Janus γ-Sn2OTe is found to be unstable with the negative frequencies appearing in its phonon spectrum. Both γ-Sn2OS and γ-Sn2OSe monolayers are semiconductors with indirect bandgaps. Particularly, γ-Sn2OS has a camel's back-like structure in the top valence band and Rashba spin splitting with a Rashba energy of 3.50 meV is found in γ-Sn2OS when the spin-orbit coupling is taken into account. Our calculated results reveal that the Janus γ-Sn2OS and γ-Sn2OSe monolayers are piezoelectric with out-of-plane piezoelectric coefficient d31 predicted to be 0.18 and 0.26 pm V−1, respectively. It is also indicated that γ-Sn2OS and γ-Sn2OSe exhibit highly directionally anisotropic carrier mobility and their electron mobilities are high enough for applications in nanoelectronic devices. [ABSTRACT FROM AUTHOR]

In this paper, fly-ash-loaded nano-magnesium-hydroxide composites were prepared by the heterogeneous nucleation method based on the idea of "particle design" using fly ash as a raw material and MgCl2 and NaOH as reactive coating agents, and their performance in the adsorption of lead (2+) ions [Pb(II)] and nickel (2+) ions [Ni(II)] in mono- and binary systems was investigated. Scanning electron microscopy (SEM), EDS spectroscopy, X-ray diffraction (XRD), infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and simulation equations were used for the characterization and analysis of the adsorption mechanism of the composite powder before and after adsorption. The results show that the physical and chemical properties of the modified fly ash are significantly improved. The problems of the low adsorption efficiency of fly ash as an adsorbent and the difficult separation of ash and water are successfully solved, as well as the problems of the slow settling and agglomeration of the colloidal solution of nano-magnesium hydroxide due to its small specific gravity and high surface energy. Through adsorption experiments using different systems, it is found that the composite powder has a strong adsorption effect on Ni(II) and Pb(II) in the unary system. In the binary competitive mixing system, the composite powder showed stronger selective adsorption of Pb(II), which may be related to the fact that the physical properties of Pb(II) are better than those of Ni(II). The adsorption isotherm of the overall adsorption process conforms to the Langmuir isothermal model. The maximum adsorption capacities of Pb(II) and Ni(II) reached 160.96 mg g−1 and 116.5 mg g−1 in the single system. The adsorption kinetics conform to the quasi-secondary kinetic model. The adsorption mechanism of the composite powder for Pb(II) and Ni(II) mainly involves precipitate adsorption, electrostatic adsorption, exchange interaction between cations and complexation between carbonate formed by the adsorption of CO2 from air and metal ions. [ABSTRACT FROM AUTHOR]

Chemical vapor deposition (CVD) and impregnation (IM) methods were applied in the preparation of novel Fe/LTA (Linde Type A) zeolite membrane/paper-like sintered stainless steel fiber (Fe/LTA/PSSF) catalysts for acetone oxidation. The catalysts were characterized using various techniques, such as actual iron loading (AAS), surface morphology (SEM), phase composition and crystallite size (XRD), specific surface area (BET), valence state (XPS) and reducibility (H2-TPR), to investigate the effects of the calcination process, iron loading, preparation methods and supports on their catalytic activity. The calcined catalysts were more active than the non-calcined catalysts in the catalytic oxidation of acetone due to the different oxidation states of the deposited metal species. The catalysts prepared by CVD with an Fe loading of 2.29% exhibited similar activity to the IM-prepared catalysts with Fe loadings of 4.42% and 9.69%, which may be attributed to the superior dispersion of the active Fe2O3 phases, the smaller size of metal oxide and the increased ability for oxygen storage. Among the IM-prepared catalysts, Fe/LTA/PSSF-IM-2 with an Fe loading of 4.42% exhibited the lowest T90 of 230 °C. Additionally, the catalysts coated on LTA/PSSF showed higher activity and contact efficiency (T90 of 249 °C) compared to those on granular zeolite (T90 of 318 °C). [ABSTRACT FROM AUTHOR]

The optical properties of Mn4+-activated phosphors are heavily affected by the host and the related data are difficult to obtain, which makes quantitative design of novel phosphors with required wavelength particularly challenging. In the era of big data, computation is emerging as a vital complement to materials development. Compared with traditional calculation routes, machine learning (ML) models provide better solutions for the problems wherein understanding the underlying physics is complicated with sparse data. In this study, we developed six ML models based on a sparse and small data set to rapidly predict the peak emission wavelength of novel phosphors and use Recursive Feature Elimination (RFE) to select the best features. Among them, the K-nearest neighbors regression (KNN.r) algorithm using non-parametric regression technology can predict the value of the target variable based on the similarity between the target value and its spatial neighbors, which can tackle sparse data sets with no obvious linear relationship well and has the best prediction accuracy. These models were then used to predict 278 potential Mn4+-activated phosphor hosts extracted from the inorganic crystal structure database (ICSD), and 19 samples were selected to validate these methods. In order to overcome the lack of physical and chemical insight of KNN, a visual data analysis was carried out based on hierarchical clustering analysis (HCA), and the rule between the peak emission wavelength and the structure of host was proposed. Guided by the results of KNN and HCA, six samples were selected for the synthesis and characterization to verify our conclusions. The measured values of all these phosphors exhibit good agreement with the predicted results, suggesting the success of our methodology. Thus, the model established and the rule proposed in this paper provide a new pathway for the rapid discovery of novel phosphors. [ABSTRACT FROM AUTHOR]

The π⋯π interactions in spin crossover (SCO) complexes can be used as an important means to fine-tune the spin transition behaviors. In this paper, three novel isostructural 2D Hofmann-type frameworks, [Fe(ppo)2M(CN)4] (1, M = Pt2+; 2, M = Pd2+; 3, M = Ni2+) have been successfully synthesized by judiciously choosing a large conjugated molecule, 2-(2-pyridyl)-5-(4-pyridyl)-1,3,4-oxadiazole (ppo) as the axial ligand. Single crystal X-ray crystallography analysis showed that there are different π⋯π interactions between the axial ppo ligands in 1–3. Variable temperature magnetic susceptibility studies revealed that 1 and 3 displayed incomplete and gradual SCO behaviors with T1/2 = 94 and 78 K, respectively, while 2 stayed in a high-spin state in the measured temperature range. The stronger π⋯π interactions between the conjugated ppo ligands observed in 1 and 3 than those in 2 may result in their different magnetic behaviors. [ABSTRACT FROM AUTHOR]

Typically, perylene diimide radical anions have broad and strong absorption in the near-infrared light region and exhibit excellent photothermal conversion performance, so they are considered as new potential organic photothermal materials. However, the stability of perylene diimide radical anions in air has always been a thorny issue. We found an effective way to improve the stability of perylene diimide radical anions through formation of low barrier hydrogen bonds between perylene diimide radicals and alkyl primary amines. In this paper, we report the synthesis of a stable perylene diimide radical anion/α-phenylethylamine hydrogen bonded complex (α-PEA⋯PDI˙−), and preparation of a kind of α-PEA⋯PDI˙−/GO (graphene oxide) film using a simple impregnation method. Compared to GO films and α-PEA⋯PDI˙− powder, the film exhibited a good photothermal response with the highest photothermal conversion temperature of 82.4 °C under light, a temperature increase rate of up to 35 °C, and a photothermal conversion efficiency of 24.07%. The film is optically stable and reusable, and also exhibits superior performance compared to pure graphene oxide for solar water evaporation. [ABSTRACT FROM AUTHOR]

Nanoscale molecularly imprinted polymers (MIPs) could offer high binding capacity and fast mass transfer, but their removal after adsorption is costly and time-consuming. In this paper, Fe3O4@SiO2 nanoparticles were synthesized and a lysozyme-imprinted polymer was synthesized via surface initiated atom transfer polymerization on the surface of Fe3O4@SiO2. Temperature-controlled adsorption and desorption of lysozyme were measured, and the adsorption kinetics and isothermal adsorption were determined. The results indicate that the synthesized Fe3O4 has an inverse spinel crystalline structure and Fe3O4@SiO2 is a core–shell structured nanoparticle. The adsorption kinetics followed the Langmuir EXT1 model, and the equilibrium adsorption capacity of the Fe3O4@SiO2@MIP at 40 °C was 117.12 mg g−1 with an imprinting factor of 1.51. SDS-PAGE electrophoresis confirmed the specific adsorption of lysozyme, and 86% of the adsorbed lysozyme could be released by changing the temperature. [ABSTRACT FROM AUTHOR]

It is of great significance for chemical energy storage devices, especially for the practical application of rechargeable zinc–air batteries (ZABs), to find efficient and economical bifunctional catalysts. Metal–organic frameworks (MOFs) have recently become hot research materials, and are often used as precursors of catalysts. This paper reports a carbon skeleton-coated bimetallic sulfide derived from MOF nanostructures that were used as cathode catalysts for ZABs. The N,S co-doped carbon-loaded FeS2,CoS2 ((Co,Fe)S2/CNS) catalysts exhibit excellent electrochemical properties in alkaline solutions due to the protection of metal sulfides by the carbon structure, the synergy of bimetallic Fe and Co, and the high surface area of the carbon skeleton. (Co,Fe)S2/CNS catalysts show a very low potential difference (ΔE = 0.68 V), a high specific capacity (759.1 mA h g−1) and good charge–discharge cycling performance (360 cycles/120 h) when applied to ZABs. This indicates that the prepared (Co,Fe)S2/CNS catalysts have a broad application prospect in the field of ZABs. [ABSTRACT FROM AUTHOR]

Piperazine appended Schiff base chemosensor (HL) (Z)-2,4-dibromo-6-(4-(piperazin-1-yl)but-1-en-1-yl)phenol, developed by a simple condensation of 3,5-dibromosalicylaldehyde and 2-aminoethyl piperazine, is successfully utilized to recognize Zn(II) and Cl− ions among several competitive cations and anions in 9 : 1 ethanol–water medium via turn on fluorescence. Interestingly, this chemosensor bears novel aggregation induced emission (AIE) properties in H2O–ethanol mixtures up to a ratio of 9 : 1, and the results obtained from dynamic light scattering (DLS), scanning electron microscopy (SEM), UV, and fluorescence spectroscopic studies help to confirm the presence of this property. With the help of this AIE activity, this probe has been used for selective detection of Cd (II) and Hg(II) via turn-on and off fluorescence, respectively, in a near aqueous medium. At the same time, in AIE active medium, the chemosensor can recognize picric acid also via turn-off fluorescence. All the sensing phenomena have been spectroscopically handled. In the presence of adenosine triphosphate (ATP)/AgNO3/Cl−, individual detection of the analyte is possible when four aforementioned analytes [Zn(II), Cd(II). Hg(II), Cl−] are present together in a solution. The moderately high host–guest binding constant values assure us about the chemosensor-analyte adduct formation, and the chemosensor-analyst binding mechanism is confirmed by IR and mass spectroscopy. The density functional theory (DFT) study gives the optimized structure of probe–analyte complexes. The on-site clear visual detection of the analytes in paper strips, along with AIE property, is shown by the investigated chemosensor. As a practical application, this chemosensor can notably track Zn(II) and Hg(II) in plant cells and HeLa cells, respectively. The detection of Hg(II) and Cd(II) is also possible in real water samples. [ABSTRACT FROM AUTHOR]

In this paper, we propose the novel ZrTeS4 single layer and investigate its properties using first-principles calculations. In the equilibrium state, the ZrTeS4 single layer has an anisotropic lattice with high structural stability. The direct band gap of ZrTeS4 is found to be approximately 1.89 eV. Like other narrow-band-gap 2D materials, ZrTeS4 is rather ductile, however its Poisson's ratio is close to that of graphene. Single-layer ZrTeS4 is expected to be a promising non-linear optical material due to its good birefringence and perfect transparency in most of the infrared region. Single-layer ZrTeS4 is favorable for hole–electron separation because it only allows fast mobility of electrons along the x-axis. The absorption coefficient α(ω) is very high in the visible region (at 105 cm−1) and ultra-violet region (at 106 cm−1). The electronic and optical properties of single-layer ZrTeS4 can be tuned by applying different strains. It is reasonable to suggest single-layer ZrTeS4 as a good candidate for optoelectronic applications. [ABSTRACT FROM AUTHOR]

Designing a robust bifunctional water splitting catalyst at low cost is of great importance for water splitting. Herein, the in situ-generated MoS2/NiS2 nanosheet heterostructures by cobalt incorporation on carbon paper (Co–MoS2/NiS2/CP) are first obtained by applying a scalable chemical vapor vulcanization approach. Based on the synergistic effects of cobalt element doping and the construction of MoS2/NiS2 heterostructures, the much enhanced electrocatalytic performance for full water electrolysis is clearly revealed. In particular, the electronic structure of MoS2/NiS2 heterostructures was further effectively modified by cobalt incorporation along with the electron density of catalytic sites, which both promote the Volmer step to speed up alkaline hydrogen evolution reaction (HER) and optimize the oxygen-containing intermediate adsorption to enhance oxygen evolution reaction (OER). Consequently, Co–MoS2/NiS2/CP heterostructures presented low overpotentials (HER: η10 = 109 mV; OER: η10 = 323 mV) in the basic solution. Furthermore, Co–MoS2/NiS2/CP was designed as a two-electrode alkaline electrolytic configuration for full water electrolysis. This strategy experimentally illustrates the feasibility of designing a conventional electrocatalyst for water electrolysis via the cooperative effects of metal doping and heterostructured engineering. [ABSTRACT FROM AUTHOR]

The cathode material of layered manganese-based sodium-ion batteries has attracted the extensive attention of industries due to its simple preparation, low cost, and high theoretical specific capacity. However, a quick decay of the specific capacity caused by an irreversible redox reaction still is under investigation. In this paper, titanium doping is used to improve the structural stability of the cathode material. XRD, EDS, XPS, SEM, and TEM were employed to characterize the morphology and structure of cathode material doping by titanium. The pre- and post-doping of titanium are investigated and discussed. The XPS results demonstrated that the modified cathode material after doping titanium (Na0.77Ni0.23Mn0.77Ti0.02O2) shows stronger Mn–O bonds and higher energy storage performance. Furthermore, the electrochemical performances of batteries using the modified cathode material are evaluated. The first discharge specific capacity is measured at 202.6 mA h g−1 under a 25 mA g−1 current density and an 85.9% capacity retention rate under 254 mA g−1 current density after 200 cycles. [ABSTRACT FROM AUTHOR]

In this paper, we used DC electrophoretic force and electrical resistance measurement between two microwires in a microchannel to respectively extract and detect 1–10 μm polystyrene microplastics in water at 5–100 ppm concentration range. Ex situ microplastic detection methods like visual recognition and optical spectroscopy are expensive, time-consuming, and labor-intensive, highlighting the need for on-site rapid detection and quantification technologies. While micro-electro-fluidic devices have been introduced, they require advanced microfabrication and expensive signal processing instruments, while being prone to blockage with larger microplastics, limiting their point-of-need applications. We developed a simple wide PDMS channel equipped with two copper microwire electrodes, orthogonal to the flow direction and connected to a DC sourcemeter, for electrical resistance-based sensing of polystyrene microplastics in water. Electrical resistance between the two microwires was associated with microplastics' size and concentration, following their electrophoretic accumulation around the positive electrode. A positive correlation was found between microplastic concentration and reduction in the normalized resistance. Reducing the flow rate strengthened the extraction and detection of larger microplastics. In the future, the sensor will be tested for other types of microplastics in real samples and can be integrated into a handheld device for low cost and on-site microplastic detection. [ABSTRACT FROM AUTHOR]

Calcite is widely used in many fields. The synthesis of calcite is strongly influenced by solvents and additives. In this paper, the adsorption of water and formic acid molecules on the (104) surface of calcite was systematically studied on the atomic scale using the density functional theory (DFT) method. The results show that both molecules can be adsorbed on the calcite surface by occupying the top position of Ca. The results of differential charge density and the projected crystal orbital Hamiltonian population show that the adsorption is controlled by the charge transfer from the oxygen atom to the surface calcium. Formic acid has a carbonyl oxygen and it plays a greater role in stabilizing the surface than water. Moreover, the adsorption of two molecules can be further stabilized by hydrogen bonds formed between the hydrogen atom in the adsorbed molecules and the oxygen in calcite. This work provides a clear understanding of the stabilization of the calcite surface by adsorbing different molecules and also provides the possibility of tuning the synthesis of calcite by choosing a suitable solvent and additives. [ABSTRACT FROM AUTHOR]

To meet the increasing demand for power sources, scientists are continuously trying to improve the efficiency of solar cells. In these circumstances, Cs-based perovskites have attracted attention due to their intriguing performance. In this paper, eight different solar cells based on Cs-halide perovskite absorbers (CsPbI3, CsPbBr3, CsSnI3, CsSnCl3, Cs2BiAgI6, Cs3Bi2I9, CsSn0.5Ge0.5I3, and Cs3Sb2I9) are investigated using the SCAPS-1D simulation program. Besides, ZnO and CFTS materials are proposed as promising candidates for charge transport material application, along with gold as the back contact. Initially, the impact of the absorber and the electron transport layer (ETL) thickness on the photovoltaic performance was evaluated. In addition, various parameters, such as the thickness, the donor and acceptor densities and the defect density, are investigated to locate the final optimized Cs-based structures. From this optimization, it is evident that among all the optimizing features, absorber materials and the hole transport layer (HTL) thickness, the HTL acceptor density enhanced the performance much more than the other optimizing features. Furthermore, to evaluate the characteristics of these devices, the series resistance, shunt resistance, working temperature, current–voltage density, and quantum efficiency are also simulated. Among all eight Cs-based perovskites, the ITO/ZnO/CsPbBr3/CFTS/Au and ITO/ZnO/Cs3Bi2I9/CFTS/Au devices achieved the best performance, with a conversion efficiency of 19.28% and 19.23%, respectively. Lastly, the performance of the SCAPS-1D simulator software is verified using the wxAMPS simulation program, where both yield results that are in excellent agreement. In conclusion, this research provides useful information for optimizing solar cell architectures and understanding the effects of various device components. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) prepared from biomass exhibit excellent potential for use in sensing and bioimaging due to their charming properties. In this paper, CDs were successfully synthesized from Plumeria alba flowers as the raw material by a low-cost and green hydrothermal method for the first time and exhibited good water solubility. Ammonia and sodium hydroxide were added to the biomass solution to regulate the luminescence of the CDs. Among them, blue fluorescent CDs (B-paCDs) synthesized with ammonia as the solvent were used to specifically identify and detect Cu2+ in water. Linearity within a range of 0.1–100 μM was achieved, with an LOD of 0.08 μM. Green fluorescent CDs (G-paCDs) synthesized in a sodium hydroxide solvent were applied for pH detection. When the pH increased from 2 to 9, the green fluorescence emission region showed significant linear enhancement. In addition, a smartphone-based handheld platform was employed to directly capture and analyse fluorescence photographs, which could be further extended to the analysis of river water samples. Finally, two kinds of CDs were applied for the fluorescence imaging of living cells (HepG2 cells). The constructed platform indicates that the as-synthesized CDs have promise for applications in the fields of sensing and bioimaging. [ABSTRACT FROM AUTHOR]

The heterojunction structure of semiconductor photocatalysts is significant for making full use of their capabilities for organic molecules and dye degradation. In this paper, we present a heterogeneous junction composite fabricated with hybrid phase TiO2 and g-C3N4 for methylene blue (MB) removal through adsorption and photocatalytic degradation. The heterogeneous junction system was prepared by hydrothermal treatment with a subsequent pyrolysis process. The variation of the proportion and lattice structure of hybrid phase TiO2 in the synthesized catalysts was analyzed by refinement. Adsorption experiments showed that the maximum adsorption capacity of TiO2/g-C3N4 (1 : 10) was 1667 mg g−1, which was 45.97 times and 63.78 times higher than that of TiO2 and g-C3N4, respectively. In the photodegradation process, the TiO2/g-C3N4 (1 : 10) photocatalyst shows a removal rate of MB of 100 mg L−1, which was as high as 96.262%, significantly higher than that of pure TiO2 and g-C3N4. Brunner–Emmett–Teller (BET) measurements and Fourier transform infrared spectroscopy (FTIR) showed that the adsorption of MB onto TiO2/g-C3N4(1 : 10) was chemical adsorption, and ˙OH, which acts as an active substance, was found to play a major role in the photocatalytic degradation process. Overall, the developed hybrid phase TiO2/g-C3N4 heterojunction composite may be beneficial for the treatment of water pollution. [ABSTRACT FROM AUTHOR]

On account of the development of deep-ultraviolet (DUV) nonlinear optical (NLO) crystals, tetrahedron-based compounds have attracted more and more attention, due to their large band gap. Thus, it is urgent to study a lot of these crystals for conducting structural optimization to achieve a balance of optical properties. Thus, this paper designs and obtains the Li2NH4Rb(SO4)2 crystal, an alkali metal sulfate, which is composed of an optimized KBe2BO3F2-like structure and disordered Rb and [NH4] cations. It exhibits a strong second-harmonic generation (SHG) response of 2 × KH2PO4, a large band gap of 7.56 eV and a favorable growth habit to large crystals, simultaneously. Thus, the Li2NH4Rb(SO4)2 crystal is a typical tetrahedron-based DUV NLO example. The coordination of the optimized KBe2BO3F2-like structure and the disordered cations results in the strong SHG response. This structural design strategy will facilitate the exploration of novel DUV NLO crystals. [ABSTRACT FROM AUTHOR]

Wastewater contains inorganic pollutants, generated by industrial and domestic sources, such as heavy metals, antibiotics, and chemical pesticides, and these pollutants cause many environmental problems. Carbon-based nanomaterials can easily and effectively remove environmental pollutants from wastewater via adsorption and photocatalytic reactions. Nanotechnology, for example nanomaterials, nanoadsorbents, and nanomembranes, is an emerging technology that is used to treat many inorganic pollutants in wastewater. Carbon nanotubes, carbon-based quantum dots, fullerenes, graphene and its derivatives, graphene oxide, nanoparticles, and nanodiamonds are examples of carbon-based nanomaterials. Graphene and its derivatives and carbon-based nanomaterials have been the main focus for the treatment and removal of industrial and organic waste from wastewater. The effects on human health and the environment are reduced by the use of carbon-based nanomaterials and nanoparticles. In this paper, the removal of heavy metals and inorganic pollutants from wastewater using adsorption methods are summarized. The challenges, environmental effects, uses of nanomaterials and pollutant removal efficiency are explained in this review. In addition, industrial and nanotechnology applications are discussed. Further, the nanoadsorption process and the Fenton reaction are highlighted. Future perspectives to enhance the usage of carbon-based nanomaterials and increase their removal efficiencies are also discussed. [ABSTRACT FROM AUTHOR]

In this work, a simple and sensitive colorimetric fluorescence sensing probe was designed for the detection of uric acid (UA). UA can quench the fluorescence emission of CsPbBr3via hydrogen-bonding interactions. The probe can directly detect UA with an ultralow detection limit of 62.7 ppb and a fast response time of 30 s in a linear range of 0.0031–1.33 μM. The designed sensor displays a gradual color change from green to blue upon conjugation with UA. The applicability of the proposed sensor was also investigated as a paper sensor probe for detecting UA. Further, the method was successfully applied for the detection of UA in human blood serum. This work proposes CsPbBr3 as a novel platform for detecting UA well in clinical diagnosis. [ABSTRACT FROM AUTHOR]

The development of cyclic peptides has become a significant research direction due to their unique structural features. The spatial structure of small cyclopeptides greatly affects their biological activity. This study has presented the design and synthesis of a series of chiral valine-based cyclopeptides by the intramolecular photoinduced single electron transfer cyclization reaction (IPETC). A stereochemical study by combining ECD spectroscopy with theoretical calculations has revealed that the C-3 centers in most cyclopeptides exhibit opposite configurations to those of Val2 in cyclic skeletons, suggesting that the C-3 configurations are strongly affected by the chirality of the Val2 residue. Bioactive assays have shown that a cyclotetrapeptide 7 with three pure L -valine residues exhibits moderate antitumor activity against HepG-2 cells. Thus, this paper has provided some unique information on the chirality and bioactivity of small cyclopeptides with isoindolinone, and may be useful for further drug design based on cyclopeptides. [ABSTRACT FROM AUTHOR]

Environmental pollution is becoming increasingly serious, and photodegradation using sustainable energy sources such as solar energy is of great importance. It has been shown that semiconductor photocatalysts are capable of converting solar energy into chemical energy to generate photogenerated carriers to degrade organic dyes in wastewater. In this paper, bow-tie shaped Au/CdS/CuO ternary complex photocatalysts were prepared on Cu foil by anodic oxidation, chemical bath deposition and ion sputtering. The effects of oxidation time, oxidation temperature and deposition concentration on their microscopic morphology and structure were investigated, and the photoelectric properties and photocatalytic synergistic mechanism were further analyzed. The experimental results show that Au/CdS/CuO has a unique skeleton and pore structure and exhibits a better photoelectric response, surface wettability and catalytic activity. Compared with pure CuO, its photoelectric response current increased by 7.3 times to 190 μA cm−2, and the degradation rate of MB reached 97.3% within 180 min, and it still maintained great stability and catalytic activity after several cycles. Compared with powder and microbial catalysts, Au/CdS/CuO has the advantages of a short preparation time, good stability, reliability and no secondary pollution, which can bring greater economic benefits and better wastewater treatment results. [ABSTRACT FROM AUTHOR]

A novel carbazole–coumarin framework (CCF) has been designed for the detection of the environmental toxicant hydrazine. CCF exhibits excellent sensing behavior towards hydrazine in the presence of various nucleophilic and other relevant ions, having a detection limit in the nanomolar range. It interacts with hydrazine in a unique pathway where two hydrazine molecules simultaneously interact with it in two different sites through a chemodosimetric mechanism. The interaction yielded a vibrant turn-on blue fluorescence that was confirmed by both experimental studies and theoretical calculations. CCF has successfully been used to estimate the concentration of accumulated hydrazine in the gills of button mushrooms. The simple paper strips could be of practical use for the detection of hydrazine in both liquid and gas phases. [ABSTRACT FROM AUTHOR]

Covalent triazine frameworks (CTFs) are considered as ideal potential cathode composites for anchoring lithium sulfide compounds. In this paper, five fluorine-containing CTF materials (FN-CTFs) were successfully prepared by modulating the molar ratio of the feeding monomers TFTN and DCB. During the experiment, the optimal content of sulfur was determined to be 71.92% (mass fraction) by adjusting the sulfur content. The initial discharge capacity of the composite electrode at a rate of 0.5C is 959.5 mA h g−1, and after 200 charge–discharge cycles, the residual rate of discharge capacity is 71.32%, and the discharge capacity is 684.3 mA h g−1. Sulfur utilization, cycling stability and multiplier performance of the SFN-CTF composite cathodes are all superior to those of sulfur cathodes. [ABSTRACT FROM AUTHOR]

This paper reports a theoretical study on the structures and electronic and optical properties of M2B240/− (M = Li, Na, and K) clusters using the particle swarm optimization (CALYPSO) searching method and density functional theory (DFT) calculations. The lowest energy structures of M2B24 (M = Li, Na, and K) clusters with high symmetry are composed of three stacked ring forms, and two M atoms are located on the axis of the tubular structures. The lowest energy structure of the Li2B24− cluster exhibits an open bowl-shaped structure, while the lowest energy structures of Na2B24− and K2B24− clusters have a double-ring tubular shape. Based on these structures, some electronic properties including charge transfer, bonding character, dipole moment, polarizability, and thermodynamic properties were investigated systematically. In addition, to provide a theoretical basis for the identification and confirmation of studied clusters, the PES, IR, Raman, and UV-visible spectra with different and meaningful characteristic peaks were simulated, which can be considered as the reference for future experimental studies. [ABSTRACT FROM AUTHOR]

Rapid and intelligent identification of similar samples is an important technical aid for food quality and safety assessment. At present, relevant research studies are still relatively scarce. In this paper, Raman spectra of different brands of cheese products with different integration times were collected and analyzed statistically. The research showed that the original Raman spectral data of different brands of cheese products had a high similarity. The conventional statistical control chart method revealed that the samples of the same brand showed certain quality fluctuations, but it was still difficult to achieve effective differentiation from other brand samples. Different spectral preprocessing methods had a greater impact on the classification accuracy of the intelligent extreme learning machine algorithm, and different spectral integration times also had a greater impact. Before optimization, the intelligent recognition algorithm had only about 40% average accuracy with the integration time of 10 s. Under the optimal conditions – an 80 s Raman spectral integration time, wavelet denoising (coif wavelet basis, 5 decomposition layers), normalization processing ([−1, 1] interval), principal component dimensionality reduction (74 principal components were extracted, which can represent 100% of the information of the original data) and 400 hidden-layer neurons – the average recognition accuracy was 98%, and the algorithm operation time was less than 5 s. The establishment of this method provides a technical reference for rapid discrimination in food quality control. [ABSTRACT FROM AUTHOR]

Oxide semiconductor nanomaterials have attracted extensive attention due to their excellent surface-enhanced Raman scattering (SERS) effect and photocatalytic degradation ability, which can be used for the detection of pollutants. In this paper, an electrochemical anodic oxidation method was used to prepare rough copper oxide with nanostructured morphology on the surface of a copper sheet, and the effects of different reaction conditions on the morphology and crystallization of CuO were studied. Using rhodamine 6G as the probe molecule, the CuO nanosheet array thin film was optimized by regulating the reaction time and current density to obtain highly sensitive SERS detection. And under the irradiation of visible light, the CuO film showed good photocatalytic degradation performance of an organic dye. [ABSTRACT FROM AUTHOR]

A Ni-rich quaternary layered material, LiNi0.88Co0.06Mn0.03Al0.03O2, demonstrates great potential as a cathode candidate for Lithium-ion batteries with high energy density. Nevertheless, the pristine LiNi0.88Co0.06Mn0.03Al0.03O2 generally suffers from severe side reactions and transformation of the surface layer to a spinel structure during cycling. In the paper, a simple but efficient approach was taken to enhance the electrochemical properties of LiNi0.88Co0.06Mn0.03Al0.03O2 by covering with the conductive polymer polyaniline (PANI), which could protect the cathode against the continuous corrosion of electrolyte. The PANI coated cathode with the optimal covering amount of 1.0 wt% delivered a specific capacity of 132.7 mA h g−1 at a high rate of 5C and 122.9 mA h g−1 at −30 °C with a rate of 1C, while the corresponding discharging capacities of only 100.2 mA h g−1 and 85.5 mA h g−1 were respectively obtained for the pristine cathode. In addition, the 1 wt% PANI coated LiNi0.88Co0.06Mn0.03Al0.03O2 also exhibited outstanding cycling stability with 92.0% capacity retention after 200 cycles at 45 °C, much better than that (82.1%) of the pristine cathode. The simple covering technology using low cost raw materials endows the modification with potential practical application value. [ABSTRACT FROM AUTHOR]

Liquid phase oxidation of 2-methylnaphthalene (2-MN) is a common synthetic route for the preparation of 2-methyl-1,4-naphthoquinone (2-MNQ). Metal-free carbon materials doped with heteroatoms have been proven to have excellent catalytic potential in various reaction fields. In this paper, the catalytic performance of N, F co-doped benzoxazine carbon materials for the selective oxidation of 2-MN was studied. The results show that the catalyst obtained at a carbonization temperature of 700 °C has the best catalytic performance. Under optimized conditions, the 2-MN conversion is 97.9%, and the 2-methyl-1,4-naphthoquinone selectivity is 84.3%. In addition, this catalyst still exhibits good catalytic activity after five cycles. Based on the experimental and characterization results, graphitic nitrogen species play a key role in the catalytic reaction and there is an almost linear relationship between the F content and the selectivity of 2-MNQ. This work provides a greener and more efficient method for the preparation of 2-MNQ with N/F co-doped mesoporous carbon. [ABSTRACT FROM AUTHOR]

p-Menthane-3,8-diol (PMD) is receiving growing attention as a natural mosquito repellent with lower toxicity compared to the widely-used N,N-diethyl m-toluamide (DEET). In this study, sustainable carbon acid catalysts derived from alkaline lignin (AL) were prepared for synthesizing PMD from a popular chemical (±)-citronellal in an environmentally friendly solvent of water. The catalytic performances of the AL-derived carbon acid catalysts prepared at different pyrolysis temperatures were better than those of other catalysts such as carbon black and H-USY. In particular, when the AL pyrolyzed at 500 °C was used as the carbon acid catalyst, the conversion of (±)-citronellal was as high as 97% with a high PMD yield of 86%, indicating that waste alkaline lignin from pulp and paper industries can be used as a source of acid catalysts. It is found that the formation of PMD is preferred over catalysts with weaker acid sites, whereas isopulegol was more easily formed over stronger acid sites. Moreover, the reaction route of the citronellal cyclization–hydration reaction was more dominant via the carbocation-hydration pathway rather than the isopulegol hydration route on the weaker carbon acid catalyst. [ABSTRACT FROM AUTHOR]

Although human beings enjoy a relatively peaceful atmosphere, chemical terrorist attacks are still a public safety emergency, and the ability to rapidly and precisely detect chemical warfare agents (CWAs) presents a major challenge. In this study, we have developed a simple fluorescent probe based on naphthalimide that displays high selectivity and sensitivity for the nerve agent mimic diethyl chlorophosphate (DCP) in DMF solution. This probe, which is weakly fluorescent because of the PET character of the piperazine moiety, displays significant green emission in the presence of DCP. Based on the fluorescence calibration curve, the detection limit of this DCP probe was measured to be as low as 5.5 nM. Futhermore, the probe solution or filter paper can be used to selectively and sensitively detect DCP vapor, which shows the potential of its practical application. [ABSTRACT FROM AUTHOR]

In this paper, we report the synthesis, characterization, properties and application of four new Zn(II) and Cd(II)-based luminescent metal–organic probes, {[Zn(mbhna)(bpea)]}n (1), {[Cd(mbhna)(bpea)]}n (2), {[Zn(mbhna)(bpba)]·CH3OH·H2O}n (3) and {[Cd(mbhna)(bpba)]}n (4), composed of a commercially available bis(naphthalene)-based dicarboxylate (mbhna) acting as the luminescent tag. In addition to spectroscopic and compositional characterization of 1–4 by FTIR spectroscopy, elemental analysis, and EDX and elemental mapping, their surface morphology was analysed by FESEM and TEM. Their (dispersed in water) green emission (at 548 nm for 1 and 2, 551 nm for 3, and 547 nm for 4) established by fluorescence spectroscopy on excitation at 380 nm was further explored for the effect of different solvents on their emission intensities. Taking their emissive nature into account, 1–4 were utilised for the detection of harmful amines in water. These were found to recognise the presence of 4-nitroaniline (4-NA) in water with high efficiency (as low as 97 ppb) and selectivity. The ultrafast detection as well as paper strip detection of 4-NA by 1–4 and their recyclability have confirmed that these probes can be useful for real time applications. [ABSTRACT FROM AUTHOR]

NJC New Journal of Chemistry A journal for new directions in chemistryrsc. li/ njc ISSN 1144- 0546 PAPER Yan Jing, Fei Shao et al . The enrichment of 7 Li by extraction with a Sudan I- Ionic liquid system Volume 48 Number 15 21 April 2024 Pages 6517– 7024 Industrial Chemistry & Materials GOLD OPEN ACCESS Focus on industrial chemistry Advance material innovations Highlight interdisciplinary feature Innovative. Interdisciplinary. Problem solving APCs currently waived Learn more about ICM Submit your high- quality article rsc. li/ icm @ IndChemMater @ IndChemMater [Extracted from the article]

Natural laccase exhibits a broad substrate scope and only water is a by-product of its action, making it an environmentally friendly enzyme. It has good application prospects in food engineering, paper making, textiles, environmental pollutant treatment, and biosensing. However, natural laccase often has inherent defects like a high price, poor stability, and difficulty of being recycled. Nanomaterials with laccase-like activity have been rapidly developed in recent years to overcome these drawbacks. In comparison with laccase, nanozymes possess the benefits of being low price, mass-produced, having long-term storage, high stability, and adjustable activity. This review first briefly introduces the catalytic mechanism and the application of laccase, hoping to stimulate future research ideas for laccase mimics and expand its application fields. Then, nanomaterials with laccase activity are reviewed, and their application directions are introduced. Finally, it summarizes the current challenges of laccase-mimicking enzymes and proposes the development direction of future research. [ABSTRACT FROM AUTHOR]

In this paper, a computational study, at the M06L/def2-SVP and BP86/def2-SVP levels of theory, on [M(η5–C60Me5)(CO)n] (n = 3, M = Mn(I), Tc(I), Re(I); n = 2, M = Co(I), Rh(I), Ir(I)) complexes as well as the corresponding classical half-sandwich structures, [M(η5–Cp)(CO)n], is reported. By considering the above metal complexes as an ABC system, where B is the central metal ion, A corresponds to three (or two) CO ligands and C is a η5–Cp or η5–C60Me5 ligand, four types of bonding interaction energies defined as A–BC, AB–C, A–B and B–C, as well as the total interaction energy of the complexes, were calculated and corrected for the basis set superposition error (BSSE). In the most interesting part of the paper, the possible existence of cooperativity/anticooperativity between the metal–carbonyl and the metal–(η5-ligand) bonds was also investigated for the first time. The nature of the bond in these complexes was also studied using energy decomposition analysis-natural orbital for chemical valence (EDA–NOCV) calculations. [ABSTRACT FROM AUTHOR]

Two supramolecular components {[3-BCBPY][H3BTEC]2}n (1) and {[H2BPYBC]1/2[H3BTEC]·H2O}n (2) based on benzene carboxylic acid (H4BTEC = 1,2,4,5-benzenetetracarboxylic acid) and different viologen cations (3-BCBPY·2Cl = 1,1′-bis(3-cyanobenzyl)-4,4′-bipyridinium chloride, and 4-BCBPY·2Cl = 1,1′-bis(4-cyanobenzyl)-4,4′-bipyridinium chloride) were synthesized. Single crystal X-ray diffraction analysis showed that the three-dimensional supramolecular network was constructed in compounds 1 and 2, due to the hydrogen bond between H3BTEC− and 3-BCBPY2+ and the hydrogen bond between H3BTEC−, H2BPYBC2+ and water molecules, respectively. Both compounds 1 and 2 exhibit photochromic behavior of electron transfer. However, the discoloration speed of compound 2 is slower than that of compound 1, which may be due to the higher ionic state of compound 1 increasing the potential. At the same time, the two compounds also showed interesting photomodulated fluorescence behavior. Time-dependent density functional theory (TDDFT) was used to study the discoloration mechanism of compounds 1 and 2. Compound 1 exhibits selective sensing of aniline and triethylamine when exposed to different organic amines. And through the phenomenon of visual discoloration and fluorescence quenching, the sensing of aniline by compound 1 was confirmed, and the minimum concentration of detection was 10−5 M. It is also possible to completely dissolve compound 1 in ammonia water or coat and deposit compound 1 on paper with an absolute ethanol solution. These two types of paper can be used as inkless and erasable printing media and can be printed repeatedly at least five times. [ABSTRACT FROM AUTHOR]

In this paper, NiCo2S4 was coated on the surface of WS2 of a 1T/2H mixed phase by a two-step hydrothermal method to form an in situ core–shell structure. The unique S-scheme heterojunction of the NiCo2S4@WS2 core–shell composite photocatalyst improved the easy recombination of carriers caused by the narrow band gap of NiCo2S4 and WS2, and improved the photocatalytic hydrogen production performance. The loading ratio of NiCo2S4@WS2, the addition of Eosin Y, and the pH value of TEOA were optimized. Under the optimal conditions, the hydrogen production rate reached 5.814 mmol g−1 h−1, which is about 8.55 times and 3.35 times the hydrogen evolution rates of NiCo2S4 and WS2, respectively. The composite catalyst exhibits excellent charge separation efficiency in photoelectrochemistry, PL and BET tests, carrier transport rate and large specific surface area that can provide more active sites, which are the main factors for the improvement of the hydrogen evolution performance. This paper demonstrates new design strategies to drive efficient photocatalytic hydrogen production by building in situ core–shell structures and optimizing the carrier transport paths, which will yield new insights. [ABSTRACT FROM AUTHOR]

Phosphines bearing guanidine substituents at the backbone are attractive hybrid ligands that have not yet received adequate attention. This paper describes group 11 metal complexes of a guanidine-substituted triphenylphosphine, viz., N′′-[2-(diphenylphosphino)phenyl]-N,N′-diisopropylguanidine (1). Reactions of 1 with Cu(I) and Ag(I) precursors yielded the P,N-chelate complexes [M(1-κ2P,N)2]X, where M/X = Cu/BF4, Cu/Br, Ag/SbF6 and Ag/Br. Conversely, reacting 1 and the hydrochloride 1·HCl with [AuCl(SMe2)] produced the corresponding phosphine complexes [AuCl(1-κP)] and [AuCl(1H-κP)]Cl, which were further converted into [{μ(P,N)-1}2Au2][SbF6]2 and [AuCl(1H-κP)][SbF6], respectively, by reacting with Ag[SbF6]. These compounds and the bis-phosphine complex [Au(1-κP)2][SbF6] were studied as precatalysts in the Au-mediated cyclisation of N-propargylbenzamide and the addition of benzoic acid across terminal alkynes. Of the Au(I)-1 complexes studied, the complex [{μ(P,N)-1}2Au2][SbF6]2 was particularly attractive as a stable and well-defined, silver-free precatalyst, which can be conveniently activated in situ by the addition of a protic acid (either as an additive or a substrate). [ABSTRACT FROM AUTHOR]

As a rare metal, indium is an important component of ITO targets in liquid crystal displays (LCDs). In order to alleviate the problem of resource loss, the recycling of indium in waste LCDs has become more and more important. In this paper, the adsorbent (CM-HPEI-HD-1) was prepared by modifying the weakly acidic macroporous resin (HD-1) with hyperbranched polyethyleneimine (HPEI) and sodium chloroacetate. The adsorbent was characterized using SEM, XRD, FTIR, TGA, and XPS. And its adsorption performance for In(III) in the hydrochloric acid system was investigated. The experimental results showed that the maximum adsorption capacity of the CM-HPEI-HD-1 for In(III) was 97.78 mg g−1 at 35 °C. Kinetic experiments showed that the adsorption of In(III) on CM-HPEI-HD-1 was in accordance with the pseudo-second-order kinetic model. The adsorption process is an endothermic process. The adsorption isotherm data were consistent with the Freundlich isotherm model. The cyclic performance of CM-HPEI-HD-1 was evaluated using the dynamic adsorption–desorption method. The cyclic experiments showed that the adsorption performance of the adsorbent remained basically unchanged after five adsorption–desorption cycles. The separation performance of the adsorbent for In(III) and Sn(II) was investigated, and it was found that the adsorbent had a better adsorption performance for In(III). In addition, the adsorption mechanism of In(III) on CM-HPEI-HD- was investigated based on XRD and XPS. It was found that both carboxyl groups and amine groups interact with In(III). [ABSTRACT FROM AUTHOR]

The directional arrangement of thermally conductive lamellar fillers is an effective way to improve the thermal conductivity of polymer composites, which is achieved by the pre-construction of the thermal conductive network in most of the current research. Simplifying the process of the lamellar fillers' directional arrangement is significant for practical application, and a novel and facile fabricating method is reported in this study. First, the amino hexagonal boron nitride (BNNH2) was mixed with polyvinyl alcohol (PVA) water solution to prepare PVA/BNNH2 mixture. Subsequently, the mixture was dropped on the saturated sodium sulfate solution to obtain PVA/BNNH2 film through the salting-out function of PVA. The in-plane thermal conductivity of the as-prepared PVA/BNNH2 film can reach 3.09 W m−1 K−1 with 30 wt% filler content. Furthermore, the PVA/BNNH2 films present excellent flexibility and good insulation. This paper may provide a new strategy for fabricating anisotropic thermally conductive polymer composites. [ABSTRACT FROM AUTHOR]

In this paper, a novel fluorescent probe, TPA-PAT, with continuous recognition based on triphenylamine was designed, synthesized, and characterized by NMR, IR, and fluorescence spectrophotometry techniques. The research results showed that the probe could specifically recognize Cu2+ in DMSO/H2O (99:1, v/v) with a detection limit as low as 0.40 mM and a coordination ratio of 1: 2. On this basis, it was found that its complex TPA-PAT-Cu2+ could achieve a continuous progressive recognition of the anion S2- and amino acids GSH, L-His, and L-Gly, while simultaneously showing high sensitivity for them with low detection limits of 25.7, 18.9, 21.7, and 45.9 nM, respectively. The probe had good reversibility and could be recycled. In addition, the probe TPA-PAT could simultaneously recognize Cu2+ and Hg2+ in acetone/H2O (99:1, v/v) with detection limits of 0.16 and 0.20 mM, respectively, while their coordination ratios were 1: 2. Similarly, its complex TPA-PAT-Hg2+ was able to continuously recognize the amino acids Cys and GSH with detection limits of 0.34 and 0.29 mM, respectively. It was also found that the probe and its complexes were able to be prepared for convenient dipstick applications, which could achieve a rapid fluorescence response to anions and amino acids and suggested its very good application prospects. [ABSTRACT FROM AUTHOR]

In this paper, using a molten salt process, nickel cobaltite nanoparticles were successfully synthesized for the first time from non-standard reagents. Diverse techniques were applied for the characterization of this multifunctional nanomaterial. TGA shows the thermal behavior of the mixed non-annealed powder. XRD, FTIR, TEM, EDS, XPS, and MPMS were used to characterize the composition, structural properties, morphology, oxidation states, and magnetic measurements of the prepared samples, respectively. All the analyzed results indicated that the NiCo2O4 nanoparticles were successfully obtained with a spinel structure and a high purity at 300 1C. The two M-O absorption bands characteristic of the NiCo2O4 spinel structure are detected. The nanoparticles have a hexagonal and spherical morphology with an average size close to 7 nm. EDS spectra confirm the purity of the nickel cobaltite. The magnetic measurements illustrate a ferrimagnetic behavior of NiCo2O4 at room temperature. This work presents a very promising approach for the first-time synthesis of multifunctional nickel cobaltite nanoparticles from non-standard reagents that are very competitive in many electrochemical applications as supercapacitors. [ABSTRACT FROM AUTHOR]

As the most common weed killer used worldwide in farms and home gardens or lawns, glyphosate's excessive discharge has caused serious harm to the water environment and human health. Therefore, effective treatment of glyphosate wastewater becomes a matter of emergency. In this paper, novel modified mesoporous silica absorbents were prepared and used to treat glyphosate wastewater. First, worm-like mesoporous silica (HECMS) was prepared using the sol–gel method with cheap and resourceful hydroxyethyl cellulose (HEC) as the template and sodium metasilicate as the silica source, respectively. After that, 3-aminopropyltrimethoxysilane (APTMS) was grafted on the surface of HECMS and then zirconium was introduced onto AP-HECMS through the coordination of Zr4+ with the amino groups in APTMS, denoted as Zr-AP-HECMS. For the adsorption of glyphosate on Zr-AP-HECMS, the optimal pH range was found to be 3–6, and the maximum adsorption amount was 107.38 mg g−1. The adsorption process followed the pseudo-second-order dynamics model and the adsorption equilibrium followed the Langmuir model. The adsorption mechanism was also investigated as the electrostatic attraction of the protonated amino group on Zr-AP-HECMS to the glyphosate ion in water, as well as the ligation between Zr4+ and P–O in glyphosate, and the ligation is stronger than the electrostatic attraction. The preparation of the adsorption material is simple and the cost is low. What is more, it can effectively remove glyphosate in water. This work would provide some guidance for the modification and application of mesoporous silica in pesticide wastewater treatment. [ABSTRACT FROM AUTHOR]

Due to the wide usage of H2O2 in daily products and its adverse effects on organisms, developing effective, simple and sensitive approaches for detecting H2O2 in multiple real cases has always been of concern. In this paper, a pyridinic nitrogen doped carbon loaded nano-copper (N-C@Cu) sheet composite has been successfully prepared and used as an effective electrochemical material for detecting H2O2. The characterization of the fabricated electrode material sensor was performed by transmission electron microscopy (TEM), X-ray spectroscopy (XRD), energy-dispersive spectroscopy (EDS), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The prepared electrode presented high sensitivity, a wide linear range, excellent repeatability and multi-day detection stability as a result of high content of pyridinic nitrogen in the N-C@Cu/Nafion/GCE. Under the optimized experimental parameters, the detection range was from 4 to 1400 μM and the limit of detection was 2.98 μM (S/N = 3). The N-C@Cu sensor has also been successfully used for detecting H2O2 in environmental water samples and domestic products. [ABSTRACT FROM AUTHOR]

The application of cellulose nanocrystals (CNCs) as a PM2.5 capture agent is demonstrated. CNCs are prepared using sulfuric acid hydrolysis of laboratory filter paper. The obtained CNCs are characterized to obtain their molecular information, morphology, and crystallinity using ATR FT-IR spectroscopy, transmission electron microscopy, and X-ray diffraction, respectively. The negatively charged surfaces of the CNCs with an average zeta potential of −51 mV could strongly interact with PM2.5 particles, and are principally utilized for PM2.5 capture. In order to evaluate the PM2.5 removal efficiency of the CNCs, they are fabricated into an air filter by dip-coating onto a cotton mesh fabric employed as the substrate. The CNCs could be homogeneously coated onto the cotton fibers, as observed via scanning electron microscopy. The air filter fabricated using the optimized conditions possesses a PM2.5 removal efficiency of 94%. The CNC-coated air filter has good air penetrability, with a low pressure drop of 20.7 Pa. The surfaces of the air filters before and after PM2.5 capture are characterized using optical microscopy and scanning electron microscopy. The PM2.5 capture mechanism of the CNC-based air filter is also proposed. Our findings reveal the important discovery that negatively charged CNCs can be directly employed as a renewable PM2.5 capture agent. [ABSTRACT FROM AUTHOR]

Nowadays, physical absorption has become a feasible method to tackle the increasingly severe marine pollution. However, traditional aerogels suffer from low oil absorption capacity and poor compressibility, and high performance aerogels typically have the drawbacks of complex process flow and expensive raw materials. In this paper, inexpensive industrial raw material melamine was introduced into a graphene aerogel framework, and the aerogel presented ultralow density (3.54 mg cm−3), super-hydrophobicity (water contact angle is 158.2°), and excellent absorption capacity (440 g g−1). Melamine doping gives the graphene aerogel a honeycomb-like porous structure and excellent hydrophobicity, enhancing the flow and adsorption of organic solvents in the aerogel. It has a high application value for solving water pollution problems caused by oil spill accidents and chemical spills. [ABSTRACT FROM AUTHOR]

A xanthene fluorophore-based probe, Xanth-NO2, has been reported for the detection of thiophenol. Xanth-NO2 exhibited quenched fluorescence in an aqueous buffer due to its aggregate state, which allows a fluorescence turn-on response via the PhSH-induced transetherification process. In an aqueous buffer, the half-time for the reaction of Xanth-NO2 with thiophenol is 15 min. There is a linear overlap between the Xanth-NO2 fluorescence and thiophenol concentrations (0–10 μM), with a 130 nM detection limit. Xanth-NO2 reacted differently with hydrogen sulfide and thiophenol, allowing us to distinguish between these two analytes. Additionally, the ability of Xanth-NO2 to detect thiophenol in the presence of competing molecules or ions was demonstrated. Real-water samples and paper strip-based vapour phase detection of thiophenol were used to show the potential use of the reported probe. [ABSTRACT FROM AUTHOR]

To solve the problem of excessive energy consumption in the process of catalytic water splitting, it is quite essential to exploit high-activity and low-cost electro-catalysts. The present paper proposes a highly catalytically active Ni/Fe hydroxide electro-catalyst for the oxygen evolution reaction (OER), which is in situ formed on the surface of the stainless steel fiber felt using a sacrificial template by adding the oxidizing agent K2S2O8 to the alkaline solution under mild conditions. The electrode prepared using this simple one-step chemical oxidation method obviously shows enhanced catalytic activity for the OER. The overpotentials at 10 mA cm−2 are only 214 mV and 263 mV in KOH and Na2CO3/NaHCO3 solutions, respectively. In addition, the potential and morphology of the electrode remain stable for 180 h at 10 and 100 mA cm−2 in the Na2CO3/NaHCO3 system, demonstrating its ultra-high stability. This new route to prepare OER electrode materials has a promising bright application prospect for large-scale production. [ABSTRACT FROM AUTHOR]

Intentionally heteroatom-doped mesoporous carbon was generated from spent disposable paper cups and explored as an air-breathing electrode for a rechargeable lithium–oxygen (Li–O2) battery. The crystal structures and morphologies of the respective boron, nitrogen and selenium-doped carbons were generated and were characterized using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) techniques. The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics conducted on a rotating ring disk electrode (RRDE) under Ar and O2 atmospheres in 0.1 M KOH revealed that the Se heteroatom-doped carbon (SeC900) electrocatalyst achieved inherently high catalytic activity as compared to the boron and nitrogen-doped carbon. The high surface area, effective O2 adsorption and enhanced active sites provided by the Se heteroatom lead to high ORR and OER catalytic activities for the SeC900 electrocatalyst. A CR2032 coin cell was fabricated to demonstrate the Li–O2 battery using the SeC900 electrocatalyst as an air-breathing electrode, which showed a stable open circuit voltage (OCV) of 3.14 V and a high discharge capacity of 1618 mA h g−1 at a current density of 50 Ag−1. Thus, a metal-free bifunctional air-cathode has been developed for the Li–O2 battery. The fabricated air coin cell was applied for practical implementation by lighting three series-connected commercial red LED bulbs continuously for about 5 h on a single charge. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are efficient semiconductor materials with superior catalytic activity and adjustable band gaps for the efficient degradation of organic pollutants in water. However, the synthetic yield of COF is generally small and only exists in the laboratory stage. In this paper, we introduced an emulsifier-mediated strategy into the synthesis of a COF for the first time and synthesized a COF with higher crystallinity and a higher synthetic yield of 84.7%. The specific surface area of BJH was also increased from 388.7 m2 g−1 to 1678.5 m2 g−1 and the photocatalytic degradation efficacy of 10 ppm methylene blue was increased from 26% to 100% within 50 min. This work provides a promising strategy to achieve a COF with a higher surface area, synthetic yield and photocatalytic efficacy via the emulsifier-mediated strategy, which would promote the industrial and practical production of COFs. [ABSTRACT FROM AUTHOR]