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Reactive molecular dynamics is used to investigate the oxidation of anisotropic silver nanoparticles (nano-Ag) of various shapes, including sphere, cube, disk, cylinder, triangle, and pyramid. The effect of the nano-Ag initial morphology on their stability and composition during oxidation is quantified. Surface oxidation at 600 K leads to the formation of a core–shell structure for all nano-Ag shapes. The surface composition of facet orientations of pristine nano-Ag can be correlated with particle stability due to their different surface energies and oxygen reactivity. In particular, pyramid and triangular nano-Ag, having a high surface fraction of (110) facets, are more prone to morphological changes upon oxidation and loss of their crystallinity, compared to nanospheres and nanocubes, which exhibit the highest stability among all shapes, attributed to the large fraction of highly coordinated atoms. Spherical and cubic nano-Ag oxidize faster, owing to their large surface fractions of (100) and (111) facets, which are more reactive than (110) ones. Understanding the effect of surface crystal structure and shape of anisotropic nano-Ag can improve the design of superior metal oxide nanomaterials with desired characteristics. [ABSTRACT FROM AUTHOR]

Metal oxide transistors have garnered substantial attention for their potential in low-power electronics, yet challenges remain in achieving both high performance and low operating voltages through solution-based fabrication methods. Optimizing interfacial engineering at the dielectric/semiconductor interface is of utmost importance in the fabrication of high-performance thin film transistors (TFTs). In the present article, a bilayer Ti3C2Tx-MXene/SnO2–semiconductor (Tx stands for surface termination) configuration is used to fabricate a high-performance n-type thin film transistor by using an ion-conducting Li-Al2O3 gate dielectric on a p+-Si substrate, where electrical charges are formed and modulated at the Li-Al2O3/SnO2 interface, and Ti3C2Tx-MXene nanosheets serve as the primary electrical charge channel due to their long lateral size and high mobility. A comparative characterization of two distinct TFTs is conducted, one featuring Ti3C2Tx MXene and SnO2 semiconductor layer and the other with SnO2 only. Notably, the TFT with the Ti3C2Tx MXene layer has shown a significant boost in the carrier mobility (10.6 cm2/V s), leading to remarkable improvements in the on/off ratio (1.3 × 105) and subthreshold swing (194 mV/decade), whereas the SnO2 TFT without the Ti3C2Tx MXene layer shows a mobility of 1.17 cm2/V s with 8.1 × 102 on/off ratio and 387 mV/decade subthreshold swing. This investigation provides a possible way toward the development of high-performance, low-voltage TFT fabrication with the MXene/semiconductor combination. [ABSTRACT FROM AUTHOR]

Non-transition metal oxides, including major minerals of the early Solar System, are known to evaporate decomposing into multiple gas molecules, while maintaining their stoichiometric compositions (dissociative congruent evaporation). Here, we derived the absolute rate of this type of evaporation using the transition state theory. In our modified transition state theory, the activation energy closely corresponds to the average energy of the molecules at the transition state, reflecting the degree of decomposition at the potential energy barrier along the reaction coordinate of evaporation. By comparing the theoretical and experimental evaporation rates for the reaction MgO (s) → Mg (g) + O (g), we found that there is an activation barrier close to the product side (i.e., "late" barrier) where the decomposition is almost achieved. The present theory is advantageous to the Hertz–Knudsen equation, which is essentially formulated as the evaporation rate in equilibrium based on the detailed balance, in that it describes dissociative congruent evaporation as a non-equilibrium process and thus provides the link between the experiments and the reaction dynamics. [ABSTRACT FROM AUTHOR]

Two-terminal structure memristors are the most promising electronic devices that could play a significant role in artificial intelligence applications of the next generation and the post-Moore era. In this work, we fabricated the memristive device by depositing a heterojunction WOx/TiOy functional layer onto an indium tin oxide substrate using magnetron sputtering. The Ag/WOx/TiOy/ITO device exhibits improved memory behavior of bipolar resistive switching (RS) nonvolatile compared to TiOy-based single-layer memristors, enabling it to meet high-density information storage requirements. Moreover, our device exhibited the coexistence of the negative differential resistance effect and the behavior of the RS memory. Through a comprehensive analysis of conductivity on the curve of current–voltage (I–V), a physical model based on the mechanism of space charge-limited current, ohmic conduction, and Schottky emission was suggested to explain the behavior device RS memory. This study's findings demonstrate that including a heterojunction bilayer WOx/TiOy as a functional layer can significantly improve the performance of memristive devices. This advancement expands the potential application of ferroelectric metallic oxide heterojunctions within the field of memristors. [ABSTRACT FROM AUTHOR]

Functional thin films of nanoscale metal pillars in oxide or nitride matrices known as vertically aligned nanocomposite (VAN) have gained much interest owing to their unique strain-coupled and highly anisotropic properties. So far, the deposition of these films has been explored mostly experimentally. In this work, a density functional theory (DFT)-based kinetic Monte Carlo simulation model using Bortz–Kalos–Lebowitz algorithm was developed to understand the growth of VAN films deposited by pulsed laser technique on mismatching substrates. The model has been parameterized and applied to understand the kinetics of growth thin films consisting of Au pillars in CeO2 matrix deposited on SrTiO3 substrates. The effects of pulsed laser deposition (PLD) conditions including the pulse frequency, deposition flux, and substrate temperature were explored. The simulations indicate that the Au pillar size and shape exhibit significant dependence on the PLD conditions. Namely, increasing the temperature increases the average pillar size and lowers the pillar density, and vice versa. In addition, the simulations revealed that increasing the deposition rate results in lowering the average pillar size and increasing the density. Particularly, the DFT results suggest that Au pillar size can be tuned during the initial growth of the first monolayer due to the significantly low activation barrier. Our analysis showed that the relationship between the average pillar size and pillar density is influenced by the kinetics. Furthermore, autocorrelation analysis showed that pillars self-organize in quasi-ordered patterns at certain windows of the deposition conditions, which is attributed to the complex nature of the chemical interactions in the system, the kinetics, and the deposition parameters. [ABSTRACT FROM AUTHOR]

The immobilization of Re(I) complexes onto metal oxide surfaces presents an elegant strategy to enhance their stability and reusability toward photocatalytic CO2 reduction. In this study, the photocatalytic performance of fac-[ClRe(CO)3(dcbH2)], where dcbH2 = 4,4′-dicarboxylic acid-2,2′-bipyridine, anchored onto the surface of 1%m/m CuO/Nb2O5 was investigated. Following adsorption, the turnover number for CO production (TONCO) in DMF/TEOA increased significantly, from ten in solution to 370 under visible light irradiation, surpassing the TONCO observed for the complex onto pristine Nb2O5 or CuO surfaces. The CuO/Nb2O5 heterostructure allows for efficient electron injection by the Re(I) center, promoting efficient charge separation. At same time CuO clusters introduce a new absorption band above 550 nm that contributes for the photoreduction of the reaction intermediates, leading to a more efficient CO evolution and minimization of side reactions. [ABSTRACT FROM AUTHOR]

We have attained low leakage current, low interfacial traps, and low border traps by effectively passivating both p- and n-In0.53Ga0.47As (InGaAs) surfaces using the same gate dielectrics of ultra-high-vacuum deposited Al2O3/Y2O3. Gate leakage currents below 2 × 10−7 A/cm2 at gate fields of ±4 MV/cm were obtained after 800 °C rapid thermal annealing, demonstrating the intactness of the interface and heterostructure. Negligibly small frequency dispersions in the capacitance–voltage (C–V) characteristics of p- and n-type metal-oxide-semiconductor capacitors (MOSCAPs) were obtained from accumulation, flatband, to depletion as measured from 300 K to 77 K, indicative of low border and interfacial trap density; the C–V frequency dispersions in the accumulation region are 1.5%/dec (300 K) and 0.19%/dec (77 K) for p-InGaAs, and 2.2%/dec (300 K) and 0.97%/dec (77 K) for n-InGaAs. Very low interfacial trap densities (Dit's) of (1.7–3.2) × 1011 eV−1cm−2 and (6.7–8.5) × 1010 eV−1cm−2, as extracted from the conductance method, were achieved on p- and n-InGaAs MOSCAPs, respectively. [ABSTRACT FROM AUTHOR]

Zeolite imidazole framework −8 (ZIF-8) was used as the encapsulation layer to improve the stability and activity of ZnO nanoparticles. Under the voltage of 2.0 V vs.RHE, the stability test could be carried out for 60 h, and the yield of H 2 O 2 did not decrease significantly. [Display omitted] A promising method of producing hydrogen peroxide (H 2 O 2) is the electrochemical two-electron water oxidation reaction (2e− WOR). In this process, it is important to design electrocatalysts that are both earth abundant and environmentally friendly, as well as offering high stability and production rates. The research of WOR catalysts, such as the extensively used transition metal oxides, is mainly focused on the modification of transition metal elements. Few studies pay attention to the protective heterostructure of metal oxides. Here, we demonstrate for the first time an organometallic skeleton protection strategy to develop highly stable WOR catalysts for H 2 O 2 generation. Unlike the pure ZnO and zeolite imidazole framework-8 (ZIF-8) catalysts, ZnO@ZIF-8 enabled the production of hydrogen peroxide at high voltages. The experimental results demonstrate that the ZnO@ZIF-8 catalyst stably generates H 2 O 2 even under a high voltage of 3.0 V vs. RHE, with a yield reaching 2845.819 μmolmin−1 g−1. ZnO@ZIF-8 shows a relatively low overpotential, with a current density of 10 mA cm−2 and an overpotential of 110 mV. The ZnO@ZIF-8 catalyst's maximal FE value was 4.72 %. Moreover, the ZnO@ZIF-8 catalyst exhibits remarkable durability even after an extended 60-hour stability test. Operando Raman and theoretic calculation analyses reveal that the metal–organic skeleton being encapsulated on the metal oxide surface synergizes with each other, not only expanding the electrochemical surface area, but also adjusting the catalyst metal sites' adsorption capacity. A novel approach to the modification of 2e− WOR metal oxide catalyst is presented in this work. [ABSTRACT FROM AUTHOR]

Recent directions concerning hydrogen production, storage and utilization result in growing the demand for efficient technologies, a huge part of which is connected with the application of materials based on complex oxides as efficient catalysts for the fuel reforming, permselective membranes, components of solid oxide fuel cells and electrolyzers. These materials are generally based on the oxides with perovskite and fluorite structures or their derivatives. On the other hand, other classes of materials are recently considered as promising materials for these applications due to their peculiar functional characteristics or an outstanding potential of their improvement. They include a variety of types of rare earth element tungstates/molybdates, Co and Ba cobalitites with layered structure as well as other materials including langasites, magnetoplumbites, swedenborgites, etc., and composites based on them. In this work, structural, transport features and performance of such modern materials are reviewed. [Display omitted] • Various complex oxides are used in catalysis, electrochemistry and other fields. • There are uncommon materials showing prospective transport and catalytic properties. • Promising materials include REE tungstates/molybdates, misfit phases, bixbyites etc. • Structure and important functional properties of novel materials are addressed. [ABSTRACT FROM AUTHOR]

An eco-benign, efficient, cost-effective, high energy-efficient method has been devised for synthesizing diamino-4-phenyl-3,5-dicyano-2-pyridone through a one-pot, three-component reaction. The technique involves the reaction of aryl aldehyde, malononitrile, and cyanoacetic acid hydrazide at 60 °C, utilizing water extract of incense stick ash as a catalyst and recyclable medium. Utilizing water extract as a solvent and catalyst reduces dependency on hazardous and harmful solvents, which are typically non-renewable and contribute to unfavorable emissions. The used incense stick ash was characterized by XRD and EDS analysis. The ash extract consists of metal oxides and carbonates which are basic and can act as catalysts. The reaction proceeds through the Knoevengel reaction, subsequent Michael addition and followed by intramolecular cyclization to furnish N-amino-2-pyridone in good to excellent yields. The structures of the synthesized compounds were confirmed based on IR, 1H, and 13C NMR spectral data analysis. [ABSTRACT FROM AUTHOR]

This paper presents an innovative readout scheme that utilizes a pair of differential‐clocks‐assisted time‐to‐digital converter (DCA‐TDC) in CMOS image sensors (CISs). The DCA‐TDC utilizes only half the number of ordinary TDC delay chain units by employing a binary‐weighted search algorithm to determine the most significant bit (MSB) for fine quantization of a single‐slope analog‐to‐digital converter (SS ADC). Additionally, the layout area and dynamic power introduced by the improved DCA‐TDC delay chain are halved compared to an ordinary TDC delay chain. The proposed SS ADC is designed and simulated using the 0.11 μm standard CMOS proces, achieving an 11‐bit ADC with a column‐level power consumption of 65.4 μW, and a row conversion time of 2.72 μs, within a design environment featuring an analog voltage of 3.3 V, a digital voltage of 1.5 V, a clock frequency of 62.5 MHz, and a temporal resolution of 500 ps. Furthermore, this design achieves an effective number of bits (ENOB) of 10.71 and a figure of merit (FoM) of 110.5 fJ/step. By interpolating a DCA‐TDC, the quantization speed is enhanced compared to traditional SS ADCs, presenting an effective solution for high‐frame‐rate CIS implementations. [ABSTRACT FROM AUTHOR]

Oxygen vacancies are commonly observed defects in metal oxides that contribute to the unique physiochemical properties of these materials. Despite the abundant evidence of oxygen vacancies in transition metal oxides and their intriguing properties in catalysis, there remain questions in understanding their formation, structure, and properties. In this study, we employ in situ diffuse reflectance infrared Fourier transform spectroscopy and electron paramagnetic resonance spectroscopy to investigate the genesis of oxygen vacancies and Ni species, focusing on the significance of Ni species relating to the reduction temperature. Our findings reveal a reduction temperature dependence on the formation of oxygen vacancies and atomically dispersed Niδ− species in anatase TiO2 (TiO2-A). In pristine TiO2-A, the reduction temperature between 300 and 400 °C led to the creation of a substantial number of oxygen vacancies. With supported Ni on TiO2-A, oxygen vacancies are favorably formed at 200 °C. As the reduction temperature is increased to 300 °C, Ni species migrate to the oxygen vacancies and become stabilized by forming Niδ− species while reducing the number of oxygen vacancies. Subsequent oxidation at 300 °C led to the oxidation of some Niδ− species alongside the liberation of the oxygen vacancies they previously occupied. These findings shed light on the mechanisms in forming oxygen vacancies and Niδ− species. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Extractive Metallurgy) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Efficient and stable lithium-ion batteries (LIBs) have garnered considerable attention; yet, the development of anode electrode materials continues to pose substantial challenges. While CoO electrode material boasts an ideal specific theoretical capacity, it is not without drawbacks, including significant volume expansion and concerns over safety performance, which hinder its viability as an anode material. In this research, we synthesized CoO/Co3O4 through a straightforward secondary hydrothermal treatment that locally oxidizes CoO, simultaneously creating oxygen vacancies. The incorporation of oxygen vacancies enhances the material's internal conductivity and expedites the diffusion of electrons and ions, culminating in superior rate performance. Furthermore, the heterojunction structure diminishes the diffusion barrier, significantly enhancing the electrode's reaction kinetics and overall electrochemical performance. At a modest current density of 0.1 A g−1, the CoO/Co3O4 composite demonstrates enhanced cycling stability, delivering a capacity of 1022 mAh g−1 after 100 cycles. Remarkably, even at an elevated current density of 1 A g−1, it sustains a capacity of 768.8 mAh g−1 over 400 cycles. The method of creating oxygen vacancies via autoxidation may pave the way for the advancement of multivalent oxide anode materials. [ABSTRACT FROM AUTHOR]

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Perovskite solar cells (PSCs) have acquired popularity owing to their high efficiency, ease of fabrication, and affordability. In this context, the development of electron transport layers (ETLs) for highly efficient planar photovoltaic devices has received considerable attention. This study investigates the potential of zinc‐tin‐based ternary metal oxide ETLs for application in planar PSCs. Solution‐processed methods are used to fabricate crystalline zinc stannate (Zn2SnO4), amorphous zinc‐tin oxide (ZTO), and Zn2SnO4/ZTO‐based bilayer films, and their structural, morphological, and optoelectronic properties are thoroughly studied. X‐ray diffraction (XRD) analysis and scanning electron microscopy (SEM) images show enhanced crystallite size and better surface morphology of perovskite films deposited on bilayer ETL. Photoluminescence (PL) studies and Hall effect measurements reveal superior charge extraction, improved charge carrier mobility (21.84 cm2 V−1 s−1) and enhanced n‐type conductivity in the bilayer ETL. Moreover, contact angle analysis of perovskite layer deposited on bilayer ETL shows increased resistance to moisture erosion (52.20°), which is particularly significant given the detrimental effects moisture can have on the performance of PSCs. [ABSTRACT FROM AUTHOR]

1,1‐Diaminobenzalazine has been recently reported to catalyze different types of Michael addition reactions; this organic molecule has unique characteristic features for bifunctional organocatalysis. Organocatalysts were shown to be useful in different aldol/cyclization cascade reactions, it is important to establish whether 1,1‐diaminobenzalazine can be employed in the aldol/cyclization cascade reactions. In this work, the synthesis of oxazolines with the help of organocatalyst, 1,1‐diaminobenzalazine, has been reported. This method is relatively more efficient, cost‐effective, and environmentally safe as it avoids the use of metal oxides as co‐catalysts. [ABSTRACT FROM AUTHOR]

Biohydrogen has gained several advantages due to its high–energy content, pollution–free byproduct emission, ambient operating conditions, and ability to use various substrates for production. Further, the use of organic waste can be considered as a promising source for the production of biohydrogen while overcoming the possible environmental issues upon its disposal. However, the routes of biohydrogen production i.e. photo and dark fermentation encounter several challenges for commercialization due to lower yields. To make the process more expedient, nanomaterials such as metal, metal oxides, carbon–based, and inorganic are used to improve the hydrogen production owing to their unique physical and physical properties. In view of this, the current review highlights the role of these nanomaterials in the biological conversion of organic waste to biohydrogen. Further, emphasis is given on the mechanisms of nanomaterials' interaction with microorganisms, life cycle, and techno–economic analyses along with its major challenges and future prospects. • Photo/dark fermentative biohydrogen production from organic wastes. • Application of nanoparticles in pretreatment, hydrolysis, and fermentation process. • Mechanism of interaction of nanoparticles with microorganisms during fermentation. • Techno-economic and life cycle analysis of biohydrogen production. [ABSTRACT FROM AUTHOR]

The metal-support interaction is one of the most important pillars in heterogeneous catalysis, but developing a fundamental theory has been challenging because of the intricate interfaces. Based on experimental data, interpretable machine learning, theoretical derivation, and first-principles simulations, we established a general theory of metal-oxide interactions grounded in metal-metal and metal-oxygen interactions. The theory applies to metal nanoparticles and atoms on oxide supports and oxide films on metal supports. We found that for late-transition metal catalysts, metal-metal interactions dominated the oxide support effects and suboxide encapsulation over metal nanoparticles. A principle of strong metal-metal interactions for encapsulation occurrence is formulated and substantiated by extensive experiments including 10 metals and 16 oxides. The valuable insights revealed on (strong) metal-support interaction advance the interfacial design of supported metal catalysts. [ABSTRACT FROM AUTHOR]

In this study, we demonstrate the emergence of NO2 gas sensing capabilities in the typically non-active NiWO4, a strongly correlated electron system (SCES), by introducing substitutional Fe at the Ni site. NiWO4 typically exhibits strong Coulombic repulsion between Ni atoms, resulting in a large band gap of over 3.0 eV and insulating behavior. This correlated behavior is clearly reflected in the significant increase of band gap when considering the Hubbard U correction for the cations, bringing the theoretical value closer to the observed value. The single-phase Fe0.5Ni0.5WO4 displays a notable shift in the [NiO6] symmetric vibration mode and an increase in magnetization. Additionally, theoretical calculations confirm the preservation of the wide band gap, with the Fe and O levels generated within the band gap. These findings indicate that Fe located in the Ni sites modulate Coulombic repulsion in NiWO4 SCES insulators. Unlike the poor gas-sensing performance of intrinsic NiWO4, Fe0.5Ni0.5WO4 exhibits a significant NO2 response (Rg/Ra) of 11 at 200°C than other gases and a limit of detection (LOD) of 46.4 ppb. This study provides a pathway for realizing gas-sensing performance in strongly correlated electron insulators with large band gaps through the introduction of dopant levels at the cation sites. [ABSTRACT FROM AUTHOR]

Nanomaterials with enzyme-like properties are known as 'nanozymes'. Nanozymes are preferred over natural enzymes due to their nanoscale characteristics and ease of tailoring of their physicochemical properties such as size, structure, composition, surface chemistry, crystal planes, oxygen vacancy, and surface valence state. Interestingly, nanozymes can be precisely controlled to improve their catalytic ability, stability, and specificity which is unattainable by natural enzymes. Therefore, tailor-made nanozymes are being favored over natural enzymes for a range of potential applications and better prospects. In this context, metal oxide nanoparticles with nanozyme-mimicking characteristics are exclusively being used in biomedical sectors and opening new avenues for future nanomedicine. Realising the importance of this emerging area, here, we discuss the mechanistic actions of metal oxide nanozymes along with their key characteristics which affect their enzymatic actions. Further, in this critical review, the recent progress towards the development of point-of-care (POC) diagnostic devices, cancer therapy, drug delivery, advanced antimicrobials/antibiofilm, dental caries, neurodegenerative diseases, and wound healing potential of metal oxide nanozymes is deliberated. The advantages of employing metal oxide nanozymes, their potential limitations in terms of nanotoxicity, and possible prospects for biomedical applications are also discussed with future recommendations. [ABSTRACT FROM AUTHOR]

The pure nanostructured anatase titanium dioxide (TiO 2) and subsequent nitrogen–doped derivatives (TiO 2–x N x; where, x = 0.005, 0.01, 0.05) were synthesized by sol–gel auto–combustion technique. XRD analysis confirms the formation of pure anatase phase of TiO 2 up to doping of 1 mol% (x = 0.01) of nitrogen having tetragonal structure with space group of I 4 1 / amd whereas an additional monoclinic phase of TiO 2 –B was observed at 5 mol% of nitrogen doping in TiO 2. This sample has smallest crystallite size of ∼4.7 ± 0.2 nm corresponding to TiO 2 –B phase and ∼12.0 ± 0.1 nm corresponding to anatase phase. XRD also reveals that the crystallite size of all other samples having pure anatase phase ranges between ∼8.7 ± 0.1 nm & 13.9 ± 0.1 nm. The crystalline phase revealed from XRD of all samples was further supported by the Raman analysis. The direct optical band gap of pure TiO 2 (∼3.4 eV) was reduced non–monotonically after nitrogen doping in the ranges from ∼2.8 eV (TiO 1.95 N 0.05) to ∼2.0 eV (TiO 1.99 N 0.01). FTIR spectra confirm the metal oxide bond formation, surface adsorption of water molecules and presence of residual hydroxyl group in all crystalline samples. HRTEM analysis validates the coexistence of secondary phase of TiO 2 –B along with anatase phase of TiO 2 in studied highest doped sample (TiO 1.95 N 0.05) including its broader particle size distribution as compared to pure TiO 2. The electrical studies reveal that the highest values of dielectric constant and ac conductivity can be realized for pure TiO 2 and at 1 mol% (x = 0.01) of nitrogen doping, among all the studied nitrogen doped samples. • Influence of nitrogen doping on the physical properties of anatase TiO 2. • Highest nitrogen doping level in N:TiO 2 possesses structurally dual phase nature. • TEM images also validate the presence of dual phases within the N:TiO 2 lattice. • Nonmonotonic control of optical band gap can be realized via doping of N in TiO 2. [ABSTRACT FROM AUTHOR]

Solution‐processed lead‐free halide perovskite gas sensors possess low gas detection limits, offering promising alternatives to traditional metal oxide chemiresistors. However, halide perovskite chemiresistors often suffer from poor selectivity and durability due to a lack of coordinatively unsaturated surface metal ions and their sensitivity to humidity. To address these issues, a general strategy is presented in which the Cs2PdBr6 perovskite surface is coated with covalent organic framework (COF) to provide hybrid sensor materials that are highly sensitive to specific gases and demonstrate excellent stability under real‐working conditions. The hybrid chemiresistors demonstrate high sensitivity and controllable selectivity toward NO2 or NH3 gases. Specifically, TAPB–PDA@Cs2PdBr6 achieves a detection limit of 10 ppb for NO2, the lowest value reported for a perovskite‐based gas sensor, maintaining its performance after continuous exposure to ambient air for several weeks. In contrast, COF‐5@Cs2PdBr6 shows high selectivity to NH3 and has a detection limit of 40 ppb. Structural and spectroscopic characterization combined with mechanistic studies provide molecular‐level insights into the outstanding properties of these new hybrid sensor materials, which set a new benchmark in the field, i.e., surpassing the selectivity and sensitivity of conventional halide perovskite sensors. [ABSTRACT FROM AUTHOR]

The thin film thermoelectric (TE) materials with higher values of the figure of merit are of special interest due to their promising applications. In this regard, metal oxide thin films are introducing flexible and stretchable devices, a type of next-generation electronic gadgets, and hence possess the potential for TE applications at high temperatures and in novel devices. The mobility, concentration, and scattering of carriers in metal oxide and thin films determine the thermoelectric properties of the materials. The carrier properties can be changed by doping and precise methods of processing, which are not always straightforward. There are, therefore, still many challenges and opportunities to further improve their TE performance and device integration. Future research directions may include exploring new materials and structures, optimizing the doping and fabrication conditions, understanding the transport mechanisms and interfacial effects, and developing scalable and reliable TE devices. In this work, we first introduce the foundation of metal oxide and metal oxide-based TE materials, briefly describe their syntheses, and finally discuss their application underlining the challenges and opportunities. [ABSTRACT FROM AUTHOR]

Researchers are exploring sustainable methods for synthesizing metal oxide nanoparticles to address wastewater pollution, which poses a global threat to aquatic life and human health. The present research aims to biosynthesize recyclable Lemon peel‐extracted copper oxide nanoparticles (CuO NPs) to remove methylene blue dye via adsorption. Our approach involves a comprehensive range of techniques, such as FTIR, XRD, SEM‐EDX, Zeta potential, and UV‐VIS, to thoroughly characterize the NPs. SEM analysis confirmed that the CuO NPs, with an average size of 64.5 nm and a nearly spherical shape, exhibited a zeta potential value of – 16.34, indicating their relative stability. Optimized conditions for the 92.20% adsorption efficiency for methylene blue dye were pH at 6, contact time of 90 min, 0.06 g of adsorbent dose, 10 ppm dye conc., and Temp. 27 °C. Langmuir 1‐based maximum adsorption capacity (qm) was 617.28 mg/g for CuO NPs. Langmuir 1 and Freundlich are the most suitable isotherm models for experimental data, supporting Physi‐chemisorption and chemisorption as rate‐limiting steps in the exothermic adsorption process. A reusability study of up to three cycles proved the sustainability of the materials. [ABSTRACT FROM AUTHOR]

In the reaction environment of wax gourd extract, titanium dioxide (TiO2) and magnesium oxide (MgO) were synthesized by microemulsion method. Under atmospheric pressure, the optimum conditions for preparing TiO2 and MgO nanoparticles were investigated at different reaction temperatures and time. The obtained optimal reaction conditions are as follows: when the amount of TiCl3 solution was 70 µL, the mass ratio of wax gourd extract to water was 1:2, the reaction time was 60 min, and the reaction temperature was 35 °C, rod‐like TiO2 particles with the best dispersion and crystallinity were obtained. When the amount of MgCl2 solution was 10 mL, the amount of wax gourd extract was 40 mL, the reaction time was 120 min, and the reaction temperature was 70 °C, the prepared MgO particles exhibited a spindle shape with the best dispersion and crystallinity. Wax gourd‐assisted synthesis of TiO2 and MgO provides not only a new synthesis idea for the preparation of metal oxides, but also a green environmental protection system, which conforms to the concept of sustainable development. [ABSTRACT FROM AUTHOR]

This research paper investigates the impact of loading nano-oxides of zinc and copper metal particles into a polyethersulfone (PES) matrix to enhance its structural and mechanical responses. The co-precipitation method was adopted for the synthesis of metallic oxides consisting of zinc and copper. The presence of strain in metallic oxide NPs illustrated in metallic oxide-loaded PES films arises due to the interaction between NPs and PES. As a result of NPs and PES interactions, the particle size of PES has also been increased in PES blended films. Furthermore, we observed that the mechanical properties of PES-loaded films have been improved as the tensile strength was increased from 2.63 to 5.65 MPa, Young's modulus was enhanced from 8.92 to 10.02 MPa by adding ZnO NPs, whereas the more prominent increase in mechanical properties has been noticed in case of CuO NPs loaded PES blended films. The present work suggested that the loading of nano-oxides in PES enhances the mechanical strength of PES, which may significantly contribute to the field of mechanical engineering as oil level indicators, part for miking machines, and automatic beverage dispensers and pumps. Employing solution casting methodology synthesized metallic oxide NPs were loaded in PES to prepare their blended films. Three major functional groups such as sulfone, benzene, and ether are present in PES, and metal–oxygen vibrational groups have been identified in all prepared polymeric composites by FTIR spectroscopy. The electron microscopy (FESEM) reveals that the oxides of zinc appeared in rod-like structures, copper oxide adopted spherical and rhombus shapes, whereas the composite blended sheets appeared smooth. [ABSTRACT FROM AUTHOR]

Efficient 2D-inorganic spinel perovskites nanostructure materials are used as potential candidates for highly sensitive detection of harmful substances present in the environment. In this regard, a facile one-pot hydrothermal synthesis was employed to fabricate nanocomposite material containing iron manganese oxide (FeMn 2 O 4) decorated with reduced graphene oxide (rGO) which is used as an electrochemical detection of metronidazole (MTZ). The crystalline nature and structural insights of the as-synthesized FeMn 2 O 4 -rGO nanocomposite were established using various spectroscopic and electrochemical techniques. Distinctively FeMn 2 O 4 -rGO nanocomposite fashioned glassy carbon electrode (GCE) showed excellent linear range (0.01–512.2 μM), sensitivity (71.4 μA mM−1 cm−2), limit of detection (0.0129 μM), reproducibility, stability and resist-interference capability towards metronidazole (MTZ) antibiotic drug. In addition, the fabricated FeMn 2 O 4 -rGO/GCE electrochemical sensor exhibited a remarkable MTZ detection in spiked water as well as urine samples with better recovery percentages supporting its facile and feasible nature for environmental applications. The present work established the fabrication of FeMn 2 O 4 -rGO/GCE nanocomposite for effective determination of antibiotic drugs in real sample analysis. [ABSTRACT FROM AUTHOR]

The objective of this study is to evaluate the performance and emission characteristics of a diesel engine using metallic graphene oxide (GO) and nonmetallic zinc oxide (ZnO) nanoparticles in a Mahua biodiesel blend (B20). At a concentration of 75 mg/L, both GO and ZnO nanoparticles were considered and a surfactant (CTAB) and a dispersant (TWEEN 80) were added at a 1:1 ratio for surface modification. The nanofuel samples were analyzed for stability using a spectrophotometer. The nanoparticles mixed with dispersants and surfactants have shown improved stability. In addition, the injection pressure was varied from 200 to 250 bar. Dispersion of GO and ZnO nanoparticles in BD20 improved performance parameters such as BTE and BSFC. In addition, there was a significant decrease in CO, HC, smoke, and NOx emissions. TWEEN 80-added GO and ZnO nanoparticles in B20 achieved the best results, followed by the CTAB-added nanoparticles. In addition, the operating parameters showed a favorable trend toward improvement at higher injection pressures. At 250 bar, BTE was improved by 4.24% and BSFC was reduced by 3.59% compared to diesel. Also, the CO, UHC, NOx, and smoke opacity were reduced by 47.05%, 15.12%, 18.96%, and 37.09% for B20 + ZnO75 mg/L + TWEEN75 mg/L, respectively. [ABSTRACT FROM AUTHOR]

The direct conversion of syngas into hydrocarbons, catalyzed by a combination of metal oxide and acidic zeolite, has garnered increasing attention in the scientific community. The remarkable hydrocarbon selectivity achieved in the OX‐ZEO process is a key factor in this growing interest. This process involves two distinct steps: CO activation over the oxide and subsequent C−C coupling within the zeolite pores, connected by an unidentified oxygenate intermediate. In this study, we explored three proposed oxygenates as potential intermediates and compared their conversion within the OX‐ZEO process. Using a bifunctional ZnCr2O4/H‐MOR catalyst in a syngas‐fed batch reactor, we found that methanol (MeOH) and dimethyl ether (DME) produced a hydrocarbon distribution similar to syngas conversion. However, the conversion of acetic acid (AcOH) resulted in a notably distinct range of hydrocarbons, including short olefins not detected with other reagents. Our findings suggest that methanol/DME might serve as active intermediates in the OX‐ZEO process over the ZnCr2O4/H‐MOR catalyst. This study provides a deeper insight into the transformation of proposed intermediates, contributing to the identification of the bridging intermediate that links the two catalytic functions. [ABSTRACT FROM AUTHOR]

Hydrogen is a key component for a successful energy transition on a large scale since it boasts remarkable energy efficiency. Currently, H2 is mainly obtained through steam reforming of natural gas or hydrocarbons and low‐carbon alcohols but contains approximately 2 % CO, a contaminant detrimental to H2 fuel cells. Herein, an N‐doped carbon nanotube was prepared via the soft nitriding method to support nickel and cobalt for the PROX‐CO as the main reaction for hydrogen purification. The most efficient condition was achieved when the reaction temperature reached 250 °C and the Ni and Co loading rate was 7.5 %. In this situation, the CO2 selectivity reached almost 33 %, and CO conversion was 61 %. Regarding CO conversion among bimetallic catalysts at 250 °C a minimal variation occurred and the catalyst 10Ni/N‐CNTs slightly outperformed (64.4 %). The effect of N‐doping on the carbon nanotube's structure was also revealed. Nitrogen atoms incorporated into the lattice of carbon nanotubes impart an electron‐donor character. Consequently, Co oxide reduction to the metallic phase occurred at significantly lower temperatures compared to other supports such as SiO2, Al2O3, and graphene. For the bimetallic catalysts, the strong metal‐support interaction facilitated obtaining different oxide and metallic phases at milder temperatures. [ABSTRACT FROM AUTHOR]

The antisolvent‐assisted spin‐coating still lags behind the thermal evaporation method in fabricating perovskite films atop industrially textured silicon wafers in making monolithic perovskite/silicon solar cells (P/S‐TSCs). The inhomogeneity of hole‐selective self‐assembled monolayers (SAMs) often arises from the insufficient bonding between hygroscopic phosphonic acid anchors and metal oxide. To address this, a mixed‐SAM strategy (Mx‐SAM) is proposed to enhance the adsorption energy of SAMs on the ITO surface, facilitate the formation of dense and humidity‐resistant hole‐selective layer (HSL) on substrates, and improve hole transport capabilities. With the aid of the Mx‐SAM strategy, the optimized wide‐bandgap PSCs achieved an impressive power conversion efficiency (PCE) of 22.63% with an exceptionally high fill factor (FF) of 86.67% using the 1.68 eV perovskite. Moreover, they exhibited enhanced stability under damp‐heat conditions (ISOS‐D‐3, 85% RH, 85 °C) with a T90 of 900 h for encapsulated PSCs, representing one of the best performances for wide‐bandgap PSCs. When further extending the Mx‐SAM strategy to making P/S‐TSCs using silicon wafers from industry, a remarkable efficiency of 28.07% is reached while upholding outstanding reproducibility. This strategy holds significant promise for the feasibility of fabricating industrially‐compatible P/S‐TSCs. [ABSTRACT FROM AUTHOR]

Fluoxetine (FLX) is a selective serotonin reuptake inhibitor (SSRI) medication commonly used to treat mental health disorders, but it can be harmful to the environment if not properly disposed of due to incomplete metabolism. In this study, electrochemical anodic oxidation with mixed metal oxide anodes was studied as a method to remove FLX from water and wastewater. Iridium dioxide-coated titanium (Ti/IrO2) and ruthenium dioxide-coated Ti (Ti/RuO2) electrodes were found to be more effective than platinum-coated Ti (Ti/Pt) electrodes, with removal efficiencies of 91.5% and 93.9%, respectively. Optimal conditions for FLX removal were determined to be an applied current of 150 mA, initial pH of 5, and oxidation time of 120 min. The rate of FLX degradation (kFLX) for the Ti/Pt, Ti/IrO2, and Ti/RuO2 electrodes were determined to be 0.0081 min−1 (R2:0,8161), 0.0163 min−1 (R2:0,9823), and 0.0168 (R2:0,9901) min−1 for 25 mg/L initial FLX concentration, respectively. The kFLX values varied based on the initial FLX concentration and decreased as the initial FLX concentration increased. The specific energy consumption (SEC) after 120 min of operation was 51.0 kWh/m3 for the Ti/Pt electrode, 39.6 kWh/m3 for the Ti/IrO2 electrode, and 48.6 kWh/m3 for the Ti/RuO2 electrode under optimised conditions. Overall, electrochemical anodic oxidation is an effective method for removing FLX from water and wastewater, with Ti/IrO2 and Ti/RuO2 electrodes providing superior performance compared to Ti/Pt electrodes. [ABSTRACT FROM AUTHOR]

Single‐atom catalysts (SACs), featuring highly uniform active sites, tunable coordination environments, and synergistic effects with support, have emerged as one of the most efficient catalysts for various reactions, particularly for electrochemical CO2 reduction (ECR). However, the scalability of SACs is restricted due to the limited choice of available support and problems that emerge when preparing SACs by thermal deposition. Here, an in situ reconstruction method for preparing SACs is developed with a variety of atomic sites, including nickel, cadmium, cobalt, and magnesium. Driven by electricity, different oxygen‐containing metal precursors, such as MOF‐74 and metal oxides, are directly atomized onto nitrogen‐doped carbon (NC) supports, yielding SACs with variable metal active sites and coordination structures. The electrochemical force facilitates the in situ generation of bonds between the metal and the supports without the need for additional complex steps. A series of MNxOy (M denotes metal) SACs on NC have been synthesized and utilized for ECR. Among these, NiNxOy SACs using Ni‐MOF‐74 as a metal precursor exhibit excellent ECR performance. This universal and general SAC synthesis strategy at room temperature is simpler than most reported synthesis methods to date, providing practical guidance for the design of the next generation of high‐performance SACs. [ABSTRACT FROM AUTHOR]

Grafting organophosphonic acids (PAs) on metal oxides has shown to be a flexible technology to tune the surface properties of metal oxides for various applications. The solvents applied in the commonly used synthesis method have associated impeding effect on tailoring the resulting modification degree. In this work, an alternative solid-phase manual grinding method is proposed that (i) is straightforward, (ii) can achieve controllable and higher modification degree, and (iii) excludes the use of solvent during the synthesis. Specifically, propylphosphonic acid (3PA) was grafted onto titania by manual grinding, and different modification degrees were obtained by varying the duration of the post-synthetic thermal treatment. Importantly, the solid-phase method can achieve a modification degree that is 25.0% higher than the maximal modification degree reached by the liquid-phase method, while its atom utilization efficiency is 4.8 times (toluene-based) or 7.5 times (water-based) that of the liquid-phase method. [ABSTRACT FROM AUTHOR]

Herein, cobalt is incorporated into a polyoxotungstate (POW) to obtain a new organic–inorganic hybrid Co-containing POW with a reliable 1D nanowire structure. The Co-containing POW exhibits superior oxygen evolution reaction (OER) activity in a neutral medium compared with its isomorphic Zn-containing POW, highlighting the critical role of cobalt in enhancing OER performance. This work provides a new insight into the structure–property relationship of metal oxides in electrocatalysis. [ABSTRACT FROM AUTHOR]

In this study, a C–CoFe 2 O 4 composite is proposed for reduction in an induction heating reactor with a continuous argon flow. An impressive conversion efficiency of 87% is achieved at a maximum temperature of 325 °C in just 8 min without the need for vacuum. The impact of the molar ratio of metal oxide to reducing agent (acetylacetone) is also examined. Results indicate that a 1:1 ratio favours the reduction towards cobalt and iron monoxides, while a 1:3 ratio yields a 31% metal phase. The highest conversion (87%) is seen with a 1:17 ratio, indicating the need for excess reducing agent for effective conversion of CoFe 2 O 4 oxide. The molar ratio influences the induction heating temperature, with the 1:17 ratio having a lower temperature of 325 °C compared to 450 °C for other ratios. These operating temperatures (≤450 °C) are significantly lower than those reported in the literature for carbothermal reduction in an induction reactor (>1700 °C), which often requires vacuum and very high temperatures for high conversion efficiency. The proposed process offers advantages such as high conversion efficiency, fast processing, and simpler operational conditions. Additionally, the metallic phases produced are utilized for H 2 production in thermochemical water splitting, showcasing these materials potential for energy generation applications. [Display omitted] • Induction heated C–CoFe 2 O 4 achieves 87 % metal oxide-to-metal conversion at 325 °C. • This method results in a faster and more efficient reduction process at lower T. • Reduction efficiency is influenced by molar ratio of metal oxide to reducing agent. • The metallic phase is applied for thermochemical H 2 production (3.905 mmol H 2 g−1). [ABSTRACT FROM AUTHOR]

Zirconia has important application prospects in the field of ceramics. However, during a high-temperature heating process, pure zirconia will undergo martensite transformation, which seriously affects its service performance. Metal oxides, such as Y 2 O 3 –CeO 2 doping ZrO 2, effectively improve the toughness and fire resistance of the material. Thus, the drying of Y 2 O 3 –CeO 2 co-doped ZrO 2 powder is an essential step before practical application. The study employs contemporary microwave drying techniques. The results of the experiment show that the average microwave drying rate increases with an increase in mass, water content, and microwave heating power. When the initial mass was 30 g, the initial moisture content was 12 %, microwave power was 720 W, and the drying rate was the fastest. We used four dynamic models: Modified Page, Quadratic, Wang and Singh, and Page to fit the experiment data. The best model was Modified Page, which describes the kinetic process most accurately. Fick's second law describes how, in the drying process, when microwave power is 720 W, initial mass is 15 g and initial water content is 8 %, the effective diffusion coefficient is 5.25 × 10−16 m2/s. Fourier Transforms of the infrared spectrum of the samples before and after drying were analyzed, the intensity of the O–H absorption peak located at 3442.03 cm/s, and O–H–O absorption peak located at 1594.48 cm/s. Both decreased significantly after drying. To discuss the relationship between the microwave power and the diffusion coefficient, the activating energy of microwave heating was 32.01 W/g. The experimental results show high heating efficiency and selective heating of the microwave method. This study provides a theoretical basis and research data for microwave drying of Y 2 O 3 /CeO 2 co-doped ZrO 2 powder in industry. [ABSTRACT FROM AUTHOR]

Atom-thin SnO 2 (a-SnO 2) shows promising potential for applications in gas sensors. However, its high working temperature can cause agglomeration, leading to a decrease in the specific surface area and resulting in performance deterioration of the sensors. In this study, g-C 3 N 4 was utilized as a thermal support to address this issue and improve the gas-sensing properties of a-SnO 2. When a-SnO 2 was grown with 10 wt% g-C 3 N 4 dispersed evenly in ethylenediamine, the gas-sensing performance of the composite improved significantly, including the response value (R a / R g = 8.8–10 ppm HCHO), fast response (τ res = 1.6 s), ultralow detection limit (0.1 ppm), long-term stability and humidity-resistance properties. This work not only introduces a method to utilize a thermal support for atom-thin metal oxides, enhancing their stability at high working temperatures but also investigates the underlying mechanism. This study provides valuable insights into the application of ultrathin metal oxides. Additionally, it facilitates the development of a portable smart system for detecting HCHO contamination in practical settings. [ABSTRACT FROM AUTHOR]

Thermodynamic modeling of metal oxide reduction is crucial for optimizing chemical processes and materials in systems dependent on off-stoichiometric reduction/re-oxidation cycling. Two prevalent methods for extracting reduction thermodynamics from thermogravimetric data are linearized van 't Hoff (VH) analysis and the compound energy formalism (CEF). This work evaluates the accuracy of these methods by constructing invertible ground truth thermodynamic models, generating hypothetical thermogravimetric data, and determining the reduction thermodynamic using both VH and CEF methods. Our findings reveal that the VH method produces absolute errors 3–5 times higher than the CEF in kJ/mol O or J/mol O K for enthalpy and entropy of reduction, respectively. In contrast, the CrossFit CEF (CF-CEF) method yields errors often less than 10 kJ/mol O or J/mol O K. Moreover, the CF-CEF method provides models based on mole fraction, temperature, and extent of reduction, while a typical VH analysis provides thermodynamics of only the specific compositions measured. Although simple to implement, the VH method suffers from significant, non-systematic errors due to entropy/enthalpy compensation and defect modeling. Consequently, we recommend the more complex but robust, CF-CEF method for extracting redox thermodynamics from thermogravimetric measurements. [ABSTRACT FROM AUTHOR]

Quantifying methane emissions is essential for meeting near-term climate goals and is typically carried out using methane concentrations measured downwind of the source. One major source of methane that is important to observe and promptly remediate is fugitive emissions from oil and gas production sites but installing methane sensors at the thousands of sites within a production basin is expensive. In recent years, relatively inexpensive metal oxide sensors have been used to measure methane concentrations at production sites. Current methods used to calibrate metal oxide sensors have been shown to have significant shortcomings, resulting in limited confidence in methane concentrations generated by these sensors. To address this, we investigate using machine learning (ML) to generate a model that converts metal oxide sensor output to methane mixing ratios. To generate test data, two metal oxide sensors, TGS2600 and TGS2611, were collocated with a trace methane analyzer downwind of controlled methane releases. Over the duration of the measurements, the trace gas analyzer's average methane mixing ratio was 2.40 ppm with a maximum of 147.6 ppm. The average calculated methane mixing ratios for the TGS2600 and TGS2611 using the ML algorithm were 2.42 ppm and 2.40 ppm, with maximum values of 117.5 ppm and 106.3 ppm, respectively. A comparison of histograms generated using the analyzer and metal oxide sensors mixing ratios shows overlap coefficients of 0.95 and 0.94 for the TGS2600 and TGS2611, respectively. Overall, our results showed there was a good agreement between the ML-derived metal oxide sensors' mixing ratios and those generated using the more accurate trace gas analyzer. This suggests that the response of lower-cost sensors calibrated using ML could be used to generate mixing ratios with precision and accuracy comparable to higher priced trace methane analyzers. This would improve confidence in low-cost sensors' response, reduce the cost of sensor deployment, and allow for timely and accurate tracking of methane emissions. [ABSTRACT FROM AUTHOR]

This paper showcases the development of CuO nanoparticles (CuO NPs) deocrated on the surface of carbon nanotubes (CNTs) in polymer nanofiber structure. Both pulsed laser ablation and electrospinning were used to form decorated CNTs electrospun nanofibrous membrane. These technologies combine the decorated CNTs with electrospinning to create multifunctional membranes from polyurethane (PU) in a straightforward and cost-efficient manner. Different techniques were used to confirm the results. Simultaneously, we observed the morphological features and the particle size of the decorated CuO using scanning and transmission electron microscopy (SEM and TEM) with energy-dispersive X-ray spectroscopy (EDX). XRD analysis revealed sharp diffraction peaks, indicating the high crystalline structure of CuO NPs grown alongside nanotubes. Additionally, the presence of PU in the diffractogram showed minimal difference in the peak strength of the polyurethane matrix. FT-IR analysis also showed unique peaks that confirmed the substitution of graphite structure of CNTs, which shows that the successful decoration of metal oxide. In terms of catalytic performance, the produced samples demonstrated high efficiency in completing the reduction of 4-nitrophenol, particularly when CuO nanoparticles adorned the outer surface of CNTs in the membrane structure. This confirms the potential of using CuO/CNTs/PU nanofibrous membrane in significant quantities to enhance efficiency against hazardous compounds. [ABSTRACT FROM AUTHOR]

Mixed metal oxide (MMO) nanoparticles (NPs) are hybrids consisting of two or more nanoscale metal oxides. Advantages of MMO NPs over single metal oxides include improved catalytic activity, enhanced electrical and magnetic properties, and increased thermal stability due to the synergy of the different oxide components. This study presents a novel fabrication route for TiO2‐CeO2 NPs enriched with oxygen vacancies using a Haberland‐type gas aggregation cluster source. The NPs, deposited from different segmented Ti/Ce targets under varying O2 addition, were examined with respect to final composition, morphology, and Ti, Ce surface oxidation states. Particle formation mechanisms are proposed for the observed morphologies. Additionally, available O2 during deposition and its impact on the formation of defective sites were investigated. Defective sites in TiO2‐CeO2 NPs were analyzed using transfer to X‐ray photoelectron spectroscopy and transmission electron microscopy without contact to ambient oxygen. The incorporation of Ce to the target exhibits synergistic effects on the synthesis process. Segmented Ti/Ce targets enable the deposition of a broad range of mixed oxide NPs with diverse compositions and morphologies at considerably enhanced deposition rates, which is vital for practical applications. The presented fabrication approach is expected to be applicable for a broad variety of MMO NPs. [ABSTRACT FROM AUTHOR]

We are proposing a novel self-assembled monolayer (SAM) functionalized ZnO nanowires (NWs)-based conductometric sensor for the selective detection of hydrogen (H2). The modulation of the surface electron density of ZnO NWs due to the presence of negatively charged terminal amine groups (−NH2) of monolayers leads to an enhanced electron donation from H2 to ZnO NWs. This, in turn, increases the relative change in the conductance (response) of functionalized ZnO NWs as compared to bare ones. In contrast, the sensing mechanism of bare ZnO NWs is determined by the chemisorbed oxygen ions. The functionalized ZnO NWs exhibit an eight times higher response compared to bare ZnO NWs at an optimal working temperature of 200 °C. Finally, in comparison to studies in the literature involving strategies to enhance the sensing performance of metal oxides toward H2, like decoration with metal nanoparticles, heterostructures, and functionalization with a metal–organic framework, etc., SAM functionalization showed superior sensing results. [ABSTRACT FROM AUTHOR]

A strategic option for the production of H2 from renewable resources is use of the ethanol steam reforming reaction. Catalysts based on nickel have been widely investigated for this reaction, offering the advantages of low cost and high activity. However, a difficulty is that nickel may be strongly deactivated by coke formation. Perovskite-type mixed oxides are promising precursors for nickel-based catalysts, since their reduction leads to the formation of highly dispersed metal particles that can mitigate carbon deposition. However, high calcination temperatures are required for perovskite structure formation, resulting in low surface areas and limiting the effectiveness of this method. In order to address this difficulty, the present work proposes a novel strategy whereby the perovskite-type oxide LaNiO3 is supported on SBA-15. Characterization of the catalysts was performed using XRF, XRD, SEM, TPR, TEM, BET, H2-TPD, and TGA techniques. Their performances were then evaluated in catalysis of the ethanol steam reforming reaction to produce hydrogen. Calcination at 750 °C resulted in formation of highly dispersed perovskite on a support that presented high specific surface area. The catalyst obtained from reduced LaNiO3/SBA-15 with 33 wt% perovskite was the most active in the reaction. Analyses using TGA and SEM showed the formation of carbon mainly over Ni catalysts obtained from bulk LaNiO3 perovskite, while supporting LaNiO3 on SBA-15 led to lower deposition of carbon. The superior performance of this material in catalysis could be attributed to the dispersion of the perovskite on SBA-15, resulting in smaller size of the Ni metal particles formed during the reduction, compared to the catalyst derived from bulk perovskite. This promising method could be used in the production of a wide range of other catalysts. [ABSTRACT FROM AUTHOR]

The use of metal oxide nanoparticles (NPs) in skincare products has significantly increased human skin exposure, raising safety concerns. Whilst NP's ability to penetrate healthy skin is minimal, studies have demonstrated that metal oxide NPs can induce toxicity in keratinocytes through direct contact. Moreover, NP's effect on common skin disorders like psoriasis, where barrier impairments and underlying inflammation could potentially increase NP penetration and worsen nanotoxicity is largely unstudied. In this paper, we investigated whether psoriasis-like human keratinocytes (Pso HKs) would exhibit heightened toxic responses to titanium dioxide (TiO2), zinc oxide (ZnO), and/or silica (SiO2) NPs compared to healthy HKs. Cells were exposed to each NP at concentrations ranging between 0.5 and 500 µg/ml for 6, 24, and 48 h. Amongst the metal oxide NPs, ZnO NPs produced the most pronounced toxic effects in both cell types, affecting cell viability, inducing oxidative stress, and activating the inflammasome pathway. Notably, only in ZnO NPs-treated Pso HKs, trappin-2/pre-elafin was cleaved intracellularly through a non-canonical process. In addition, tissue remodelling-related cytokines were upregulated in ZnO NP-treated Pso HKs. The full impact of the observed outcomes on psoriatic symptoms will need further evaluation. Nonetheless, our findings indicate the importance of understanding the sub-lethal impacts of NP exposures on keratinocytes, even though direct exposure may be low, particularly in the context of skin disorders where repeated and long-term exposures are anticipated. [ABSTRACT FROM AUTHOR]

[Display omitted] • The catalytic ozonation performances for seven CeO 2 catalysts with different morphologies and exposed facets are disclosed. • CeO 2 nanorods with (1 1 0) and (1 0 0) facets exposed show the best performance. • A linear relationship between Frenkel-type OV density and O 3 decomposition rate is revealed regardless of morphology and exposed facet. • DFT calculation and experimental data reveal OV boosts O 3 activation on both the Ce and hydroxyl sites of CeO 2. Morphology and facet effects of metal oxides in heterogeneous catalytic ozonation (HCO) are attracting increasing interests. In this paper, the different HCO performances for degradation and mineralization of phenol of seven ceria (CeO 2) catalysts, including four with different morphologies (nanorod, nanocube, nanooctahedron and nanopolyhedron) and three with the same nanorod morphology but different exposed facets, are comparatively studied. CeO 2 nanorods with (1 1 0) and (1 0 0) facets exposed show the best performance, much better than that of single ozonation, while CeO 2 nanocubes and nanooctahedra show performances close to single ozonation. The underlying reason for their different HCO performances is revealed using various experimental and density functional theory (DFT) calculation results and the possible catalytic reaction mechanism is proposed. The oxygen vacancy (OV) is found to be pivotal for the HCO performance of the different CeO 2 catalysts regardless of their morphology or exposed facet. A linear correlation is discerned between the rate of catalytic decomposition of dissolved ozone (O 3) and the density of Frenkel-type OV. DFT calculations and in-situ spectroscopic studies ascertain that the existence of OV can boost O 3 activation on both the hydroxyl (OH) and Ce sites of CeO 2. Conversely, various facets without OV exhibit similar O 3 adsorption energies. The OH group plays an important role in activating O 3 to produce hydroxyl radical (∙OH) for improved mineralization. This work may offer valuable insights for designing Facet- and OV-regulated catalysts in HCO for the abatement of refractory organic pollutants. [ABSTRACT FROM AUTHOR]

With the increasing market demands for wearable and portable electronic devices, binary metal oxides (BMOs) with a remarkable capacity and good structure stability have been considered as a promising candidate for fabricating coplanar micro-supercapacitors (CMSCs), serving as the power source. However, the current fabrication methods for BMO microelectrodes are complex, which greatly hinder their further development and application in BMO CMSCs. Herein, the one-step fabrication of 2.5D CuMoOx-based CMSCs (CuMoCMSCs) has been realized by numerically controlled electric discharge machining (NCEDM) for the first time. In addition, the controllable capacity of CuMoCMSCs has been achieved by adjusting the NCEDM-machining voltage. The CuMoCMSCs machined by a machining voltage of 60 V (CuMoCMSCs60) showed the best performance. The fabricated CuMoCMSCs60 with binary metal oxides could operate at an ultra-high scanning rate of 10 V s−1, and gained a capacity of 40.3 mF cm−2 (1.1 mA cm−2), which is more than 4 times higher than that of MoOx-based CMSCs (MoCMSCs60) with a single metal oxide. This is because CuMoOx BMOs materials overcome the poor electroconductivity problem of the MoOx single metal oxide. This one-step and numerically controlled fabrication technique developed in this research opens a new vision for preparing BMO materials, BMO microelectrodes, and BMO microdevices in an environmental, automatic, and intelligent way. [ABSTRACT FROM AUTHOR]

Spinel metal oxides are extensively studied for supercapacitors (SCs) in alkaline electrolytes, where charge storage capacity is limited by surface site availability due to surface reconstruction forming metal hydroxides/oxyhydroxides. The use of an acidic medium, which can boost the charge storage capacity of spinel oxides offering an additional channel of intercalation‐deintercalation of protons, is underexplored. Moreover, the impact of chemical compositions and the cationic distributions is crucial on the electrocatalysis performance of spinel oxides, however, such a correlation is first time reported for charge storage properties of spinel ferrite NiFe2O4 nanoparticles (NFO NPs). Besides, a low‐cost and scalable synthesis of NFO NPs involving the thermal decomposition of Ni‐Fe glycolate, followed by controlled air‐calcination is reported. Thus crafted NFO NPs‐based device shows impressive specific capacitance (2112 F g−1 at 10 A g−1) in half‐cell configuration. A flexible all‐solid‐state asymmetric device (full‐cell) configuration depicts impressive energy density (20.7 Wh kg−1), power density (4000 W kg−1), gravimetric capacitance (140 F g−1 at 2 A g−1), and retention of its performance (≈75% after 10,000 charging/discharging cycles). The results depict a new insight toward the tuning of electronic and charge storage properties in NFO, which otherwise are predominately attributed to only the crystallite size and morphological effects. [ABSTRACT FROM AUTHOR]

Thin‐film tandem photovoltaic (PV) technology has emerged as a promising avenue to enhance power conversion efficiency beyond the radiative efficiency limit of single‐junction devices. Combining a tunable wide‐bandgap perovskite cell with a commercially established narrow‐bandgap cadmium selenium telluride (CdSeTe) cell in a comparatively easy‐to‐fabricate four‐terminal (4‐T) arrangement is a great step in that direction. Herein, the impact of the transparent back contact and the perovskite absorber bandgap on the performance of 4‐T perovskite–CdSeTe tandem solar cells is investigated. 4‐T perovskite–CdSeTe tandem device architecture with ≈25% efficiency is demonstrated and a feasible pathway is shown to improve the tandem efficiency to more than 30%. The results show that the integration of CdSeTe with perovskite in 4‐T tandem PV configurations represents a significant advancement toward achieving higher efficiency and low‐cost tandem PVs. [ABSTRACT FROM AUTHOR]