Photoelectrochemical (PEC) two-electron oxygen reduction reaction (2e- -ORR) offers a sustainable and decentralized route for hydrogen peroxide (H2O2) production, presenting a promising alternative to an energyintensive anthraquinone process. The performance of a PEC 2e--ORR system, including its selectivity, yield and stability, is largely governed by the photocathode. Thus, developing efficient, stable, and cost-effective photocathode materials is essential for practical H2O2 production. This review highlights recent progress in photocathode materials for PEC 2e- -ORR, with an emphasis on material design strategies. The fundamental mechanisms and key characteristics of PEC 2e--ORR are first introduced, followed by a comprehensive overview of various photocathode materials (e.g., oxides, sulfides, polymers) with an emphasis on their design principles. Special attention is given to unique modification strategies and rational structural configurations that enhance photocathode performance. Finally, current challenges and future research opportunities for advancing the practical PEC 2e- -ORR systems are outlined. This review aims to deepen the understanding of photocathode materials for PEC 2e- -ORR, while also inspiring new concepts and substantial innovation in the field.

Increasing the covalency of metal-oxygen bonds can significantly promote lattice oxygen activation, which subsequently enhances catalytic oxidation of VOCs. Herein, MXene-derived accordion-like TiO2-supported MnOx (TiO2-MnOx) is prepared for catalytic oxidation of toluene. This composite material exhibits enhanced toluene oxidation performance with T50 of 225 degrees C and T90 of 255 degrees C, achieving a 110 degrees C reduction in T90 compared to pure Mn2O3. In-situ diffuse reflectance infrared Fourier transform spectroscopy further confirms that the catalytic oxidation of toluene over TiO2-MnOx follows the Mars-van Krevelen mechanism, in which lattice oxygen actively drives the mineralization of toluene to H2O and CO2. Density functional theory reveal that Mn2O3 supported on TiO2 reduces the oxygen vacancy formation energy and promotes O2 adsorption. Crucially, Mn2O3 phase supported on TiO2 exhibts enhanced Mn-O covalency, facilitating lattice oxygen participation in toluene oxidation. This work provides an insight into designing high-performance transition metal oxide catalysts with enhanced metal-oxygen covalency for low-temperature catalytic oxidation of toluene.

Catalytic oxidation technology was the mainstream technology for the industrial-scale degradation of volatile organic compounds (VOCs). Enhancing O2 activation capacity served as an effective strategy to boost catalytic oxidation of VOCs dominated by the MvK mechanism. Local electron redistribution induced by asymmetric oxygen vacancies (As-OVs) resulted in polar electron distribution which enhanced facilitation of the activation of O2. Herein, a series of transition metal oxide-based (Fe2O3, Co3O4, NiO and CuO) monolithic catalysts were prepared via successive ionic layer adsorption reaction (SILAR) method combined with calcination. Ce-doping weakened the transition metal-O bonds, which induced the electron redistribution around As-OVs. Experimental results demonstrated that TiCeNi-Ce exhibited excellent catalytic performance for toluene oxidation, with its T90 and T50 reaching 210 degrees C and 176 degrees C, respectively. The As-OVs led to polar electron distribution, which enhanced pi back donation to improve O2 activation capacity. Meanwhile, the As-OVs strengthened the adsorption of reactants while reducing the adsorption of H2O. This work provided mechanistic insights into the formation of As-OVs induced by Ce doping and presented a rational design strategy for constructing highperformance monolithic catalysts in thermal catalytic oxidation processes.

Electrocatalytic nitrate reduction (NO 3 RR) offers a promising approach to address nitrate pollution by converting harmful nitrates into environment-benign or valuable products like nitrogen gas (N 2 ) or ammonia (NH 3 ). This review explores the mechanisms, challenges, and catalysts involved in NO 3 RR, highlighting the role of catalyst selectivity, stability, and external reaction conditions. The discussion also covers the environmental and economic benefits of NO 3 RR for water treatment, alongside potential future directions in scaling-up, system integration, and expanding research into tackling related nitrogen-based pollutants as well as real world applications.

Chalcogenide perovskite has attracted significant attention as a potential optoelectronic material due to its excellent light absorption, suitable direct band gap, and effective carrier transportation. While the luminescence properties of Sr-based chalcogenides have been explored recently, challenges such as low luminescence efficiency and limited performance persist. In this work, rare earth element Eu, which possesses distinctive luminescent properties, was selected to tune the luminescent properties of chalcogenide perovskites. The synthesized Eu-doped SrZrS3 powders are demonstrated to exhibit enhanced green light emission at 550 nm under 350 nm excitation, which is attributed to the 4f65d1-4f75d0 transition of Eu2+. Moreover, an investigation into the temperature-dependent luminescent measurements reveals that the PL intensity of the optimized 8 at% Eu-doped specimen at 380 K remains at 50% of that at 280 K. In addition to the well-performed thermal stability and photostability, this material exhibits excellent air stability, even when stored in air for over a year. Moreover, the direct bandgap characteristics are confirmed through experiments and calculations. And the application of this material in the luminescent anticounterfeiting field was preliminarily explored. These findings offer an approach to tune the luminescence performance of chalcogenide perovskites and promote their potential applications in the field of luminescence.

Ni-Promoted Cu/ZSM-5 catalyst presented an excellent methanol yield of 82 162 μmol g cat −1 h −1 (with a methanol selectivity of ∼74%) in direct conversion of methane to methanol.

Electrosynthesis of hydrogen peroxide (H2O2) via two-electron oxygen reduction reaction (2e- ORR) is a promising alternative to the anthraquinone oxidation process. To improve the overall energy efficiency and economic viability of this catalytic process, one pathway is to develop advanced catalysts to decrease the overpotential at the cathode, and the other is to couple 2e- ORR with certain anodic reactions to decrease the full cell voltage while producing valuable chemicals on both electrodes. The catalytic performance of a 2e- ORR catalyst depends not only on the material itself but also on the environmental factors. Developing promising electrocatalysts with high 2e- ORR selectivity and activity is a prerequisite for efficient H2O2 electrosynthesis, while coupling appropriate anodic reactions with 2e- ORR would further enhance the overall reaction efficiency. Considering this, here a comprehensive review is presented on the latest progress of the state-of-the-art catalysts of 2e- ORR in different media, the microenvironmental modulation mechanisms beyond catalyst design, as well as electrocatalytic system coupling 2e- ORR with various anodic oxidation reactions. This review also presents new insights regarding the existing challenges and opportunities within this rapidly advancing field, along with viewpoints on the future development of H2O2 electrosynthesis and the construction of green energy roadmaps.

Magnetron sputtering deposition with regulated Cu target power was used for depositing Cucontaining high-entropy alloy nitride (Cu-(HEA)N) films on TC4 titanium alloy substrates. The microscopic morphologies, surface compositions, and thicknesses of the films were characterized using SEM+EDS; the anti-corrosion, wear resistance and antibacterial properties of the films in simulated seawater were investigated. The experimental results show that all four Cu-(HEA)N films are uniformly dense and contained nanoparticles. The film with Cu doping come into contact with oxygen in the air to form cuprous oxide. The corrosion resistance of the (HEA)N film without Cu doping on titanium alloy is better than the films with Cu doping. The Cu-(HEA) N film with Cu target power of 16 W shows the best wear resistance and antibacterial performance, which is attributed to the fact that Cu can reduce the coefficient of friction and exacerbate corrosion, and the formation of cuprous oxide has antibacterial properties. The findings of this study provide insights for engineering applications of TC4 in the marine field.

AbstractDue to the limitations of the raw materials and processes involved, polyolefin separators used in commercial lithium‐ion batteries (LIBs) have gradually failed to meet the increasing requirements of high‐end batteries in terms of energy density, power density, and safety. Hence, it is very important to develop next‐generation separators for advanced lithium (Li)‐based rechargeable batteries including LIBs and Li–S batteries. Nonwoven nanofiber membranes fabricated via electrospinning technology are highly attractive candidates for high‐end separators due to their simple processes, low‐cost equipment, controllable microporous structure, wide material applicability, and availability of multiple functions. In this review, the electrospinning technologies for separators are reviewed in terms of devices, process and environment, and polymer solution systems. Furthermore, strategies toward the improvement of electrospun separators in advanced LIBs and Li–S batteries are presented in terms of the compositions and the structure of nanofibers and separators. Finally, the challenges and prospects of electrospun separators in both academia and industry are proposed. We anticipate that these systematic discussions can provide information in terms of commercial applications of electrospun separators and offer new perspectives for the design of functional electrospun separators for advanced Li‐based batteries.

The crucial step for splitting water is the oxygen evolution reaction. The key to promote this reaction lies in the catalyst. Molybdenum disulfide, as a two-dimensional material with molybdenum and sulfur atoms stacked, is especially suitable as a doping platform to develop high-performance OER catalysts. Fe/Co/Ni ternary transition metal combination has always been a highly active catalytic site for OER. Heteroelement of Fe/Co/Ni doping is expected to effectively modify the local electronic configuration of matrix materials and thus enhances their electrocatalytic OER capability. With this in mind, we report a simple in-situ hydrothermal doping of MoSx nanowires on iron-nickel alloy foam with ternary transition metal of Fe/Co/Ni. This ternary transition metal of Fe/Co/Ni doped f self-supported electrode (denoted Fe/Co/Ni-MoSx/INF) displays outstanding OER performance in terms of small overpotentials of 214 and 263 mV at current densities of 10 and 100 mA/cm2, respectively, in alkaline solution. It was far better than the commercial Ir/C catalysts (253 and 434 mV@10 and 100 mA/cm2). The Tafel slope is about 48.1 mV/dec. Moreover, Fe/Co/Ni-MoSx/INF also has an excellent catalytic stability without any obvious performance decay after 20 h operation. This work contributes to the investigation of high-efficiency OER catalysts based on transition metal-doped MoSx and offers a substitute for noble metal catalysts.

Electrocatalytic hydrogen peroxide (H 2 O 2 ) production via the two-electron oxygen reduction reaction is a promising alternative to the energy-intensive and high-pollution anthraquinone oxidation process. However, developing advanced electrocatalysts with high H 2 O 2 yield, selectivity, and durability is still challenging, because of the limited quantity and easy passivation of active sites on typical metal-containing catalysts, especially for the state-of-the-art single-atom ones. To address this, we report a graphene/mesoporous carbon composite for high-rate and high-efficiency 2e − oxygen reduction catalysis. The coordination of pyrrolic-N sites -modulates the adsorption configuration of the *OOH species to provide a kinetically favorable pathway for H 2 O 2 production. Consequently, the H 2 O 2 yield approaches 30 mol g −1 h −1 with a Faradaic efficiency of 80% and excellent durability, yielding a high H 2 O 2 concentration of 7.2 g L −1 . This strategy of manipulating the adsorption configuration of reactants with multiple non-metal active sites provides a strategy to design efficient and durable metal-free electrocatalyst for 2e − oxygen reduction.

Aqueous zinc-ion batteries (ZIBs) have been regarded as a promising alternative to traditional lithium-based batteries due to their intrinsic advantages of safety, low cost, and abundance. However, the strong electrostatic interaction between Zn2+ and the layer-structured cathodes is still a key issue that hinders the batteries from storing more Zn. Herein, we report partially nitrided and cation-doped vanadium oxide for improved Zn storage performance. Specifically, the defects and nitride species that are generated inside the material upon nitriding improve the conductivity of the material and introduce a new Zn storage mechanism. The intercalation of cations, in contrast, widens the interlayer spacing to store more Zn2+ ions and enhances the cycling stability of the material. These merits synergistically lead to significantly enhanced electrochemical Zn2+ ion storage performance, in terms of a high specific capacity of 418.5 mAh·g−1 at a current density of 0.1 A·g−1 and a capacity retention of 81.2% after 500 cycles at 2.0 A·g−1. The new modification strategy for V2O5 suggested in this work could provide insight into the development of high-performance ZIBs.

Rechargeable aqueous zinc-ion batteries (ZIBs) have been gradually attracting attention, because they are inexpensive and abundant; thus, they are favorable choice for energy storage system. Layered vanadium oxides have excellent zinc-ion storage capacity; however, significant challenges, such as poor conductivity and slow zinc-ion intercalation/deintercalation reaction, remain. Herein, we fabricated a material comprising V2O5 and Ag (Ag0.3V2O5, AVO) with a high conductivity and stable structure. Using this strategy, the ZIBs based on the AVO electrode achieved a high capacity of 340 mAh g−1 at 0.10 A g−1, long-term cyclic stability with over 93.75

To create hybrid composites for highly effective photocatalytic hydrogen evolution reactions, the photogenerated charge separation efficiency at the hybrid interface and the surface reaction kinetics at the reactive sites are key factors. In this work, CoFe hydroxide nanosheets prepared by dealloying were first mixed with graphitic carbon nitride (g-C3N4) to synthesize a CoFe2O4/g-C3N4 composite with strong Co-N bonds at the interface by a simple hydrothermal method. It was found that the presence of Co-N bonds between the components in the composites enhances the separation and transfer by photogenerated carriers at the composite interface. Furthermore, the presence of Co-N bonds enhanced the synergistic effect of the hybrid, which significantly boosts their photocatalytic performance in comparison to their counterparts. Under full-spectrum light, the composite photocatalyst has a greater efficiency of photocatalytic water H2 evolution (6.793 mmol/g−1·h−1) and exceptional stability when compared to pure g-C3N4 (0.236 mmol/g−1·h−1) and CoFe2O4 (0.088 mmol/g−1·h−1). Under visible irradiation, the photocatalytic activity of the composite (0.556 mmol/g−1·h−1) for H2 evolution increased by factors of 28.37 and 75.8 when compared to pure g-C3N4 and CoFe2O4, respectively.

nitride nanotubes were prepared by ball milling and annealing method using boron oxide and ammonia as raw materials and iron or magnesium powder as catalyst. The effect of iron or magnesium content on morphology and yield of boron nitride nanotubes was studied. The results show that uniform fine boron nitride nanotubes can be obtained by annealing process when the precursor of boron oxide does not contain catalyst, but the yield is very low. Appropriate iron can play a good catalytic role, a large number of boron nitride nanotubes with uniform size can be obtained. With the increase of iron content, the productivity of the product decreases and the morphology of the annealed products changes from boron nitride nanotubes with uniform size to boron nitride nanotubes with uneven diameter and length. When the molar ratio of boron oxide and iron content reaches 1 : 1, the productivity of the product increases and the morphology of them changes from smooth boron nitride nanotubes to coral-like boron nitride micro-nanostructures with a large number of boron nitride nanosheets growing vertically on the surface of boron nitride nanotubes, and the diameter of the product increases obviously. The change of magnesium content only affects the size, uniformity and productivity of the product, no effect on morphology was observed. Changes in morphology and yield of boron nitride nanotubes can be explained by gas-liquid-solid growth mechanism.

The rare-earth based multicomponent (Ce0.71Pr0.07Nd0.22)2Fe17-xSix (x = 0-0.6) alloys were fabricated by conventional arc melting following the standard annealing and quenching processes. The prepared alloys were characterized by X-ray diffraction (XRD), backscattered scanning electron (BSE) microscope, energy dispersive X-ray (EDX) spectroscopy, magnetization, and heat capacity measurements. Combination of Rietveld refinement of XRD patterns, EDX/BSE analyses confirm the formation of stable rhombohedral Th2Zn17 type crystal structure with R-3 m space group in all studied samples. The investigated samples experience second-order phase transition as confirmed through phenomenological universal scaling ana-lysis. The magnetic entropy change (-& UDelta;SM) and associated relative cooling power (RCP) values for all compositions were found in the range of 1.1-1.4 Jkg-1K-1 and 55-66 Jkg-1 under magnetic field change (& UDelta;H) of 0-1 T. The & UDelta;SM curves as a function of temperature exhibit a wide working temperature range (& delta;TFWHM) over 40 K for all studied compositions. The performance-cost ratio - & UDelta;SM/cost and RCP/cost values are estimated to be 0.1 JK-1$-1 and 5.0 J$-1, respectively. In particular, a large adiabatic temperature change of 7.36 K and 8.09 K was achieved for x = 0.2 and x = 0.4, respectively, at low & UDelta;H= 0-1 T. The better perfor-mance-cost ratio and good magnetocaloric properties with near-zero magnetic hysteresis loss may make these alloys promising candidates for magnetic refrigeration.& COPY; 2023 Elsevier B.V. All rights reserved.

The hazards associated with handling hydrogen fuels have driven people to consider alternative clean and sustainable fuel types. Ammonia shows significant potential for this task as both a direct fuel and hydrogen carrier due to its unique features of facile transportation and low cost. Regarding this, electrochemical ammonia oxidation reaction (AOR) is the essential process for utilizing ammonia for energy applications, either for hydrogen production via ammonia splitting or energy generation via direct ammonia fuel cells, which is highly commercially promising. On this basis, the development of high‐performance and economic electrocatalysts for AOR is critical. In this review, the kinetics and mechanism of ammonia electrooxidation are first discussed to provide a foundation to understand the current issues associated with this technology, and then a comprehensive presentation on the different types of electrocatalysts for AOR is illustrated. Afterward, an outlook is presented and the possible research directions for AOR electrocatalysis are proposed, which is expected to shed light on the future development of this promising technology.

Two-dimensional (2D) carbon nitride (CN) materials have received tremendous attention as photocatalysts for clean energy and environmental treatment. However, the photocatalytic efficiency of CN is constrained by the high exciton binding energy and sluggish charge kinetics due to weak dielectric screening, impeding the overall process. Herein, localized flexo-/piezoelectric polarization is introduced via strain engineering, boosting exciton dissociation and promoting charge separation to enhance the multielectron photocatalytic process. Consequently, the exciton binding energy of polarized CN is reduced from 52 to 34 meV, and the hydrogen evolution yield increased by 2.9 times compared to that of the pristine CN. For other photocatalytic reactions (e.g., H2O2 production), the polarized CN also maintained a 2.1-fold increase compared to the pristine CN. This strategy of inducing localized polarization via strain engineering provides new insights for boosting photocatalytic reactions involving electrons.

Electrocatalytic oxygen reduction via a two-electron pathway (2e--ORR) is a promising and eco-friendly route for producing hydrogen peroxide (H2O2). Single-atom catalysts (SACs) typically show excellent selectivity towards 2e--ORR due to their unique electronic structures and geometrical configurations. The very low density of single-atom active centers, however, often leads to unsatisfactory H2O2 yield rate, significantly inhibiting their practical feasibility. Addressing this, we herein introduce fluorine as a sec-ondary doping element into conventional SACs, which does not directly coordinate with the single -atom metal centers but synergize with them in a remote manner. This strategy effectively activates the surrounding carbon atoms and converts them into highly active sites for 2e--ORR. Consequently, a record-high H2O2 yield rate up to 27 mol g-1 h-1 has been achieved on the Mo-F-C catalyst, with high Faradaic efficiency of 90%. Density functional theory calculations further confirm the very kinetically facile 2e--ORR over these additional active sites and the superiority of Mo as the single-atom center to others. This strategy thus not only provides a high-performance electrocatalyst for 2e--ORR but also should shed light on new strategies to significantly increase the active centers number of SACs.(c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Achieving intimate particle-to-particle and particle-to-substrate contacts is the first priority for fabricating high-quality photoelectrodes to ensure sufficient visible light absorption and efficient charge separation/transport. To achieve this goal, a seeding strategy is designed to construct a robust carbon nitride (CN) homojunction photoelectrode, in which vaporized precursors are condensed into a compact seeding layer at low temperatures, inducing the further deposition of the top layer. This optimized photoelectrode displays an excellent photocurrent density of 320 μA cm-2 in 0.1 M NaOH electrolyte at 1.23 VRHE (V vs reversible hydrogen electrode) under AM 1.5G illumination, with H2 and O2 evolution rates of 2.98 and 1.47 μmol h-1 cm-2, respectively. Characterizations show that both the robust contact and the homojunction of the double-layered CN film contribute to enhanced photoelectrochemical performance. This work may provide a new strategy for the design of high-performing CN photoelectrodes.