Hydrogen production technologies that can efficiently operate across the entire pH range hold great promise for diverse application scenarios, especially in seawater electrolysis. In this work, we report a facile colloidal-chemistry synthesis of manganese-doped vanadium disulfide (Mn-VS₂) monolayer nanosheets with superior hydrogen evolution reaction performance. The incorporation of manganese lowers the formation energy of sulfur vacancies and modifies electronic states, thereby creating additional catalytic sites and enhancing reaction kinetics. Benefiting from these features, Mn-VS₂ achieves an overpotential of 40 mV at -10 mA·cm^-2 in simulated seawater and maintains excellent operational stability for over 100 h. These findings underscore the potential of Mn-VS₂ as a robust electrocatalyst for direct seawater electrolysis, providing a viable avenue for exploring sustainable hydrogen production in practical marine environments.

Dual-atom catalysts (DACs) have triggered the burgeoning interest in the field of catalysis. The identification of coordination structures and the understanding of the catalytic role of dual-atom centers are of great significance to designing highly efficient DACs. This review summarizes the current synthesis methods for the construction of DACs. Then, we highlight the differences in geometric and electronic structures of DACs in terms of modulation strategies and engineering dual-metal interaction. In particular, the combination of various advanced characterizations and density functional theory (DFT) insights disclose the state of the dual-atom active center microenvironment. Moreover, the catalytic role of DACs in heterogeneous catalysis is discussed, involving the electronic effect of one metal as the main active center and the synergistic effect between dual metals. The structure-activity relationship and reaction mechanism based on experimental studies and theoretical exploration are discussed. Finally, the challenges and opportunities of DACs for the efficient valorization of energy-related small molecules are proposed. This review can offer new inspiration on developing DACs for energy conversion.

Crystalline zeolites are highly ordered inorganic microporous materials widely used in catalysis, ion exchange, gas separation and biomass conversion. The investigation of crystal growth pathways and mechanisms is needed to enhance the performance of zeolites. However, understanding these mechanisms is highly challenging, as zeolites usually grow in a closed autoclave, which is known as a “black box”. This review provides a comprehensive overview of the progress made in understanding the crystallization mechanism of zeolites in recent years and summarizes the application of advanced characterization in studying these issues. Emphasis is placed on the host-guest interaction and crystallization kinetics during the zeolite crystallization process.

CO₂ photoreduction is a sustainable strategy for converting CO₂ into high-value solar fuels. However, its complex reaction pathways, kinetics, and thermodynamic challenges limit its application. MXenes, as an emerging two-dimensional material, have become a focus in photocatalysis due to their unique structural characteristics and highly tunable electrical and optical properties. As for the MXenes-based photocatalysts towards CO₂ reduction, significant advances have been achieved in this field. This review starts with an introduction to the key thermodynamic and kinetic factors limiting CO₂ photoreduction performance. The structural, electronic and optical properties of MXenes will be discussed to highlight their potential applications in CO₂ photoreduction. Then, the latest research progress in MXenes-based photocatalysts for CO₂ reduction will be summarized from the perspective of the role of MXenes in MXenes-based photocatalysts. Finally, the review concludes with a summary and future perspectives, outlining potential research directions in this rapidly evolving field. This work can serve as a guide for the development of MXenes-based catalysts for photocatalytic CO₂ reduction, benefiting researchers working in this potentially game-changing field.

The rapid and accurate detection of NO₂ gas at ppm level is of great value in human health and environmental protection. However, the most widely used metal-oxide semiconductor (MOS)-based NO₂ sensors usually require high operating temperatures (> 200 °C) to perform sensing functions. The preparation of these sensors possessing excellent sensing performance at room temperature (RT) remains a challenge. In this paper, copper oxide (CuO)-polyaniline (PANI) composites were prepared by heat treatment of copper foam and in situ growth of PANI. These composites exhibited a response value of 7.63 to 100 ppm NO₂ at RT, which was 4.8 times higher than that of pure PANI. Moreover, the response time (3 s) was dramatically shortened compared with PANI (27 s). In addition, the prepared sensors demonstrated excellent stability and high NO₂ selectivity. The excellent NO₂ sensing properties of CuO-PANI were attributed to the p-p heterojunction between CuO and PANI and the large number of oxygen vacancies. This research contributes to a practical and cost-effective approach for the development of high-performance NO₂ sensors operating at RT and offers potential applications for air quality testing.

Perovskite oxides are potential materials that can replace noble metals for industrial catalysis. However, the high temperature (> 700 °C) required in the preparation process causes the lack of low-coordinated defect sites that are essential for catalytic reactions. To this end, herein we develop a top-down strategy to synthesize ABO₃-type perovskite, by selectively etching the non-perovskite unit of a Ruddlesden-Popper (R-P) compound. The etching treatment not only promotes the formation of stable, three-dimensional reticular structure composed of nanosheets, but also generates rich amounts of grain boundaries and lattice defects, altering the electronic and surface properties. The LaMnO₃, obtained by etching the La-O unit of R-P La₃Mn₂O₇, exhibits not only enriched grain boundaries and lattice defects, but also excellent surface hydrophobicity. Moreover, the material possesses surface area of up to 212.3 m²/g, which is the highest value for perovskite oxides reported in literature, to the best of our knowledge. Owing to these exciting properties, the LaMnO₃ shows prominent catalytic performances for oxygen involved oxidation reactions, including the full oxidation of volatile organic compounds and partial oxidation of alcohols, with stable activity and strong resistance to water. These results suggest that the top-down strategy is a promising method for synthesizing ABO₃-type perovskites and could be a driving force to promote their progress for industrial catalysis.

One of the biggest challenges in the electrochemical synthesis of H₂O₂ is the development of high-performance and economical catalysts. In this work, a two-dimensional composite material consisting of NiO_x nanosheets and defective graphene (DG) (NiO_x@DG) was prepared and showed excellent electrocatalytic performance toward electrosynthesis of H₂O₂ from oxygen reduction reaction. Particularly, the NiO_x@DG catalysts present superior activity indicators to physical mixing counterparts (NiO_x-DG), encompassing a high onset potential of 0.78 V, high efficiency and 2e^- selectivity over a wide potential range between 0.20-0.60 V (maximal value of 95%). The high activity of NiO_x@DG can be attributed to the dual-defects (oxygen vacancies on NiO_x and topological defects on DG)-induced strong electronic metal–support interaction. Such multi-defects collaborative enhancement strategy may provide a promising avenue for the preparation of high-performance catalysts toward application in different reactions.

The development of high-performance catalysts for the activation of peroxymonosulfate remains a persistent challenge in the degradation of contaminants in waste water. Herin, a catalyst, Co/N@ZS-polydopamine, with excellent recovery and recyclability, was synthesized by employing the structurally ordered Co/N@ZS and polydopamine with strong adhesion. This catalyst effectively activated 0.30 g/L peroxymonosulfate for the degradation of 20 mg/L carbamazepine, demonstrating a remarkable degradation rate of 94.46%. The combination of electron paramagnetic resonance analysis and reactive oxygen species quenching research revealed that carbamazepine degradation is caused by both radical (SO₄^•- and O₂^•-) and non-radical (¹O₂ and electron transfer) processes. In addition, the possible degradation pathways were proposed based on the identification of intermediate products through liquid chromatography-mass spectrometry analyses. More importantly, the catalyst-assisted thin films exhibit exceptional stability and long-term efficacy in dynamic water treatment. The present study provides innovative perspectives on the application of highly efficient and stable catalysts in water treatment procedures for advanced oxidation processes.

In the current era of pursuing low carbon, hydrogen energy emerged as a pivotal zero-carbon energy source, but faces a critical challenge in terms of its practical implementation. Trace CO contaminants (~1% CO) in industrial hydrogen streams derived from hydrocarbon reforming can irreversibly poison Pt electrodes of proton-exchange-membrane fuel cells. The preferential oxidation of CO in H₂-rich stream (PROX) is considered as an effective strategy to eliminate CO. In this work, we synthesized the catalyst of 0.3Pt/CNTs-CIW via a colloidal impregnation method, which achieves unprecedented performance in PROX, delivering 100% CO conversion with 50% CO₂ selectivity across an exceptionally broad operational temperature window from 20 to 200 °C with a minimal Pt content of 0.3 wt%. Various characterizations reveal that the high efficiency derives from the active structures with the synergies of Pt-OH and Pt⁰. The adsorption of CO is weakened by the construction of Pt-OH and couples with OH in the form of COOH^* which is then oxidized by OH^* derived from adsorbed O₂ and H₂ on Pt⁰ with a low activation energy, resulting in high efficiency of CO oxidation. Beyond CO-PROX, this bifunction activation paradigm offers transformative potential for diverse catalytic systems involving competitive adsorption and redox coupling, such as low-temperature oxidation of methane and volatile organic compounds abatement.

Homogeneous carbon nitride (C₃N₄) photocatalysts with their suitable electronic structure, environmental benignity, and outstanding chemical stability properties have been exhibiting excellent performances in various fields. However, their mechanism is still relatively unclear, and there is limited research on treating high-concentration water pollutants. This work presents a crystallized carbon nitride homojunction (HCN) catalyst originating from triazine-based C₃N₄ and bulk phenazine-based C₃N₄ (BCN) via one-step calcination. As a result, the optimized HCN first demonstrates significantly enhanced photocatalytic reduction efficiency (≈1.44 min^-1) towards 150 mg/L high-concentration 4-nitrophenol (4-NP) under visible light irradiation, up to two-fold better than BCN. The concentration and pH were meticulously adjusted, accompanied by a thorough exploration of the underlying mechanisms. Subsequently, comprehensive verification was conducted to confirm the existence of a type-II homojunction and the establishment of an interfacial electric field in HCN, which serve as potent facilitators for the separation and migration of photo-excited carriers. This novel study provides a comprehensive understanding of homojunction catalyst design and advances the development of efficient metal-free photocatalysts for degrading high-concentration pollutants.

Single-atom catalysts (SACs) have demonstrated immense potential in the fields of energy and biochemical conversions. Their unique properties make them particularly efficient and selective. Characterized by their unique isolated state on supports, SACs often showcase poor synergy in the multiple molecule conversion because of the infrequent communications with others. Recently, some interesting synergetic processes of SACs in some special reactions have been found; however, to our best knowledge, the synergetic catalytic effect of SACs has not been systematically summarized. This article comprehensively overviews the basic concepts, mainstream synthetic methods, and modification strategies of SACs and emphasizes the synergetic catalysis effect in biomass conversion, CO₂ reduction, and cascade reaction by itself or other media. To maximize the advantage of SACs, various synthetic methods for them, including impregnation, co-impregnation, co-precipitation, atomic layer deposition, electrochemical methods, photochemical methods, pyrolysis synthesis, spray pyrolysis method, ball-milling and chemical vapor deposition method are discussed. This review provides a comprehensive discussion concerning the dynamic interplay between precisely engineered atomic architectures and their synergistic functionalities in modulating catalytic efficacy, with focused exploration of activity enhancement strategies and operational stability optimization. Distinctively, it pioneers the establishment of comprehensive theoretical frameworks that unify SAC-driven synergistic catalytic mechanisms across three critical domains: biomass valorization, electrochemical CO₂ conversion, and multi-step cascade processes. Through systematic synthesis of cutting-edge developments in coordination microenvironment modulation, inter-site electronic communication, and fundamental mechanistic studies, this work affords some interesting insight into rational design of synergistic SAC systems, thereby addressing current challenges in translating atomic-scale precision to heterogeneous catalytic performance.

After decades of development, lithium-ion and sodium-ion batteries have established mature material systems, electrode structures and production technologies. In spite of this, high-performance batteries with both favorable energy density and power density are substantially explored to meet the requirement of long-mileage electric vehicles and long-duration energy storage. To balance the contradiction between energy density and power density, engineering micro-/nano-structures is recognized as an effective approach that combines the advantages of both micro- and nanoarchitectures. This paper comprehensively summarizes the micro-/nano-engineering in material production, electrode manufacture, and interface regulation of lithium-ion and sodium-ion batteries. The benefit of micro-/nano-structure on the enhanced cycling life and rate capability is discussed in detail, and promising engineering strategies in future commercial batteries are envisaged. This review provides a basic understanding of the role of micro-/nano-structural engineering in promoting battery performance, and also guidance for the multidimensional and multiscale design of micro/nano-architectures toward practical applications.

CO₂ electrochemical reduction (CO₂ER) is a promising alternative for the conversion of CO₂ into green and value-added chemicals. Among these chemicals, CO is an important product and platform molecule of the CO₂ER, which is always used to produce various chemicals such as methanol, aldehydes, and synthesis gas (H₂/CO). Developing efficient catalytic systems for the CO₂-to-CO, especially via the electrolytic chemical way, is highly important. In the present work, a N and P co-doped MnZn-bimetal supported 3D graphene aerogel (GA) catalyst, denoted as MnZn/N,P-3D-GA, was prepared and used for the CO₂ER to produce CO, which delivered high performance in the reaction. When the potential was -0.92 V [vs. reversible hydrogen electrode (RHE)], the Faradaic efficiency of CO (FE_CO) reached 96.6% and the current density was 12.0 mA·cm^-2. In addition, at the potential range from -0.97 to -1.12 V (vs. RHE), the obtained FE_CO was all more than 90%, indicating that the catalyst has a wide electrochemical window for the reaction. Density functional theory calculations indicated that the catalytic processes mainly involve *CO₂, *COOH, and *CO intermediates. The enhanced catalytic performance of the catalyst originated from the synergistic effect among the MnZn, N, P, and GA. The present work provides an important reference in the design and construction of catalysts using dual-metal-loaded and dual-heteroatom-modified GAs.

Silver metalized organic porous polymer (Ag@POP-HCO₃) was prepared by copolymerizing the HCO₃^- modified N-heterocyclic carbene monomer loading silver with divinylbenzene. The in-situ conversion of low concentration CO₂ from coal-fired flue gas or air into oxazolidinone compounds was achieved through carboxylation cyclization reaction catalyzed by Ag@POP-HCO₃ under ambient conditions, without the addition of any cocatalyst. Additionally, both SO₂ and NO₂ did not interfere with the reaction at normal concentration presented in flue gas. The Ag@POP-HCO₃ can effectively catalyze the gram reaction, and its catalytic activity is not significantly reduced after being recycled. The introduction of HCO₃^- increased the specific surface area and microporous volumes of the catalyst, enhancing its ability to adsorb CO₂. Furthermore, N-heterocyclic carbene and HCO₃^- collaborated to expedite the activation of CO₂, while the coordination of silver serves to activate the substrate. The proposed approach avoids cost issues of traditional carbon capture, utilization and storage technology and promotes green chemical process development.