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.

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.

Photocatalytic conversion of O<sub>2</sub> and H<sub>2</sub>O provides a green and low-cost route for H<sub>2</sub>O<sub>2</sub> synthesis; however, most reaction systems involve sacrificial agents, and achieving efficient photosynthesis of H<sub>2</sub>O<sub>2</sub> in pure water remains a challenge. In this work, a Z-scheme Bi<sub>2</sub>S<sub>3</sub>/ZnIn<sub>2</sub>S<sub>4</sub> heterojunction with rich sulfur defects was prepared by a one-step hydrothermal method. The combination of Bi<sub>2</sub>S<sub>3</sub> with ZnIn<sub>2</sub>S<sub>4</sub> greatly enhanced visible-light absorption. The intimate heterojunction interface bonded through sulfur bridge efficiently promoted the separation and migration of photogenerated carriers. Moreover, the enlarged specific surface area, the existence of sulfur defects and the increase of surface hydrophobicity facilitated the oxygen reduction reaction. As a result, the H<sub>2</sub>O<sub>2</sub> production rate of the Bi<sub>2</sub>S<sub>3</sub>/ZnIn<sub>2</sub>S<sub>4</sub> heterojunction in pure water under visible light reached 1,634 μmol·g<sup>-1</sup>·h<sup>-1</sup>, which was 5.3 and 43.0 times that of ZnIn<sub>2</sub>S<sub>4</sub> and Bi<sub>2</sub>S<sub>3</sub>, respectively. This work provides new ideas for the construction of novel heterojunction photocatalysts for H<sub>2</sub>O<sub>2</sub> production.

Over the past 15 years, the new carbon allotrope graphdiyne (GDY) has been artificially synthesized and has rapidly garnered attention in fields such as energy, catalysis, electronics, and healthcare. Despite its promising potential, the synthetic methods for GDY and its derivatives have been constrained by limitations in application scenarios. This mini-review provides an overview of the synthetic methods for GDY developed in the past 15 years, including the synthesis of pristine GDY on Cu foil, interface-limited synthesis (liquid-liquid, gas-liquid, and solid-liquid interfaces), explosion techniques, chemical vapor deposition, and the preparation of GDY derivatives. The advancement of these methods has significantly broadened the range of applications for GDY-based nanomaterials across various scientific fields. This review not only summarizes GDY synthesis techniques but also discusses key factors influencing the quality of GDY synthesis, offering a novel perspective for the design of GDY-based nanomaterials.

Volatile organic compounds are important precursors of air pollution and photochemical smog, and they pose potential risks to human health and the ecological environment. Among them, propane is particularly challenging to eliminate due to its stable chemical nature. The catalytic oxidation of propane offers a promising strategy to tackle this pressing environmental issue and serves as an excellent model reaction for investigating the C–H and C–C bond activation and oxygen redox processes on supported noble metal catalysts. In this review, we focus on commonly used supported noble metal catalysts and systematically discuss how the chemical state, particle size, support type, addition of promoters, and metal-support interactions influence the catalytic performance in complete propane oxidation. Subsequently, the thermal stability of different noble metal catalysts is summarized. We then provide an overview of the common propane oxidation mechanisms reported in the literature, including Langmuir-Hinshelwood, Eley-Rideal, and Mars-van Krevelen mechanisms. Finally, we summarize and prospect the precise regulation of noble metal-support interface and the application of newly developed electrothermal catalytic technologies for highly efficient propane oxidation, guiding the design of future high-performance catalysts. This review aims to provide mechanistic insights and design principles bridging fundamental catalysis and practical oxidation applications.

Carbon-doped boron nitride (CBN) materials are a novel class of non-metallic catalysts with significant potential in catalyzing the oxidative dehydrogenation of propane (ODHP) process. Zeolitic imidazolate framework (ZIF-8) is a type of metal-organic framework material featuring a ZIF skeleton. Boron nitride materials derived from ZIF-8 inherit its advantages, including customizable structure, tunable mesoporous properties and high specific surface area. The present work has developed a novel synthetic method to introduce and engineer the B-terminated defect in ZIF-8 derived carbon-doped boron nitride (CBN-Zx) through the co-pyrolysis of ZIF-8 and other typical precursors containing boron and nitrogen. The unique role of ZIF-8 precursors was to produce mesopores in CBN-Zx, which contained plenty of B-terminated defects formed via the volatilization of Zn and the elimination of C and N species during the pyrolysis process, and these defects could transform into active boron oxygen (BOx) species, which enhanced the ODHP activity. The optimized CBN-Z0.4 catalyst exhibited high propane conversion at 23.9% in ODHP with the olefin selectivity at 86.1%, which had reached the best level among boron-based catalysts in ODHP. The present work not only provides a new idea for synthesizing highly efficient boron-based catalysts for ODHP reactions, but also sheds light on the structure-function relations, rational design and practical applications of CBN catalysts for ODHP reactions.

Research on functional separators is crucial for the performance of batteries owing to the inability of commercial polyolefin separators to suppress dendrites growth in lithium metal batteries, resulting in poor performance and safety hazards. Herein, we report polar groups of terminal amino and amide functionalized polyetherimide separators [ethylenediamine grafting polyetherimide (PEI-EDA)] with uniformly connected pore structures. The PEI-EDA separator displays excellent thermal stability, electrolyte affinity and ion transport ability with an ionic conductivity of 1.96 mS·cm-1 and a Li+ transference number of 0.74. Notably, the lone-pair electrons in nitrogen atoms of the −NH2 and −CONH− groups have interaction with Li+, and the active hydrogens on them have the electrostatic interaction with PF6-, which achieves the desolvation of Li+, and improves ion transport rate and uniform lithium-ion flux, synergistically inducing homogeneous deposition of Li+, suppressing the growth of dendritic lithium and forming a stable fluorine-rich solid interphase layer and uniform cathode interphase layer. Furthermore, the data from online electrochemical mass spectroscopy (OLEMS) show that the gas production of a battery with a PEI-EDA separator is significantly reduced during the cycling process, which effectively improves the battery safety. Uniform and dense lithium deposition not only prolongs the cycle-life of Li||Cu and Li||Li cells but also enhances the rate capability and cycling stability of Li||LiFePO4 batteries even under high cathode loading and extreme temperature conditions. Moreover, the Li||LiFePO4 pouch battery displays stable cycling performance and benign safety under the folding state. This suggests the PEI-EDA separator has a promising application prospect in the next-generation secure dendrite-free metal batteries.

Ammonia (NH3) is widely utilized in agriculture to manufacture fertilizers and is an important feedstock in the pharmaceutical, metallurgical, and textile industries. Owing to its highly compressible nature, NH3 is also regarded as an ideal carbon-free hydrogen carrier for the next-generation fuel cells. The Haber-Bosch process is currently the main method for NH3 production but suffers from high energy consumption and intensive carbon emission. Recently, the plasma-electrochemical cascade pathway - plasma nitrogen fixation from air in tandem with electrocatalytic synthesis of NH3 - has emerged as an alternative by the simplified process, low carbon emission, and high NH3 yield. However, the research in this area has not been summarized timely. This review systematically summarizes the research progress of plasma-electrochemical cascade pathway for the first time. Through performance and energy consumption analysis, key issues that need to be addressed have been identified: improving the efficiency of plasma nitrogen fixation and NH3 electrosynthesis. In response to these challenges, corresponding optimization strategies are provided in the end, pointing out the direction for the subsequent research on this emerging field.

LIAC