Ammonia is one of the most important chemicals due to its enormous applications in fertilizer production and as an energy carrier. The production of ammonia mainly relies on the traditional Haber–Bosch process under high temperature and pressure, leading to massive energy consumption and notable environmental issues. Recently, electrocatalytic and photocatalytic nitrogen (N2) fixation have emerged for achieving green production of ammonia owing to their features of environmental friendliness and cost‐effectiveness. However, ammonia production through electrocatalysis and photocatalysis is still far away from practical applications. To facilitate the practical applications, a thorough understanding of nitrogen fixation is highly desired for the future design of high‐efficiency catalysts. Here, the fundamental investigations on electrocatalytic and photocatalytic N2 reduction are summarized. Based on the fundamental understanding, the current approaches and design strategies for heterogeneous catalysts toward electrocatalytic and photocatalytic N2 reduction are then presented. Finally, the remaining challenges and future opportunities in this field are outlined, leveraging the existing understanding on structure–property relationships. It is anticipated that this review sheds some light on the development of advanced catalytic systems for ammonia production through N2 fixation.

Adsorption and activation of molecules on a surface holds the key to heterogeneous catalysis toward aerobic oxidative reactions. To achieve high catalytic activities, a catalyst surface should be rationally tailored to interact with both organic substrates and oxygen molecules. Here, a facile bottom-up approach to defective tungsten oxide hydrate (WO ·H O) nanosheets that contain both surface defects and lattice water is reported. The defective WO ·H O nanosheets exhibit excellent catalytic activity for aerobic coupling of amines to imines. The investigation indicates that the oxygen vacancies derived from surface defects supply coordinatively unsaturated sites to adsorb and activate oxygen molecules, producing superoxide radicals. More importantly, the Brønsted acid sites from lattice water can contribute to enhancing the adsorption and activation of alkaline amine molecules. The synergistic effect of oxygen vacancies and Brønsted acid sites eventually boosts the catalytic activity, which achieves a kinetic rate constant of 0.455 h and a turnover frequency of 0.85 h at 2 h, with the activation energy reduced to ≈35 kJ mol . This work provides a different angle for metal oxide catalyst design by maneuvering subtle structural features, and highlights the importance of synergistic effects to heterogeneous catalysts.

Plant biomass, the most abundant and sustainable carbon source, offers a rich chemical space to design hard carbons for sodium ion batteries.

Low power consumption and minimal potential hazards are ultimate goals for the modern development of chemical manufacturing; however, it often reduces the selectivity of chemical reactions by implementing a new reaction system. A nanocatalyst design is reported for achieving efficient and selective alkyne semihydrogenation through the photocatalytic hydrogen transfer from water, which avoids the use of a heat source and explosive H . The PdPt catalytic sites that are implemented on the TiO photocatalyst hold the key to achieving both high activity and selectivity. As compared with pure Pd or Pt, the alloy cocatalysts can better harness H diffusion/desorption for selective semihydrogenation as well as suppress competitive H evolution. This work opens up new possibilities for green and selective alkyne semihydrogenation and highlights the importance of lattice engineering to catalytic selectivity.

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Understanding the transformation of graphitic carbon nitride (g-C3N4) is essential to assess nanomaterial robustness and environmental risks. Using an integrated experimental and simulation approach, our work has demonstrated that the photoinduced hole (h+) on g-C3N4 nanosheets significantly enhances nanomaterial decomposition under •OH attack. Two g-C3N4 nanosheet samples D and M2 were synthesized, among which M2 had more pores, defects, and edges, and they were subjected to treatments with •OH alone and both •OH and h+. Both D and M2 were oxidized and released nitrate and soluble organic fragments, and M2 was more susceptible to oxidation. Particularly, h+ increased the nitrate release rate by 3.37–6.33 times even though the steady-state concentration of •OH was similar. Molecular simulations highlighted that •OH only attacked a limited number of edge-site heptazines on g-C3N4 nanosheets and resulted in peripheral etching and slow degradation, whereas h+ decreased the activation energy barrier of C–N bond breaking between heptazines, shifted the degradation pathway to bulk fragmentation, and thus led to much faster degradation. This discovery not only sheds light on the unique environmental transformation of emerging photoreactive nanomaterials but also provides guidelines for designing robust nanomaterials for engineering applications.

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Online health communities (OHCs) have enjoyed increasing popularity in recent years, especially in the context of the COVID-19 pandemic. However, several concerns have been raised regarding the privacy of users’ personal information in OHCs. Considering that OHCs are a type of data-sharing or data-driven platform, it is crucial to determine whether users’ health information privacy concerns influence their behaviors in OHCs. Thus, by conducting a survey, this study explores the impact of users’ health information privacy concerns on their engagement and payment behavior (Paid) in OHCs. The empirical results show that users’ concerns about health information privacy reduce their Paid in OHCs by negatively influencing their OHC engagement. Further analysis reveals that if users have higher benefit appraisals (i.e., perceived informational and emotional support from OHCs) and lower threat appraisals (i.e., perceived severity and vulnerability of information disclosure from OHCs), the negative effect of health information privacy concerns on users’ OHC engagement will decrease.