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Solar-driven conversion of bicarbonate (HCO3−) to carbonaceous fuels and/or chemicals provides an alternative route for the development of sustainable carbon economies. However, promoting the HCO3− reduction rate and tuning product selectivity remain significant challenges. This study reports the identification of isolated Ni/Cu atomic pairs dispersed on a BiOCl surface (Ni1/Cu1-BOC) as a promising candidate for efficient HCO3− reduction under UV-vis light irradiation. The optimized photocatalyst exhibits a high CO formation rate of 157.1 μmol g−1 h−1 with nearly 100% selectivity, even in the absence of added proton sources, sacrificial agents, or sensitizers. Experimental and theoretical investigations reveal that the atomically dispersed Ni/Cu pairs facilitate the protonation of HCO3− to CO2, which then undergoes a H+-assisted reduction pathway to produce CO, with *COOH as the intermediate. The synergistic effects of the Ni/Cu atomic pairs simultaneously promote the HCO3−-to-CO2 conversion and the subsequent CO2-to-CO reduction, providing valuable insights for the development of efficient diatomic catalysts for photocatalytic HCO3− reduction reactions. [ABSTRACT FROM AUTHOR]

The discovery of improved chemical processes for CO and CO2 hydrogenation to valuable hydrocarbon fuels and alcohols is of paramount importance for the chemical industry. Such technologies have the potential to reduce anthropogenic CO2 emissions by adding value to a waste stream, whilst also reducing our consumption of fossil fuels. Current thermal catalytic technologies available for CO and CO2 hydrogenation are demanding in terms of energy input. Various alternative technologies are now being developed for COx hydrogenation, with solar-driven processes over two-dimensional (2D) and 2D-related composite materials being particularly attractive due to the abundance of solar energy on Earth and also the high selectivity of defect-engineered 2D materials towards specific valuable products under very mild reaction conditions. This review showcases recent advances in the solar-driven COx reduction to hydrocarbons over 2D-based materials. Optimization of 2D catalyst performance demands interdisciplinary research that embraces catalyst electronic structure manipulation and morphology control, surface/interface engineering, reactor engineering and density functional theory modelling studies. Through improved understanding of the structure–performance relationships in 2D-related catalysts which is achievable through the application of modern in situ characterization techniques, practical photo/photothermal/photoelectrochemical technologies for CO and CO2 reduction to high-valuable products such as olefins could be realized in the not-too-distant future. [ABSTRACT FROM AUTHOR]

We present a surfactant-mediated approach to the production of single-crystal Bi3O4Br nanorings via a simple solvothermal method. The ring-like morphology is rare among bismuth oxyhalides, and the reaction pathways are superior to traditional chemical transformations. In detail, Bi3O4Br nanorings are prepared in three stages: (1) the formation of precursors, (2) selective etching and (3) Ostwald ripening. During these steps, the extra usage of templates is avoided and a series of useful intermediates are obtained. Besides, this method can be extended to fabricate other bismuth oxyhalide nanorings. Under visible-light irradiation, all of our samples are photo-activated. The Bi3O4Br nanorings exhibit an efficient oxygen-evolution rate (72.54 μmol h−1) and pollutant degradation rate (4.71 × 10−2 g min−1 m−2), which can be attributed to their unique ring structures and band potentials. Thus, the surfactant-mediated chemical conversion strategy not only paves a new way to enhance the photocatalytic activity of bismuth oxyhalides, but also provides an important large-scale route for designing other nanomaterials with ring-like structures. [ABSTRACT FROM AUTHOR]