Progress in photocatalytic CO reduction based on single-atom catalysts.

Reduced CO emissions, conversion, and reuse are critical steps toward carbon peaking and carbon neutrality. Converting CO into high-value carbon-containing compounds or fuels may effectively address the energy shortage and environmental issues, which is consistent with the notion of sustainable development. Photocatalytic CO reduction processes have become one of the research focuses, where single-atom catalysts have demonstrated significant benefits owing to their excellent percentage of atom utilization. However, among the crucial challenges confronting contemporary research is the production of efficient, low-cost, and durable photocatalysts. In this paper, we offer a comprehensive overview of the study growth on single-atom catalysts for photocatalytic CO reduction reactions, describe several techniques for preparing single-atom catalysts, and discuss the advantages and disadvantages of single-atom catalysts and present the study findings of three single-atom photocatalysts with TiO, g-CN and MOFs materials as carriers based on the interaction between single atoms and carriers, and finally provide an outlook on the innovation of photocatalytic CO reduction reactions.