Two-dimensional photocatalysts for photoreduction of CO2

Abstract

Photocatalytic CO₂ reduction represents a forefront area of research with the potential to convert CO₂ into the higher value-added products. Notably, within the process of photocatalytic CO₂ reduction, the optimization of light absorption efficiency, photogenerated carrier separation and transport, and surface redox reactions remains imperative. Two-dimensional (2D) semiconductors demonstrate significant potential in advancing photocatalytic CO₂ reduction. The bandgap of 2D materials can be modulated by altering the layers and element ratios during preparation, thereby allowing for adjustable light absorption efficiency. Additionally, the ultra-thin nature of these materials reduces the diffusion path of photogenerated electron-hole pairs from the interior to the surface, thereby expediting the charge transfer process. Furthermore, the 2D structure offers a higher specific surface area and abundance of unsaturated coordination atoms on the surface, thus providing more active sites. In this review, we firstly introduce the photocatalysis process in 2D semiconductors, and the advantages of 2D materials are detailed stated. Subsequently, the synthesis strategies are well elaborated. Finally, the mechanisms and promoting strategies of various typical 2D photocatalysts are reviewed. With a prospective outlook, combined with machine learning, high-quality resource integration strategies may significantly advance the development of 2D semiconductors in photocatalytic CO₂ reduction.