Artificial CO2 photoreduction: a review of photocatalyst design and product selectivity regulation

Mimicking natural photosynthesis, artificial photosynthesis for the reduction of CO2 into valuable hydrocarbon fuels is a promising approach for solar energy utilization and carbon neutrality. However, great challenges are present in the development of efficient photocatalysts for CO2 reduction and controlling the selectivity for reduction products. This review summarizes the progress in photocatalyst design strategies to improve the efficiency and selectivity of photocatalytic CO2 reduction. Six popular modification methods are introduced, namely, creation of defect structures, cocatalyst loading, doping, heterojunction formation, single-atom engineering, and surface organometallic catalysis. The effects of these different strategies on the promotion of light absorption, charge separation and migration and catalyst surface reactions in the process of CO2 reduction are analyzed. In addition, the latest research results on selective reduction to C1, C2, and C2+ products in CO2 and H2O systems are summarized. Finally, the article delves into the future prospects and inherent hurdles in photocatalyst design, focusing on enhancing the selectivity of CO2 conversion towards specific products. This review provides insights into the efficiency and selectivity of photocatalytic CO2 reduction across various photocatalysts, thereby serving as valuable guidance for the advancement of high-performance photocatalysts.