Advanced metal oxide photocatalysts for CO2 to C1 conversion: From structural engineering to selectivity regulation

Photocatalytic CO 2 reduction reaction (CO 2 RR) has emerged as a promising strategy for converting greenhouse gases into value-added solar fuels and chemicals; however, achieving high activity, selectivity, and long-term stability remains a major challenge. Among the various photocatalytic systems investigated, metal oxide-based photocatalysts have attracted considerable attention owing to their tunable electronic structures, structural robustness, abundant active sites, and favorable charge-transfer characteristics. This review systematically summarizes recent advances in metal oxide photocatalysts for selective CO 2 conversion into C 1 products, with particular emphasis on CO, CH 4 , HCOOH, and CH 3 OH production pathways. The discussion highlights catalyst engineering strategies together with mechanistic insights into CO 2 adsorption, intermediate stabilization, and product selectivity control. In addition, emerging opportunities associated with structure–activity relationships, artificial intelligence-assisted catalyst design, and scalable photocatalytic systems using continuous flow photoreactors are critically discussed. By integrating mechanistic understanding with advanced material design strategies, this review provides a comprehensive perspective for the rational development of highly efficient and selective metal oxide-based photocatalysts for sustainable CO 2 conversion.