Rational design and mechanistic insights of advanced photocatalysts for CO2-to-C2+ production: Status and challenges

Photocatalytic CO2 conversion into high-value chemicals is becoming an increasingly promising avenue of research in the quest for sustainable carbon resource utilization. Particularly, compounds with two or more carbons (C2+) have higher added value than methane, carbon monoxide, or formate, which are typically the major products of CO2 reduction. In this review, we present a detailed account of recent advancements in the field of photocatalytic CO2 conversion, with a specific focus on the synthesis of multi-carbon oxygenates. We systematically introduce the rational design of photocatalysts with high effectivity and selectivity, which follows a methodical inside-to-outside order. These strategies consider various aspects of photocatalyst optimization, from the core structure to the surface properties. Meanwhile, we delve into an in-depth analysis of the underlying catalytic mechanisms, particularly emphasizing the C-C coupling and multi-electron-coupled proton transfer processes. Lastly, we examine the prospects and challenges in developing photocatalysts for CO2 conversion, providing valuable insights for researchers and practitioners. This review aims to serve as a valuable resource for those seeking to design advanced catalysts for efficient photocatalytic CO2 reduction.