Rational-Designed Principles for Electrochemical and Photoelectrochemical Upgrading of CO 2 to Value-Added Chemicals.

The chemical transformation of carbon dioxide (CO 2 ) has been considered as a promising strategy to utilize and further upgrade it to value-added chemicals, aiming at alleviating global warming. In this regard, sustainable driving forces (i.e., electricity and sunlight) have been introduced to convert CO 2 into various chemical feedstocks. Electrocatalytic CO 2 reduction reaction (CO 2 RR) can generate carbonaceous molecules (e.g., formate, CO, hydrocarbons, and alcohols) via multiple-electron transfer. With the assistance of extra light energy, photoelectrocatalysis effectively improve the kinetics of CO 2 conversion, which not only decreases the overpotentials for CO 2 RR but also enhances the lifespan of photo-induced carriers for the consecutive catalytic process. Recently, rational-designed catalysts and advanced characterization techniques have emerged in these fields, which make CO 2 -to-chemicals conversion in a clean and highly-efficient manner. Herein, this review timely and thoroughly discusses the recent advancements in the practical conversion of CO 2 through electro- and photoelectrocatalytic technologies in the past 5 years. Furthermore, the recent studies of operando analysis and theoretical calculations are highlighted to gain systematic insights into CO 2 RR. Finally, the challenges and perspectives in the fields of CO 2 (photo)electrocatalysis are outlined for their further development.