Nitrogen‐Doped Graphene Quantum Dots Enhance the Activity of Bi2O3 Nanosheets for Electrochemical Reduction of CO2 in a Wide Negative Potential Region

Abstract Large numbers of catalysts have been developed for the electrochemical reduction of CO 2 to value‐added liquid fuels. However, it remains a challenge to maintain a high current efficiency in a wide negative potential range for achieving a high production rate of the target products. Herein, we report a 2D/0D composite catalyst composed of bismuth oxide nanosheets and nitrogen‐doped graphene quantum dots (Bi 2 O 3 ‐NGQDs) for highly efficient electrochemical reduction of CO 2 to formate. Bi 2 O 3 ‐NGQDs demonstrates a nearly 100 % formate Faraday efficiency (FE) at a moderate overpotential of 0.7 V with a good stability. Strikingly, Bi 2 O 3 ‐NGQDs exhibit a high activity (average formate FE of 95.6 %) from −0.9 V to −1.2 V vs. RHE. Additionally, DFT calculations reveal that the origin of enhanced activity in this wide negative potential range can be attributed to the increased adsorption energy of CO 2 (ads) and OCHO* intermediate after combination with NGQDs.