Abstract
Introducing an external light field can increase the intrinsic activity and energy efficiency for electrochemical CO2 reduction. Herein, a synergistic strategy that introduces photosensitive components and visible light into a stable system is reported to improve the performance for CO2 reduction. The catalytic kinetics studies indicate that the synergistic effect of implantation of cationic Ti and additional light driving is the primary responsibility for accelerating the first electron transfer to form a *COO- intermediate. This leads to a satisfactory CO2-to-CO conversion for Zr/Ti-NB-Co in terms of high selectivity (Faradaic efficiency of 93.6% at -0.7 V), remarkable catalytic activity (production rate up to 546 mmol g(-1) h(-1) at -1.1 V), excellent long-term stability (without performance decay over 11 h), and large turnover frequency of 1028 h(-1) at -1.1 V under visible light. These results imply that the photodriven Ti-based porphyrin catalyst not only can deliver more electrons, but also can act as a photoswitch to adjust the electron transfer pathway.