Construction of built-in electric field within ZIF-67/BCN heterojunction for high selectivity photocatalytic CO2 conversion

The CO 2 photoreduction and hydrogen evolution reaction (HER) share similar reduciton potentials, making HER a significant competing process in CO 2 photoreduction that severely impacts CO 2 conversion yield. Improving the selectivity of the photocatalytic CO 2 reduction reaction has thus emerged as a crucial research focus aimed at boosting photocatalytic efficiency. Given that, an in-situ growth strategy was proposed to synthesize rod-like ZIF-67/BCN-2 heterojunctions , which demonstrated a CO selectivity of 90.48 %. In addition, the experimental results showed that the photocatalytic conversion efficiency of CO 2 to CO reached 4728.47 μmol h −1 g −1 , maintaining excellent stability over six cycles. We proposed that a robust interfacial electric field was established through the strong binding between ZIF-67 and BCN . This interface electric field facilitated the transfer of photogenerated electrons from ZIF-67 to BCN , enhancing charge-hole separation and significantly improving photocatalytic performance. Theoretical calculations revealed that the formation energy of *COOH intermediate on ZIF-67/BCN is lower than that on BCN and ZIF-67, suggesting that ZIF-67/BCN is more favorable for the reduction of CO 2 to CO. These findings provide valuable insights for the design and synthesis of non-precious metal photocatalysts with high selectivity and activity.