Revealing the Effect of Electronic Configuration in Cu ^x Species on CO ₂ Photoreduction Characteristic Products

As of the present time, the in-depth study of the structure-activity relationship between electronic configuration and CO₂ photoreduction performance is often overlooked. Herein, a series of Cu^x species modified CeO₂ nanodots are constructed in situ by flame spray pyrolysis (FSP) to achieve an efficient photocatalytic CO₂-to-C₂ conversion with an electron utilization of up to 142.5 µmol g^-1. Through an in-depth study of the electronic behavior and catalytic pathways, it is found that the Cu⁰/Cu⁺ species in the coexistence state of Cu⁰/Cu⁺/Cu²⁺ can optimize the energy band structure, photocurrent stability, and provide a kinetic basis for the active surface catalytic reaction process that requires the conversion of multiple electrons into C₂ products, which ultimately enhances the CO₂-to-C₂H₆ photoreduction by 3.8-fold and that for CO₂-to-C₂H₄ photoreduction by 5.2-fold. Besides, the Cu²⁺ species in the coexistence state of Cu⁰/Cu⁺/Cu²⁺ are able to regulate the electronic behavior and the choice of the catalytic pathway, enabling the transitions between CO₂-to-C₂H₆ and CO₂-to-C₂H₄. This work indicates that electronic configuration optimization is an effective strategy to significantly enhance the CO₂ photoreduction performance and provides new ideas for the design and synthesis of high-performance heterostructure photocatalysts.