Cd3(C3N3S3)2 Polymer/Sn Schottky Heterojunction for Broadband-Solar Highly Selective Photocatalytic CO2 Reduction

Solar-driven carbon dioxide reduction is a promising strategy to manage the global carbon balance. Here, we built the Sn/Cd-3(C3N3S3)(2) (CdTMT) composite to achieve nearly 99% selectivity in the conversion of CO2 to CO. The Gibbs free energy reveals the lower activation energy barrier of CdTMT and Sn to the formation of the *OCHO intermediate. The metal Sn on the surface of CdTMT to form the Schottky heterojunction significantly improves the separation efficiency of photogenerated carriers, and the surface plasmon resonance of Sn can expand and enhance the visible light response range and absorption intensity, boosting the photocatalytic activity for CO2 reduction, which was about 3.7 times that of the pure CdTMT. Therefore, this study can provide new insights into the design and construction of metal-organic semiconductors to realize high-selectivity heterojunctions in CO2 photoreduction conversion.

Automated summary

In this study, a Sn/Cd-3(C3N3S3)(2) (CdTMT) composite was developed to achieve nearly 99% selectivity in the conversion of CO2 to CO. The presence of metal Sn on the surface of CdTMT forming a Schottky heterojunction significantly enhanced the separation efficiency of photogenerated carriers and boosted the photocatalytic activity for CO2 reduction by about 3.7 times compared to pure CdTMT.