Polymeric carbon nitride loaded with atomic Cu sites for improved CO2 photocatalytic conversion performance

CO2 photocatalytic conversion has been considered as a promising strategy to reduce CO2 level and produce chemical feedstocks. However, developing highly efficient photocatalysts still remains a challenge. Here, copper (Cu) single atom sites (SAs) have been loaded into polymeric carbon nitride (CN) framework through one-step thermal polymerization method. The Cu sites loaded in CN framework can not only enhance the visible light absorption, but also accelerate the mobility of charge carriers. The range of light absorption can be extended to a longer wavelength, and the recombination of photogenerated electron and hole pairs can be considerably suppressed. Furthermore, the valence band of obtained photocatalysts shift more negative with Cu loading, resulting in stronger reduction potential for CO2 photocatalytic conversion. As a result, the CO2 photocatalytic activity can be considerably enhanced a lot. By regulating the content of Cu, the CO production amount (1.62 μmol/g.h) can be enhanced 2.7 times higher than that of bulk CN (0.6 μmol/g.h). This work proposes a facile and eco-friendly way to modify CN photocatalyst, which is inspiring to design high efficiency photocatalysts.