Rich S vacant g-C3N4@CuIn5S8 hollow heterojunction for highly efficient selective photocatalytic CO2 reduction

Photocatalysts with rich S vacant g-C3N4@CuIn5S8 hollow heterojunction are assembled through a facile strategy. The S vacancy is realized by rapid heating method arrived at 450 ℃ in only 5 min. Vacancies could effectively trap surface-arrived charge carriers, which significantly improve charge separation efficiencies. Simultaneously, the electron-donating nature of localized electrons around defects can activate inert absorbed molecules. The specific hollow nanosphere structures can make multiple scattering light inside the cavity, shortening the distance of charge carriers. Therefore, the as-prepared photocatalysts exhibit the outstanding capacity of selective reduction of CO2 with yields of CH4 28.8 μmol g−1 and CO 8.2 μmol g−1, respectively. Furthermore, the photocatalytic CO2 reaction mechanism is adequately investigated through DFT theory and in-situ analysis technology. This synthesis strategy provides a novel way for CO2 reduction and enlightens the development of eco-friendly fuels.