Assembling CeO2 nanoparticles on ZIF-8 via the hydrothermal method to promote the CO2 photoreduction performance

Photocatalytic reduction of CO2 to valuable carbon fuel is a prospective technique to decrease CO2 emissions and simultaneously generate efficient chemical energy. In this paper, a novel high-efficiency photocatalyst ZIF-8@CeO2 heterogeneous composite (ZIF = zeolitic imidazolate framework) was prepared by the hydrothermal method, where CeO2 nanospheres were uniformly grown on the surface of ZIF-8. Compared to pristine ZIF-8 or CeO2 nanoparticles (NPs), the ZIF-8@CeO2 composite shows significantly better efficiency in the reduction of CO2 into CO and CH4 under light irradiation, that is the CO evolution rate can reach 465.01 μmol g-1 h-1 and the CH4 evolution rate can reach 181.27 μmol g-1 h-1. Analyses indicated that the addition of CeO2 in the composites will expand the photoresponse region; the formation of the ZIF-8/CeO2 heterojunction significantly promoted the separation of photogenerated electron-hole pairs within the composite. This work provided an effective method to further improve the catalytic activity of ZIF-based materials, which paved a new way for eco-friendly conversion of carbon dioxide into clean fuels and they could also have huge potential for application in energy and environmental science.