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.