Boosting total oxidation of methane over NiO nanocrystalline decorated ZnO-CoNi solid solution via photothermal synergism

Abstract

In the context of global warming and atmospheric methane growth, photo-assisted total oxidation of methane is of great importance to diminish greenhouse effect. However, catalytic oxidation of methane at ambient conditions remains a formidable challenge because of its high structure stability. Herein, we report a highly active and stable NiO nanocrystalline decorated on ZnO-CoNi solid solution (NiO/ZnO-CoNi) catalyst which enables 88 % photocatalytic conversion of methane to CO2 and H2O under ambient conditions to maintain a continuous reaction. The unprecedented photocatalytic performance of NiO/ZnO-CoNi originates from the high mobility of surface lattice oxygen of supported NiO nanocrystallines driven by the photogenerated electrons and internal electric field of ZnO-CoNi solid solution. More importantly, the methane conversion of NiO/ZnO-CoNi remains higher than 37 % even when the methane concentration is up to 5000 ppm, showing promise for methane elimination applications in the vicinity of large methane emission sources.