A novel Au/g-C3N4 nanosheets/CeO2 hollow nanospheres plasmonic heterojunction photocatalysts for the photocatalytic reduction of hexavalent chromium and oxidation of oxytetracycline hydrochloride

• A novel Z-scheme Au/g-C 3 N 4 /CeO 2 plasmonic photocatalyst was achieved successfully. • Au/g-C 3 N 4 /CeO 2 shows superior photocatalytic activity for the removal of OTH and Cr 6+ . • The degradation pathway of OTH is proposed based on degradation products confirmed by GC–MS. • Z-scheme photocatalysis mechanism is proposed based on the experiments and simulations. Au/g-C 3 N 4 /CeO 2 plasmonic heterojunction has been successfully fabricated, which was constructed by forming the three-dimensional hollow CeO 2 mesoporous nanospheres on the two-dimensional Au/g-C 3 N 4 nanosheets. The photocatalysts not only exhibited excellent catalytic reduction activity against Cr 6+ , but also oxidized oxytetracycline hydrochloride (OTH), and OTH catalytic degradation route was suggested by the degradation products determined by GC–MS. The improvement of photocatalytic performance comes from the high absorption capability of visible light and effective interface charge separation. Finally, it speculated that the Au/g-C 3 N 4 /CeO 2 heterostructures followed Z-scheme charge transfer mechanism in this study, which is verified by the analysis of experiment and theoretical calculation results.