Fabrication of Z-Scheme Heterojunction by Anchoring Mesoporous γ-Fe₂O₃ Nanospheres on g-C₃N₄ for Degrading Tetracycline Hydrochloride in Water

Abstract

A photocatalyst with Z-scheme heterostructure is synthesized through anchoring mesoporous γ-Fe2O3 nanospheres on a g-C3N4 nanosheet surface. The fabricated Z-scheme γ-Fe2O3/g-C3N4 heterojunction exhibits a mesoporous feature and possesses improved specific surface area, which can provide a mass of reaction active sites for pollutant molecules to improve photocatalytic activity. More importantly, the Z-scheme heterostructure constructed between γ-Fe2O3 and g-C3N4 efficiently extends the response range at the visible region and speeds up the transfer and separation of photoinduced charge carriers, which is beneficial to boosting photocatalytic activity. Compared to the original g-C3N4 sample, the Z-scheme γ-Fe2O3/g-C3N4 heterojunction exhibits remarkably improved photocatalytic degradation activity for mineralizing tetracycline hydrochloride (TC-HCl) under the visible-light irradiation. Moreover, the photocatalytic degradation mechanism of TC-HCl is put forward and investigated in depth, the results of which identify that •OH, •O2–, and photogenerated h+ all play a vital function and have the order •OH > •O2– > h+ during the TC-HCl degradation reaction.