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

A photocatalyst with Z-scheme heterostructure is synthesized through anchoring mesoporous γ-Fe 2 O 3 nanospheres on a g-C 3 N 4 nanosheet surface. The fabricated Z-scheme γ-Fe 2 O 3 /g-C 3 N 4 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-Fe 2 O 3 and g-C 3 N 4 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-C 3 N 4 sample, the Z-scheme γ-Fe 2 O 3 /g-C 3 N 4 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, • O 2 –, and photogenerated h + all play a vital function and have the order • OH > • O 2 – > h + during the TC-HCl degradation reaction.