Refining the d-band center of S-scheme CdIn2S4/MnZnFe2O4 heterostructures by interfacial electric field with boosting photocatalytic performance

The low activity of photocatalysts is mainly due to inefficient charge separation and low production of the active species. To overcome this challenge, we constructed an S-scheme CdIn2S4/MnZnFe2O4 (CIS/MZFO) heterostructure, where the strong interface of the heterostructure leads to an upshift of the d-band center. CIS/MZFO shows higher charge transfer efficiency and oxygen adsorption/activation performance compared to CIS and MZFO separately, thereby increasing the production of ·O2− and h+ active species. As a result, it demonstrats efficient photocatalytic degradation of tetracycline hydrochloride. The optimized CIS/MZFO heterostructure also shows good tolerance to various factors, such as inorganic ions, organic acids, pH and real water environments. The heterostructure also exhibits excellent magnetic recyclability and stability. Additionally, we propose a photocatalytic degradation pathway for tetracycline hydrochloride and evaluate the ecological toxicity that may arise from intermediates. This study provides an effective approach for the design of advanced photocatalysts.