Construction of hierarchical S-scheme MgIn2S4/CeO2 heterojunction for boosted photocatalytic oxidation of tetracycline and reduction of Cr(VI)

This study explores the photocatalytic performance of a hierarchical MgIn 2 S 4 /CeO 2 S-scheme heterojunction, emphasizing its structural, morphological, and electronic features. The heterojunction was synthesized in situ by integrating a porous MgIn 2 S 4 framework with CeO 2 nanorods. Comprehensive characterization techniques such as XRD, XPS, FE-SEM, TEM, and BET confirm the heterojunction's formation and reveal its enhanced surface area, hierarchical porosity, and interfacial electronic interactions. Furthermore, the optical and photoelectrochemical properties were investigated through UV-Vis DRS, photoluminescence spectroscopy, photocurrent response, and EIS, thus demonstrating enhanced visible light absorption, reduced charge recombination, and efficient charge transfer. The photocatalytic tests show that MgIn 2 S 4 /CeO 2 has a degradation efficiency of 86% for the photooxidation of tetracycline and 96% for the photoreduction of Cr(VI) after 120 min. The enhanced properties can be attributed to the S-scheme heterostructure, which facilitates better charge transfer and separation and preserves the high redox potential photogenerated carriers for photocatalytic reactions. This work provided a systematic approach to designing advanced photocatalysts with promising applications in environmental remediation, and the findings contribute to the development of sustainable technologies for wastewater treatment.