Construction of NiWO4/Mn0.3Cd0.7S S-Scheme Heterojunction for Superior Visible Light Photodegradation of Tetracycline

The misuse of tetracycline (TC) poses a significant threat to the natural environment, necessitating the development of efficient methods for its degradation. Heterojunction photocatalysts have emerged as a promising approach for the degradation of such pollutants. This work aims to construct a novel NiWO 4 /Mn 0.3 Cd 0.7 S (NWO/MCS) S-scheme heterojunction using solvothermal coupled with mechanical mixing methods for efficient photocatalytic degradation of TC. The optimized NWO/MCS composite exhibited an 82% removal rate within 40 minutes under visible light irradiation, which represents an 18.4-fold and 1.13-fold improvement compared with pristine NWO and MCS, respectively. Various analytical methods and DFT calculations were utilized to characterize the structure and photophysical properties as well as prove the electron flow of the heterojunction, respectively. This work provides evidence of efficient charge carrier transfer between NWO and MCS within the S-scheme heterojunction, which contributes to the enhanced photocatalytic activity. The rational structural configuration of the S-scheme heterojunction has been shown to improve both the reduction and oxidation capabilities, offering a potential pathway for developing photocatalysts with high antibiotic removal efficiency.