Bentonite-Supported S-Scheme ZnFe2O4-NiO Magnetic Heterojunction Nanocomposites for Efficient Sunlight-Driven Degradation of Xanthates

Abstract

A novel S-scheme ZnFe2O4-bentonite-NiO (ZF-BT-NO) magnetic heterojunction was designed for the efficient photocatalytic degradation of xanthate under solar irradiation. The ZF-BT-NO photocatalyst achieved a high degradation efficiency of 93.57% within 120 min, demonstrating superior activity compared to individual components. Radical trapping experiments revealed that superoxide radicals were the dominant reactive species, confirming the S-scheme charge-transfer pathway as the key mechanism. The catalyst exhibited excellent reusability, and stability, as validated by seed germination assays. Moreover, its effective performance in real water matrices highlights its potential for practical wastewater treatment. This work provides a sustainable and efficient strategy for removing persistent organic pollutants using S-scheme heterojunction photocatalysts.