Engineering dual photocatalytic sites on an S-scheme MoS2@Co3O4 heterostructure for coupled PMS activation and hydrogen production

Abstract

The wide use of antibiotics poses serious ecological risks due to its environmental persistence and bioaccumulation. Although sulfate radical-based advanced oxidation processes (SR-AOPs) via peroxymonosulfate (PMS) activation exhibit promise for antibiotics elimination, practical applications is limited by excessive oxidant consumption, proton accumulation, and inefficient energy utilization. Herein, we report an S-scheme MoS₂@Co₃O₄ heterojunction that couples Co₃O₄-mediated PMS activation with MoS₂-driven H₂ evolution. The built-in electric field at the MoS₂@Co₃O₄ interface directs photogenerated electrons to MoS₂, enabling proton reduction at H₂ production rate of 2.7 mmol g⁻¹ h⁻¹. Simultaneously, the photocatalysis process accelerates Co³⁺/Co²⁺ cycle in Co₃O₄, enabling sustained PMS activation and radical generation. Under visible-light irradiation the coupled system achieves 97.77% TC degradation within 45 min. By converting reaction-generated protons into H₂, this dual-channel charge-transfer mechanism mitigates effluent acidification and obviates the need for subsequent alkaline dosing. This work provides an energy-compensated process that transforms conventional energy-intensive wastewater treatment into a sustainable system capable of simultaneous pollutant removal and energy recovery, offering new insights into multifunctional environmental catalysts.