Synergistic Catalysis over MoS2/CuS in Ultrasound-Assisted Peroxymonosulfate System: Performance and Mechanism for Degradation of Multiple Organic Contaminants

Aquatic antibiotic pollution represented by ofloxacin (OFX) causes serious ecological hazards and endangers public health due to the high persistence and bioaccumulation of antibiotic residues. Conventional water treatment techniques are insufficient for OFX elimination, limited by low removal efficiency, high energy consumption, and poor operational stability. Herein, a novel MoS2/CuS heterojunction composite was fabricated via a hydrothermal method and applied to an ultrasound-driven piezocatalysis-coupled peroxymonosulfate (PMS) advanced oxidation system for OFX wastewater remediation. The introduction of CuS effectively remedies the inherent shortcomings of pristine MoS2, including insufficient active sites and rapid photogenerated carrier recombination. The constructed heterojunction induces a strong interfacial built-in electric field, which significantly accelerates the migration of piezoelectric charges. The synergistic photo-piezoelectric effect further promotes continuous PMS activation and facilitates the massive generation of reactive oxygen species (ROS). The influences of key operating parameters and common water inorganic anions on OFX degradation performance were systematically investigated. Radical trapping experiments confirmed the synergistic mechanism between piezocatalysis and PMS activation during the catalytic reaction. The optimized MoS2/CuS heterojunction exhibits remarkable OFX degradation efficiency and excellent cyclic stability. This work provides a feasible strategy for the rational design and fabrication of high-efficiency piezocatalysts and offers a promising technical route for the remediation of refractory antibiotic wastewater via piezocatalysis-coupled PMS advanced oxidation.