Effective removal of tetracycline from water by catalytic peroxymonosulfate oxidation over Co@MoS₂: Catalytic performance and degradation mechanism

Co-based heterogeneous catalysts exhibit relatively high performance on peroxymonosulfate (PMS) activation for antibiotic pollution control in water. But the aggregation and loss of active components limit their expanded application. In this study, a 3D rose-like MoS₂ was designed and synthesized to anchor Co in its special lamellar structure and achieve its high dispersion. 98.9% of tetracycline (TC) was removed within 60 min with a mineralization rate of 50.5% under neutral condition. The accelerated valence cycle between Co²⁺ and Co³⁺ was the key to PMS activation and TC degradation. And the lamellar structure of MoS₂ endowed the catalyst with better stability and inhibited Co leaching. The influences of common anions (Cl⁻, HCO₃⁻, H₂PO₄⁻, and SO₄²⁻) and humic acid in aqueous solution on TC degradation were systematically investigated. The catalytic mechanism of PMS activation and the generation of reactive oxygen species (ROS) over Co@MoS₂ were deeply investigated. The reduced biotoxicity of the intermediates indicated the potential of Co@MoS₂/PMS system for the control of environmental risks caused by TC. This work provided a new insight for the design of metal-doped heterogeneous catalyst with high stability and a new direction for the remediation of antibiotic contamination in water.