Polydopamine-Modified Monolithic Cobalt-Based Catalyst for Activating Peroxymonosulfate: An Efficient Strategy for Tetracycline Degradation

Antibiotics play a crucial role in modern medicine, yet their improper use has resulted in significant contamination of global groundwater. Advanced oxidation processes (AOPs), especially sulfate radical-based AOPs (SR-AOPs), offer a promising solution by generating strong oxidizing species to degrade persistent organic pollutants. In this study, we developed a novel monolithic cobalt-based catalyst, MF@PDA/Co(OH)₂, fabricated by immobilizing Co(OH)₂ on polydopamine (PDA)-functionalized melamine foam (MF) through a facile impregnation approach. The PDA modification not only ensures strong Co(OH)₂ adhesion but also minimizes cobalt leaching. Comprehensive characterization confirmed the catalyst's structural integrity, while systematic evaluations demonstrated exceptional stability and reusability in peroxymonosulfate (PMS) activation. Mechanistic investigations revealed a synergistic degradation mechanism involving both radical (•SO₄⁻ and •OH) and non-radical (¹O₂ and electron transfer) pathways for tetracycline removal. This study presents a scalable strategy for developing efficient, cobalt-conserving, and durable catalytic materials, advancing practical SR-AOP applications for antibiotic-contaminated wastewater remediation.