Boosting peroxymonosulfate activation via highly active and durable cobalt catalysts

Abstract

Advanced oxidation processes (AOPs) present one of the most promising strategies to deal with the ever-growing water pollution. However, fabricating improved catalysts with large size (meter level or larger), long-term stability, and adequate activity is still a formidable challenge in practical applications. In this study, cobalt ions are covalently linked on the polypropylene nonwoven fabric (P-PFeCo) via irradiation graft polymerization and used as highly efficient and stable reaction sites to degrade highly toxic and difficult biodegradable organics by activating peroxymonosulfate (PMS). The presence of graft chains not only generates a well-defined monometallic reaction microenvironment, but also promotes electron transfer. The as-prepared catalyst combines these exceptional properties for efficient removal of dyes or antibiotics via activating PMS within 8 min and exhibits remarkable durability over a wide pH range and recyclability after five consecutive runs with trace cobalt leaching. The X-ray absorption fine structure (XAFS) spectroscopy and density functional theory (DFT) calculations reveal that the CoN₄(H₂O)₂ site acts as an active site for activating PMS. A device in a flow mode is also constructed to illustrate the potential applications of P-PFeCo. We consider that the catalytic process along with the large-sized substrate will broaden a new horizon in terms of designing high-performance catalysts for PMS activation in wastewater treatment.