Anti-perovskite Co₄N nanowhisker rooted on nickel foam to activate peroxymonosulfate for robust degradation of p-nitrophenol via non-radical dominant pathway

The fabrication of metal-nitrogen functional centers that possess features of easy recovery and high performance for degrading organic pollutants through activating peroxymonosulfate (PMS) represents a significant challenge. In this study, we present the synthesis of an anti-perovskite Co4N architecture in a granular nanowhisker form rooted on three-dimensional nickel foam (Co4N/NF) using a hydrothermal method followed by thermal nitridation with ammonia from urea pyrolysis. The resulting Co4N/NF exhibits exceptional efficiency in degrading pnitrophenol (PNP), achieving a degradation efficiency of 97.8 % and a rate constant of 0.204 min(-1) within 20 min. The unique nanostructure of granular nanowhisker Co4N on NF provides abundant surface sites for activating PMS and enhances mass/electron transport, contributing to its excellent degradation capabilities. Additionally, the Co4N/NF material exhibits outstanding stability, easy separation and recovery features, maintaining a degradation efficiency of 90.2 % within 20 min even after five cycles. This study lays the groundwork for developing advanced anti-perovskite nitrides on a 3D substrate to activate PMS for environmental contaminant remediation.