Title : Activation of peroxymonosulfate by magnetic nitrogen-doped graphene for the degradation of organic pollutants in water
Developing efficient, low-cost and environmental-friendly catalysts is of great significance for heterogeneous activation of peroxymonosulfate (PMS) degradation of organic pollutants in environmental remediation and protection fields. In this study, the Co@N doped porous graphene shells structure?(Co@NC) with different carbonization temperature (700, 800, 900 ? ) was prepared using a simple pyrolysis process.
Benefited from the rationally structural design of the carbon precursor and post- treatment with surface engineering, the derived Co@N-C can efficiently activate PMS for fast decomposition of organic pollutants with trace cobalt leaching in aqueous solution. 99.5% of TC degradation at 10 min were achieved over Co@N-C with PMS, which was faster than most carbocatalysis. Co@N-C also has an excellent long-term stability and good performance toward the pollutants degradation at a wide pH range of 3.0–9.0. Additionally, the singlet oxygen ( 1O2 ) was identified as the dominant reactive species rather than sulfate radicals in Co@NC /PMS system based on the trapping experiment and EPR analysis. Finally, possible degradation pathways were proposed based on LC-MS analysis of the reaction intermediates. The excellent performance can be attributed to the synergetic effect of N-doped graphene, underlying Co nanoparticles, and the encapsulation structure in which carbon shells protect Co from leaching and aggregation. The embedded Co NPs also afford the carbocatalysts to be magnetic for an easy recycling. This study provided a new insights in catalyst design for PMS-based advanced oxidation for organic pollutants degradation in wastewater.