Nonradical-dominated peroxymonosulfate activation by perylenetetracarboxylic acid nanosheet photocatalyst for efficient degradation of bisphenol a under visible-light irradiation

Abstract

As a green, highly efficient, and sustainable technology, photocatalytic peroxymonosulfate (PMS) activation is a promising strategy for wastewater treatment. Moreover, the development of photocatalysts with excellent PMS activation performance is highly desirable for removing refractory organic contaminants from wastewater. Herein, perylenetetracarboxylic acid (PTA) nanosheets obtained using a facile method were explored as a highly efficient photocatalyst with a high PMS activation ability for bisphenol A (BPA) removal. Experimental results indicated that BPA can be removed within 16 min using PTA under optimal conditions. As confirmed through radical quenching, electron paramagnetic resonance spectroscopy, galvanic-oxidation-process experiments, and density functional theory calculations, photoinduced electrons and holes from PTA trigger PMS activation and thereby convert the reaction routes of BPA degradation from radical- to nonradical-dominated. The BPA degradation pathway was also studied using intermediate analysis and Fukui functions. Overall, the findings of this study shed light on organic semiconductor photocatalysts for nonradical-dominated PMS activation with regard to recalcitrant-organic-pollutant removal.