Dual modulation on peroxymonosulfate activation site and photocarrier separation in carbon nitride for efficient photocatalytic organics degradation: Efficacy and mechanism evaluation

Abstract

Herein, sulfur and sodium co-doped cyano-rich polymeric carbon nitride (NaCNS) have been designed to boost photocatalytic atrazine (ATZ) degradation with peroxymonosulfate (PMS) assistance. The NaCNS was fabricated via a two-step thermal condensation with the existence of sodium chloride and cysteine, and the ATZ degradation in the system was evaluated via batch experiments. Compared to pristine carbon nitride, the reaction rate constant of NaCNS was dramatically enhanced nearly sixfold (47.66 ×10−3·min−1). Given the experiments and theoretical calculation, the ATZ degradation in the system was mainly dominated by the electrophilic attack of O21, leading to the production of 11 intermediates with reduced ecotoxicity. The promoted photocatalytic performance was originating from the dual modulation of NaCNS, where the sodium act as a PMS activation site while the cyano and sulfur construct an electronic push-pull system for better photocarrier separation. Hopefully, this study can inspire the rational design of catalysts for efficient photocatalytic PMS activation.