Photocatalytic activation of peroxymonosulfate by carbon quantum dots functionalized carbon nitride for efficient degradation of bisphenol A under visible-light irradiation

Advanced oxidation process (AOP) through the photocatalytic activation of peroxymonosulfate (PMS) has attracted much attention in wastewater treatment. Herein, a metal-free carbon quantum dots (CQDs) functioned polymer carbon nitride (PCN) was synthesized and used as an efficient photocatalyst for PMS activation toward bisphenol A (BPA) degradation under visible-light irradiation. The incorporation of CQDs in PCN endowed it with enlarged surface area, enhanced light absorption and improved charge separation, which were advantageous to photocatalytic activation of PMS. As a result, the CQDs functionalized carbon nitride exhibited an enhanced performance in photocatalytic activation of PMS toward BPA removal. The influencing factors such as catalyst dosage, PMS concentration, pH value, and anion additive on the photocatalytic performance were well examined. The catalyst exhibited a good cyclic stability. Furthermore, the reactive species and intermediates involved in BPA degradation were also investigated to elucidate the possible mineralization pathway of BPA. This work provides a facile synthetic strategy to prepare metal-free catalyst for photocatalytic activation of PMS in wastewater treatment.