Tailored poly-heptazine units in carbon nitride for activating peroxymonosulfate to degrade organic contaminants with visible light

The photocatalytic peroxymonosulfate (PMS) activation process offers great potential for organic wastewater treatment . In this study, enol-incorporated carbon nitride (ECN) catalysts were used for PMS activation to degrade organic pollutants under visible-light irradiation. Our experimental and theoretical results revealed that the incorporation of enol into the poly-heptazine-based carbon nitride framework effectively tuned the electronic structure. The obtained ECN showed promoted PMS activation capability, along with increased visible-light harvesting ability and improved photogenerated charge separation. As a result, an excellent performance with a bisphenol A removal rate of 100% within 20 min and a total organic carbon (TOC) removal rate of 86% in 30 min was achieved in the Vis-PMS/ECN process. This was because ECN functioned as an efficient photocatalyst as well as PMS activator, which enabled the PMS activation process to proceed smoothly for •SO 4 − production under visible-light irradiation. These findings could offer some guidelines for the development of efficient metal-free photocatalysts in the persulfate-based advanced oxidation process for environmental remediation.