A novel synthetic carbon and oxygen doped stalactite-like g-C3N4 for broad-spectrum-driven indometacin degradation

Achieving efficient solar utilization is a primary goal in the field of photocatalytic degradation of PPCPs. For this study, a broad-spectrum carbon and oxygen doped, porous g-C3N4 (COCN) was synthesized via a simple co-pyrolysis of dicyandiamide and methylamine hydroiodide (CH5N·HI). The 0.3COCN demonstrated an excellent photocatalytic degradation of indometacin (IDM), which was 5.9 times higher than bulk g-C3N4. The enhanced photocatalytic activity could be ascribed to the broad-spectrum utilization of solar light and improved charge separation efficiency. Reactive species (RSs) scavenging experiments have shown that O2·- and 1O2 were the dominant active species. Further, the 0.3COCN exhibits excellent yield of hydroxyl radicals which was confirmed by electron spin resonance (ESR) spectra. Meanwhile, the degradation pathways of IDM were proposed according the HRAM LC-MS/MS and total organic carbon (TOC). This research provided a new strategy for a broad-spectrum photocatalyst, and a promising strategy for environmental remediation.