Multi-heteroatom-doping promotes molecular oxygen activation on polymeric carbon nitride for simultaneous generation of H2O2 and degradation of oxcarbazepine

Simultaneously realizing the efficient generation of H2O2 and degradation of pollutants is of great significance for environmental remediation. However, most polymeric semiconductors only show moderate performance in molecular oxygen (O2) activation due to the sluggish electron-hole pair dissociation and charge transfer dynamics. Herein, we develop a simple thermal shrinkage strategy to construct multi-heteroatom-doped polymeric carbon nitride (K, P, O-CNx). The resultant K, P, O-CNx not only improves the separation efficiency of charge carriers, but also improves the adsorption/activation capacity of O2. K, P, O-CNx significantly increases the production of H2O2 and the degradation activity of oxcarbazepine (OXC) under visible light. K, P, O-CN5 shows a high H2O2 production rate (1858 μM h-1 g-1) in water under visible light, far surpassing that of pure PCN. The apparent rate constant for OXC degradation by K, P, O-CN5 increases to 0.0491 min-1, which is 8.47 times that of PCN. Density functional theory (DFT) calculations show that the adsorption energy of O2 near phosphorus atoms in K, P, O-CNx is the highest. This work provides a new idea for the efficient degradation of pollutants and generation of H2O2 at the same time.