High-efficiency ultrathin porous phosphorus-doped graphitic carbon nitride nanosheet photocatalyst for energy production and environmental remediation

Abstract

Herein, we designed and constructed an ultrathin porous phosphorus-doped g-C3N4 nanosheet (PCN) bifunctional photocatalytic system for efficient production of H2O2 and degradation of non-steroidal anti-inflammatory drugs in aqueous environment. The phosphorus atoms introduced in g-C3N4 significantly improved the utilization of light, enhanced the adsorption capacity for O2, and inhibited the recombination of photogenerated carriers, thereby boosting the photocatalytic performance. Consequently, the optimized PCN photocatalyst produced 285.34 μM of H2O2 under blue LED light irradiation, which was 3.41 times that of pristine g-C3N4, and its degradation rate constant for diclofenac (0.1248 min−1) was 46.22 times that of the g-C3N4. Density functional theory (DFT) calculations suggested that phosphorus doping modulated the local electronic structure of g-C3N4, which improved the electron-hole separation and promoted the O2 reduction reaction. This work comprehensively reveals the mechanisms of phosphorus doping on g-C3N4, while offering a promising strategy for addressing current energy demands and environmental remediation concerns.