Enhanced photocatalytic performance of phosphorus and molybdenum co-doped carbon nitride for removal of organic pollutants

Elemental doping is a widely adopted strategy for optimizing the electronic structure of carbon nitride and improving its photocatalytic performance. However, single-element doping offers limited enhancement. In this study, phosphorus and molybdenum co-doped carbon nitride (P-Mo-C₃N₄) was synthesized by wet ball-milling, a simple and scalable method. The co-doping of P and Mo synergistically modulates the band structure of g-C₃N₄, significantly enhancing its redox capability, while their compatibility effectively reduces interfacial resistance. In Rhodamine B (RhB) degradation tests, P-Mo-C₃N₄ achieved a first-order rate constant (k) of 0.1065 min^–1, surpassing those with g-C₃N₄, P-C₃N₄, and Mo-C₃N₄ by factors of 10.2, 6.5, and 8.6, respectively. Furthermore, P-Mo-C₃N₄ exhibited excellent degradation performances towards tetracycline hydrochloride (TC) and methylene blue (MB). After five cycles, the catalyst retained 90 % efficiency, demonstrating excellent stability. This work provides a cost-effective and eco-friendly approach for developing advanced C₃N₄-based photocatalysts.