Synergistic regulation of g-C3N4 band structure by phosphorus and sodium doping to enhance photocatalytic hydrogen peroxide production efficiency

In addressing the industrial need for a simple, equipment-minimal, and non-toxic method of in-situ hydrogen peroxide (H₂O₂) production, this paper presents a cost-effective, environmentally friendly photocatalyst. Our design strategy focuses on the dual-element doping of phosphorus and sodium into graphitic carbon nitride (g-C₃N₄), chosen to synergistically enhance photocatalytic performance. This approach yields a notable H₂O₂ production concentration of 3001.64 μmol·g⁻¹·L^-1 within 100 min, using isopropanol as a sacrificial agent, which was 61-fold increase compared to bulk g-C₃N₄. Density Functional Theory (DFT) calculations were performed to elucidate the alterations in the band structure of the catalyst induced by dual-element doping, which consequentially engendered an asymmetric intrinsic electric field. Additionally, oxygen’s transition state affinity due to phosphorus doping was also investigated to reveal the mechanisms of synergistic catalysis. This development contributes to meeting industrial demands for pollutant degradation via Fenton processes and presents a sustainable alternative to traditional H₂O₂ production methods.