Synthesis of VO‐TiO₂/VC‐g‐C₃N₄ Heterojunction for Improving the Photocatalytic Activity by Introducing Defect Sites

Defect engineering is a proven strategy for enhancing the performance of photocatalysts. Herein, we present a new method for preparing heterojunction photocatalytic materials, V O ‐TiO 2 /V C ‐g‐C 3 N 4 , with enhanced activity. The presence of defect sites and a heterojunction structure in the catalyst gives rise to exceptional charge separation efficiency and light absorption capabilities. The synergistic effect of the heterojunction interface and activated defect sites, which act as active sites, significantly enhanced the overall photocatalytic performance of V O ‐TiO 2 /V C ‐g‐C 3 N 4 . The catalyst V O ‐TiO 2 /V C ‐g‐C 3 N 4 exhibits superior photocatalytic activity in the NO degradation reaction: displaying 3.5‐ and 2.2 times higher degradation efficiency than V O ‐TiO 2 and V C ‐g‐C 3 N 4 , respectively. Moreover, the nitrogen fixation performance of V O ‐TiO 2 /V C ‐g‐C 3 N 4 is 3.8‐ and 3.1 times higher than that of V O ‐TiO 2 and V C ‐g‐C 3 N 4 , respectively. Electron paramagnetic resonance (EPR) spectroscopy capture experiments revealed that 1 O 2 and ⋅ OH are the primary active species in the photocatalytic reaction. The collaboration of carbon vacancy defects, oxygen vacancy defects, and the heterojunction structure created additional active sites for V O ‐TiO 2 /V C ‐g‐C 3 N 4 . The insights gained from this study offer valuable guidance for the efficient design and synthesis of V O ‐TiO 2 /V C ‐g‐C 3 N 4 heterojunction photocatalysts, and lay a solid foundation for further research and development of such systems for large‐scale environmental remediation.