Synergy of nitrogen vacancies and Fe2P cocatalyst on graphitic carbon nitride for boosting photocatalytic CO2 conversion

• Highly efficient Fe 2 P/NVsCN hybrid photocatalyst for photocatalytic CO 2 RR is prepared. • The CO evolution rate of the optimal sample achieves to 22.48 µmol g -1 h −1 with 97.5% selectivity. • Fe 2 P can be acted as an efficient cocatalyst for photocatalytic CO 2 RR. • Midgap state derived from N vacancies is beneficial to the light adsorption of photocatalyst. Photocatalytic CO 2 conversion into value-added chemicals is a promising strategy to remedy the energy crisis and environmental pollution, yet developing cost-effective photocatalysts that can efficiently and selectively convert CO 2 to desirable products is still a great challenge. Herein, we construct a Fe 2 P nanoparticles decorated on the surface of the nitrogen vacancies (NVs) modified g-C 3 N 4 nanosheet hybrid photocatalyst (Fe 2 P/NVsCN) for photocatalytic conversion of CO 2 to CO. The NVs can significantly improve the visible light absorption due to the formation of midgap state, and the metallic Fe 2 P as the cocatalyst is beneficial to promote the photo-generated charge separation and migration, impede the side reaction, in which improve the activity and selectivity. By adjusting the contents of Fe 2 P and NVsCN, the optimal 20%-Fe 2 P/NVsCN(1:5) sample shows an excellent CO evolution rate in visible light of 22.48 µmol g -1 h −1 with 97.5% selectivity, which is superior to most reported g-C 3 N 4 -based photocatalysts. Furthermore, this photocatalyst also exhibits good stability due to the timely consumption of electrons, and it maintains stable CO evolution rate over 20 h. This work opens a new horizon for design and construction of active photocatalyst with high selectivity by synergistic modulating the surface vacancy and cocatalyst.