Enhancing photocatalytic efficiency by modulating carrier relaxation at reaction levels: A case study of C2N/BlueP photocatalysts

The relaxation time of photogenerated carriers is faster than the chemical reaction time and should be prioritized in a photocatalytic reaction. Using the C2N/BlueP heterojunction as a water-splitting photocatalyst, we first confirm that hydrogen evolution is dominated by the bonding between N(pz) and hydrogen orbitals. Then, N(pz) level carrier relaxation dynamics of the free and BlueP-coupled C2N were studied based on non-adiabatic molecular dynamics simulations. The extended residence time of N(pz) electrons of coupled C2N ensures efficient utilization of photoelectrons. This finding provides insight and a solution to improve photocatalytic efficiency by modulating photogenerated carriers at reaction energy levels.