Rational design of one inorganic-organic hybrid Z-scheme heterojunction for high-performance photocatalytic water splitting

Searching high-performance Z-scheme heterojunction is of great significance for the solution of energy shortage and environmental pollution. Combining density functional theory (DFT) calculation and time-dependent ab-initio diabatic molecular dynamics (NAMD) simulation, we theoretically found one new inorganic–organic hybrid Z-scheme heterojunction CdS/C6N7, involving the stacking of CdS monolayer with C6N7 monolayer. The unique electronic properties (e.g. staggered band alignment, charge transfer) of Z-scheme heterojunction was strictly verified via the ground-state DFT calculations, and time-dependent NAMD simulations demonstrated the dynamic processes of photogenerated carriers separation and recombination. The strong built-in electric field from CdS to C6N7 layer promotes the non-adiabatic coupling of pristine carriers, resulting in the strong redox ability of CdS/C6N7. Catalytic property shown that CdS/C6N7 features outstanding performance for overall water splitting (OWS), where the synergy of strong redox ability and effective spatial separation of electron-holes plays an important role.