Covalency dominating Z-scheme perylene-dicarboximide@ZnIn2S4 organic-inorganic hybrids for overall water splitting

Exploring covalent coupling organic-inorganic hybrids (OIHs) is of great significance for improving photocatalysis. Herein, ZnIn2S4 nanosheets are anchored at the surface of high crystalline perylene-dicarboximide (HC-PDI) nanorods, generating Z-scheme HC-PDI@ZnIn2S4 (HPZ) OIHs for efficient overall water splitting (OWS). The unique hierarchical branching heterostructure of HPZ nanohybrids improve the specific surface area, pore diameter, pore volume, and visible-light-harvesting ability, which provides the basis for photocatalytic reaction. The strong covalent connection between HC-PDI and ZnIn2S4 provides a fast channel for charge transfer. Simulated calculation and in-situ analysis collectively prove that the unique electron transfers of hybridization and photoexcitation bring about (−)HC-PDI@(+)ZnIn2S4 internal interfacial electric field and Z-scheme heterojunction, respectively, further resulting in the transfer of water oxidation in ZnIn2S4 and the high-efficiency separation of photoexcited charges in the system. The optimized HPZ nanohybrid exhibit boosted visible-light-driven OWS activity (275.4 μmol g−1 h−1 for H2 evolution and 138.4 μmol g−1 h−1 for O2 evolution) and remarkable stability (40 h). This covalency dominating OIHs approach advances the exploration of OWS photocatalysts.