Synergistic Regulation of Photogenerated Electron/Hole for MoS2/Sv-ZnIn2S4/Ni(OH)2 Composites with Enhanced Hydrogen Evolution Activity

Artificial regulation of the charge transfer pathway is an effective strategy for optimizing the charge dynamics and enhancing the photocatalytic hydrogen production. Herein, MoS2/Sv-ZnIn2S4/Ni(OH)2 composites were synthesized by an in situ structure-tailored technique. Systematic investigations confirmed the existence of sulfur vacancy (Sv), Ohmic-type MoS2/Sv-ZnIn2S4 junction, and p-n-type Sv-ZnIn2S4/Ni(OH)2 heterojunction in MoS2/Sv-ZnIn2S4/Ni(OH)2 composites. Specifically, n-type MoS2 and p-type Ni(OH)2 acted as the electron transport layer and hole transport layer, which not only achieved the carrier spatial separation and directional charge transfer but also suppressed the carrier recombination and enhanced the hydrogen reduction reaction dynamics. As a result, the optimized composites displayed an outstanding photocatalytic H2-releasing rate of 12.34 mmol·g–1·h–1, which was 5.96 times higher than that of pristine ZnIn2S4. This work provides an unusual opinion for developing the multichannel-modification photocatalysts with a controllable charge transfer route.