Robust visible-light photocatalytic H2 evolution on 2D RGO/Cd0.15Zn0.85In2S4–Ni2P hierarchitectures†
Photocatalytic water-splitting to produce hydrogen (H2) is considered one of the most promising strategies to solve the increasing energy and environmental challenges facing humanity. However, the major obstacle is the lack of highly efficient photocatalysts with visible-light absorption capability and prominent charge transfer and separation. Herein, we developed for the first time an interface-engineered 2D hierarchitecture comprising ultrathin Cd-doped ZnIn2S4 (Cd0.15Zn0.85In2S4) nanosheets coupled with Ni2P nanoparticles as a cocatalyst and reduced graphene oxide (RGO) nanosheets as an electron mediator. Under visible-light (λ > 400 nm) irradiation, the RGO/Cd0.15Zn0.85In2S4–Ni2P composite displayed an enhanced H2 evolution activity of 14.56 mmol h−1 g−1 that is 22 times that of pristine ZnIn2S4, and much higher than those of RGO/Cd0.15Zn0.85In2S4, Cd0.15Zn0.85In2S4–Ni2P, Pt-loaded RGO/Cd0.15Zn0.85In2S4, and many previously reported ZnIn2S4-based photocatalysts. Additionally, the RGO/Cd0.15Zn0.85In2S4–Ni2P hybrids showed outstanding long time cycling stability. The excellent photocatalytic HER capability of our photocatalyst could be attributed to the enhanced light-harvesting capability of porous hierarchitectures, increased charge transfer and separation via the interface-engineered Schottky heterojunctions, and the many active sites of the Ni2P cocatalyst. The synergistic cooperation of the cocatalyst and electron mediator in 2D nanostructures offers a promising approach to prepare efficient solar photocatalysts.