Realization of all-in-one hydrogen-evolving photocatalysts via selective atomic substitution

Major challenges of realization of all-in-one hydrogen-evolving photocatalysts are the relatively poor charge separation efficiency and unfavorable hydrogen desorption properties owing to the strong correlation between the catalytic site and adsorbed H. Herein, an example of Ni doped few-layer ZnIn2S4 nanosheets (Ni-ZnIn2S4) is carried out to deeply understand the role of Ni dopant in tailoring the charge separation efficiency and weakening the bond energy between electronegative S sites and adsorbed H (S-Hads). Our theoretical calculations demonstrate that Ni ions preferentially incorporates into tetrahedral Zn sites rather than tetrahedral/octahedral In sites, which endows Ni-ZnIn2S4 with improved electronic conductivity and more delocalized charge carriers involved in hydrogen evolution reaction (HER). More importantly, Ni dopants can be capable of exquisitely altering the electronic structure of S sites, leading to a balanced hydrogen adsorption and desorption ability. Consequently, the as-prepared few-layer Ni-ZnIn2S4 nanosheets enable long-lived photo-excited electrons and enhanced photocatalytic HER performance.