Constructing CuNi dual active sites on ZnIn2S4 for highly photocatalytic hydrogen evolution

Abstract

Noble metal Pt as an efficient cocatalyst is widely utilized in the photocatalytic hydrogen (H₂) evolution field while its application is restricted by high price and scarcity. Herein, a feasible strategy for depositing a non-noble bimetallic cocatalyst on a ZnIn₂S₄ surface has been put forward. The low-cost and earth-abundant CuNi bimetal cocatalyst was deposited via a simple one-step photoreduction method. In this novel photocatalytic system, CuNi bimetal served as dual active sites which can inhibit the recombination of charge carriers on ZnIn₂S₄. Compared with single Cu or Ni deposited ZnIn₂S₄ samples, CuNi bimetal decorated samples showed a significant enhancement in hydrogen evolution activity. Meanwhile, 12% Cu₂Ni₁–ZIS realized the highest hydrogen generation rate (7825 μmol h⁻¹ g⁻¹, AQE = 30.19%, λ > 420 nm). The enhanced photocatalytic performance can be attributed to the spillover effect of H atoms from Ni to Cu and the synergistic effect between the metals. This work provides a novel strategy for optimizing the H₂ evolution performance of a ZnIn₂S₄-based photocatalyst by utilizing a non-noble bimetallic cocatalyst as dual active sites.