Nickel clusters accelerating hierarchical zinc indium sulfide nanoflowers for unprecedented visible-light hydrogen production

Abstract

As a typical two-dimensional (2D) metal chalcogenides and visible-light responsive semiconductor, zinc indium sulfide (ZnIn₂S₄) has attracted much attention in photocatalysis. However, the high recombination rate of photogenerated electrons and holes seriously limits its performance for hydrogen production. In this work, we report in-situ photodeposition of Ni clusters in hierarchical ZnIn₂S₄ nanoflowers (Ni/ZnIn₂S₄) to achieve unprecedented photocatalytic hydrogen production. The Ni clusters not only provide plenty of active sites for reactions as evidenced by in-situ photoluminescence measurement, but also effectively accelerate the separation and migration of the photogenerated electrons and holes in ZnIn₂S₄. Consequently, the Ni/ZnIn₂S₄ composites exhibit good stability and reusability with highly enhanced visible-light hydrogen production. In particular, the best Ni/ZnIn₂S₄ photocatalyst exhibits an unprecedented hydrogen production rate of 22.2 mmol·h^-1·g^-1, 10.6 times that of the pure ZnIn₂S₄ (2.1 mmol·h^-1·g^-1). And its apparent quantum yield (AQY) is as high as 56.14% under 450 nm monochromatic light. Our work here suggests that depositing non-precious Ni clusters in ZnIn₂S₄ is quite promising for the potential practical photocatalysis in solar energy conversion.

Keywords: In-situ photoluminescence measurement; Ni clusters; Non-precious metals; Photocatalytic hydrogen production; ZnIn(2)S(4) nanoflower.