Protruding Pt single-sites on hexagonal ZnIn<sub>2</sub>S<sub>4</sub> to accelerate photocatalytic hydrogen evolution.

Shi, Xiaowei; Dai, Chao; Wang, Xin; Hu, Jiayue; Zhang, Junying; Zheng, Lingxia; Mao, Liang; Zheng, Huajun et al. · Nat Commun · 2022

basic_science · Level V

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Abstract

Single-site cocatalysts engineered on supports offer a cost-efficient pathway to utilize precious metals, yet improving the performance further with minimal catalyst loading is still highly desirable. Here we have conducted a photochemical reaction to stabilize ultralow Pt co-catalysts (0.26 wt%) onto the basal plane of hexagonal ZnIn<sub>2</sub>S<sub>4</sub> nanosheets (Pt<sub>SS</sub>-ZIS) to form a Pt-S<sub>3</sub> protrusion tetrahedron coordination structure. Compared with the traditional defect-trapped Pt single-site counterparts, the protruding Pt single-sites on h-ZIS photocatalyst enhance the H<sub>2</sub> evolution yield rate by a factor of 2.2, which could reach 17.5 mmol g<sup>-1</sup> h<sup>-1</sup> under visible light irradiation. Importantly, through simple drop-casting, a thin Pt<sub>SS</sub>-ZIS film is prepared, and large amount of observable H<sub>2</sub> bubbles are generated, providing great potential for practical solar-light-driven H<sub>2</sub> production. The protruding single Pt atoms in Pt<sub>SS</sub>-ZIS could inhibit the recombination of electron-hole pairs and cause a tip effect to optimize the adsorption/desorption behavior of H through effective proton mass transfer, which synergistically promote reaction thermodynamics and kinetics.