Enabling Enhanced Photocatalytic Hydrogen Evolution in Water by Doping Cs<sub>2</sub>SnBr<sub>6</sub> Perovskite with Pt
Jin Wang, Meng Zhang, Zhihao Chen, Luoning Li, Guocan Jiang, Zhengquan Li
Abstract
Lead (Pb) halide perovskites (LHPs) have attracted great interest in photocatalysis. However, the unsatisfactory stability and toxicity of Pb restrict its large-scale application. Herein, lead-free Cs 2 Pt 0.25 Sn 0.75 Br 6 perovskites are reported for photocatalytic hydrogen reaction (HER) in water. The partial substitution of Sn atoms with Pt atoms dramatically enhances the HER performance and stability of the Cs 2 SnBr 6 perovskites. This doping approach allows Cs 2 Pt 0.25 Sn 0.75 Br 6 to work in the aqueous phase without saturated hydrohalic acid. The resultant dye-sensitized Cs 2 Pt 0.25 Sn 0.75 Br 6 perovskites exhibit a remarkable H 2 evolution rate of 11.49 mmol g –1 h –1 with an apparent quantum yield of 7.2%. Various investigations uncover that Pt doping significantly tunes the intrinsic properties and surface active sites of the Cs 2 Pt 0.25 Sn 0.75 Br 6 . Furthermore, the more negative formation energy and decreased surface hydrophilicity endow Cs 2 Pt x Sn 1– x Br 6 with a high stability against water. This work represents a significant stride toward the realization of water-stable lead-free perovskites for photocatalysis.