Stable Mixed-Organic-Cation Perovskite MA1–xFAxPbI3 Integrated with MoS2 for Enhanced Visible-Light Photocatalytic H2 Evolution

Unary-organic-cation lead halide perovskites like MAPbI3 have been emerging as tremendous photocatalysts for H2 evolution recently. However, their photocatalytic performances are inferior without modification. Here, a series of mixed-organic -cation perovskites MA1–xFAxPbI3 (M1–xFxPI, x = 0, 0.2, 0.3, 0.4, 0.5) were synthesized by introducing FA+ into MAPbI3 precursor and then composited with MoS2 as photocatalysts for H2 evolution reaction (HER). We demonstrate that the fabricated MoS2/M0.6F0.4PI is highly efficient and ultrastable during the photocatalytic HER process. The optimal MoS2/M0.6F0.4PI composite, i.e., 20 wt % MoS2/M0.6F0.4PI exhibits a visible HER rate of 2131 μmol h–1 g–1, increasing by 88-fold in comparison with pure MAPbI3 (24 μmol h–1 g–1) and better than the optimized Pt/M0.6F0.4PI (1328 μmol h–1 g–1). No activity degradation of 20 wt % MoS2/M0.6F0.4PI occurs in repeated HER experiments. The (photo)electrochemical performances of the composite are studied to reveal the photoinduced charge transfer and consequent HER process.