Stable Lead-Free (CH₃NH₃)₃Bi₂I₉ Perovskite for Photocatalytic Hydrogen Generation

Abstract

Lead-halide perovskites have demonstrated promising performance in the field of photocatalytic hydrogen production. However, the toxicity of lead hinders their application. Herein, an environmentally friendly and lead-free perovskite (CH3NH3)3Bi2I9 was prepared by employing a simple and efficient hydrothermal route. It is found that (CH3NH3)3Bi2I9 exhibits excellent phase stability in hydriodic acid with different concentrations. Under visible light irradiation, it showed satisfactory cycle stability after 70 h of repeated H2 evolution without any degradation or oxidization. After using platinum as a cocatalyst, the photocatalytic rate for H2 evolution is about 169.21 μmol g–1 h–1, resulting in 14 times enhancement compared with the pristine one (about 12.19 μmol g–1 H–1 with 40 mg initial amount) and a solar-to-chemical conversion efficiency of 0.48%. Our research opens new possibilities for the application of lead-free perovskites in the field of photocatalysis.