Potassium stabilization of methylammonium lead bromide perovskite for robust photocatalytic H2 generation

Abstract

Various optoelectronic applications of organic inorganic hybrid lead halide perovskites are challenged by their stability. The photocatalytic stability of lead halide perovskites are so low that chemical stabilizer such as H3PO2 are required in their applications. We report a postsynthesis potassium stabilization on methylammonium lead bromide (MAPbBr3) to form K-MAPbBr3 by doping K cation and depositing KBr layers. In absence of any stabilizer, this stable K-MAPbBr3 perovskite can exhibit an unprecedented high photostability even after 200 hours continuous photocatalytic H2 generation. Impressively, the K-MAPbBr3 cocatalyzed with Mo3S132− nanoclusters achieves a high apparent quantum efficiency up to 18.3% at 450 nm for photocatalytic H2 generation. The mechanism study reveals that the photogeneration of Pb0 and Br0 defects are effectively inhibited in K-MAPbBr3, which makes it a robust photocatalyst for H2 generation. These findings will inspire the development of stable organic-inorganic hybrid perovskites for photocatalysis and other optoelectronic applications. (Figure presented.).