Stable hybrid perovskite MAPb(I1−xBrx)3 for photocatalytic hydrogen evolution

Abstract

Hybrid organic-inorganic perovskites have been pursuing for solar/visible-driven H2 evolution from hydrohalic acid (HX) splitting, but their inherent structural stability and performance are still challenging. Herein, we report on a stable hybrid perovskite MAPb(I1−xBrx)3 (x = 0–0.20) obtained by one-pot crystallization in a mixed halide parent solution and its implementation as a newcomer photocatalyst for H2 evolution in aqueous HX solution. MAPb(I1−xBrx)3 is demonstrated to be a superior visible-light-driven photocatalyst for H2 evolution in aqueous HI/HBr solution with no Pt as a cocatalyst. An optimized MAPb(I1−xBrx)3 (x = 0.10) shows a highest H2 evolution rate of 1471 μmol h−1 g−1 under visible light (λ ≥ 420 nm) illumination, which is ˜40 times higher than that of pure MAPbI3, and the dual-halide perovskite is rather stable showing no obvious decrease in the photocatalytic activity over 60 runs (252 h). The perovskite inherent structural stability is further evidenced by XRD, UV–vis spectra and EDS elemental mapping of MAPb(I1−xBrx)3 measured after cycled photocatalytic reaction. The solar HI splitting efficiency of MAPb(I1−xBrx)3 (x = 0.10) is determined as 1.42%. The mechanism behind photocatalytic H2 evolution enhancement is elucidated by the experimental and computational methods.