Dimethylammonium iodide stabilized bismuth halide perovskite photocatalyst for hydrogen evolution

Metal halide perovskites have emerged as novel and promising photocatalysts for hydrogen generation. Currently, their stability in water is a vital and urgent research question. In this paper a novel approach to stabilize a bismuth halide perovskite [(CH3)(2)NH2](3)[BiI6] (DA(3)BiI(6)) in water using dimethylammonium iodide (DAI) without the assistance of acids or coatings is reported. The DA(3)BiI(6) powder exhibits good stability in DAI solutions for at least two weeks. The concentration of DAI is found as a critical parameter, where the I- ions play the key role in the stabilization. The stability of DA(3)BiI(6) in water is realized via a surface dissolution-recrystallization process. Stabilized DA(3)BiI(6) demonstrates constant photocatalytic properties for visible light-induced photo-oxidation of I- ions and with PtCl4 as a co-catalyst (Pt-DA(3)BiI(6)), photocatalytic H-2 evolution with a rate of 5.7 mu molh(-1) from HI in DAI solution, obtaining an apparent quantum efficiency of 0.83% at 535 nm. This study provides new insights on the stabilization of metal halide perovskites for photocatalysis in aqueous solution.

Automated summary

This study presents a novel approach to stabilize metal halide perovskites in water using dimethylammonium iodide (DAI), without the need for acids or coatings. The stability is achieved through a surface dissolution-recrystallization process, where the concentration of DAI and I- ions play critical roles.