Fabricating MAPbI/MoS Composites for Improved Photocatalytic Performance.

Although lead halide perovskites are demonstrated to be promising photocatalysts for hydrogen evolution from hydrogen halide splitting, it still remains challenging to fabricate efficient and stable catalysts. Here MoS nanoflowers with abundant active sites are assembled with methylammonium lead iodide (MAPbI) microcrystals to form a new heterostructure. Its hydrogen evolution rate can reach up to about 30 000 μmol g h, which is more than 1000-fold higher than pristine MAPbI under visible light irradiation (λ ≥ 420 nm). Importantly, the solar HI splitting efficiency reaches 7.35%, one of the highest efficiencies so far. The introduction of MoS with proper band alignment and unsaturated species can efficiently promote the charge separation and afford more active sites for H production. This finding not only provides a highly efficient and stable photocatalyst for hydrogen evolution but also offers a useful modification strategy on lead halide perovskites.