Overall photocatalytic water splitting by an organolead iodide crystalline material

Organolead halide perovskites, primarily regarded as a high-performance semiconducting component in photovoltaics, have excellent optical and charge-transport characteristics that are advantageous for photocatalysis. However, their moisture-sensitive nature largely hinders their application to water splitting. Here we report a semiconductive organolead iodide layered crystalline material ([Pb8I8(H2O)3]8+[–O2C(CH2)4CO2–]4) with a bandgap of ~2.74 eV that demonstrates a high robustness over a wide pH range as well as under aqueous boiling conditions. The Earth-abundant material maintains excellent optical characteristics similar to those of perovskites, and includes suitable band positions, excellent carrier diffusion lengths (up to 1.4 μm) and long carrier lifetimes (up to 1.2 μs). When illuminated by sunlight and combined with trace amounts of a Rh co-catalyst, the hybrid iodoplumbate steadily and efficiently produces stoichiometric amounts of hydrogen and oxygen in a recyclable manner. Our findings extend the excellent optoelectronic properties of organolead halide materials from photovoltaics to photocatalytic water splitting. Despite their promising optical properties, organolead halide perovskites are not frequently used in photocatalysis due to their low stability in water. Here, a long-lasting semiconductive organolead iodide layered crystalline material with the ability to perform overall water splitting is introduced.