Water-splitting using photoelectrodes of titania and titania-perovskite halite composite films

Titanium oxide photoelectrodes have been used for water splitting for a few decades, but have low solar-to-hydrogen efficiencies. Perovskite halides (e.g., CH 3 NH 3 PbI 3 ) have recently emerged as an efficient light absorber system. We try to combine the two materials to create new photoelectrodes to achieve a higher efficiency for hydrogen production. The photoelectrodes are investigated for water-splitting hydrogen production under Xe light irradiation by photoelectrochemical (PEC) reaction. Since perovskite halides are favorable light harvesters under UV and visible light irradiation, the composite films of titania and perovskite halide would achieve efficient water splitting. The hydrogen production rate using the composite films is higher than that using anatase TiO 2 electrode. However, the composite films are not stable in water under light irradiation and the perovskite halide gradually decomposes into lead halide.