Photocatalytic Deposition of Nanostructured CsPbBr 3 Perovskite Quantum Dot Films on Mesoporous TiO 2 and Their Enhanced Visible-Light Photodegradation Properties.

Herein, we report the in situ photocatalytic deposition of cesium lead bromide (CsPbBr 3 ) perovskite quantum dots on mesoporous TiO 2 -coated fluorine-doped tin oxide (FTO/TiO 2 ) electrodes. The mesoporous TiO 2 layer is used as a photocatalyst to promote the following: (1) the Pb deposition from a Pb 2+ aqueous solution and (2) the in situ Pb conversion into CsPbBr 3 perovskite in the presence of a CsBr methanolic solution without any organic capping agent. Both steps are carried out under ultraviolet light irradiation under ambient conditions without any post-treatment. The obtained FTO/TiO 2 /CsPbBr 3 film was characterized by UV-vis diffuse reflectance spectroscopy, X-ray diffraction, photoluminescence spectroscopy, scanning electron microscopy, and transmission electron microscopy. The FTO/TiO 2 /CsPbBr 3 heterojunction exhibited enhanced visible-light photodegradation activity demonstrated for the oxidation of curcumin organic dye as a model system. The novel and simple approach to fabricating a supported photocatalyst represents a scalable general method to use semiconductors as a platform to incorporate different perovskites, either all-inorganic or hybrid, for optoelectronic applications. The perovskite deposition method mediated by the UV light at room temperature could be further applied to flexible and wearable solar power electronics.