Photocatalytic Deposition of Nanostructured CsPbBr₃ Perovskite Quantum Dot Films on Mesoporous TiO₂ and Their Enhanced Visible-Light Photodegradation Properties

Herein, we report the in situ photocatalytic deposition of cesium lead bromide (CsPbBr3) perovskite quantum dots on mesoporous TiO2-coated fluorine-doped tin oxide (FTO/TiO2) electrodes. The mesoporous TiO2 layer is used as a photocatalyst to promote the following: (1) the Pb deposition from a Pb2+ aqueous solution and (2) the in situ Pb conversion into CsPbBr3 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/TiO2/CsPbBr3 film was characterized by UV-vis diffuse reflectance spectroscopy, X-ray diffraction, photoluminescence spectroscopy, scanning electron microscopy, and transmission electron microscopy. The FTO/TiO2/CsPbBr3 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.