Visible light-driven highly efficient self-cleaning coatings crafted on leather surface using double perovskite as the booster

The frequent accumulation of stains and inconvenient handling methods make crafting self-cleaning leather a necessity, especially for light colored ones. This study presents a sequential layer-by-layer (LBL) spraying technique to fabricate PU/SiO2/(Cs2AgBiBr6/TiO2)n coating with an efficient visible light-driven self-cleaning function on leather surface. TiO2 and Cs2AgBiBr6 were sprayed layer by layer to form [TiO2/Cs2AgBiBr6] heterojunction, thus boosting the self-cleaning ability. Nano SiO2 barrier layer was designed to inhibit the overabundant photocatalytic effect from [TiO2/Cs2AgBiBr6] units on PU or leather substrate. The electrostatic interaction between layers was involved to ensure the overall performance of coatings. Additionally, the designed PU/SiO2/(Cs2AgBiBr6/TiO2)5 coatings exhibited good photocatalytic self-cleaning performance for RhB within 1 h's visible light irradiation. Meanwhile, the coated leather demonstrated excellent durability, physical mechnical properties and water vapor permeability. This work provides new possibilities for the industrial design and development of functional coatings.