Growth of Lead-free Halide Perovskites into SiO Sub-microcapsules Toward Water-stable Photocatalytic CO Reduction

Halide perovskites (HPs) are highly susceptible to heat, light, or moisture and are easily decomposed even in an ambient environment, which greatly hinders their practical applications. Herein, an growth strategy is presented for implanting an inorganic lead-free HP, CsAgBiBr, into SiO sub-microcapsules to form a CsAgBiBr@SiO yolk-shell composite. The SiO sub-microcapsule endows CsAgBiBr with good thermal and light stability, as well as excellent corrosion resistance against polar solvents. Furthermore, when employed as a lead-free perovskite photocatalyst, the composite exhibits a higher visible-light-driven CO-to-CO rate (271.76 μmol g h) and much better stability than CsAgBiBr in water. The formation of a CsAgBiBr/SiO heterostructure using an growth method alleviates water binding on the perovskites, supported by density functional theory calculations, which is the key to an improvement in the stability of the composite. The growth strategy developed here sheds light on the design and development of HP-based materials for applications involving polar solvents.