Core-shell structuredCsPbBr3/Sn-TiO2 nanocrystals for visible-light-driven photocatalyst in aqueous solution

• The Sn doped TiO 2 (Sn-TiO 2 ) coating CsPbBr 3 perovskite quantum dots to prepared core–shell CsPbBr 3 /Sn-TiO 2 nanocrystals. • The CsPbBr 3 /Sn-TiO 2 prepared using solution techniques such as supersaturation recrystallization, sol–gel coating, and solvothermal crystallization. • The CsPbBr 3 /Sn-TiO 2 have wider absorption range and higher photocatalytic activity. • The CsPbBr 3 /Sn-TiO 2 can sustainably work in the aqueous system for a long time. All-inorganic perovskite materials have attracted much attention in the field of photocatalysts due to their unique photoelectric properties.However, the inherent poor stability of perovskite quantum dots significantlyhinders their practical applications. Herein, to settle the instabilities of inorganic perovskite materials, Sn-TiO 2 coated CsPbBr 3 quantum dots named CsPbBr 3 /Sn-TiO 2 , are fabricated via resaturated recrystallization, sol–gel coating and solvothermal crystallization.The XRD results demonstrated that the core–shell structure of CsPbBr 3 /Sn-TiO 2 nanocrystals was successfully synthesized.Moreover, excellent dispersion is verified for CsPbBr 3 /Sn-TiO 2 nanocrystals with a core–shell structure by TEM. The particle size of CsPbBr 3 /Sn-TiO 2 nanocrystals is 15–30 nm, where the core size for CsPbBr 3 quantum dots is 4–8 nm, and the Sn-TiO 2 shell thickness is 2–8 nm.The photocatalytic activity of nanocomposites was studied by the photodegradation of RhB aqueous solution under the irradiation of 100 mWcm −2 air mass 1.5 global AM1.5G sunlight. Compared with traditional photocatalyst P25, the core–shell structured CsPbBr 3 /Sn-TiO 2 nanocrystals exhibited better photocatalytic performance, with a degradation efficiency of 96.6% and a degradation rate constant of 10.68 × 10 -2 min −1 in 30 min of catalytic time, which was five times higher than that of P25.The core–shell structured CsPbBr 3 /Sn-TiO 2 nanocrystals have long-term stability in water system and have potential practical application value in the field of environmental governance.