Rapid detoxification of polluted water using ultrastable TiO2 encapsulated CsPbBr3 QDs in collected sunlight

• The 0D CsPbBr 3 was synthesized in an ambient air atmosphere. • Encapsulated colloidal CsPbBr 3 @TiO 2 nanocomposite remain ultrastable water. • Outstanding photocatalytic activity of CsPbBr 3 @30-TiO 2 studied in collected sunlight. • This work provides more insights to understand the photocatalytic activity in collected sunlight for environmental remediation. The CsPbBr 3 perovskite quantum dots (CPB PQDs) was prepared using the anti-solvent precipitation method in ambient air. The low water stability of CPB PQDs hinders photocatalytic applications, so colloidal CPB PQDs were encapsulated and protected with TiO 2 . The thickness of TiO 2 encapsulation was controlled by immersing the same volume of CPB PQDs into different concentrations of Titanium (Ti) precursor. The optimum CPB/TiO 2 composition degrades 78% Methylene Blue (MB) after 300 min under natural (diffuse) sunlight. Furthermore, the same photocatalyst detoxifies MB more than 99% after 50 min illumination of collected sunlight. This outstanding photocatalysis in collected sunlight is attributed to the improved rate of photoinduced charge carriers and their efficient separation due to favourable band alignment of CPB PQD with TiO 2 . This work provides a pathway to implement an efficient photocatalyst strategy for environmental remediation in outdoor conditions.