To analyze the degradation of BB in the presence of CsPbBr3 and Cs4PbBr6 HP's catalysts in Sol.1 (total volume of 24 mL), 6 mL of BB dye was added under constant stirring. Before adding the photocatalyst, 3 mL of the pristine dye solution was taken as a "0 min" measurement. Then, the photocatalyst was added to this solution and kept under visible light. The degradation of CsPbBr3