Perovskite cesium lead bromide quantum dots: A new efficient photocatalyst for degrading antibiotic residues in organic system

The efficient removal of antibiotic residues has drawn wide interests; however, little attention has been focused on treating them in organic system. Inorganic perovskite cesium lead bromide quantum dots were successfully prepared by anti-solvent precipitation and the prepared cesium lead bromide quantum dots were well-characterized. The photocatalytic activity was evaluated by degradation of tetracycline hydrochloride in ethanol as a model reactant under visible light for the first time. 76% tetracycline hydrochloride and 70% methyl orange were efficiently degraded in 30 min, which illustrate cesium lead bromide quantum dots could work as efficient photocatalyst for the degradation of organic pollutants in ethanol. The photoelectric conversion efficiency and photoluminescence quantum yields were measured and calculated. The photodegradation process was systematically analyzed by full-wavelength absorption. It is found that superoxide radicals may play a major role in the photocatalytic degradation process by capture experiments and the reaction mechanism has been proposed. Cesium lead bromide is not stable in water and may be converted into perovskite-related phase with water, which will result in the loss of photocatalytic activity. This work indicates that cesium lead bromide may act as an efficient photocatalyst for the removal of tetracycline hydrochloride and methyl orange in organic system, which may benefit the development/application of novel photocatalysts for special applications.