Colorimetric Determination of Chloridion in Domestic Water Based on the Wavelength Shift of CsPbBr3 Perovskite Nanocrystals via Halide Exchange

Cubic phase CsPbBr 3 perovskite nanocrystals (PNCs) was prepared by a high-temperature hot-injection method. The high photoluminescence quantum yield (PLQY) of as-prepared CsPbBr 3 PNCs was 87%, which can be used for the determination of chloridion in domestic water samples based on their wavelength-shift characteristics via halide exchange. The proposal approach for the determination of chloridion reveals a linear correlation ranged from 10 to 200 μM of the chloridion concentration and the wavelength shift of CsPbBr 3 PNCs with a correlation coefficient of R 2  = 0.9956. The as-mentioned method reveals neglectable responses towards those co-existing ions in the water aside from chloridion, due to the quick exchange between Cl and Br and the outstanding color change caused by wavelength shift. The strategy has been applied to the determination of chloridion in water samples with the recoveries of 98.9–104.2% and the limit of detection (LOD) of 4 μM. These results show that the suggested approach is promising for the development of novel fluorescence detection for chloridion in water.