Colorimetric Determination of Chloridion in Domestic Water Based on the Wavelength Shift of CsPbBr_(3) 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 200μM of the chloridion concentration and the wavelength shift of CsPbBr_(3)PNCs with a correlation coe fficient 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 4μM.These results show that the suggested approach is promising for the development of novel fluorescence detection for chloridion in water.

Monodisperse Spherical Sandwiched Structured SiO_(2)@CsPbX_(3)@SiO_(2) Perovskite Composites for the Determination of Fe^(3+) Ion in Water Samples

The application of all-inorganic CsPbX_(3)(X=Cl^(-),Br^(-)and I^(-))perovskite nanocrystals(PNCs)is hindered by their poor stability under diff erent environments(moisture,UV light and high temperature).Herein,we demonstrate a novel in-situ growth and post-coating technique to prepare monodisperse spherical sandwiched structured SiO_(2)@CsPbX_(3)@SiO_(2)perovskite composites.In this strategy,the environmental stability of CsPbX_(3)PNCs is remarkably improved due to protecting evenly distribution in the surface of composites through the design of spherical sandwiched structure,and the negative eff ects of SiO_(2)coating on photoluminescence property of CsPbX_(3)PNCs could be reduced eff ectively.Furthermore,regular monodisperse spherical structure and uniform size of composites greatly benefit their application in relative fields.The experiment results indicate that the as-prepared product have outstanding abilities of water-,oxidation-and UV radiation resistance.Finally,the SiO_(2)@CsPbBr_(3)@SiO_(2)perovskite composites are successfully used for highly sensitive detection of Fe^(3+)in water sample.The results show limit of detection(LOD)is 3μM and good linearity is between 10 and 70μM(R^(2)=0.9963).Furthermore,the proposed perovskite composites have been successfully applied for the analysis of Fe^(3+)in real samples with satisfactory results.