CsPbBr3 perovskite nanocrystals-based portable testing device for on-site detection of chloride ions from wastewater

The detrimental effects of chloride (Cl − ) ions on industrial wastewater necessitate the in-situ monitoring of Cl − , which is challenging due to the limited availability of field-applicable analytical methodologies. Herein, a novel and compact apparatus (CPB-FC-Cl) was developed for the precise quantification of Cl − in wastewater. This innovative system utilizes the rapid halide exchange of cesium lead bromide (CsPbBr 3 ) perovskite nanocrystals (NCs) with Cl − , a process marked by a pronounced wavelength blueshift and a vivid fluorescence transition from green to blue. The software in the CPB-FC-Cl system automatically identified the fluorescence emission peaks and displayed the Cl − concentration values on the user interface. The detection experiments conducted on actual hydrochloric acid wastewater confirmed the device’s ability to accurately measure Cl − concentrations within 5 min, achieving an accuracy of 98.98 %. The CPB-FC-Cl system exhibited high selectivity in the presence of various coexisting substances in hydrochloric acid wastewater, and its resistance to potential interferences supports its suitability for precise Cl − quantification. The stability of the CPB-FC-Cl system showed an average detection accuracy of 98.96 % over multiple cycles, which underscores its robustness for long-term monitoring applications.