Nanoparticles-Based Optical Chemosensors for Lead Acetate Sensing in Water: ZnO, Zn_0.97Ce_0.03O, and Zn_0.97Nd_0.03O

This study reports the synthesis, characterization, and optical properties of ZnO, Zn_0.97Ce_0.03O, and Zn_0.97Nd_0.03O nanoparticles and their interactions with lead acetate solutions. X-ray diffraction (XRD) confirmed that the nanoparticles were synthesized in a single-phase hexagonal structure, with crystallite sizes of 12.48 nm, 50.79 nm, and 39.00 nm, respectively. Doping ZnO with Ce and Nd ions significantly enhanced its paramagnetic properties, as evidenced by squareness ratios of 11.18 × 10^-3, 41.60, and 20.25 for ZnO, Zn_0.97Ce_0.03O, and Zn_0.97Nd_0.03O, respectively. UV-Vis absorption spectra revealed a redshift in lead acetate upon interaction with ZnO, indicating the formation of new chemical species. Ce and Nd doping further modified the optical properties by introducing additional absorption peaks and altering spectral profiles. Significant enhancement in photoluminescence (PL) intensity is observed due to the addition of ZnO, Zn_0.97Ce_0.03O, and Zn_0.97Nd_0.03O nanoparticles, as compared to the pure PbC₂H₃O₂​ solution across various concentrations. The incorporation of ZnO nanoparticles increases the PL intensity by approximately tenfold (from 13 to over 100 a.u.). Similarly, Zn_0.97Ce_0.03O exhibits a comparable level of enhancement. Notably, the introduction of Zn_0.97Nd_0.03O nanoparticles achieves a remarkable 100-fold increase in PL intensity, establishing it as a highly effective material for detecting lead contamination in water. This exceptional performance highlights its potential for environmental monitoring and water quality applications. These results highlight the potential of ZnO, Zn_0.97Ce_0.03O, and Zn_0.97Nd_0.03O nanoparticles as sensitive and effective chemosensors for detecting trace lead levels in environmental samples.