Utilization of Silver Nanoparticles for Practical Removal and Detection of Pb2+ and Hg2.

The presence of Pb2+ and Hg2+ in the environment is a matter of significant concern because of their potential harm to living organisms. This study presents an innovative and practical method for the detection of Pb2+ and Hg2+ using yellow silver nanoparticles (YAgNPs). These nanoparticles were synthesized through a chemical reduction process employing sodium borohydride (NaBH4) as the reducing agent and trisodium citrate (TSC) as the stabilizing agent. YAgNPs exhibit remarkable affinity for Pb2+ and Hg2+. In the presence of Pb2+, the formation of distinct yellow precipitates, accompanied by a clear supernatant solution, was observed. In addition, the presence of Hg2+ led to the formation of distinct white and cloudy precipitates accompanied by a clear supernatant solution. These characteristic changes led to the highly selective detection of Pb2+ and Hg2+ over other metal ions. The precipitation of YAgNPs in the presence of Pb2+ could be attributed to electrostatic interactions involving functionalized citrate anions, which led to coprecipitation of the AgNPs and Pb2+ complex. On the other hand, the conspicuous white precipitate in the presence of Hg2+ could be attributed to the amalgamation of Hg and Ag caused by the redox reaction of AgNPs and Hg2+. The calculated detection limits of Pb2+ and Hg2+ are 0.0282 mM and 0.0570 mM, respectively. Crucially, this study demonstrates the successful application of YAgNPs in three authentic samples without necessitating preliminary sample pretreatment. The findings underscore the robust capacity of YAgNPs to effectively detect Pb2+ and Hg2+ in real samples, thus positioning these nanoparticles as the highly promising candidates for the initial screening of Pb2+ and Hg2+ in environmental samples. Importantly, these nanoparticles exhibit potential as the efficacious agents for the removal of Pb2+ and Hg2+ during wastewater treatment processes, signifying importance in addressing environmental Pb2+ and Hg2+ contamination concerns.