Synthesis of Exclusive Star Shaped PbS Nanocrystals and Determination of Cd(II) Ions Using Hg(II)-PbS Modified Graphite Electrode by Differential Pulse Anodic Stripping Voltammetry

Abstract

The exclusive star like morphology of PbS nanocrystals has been successfully synthesized and characterized. Reactions of Pb(OAc)₂ with thioacetamide lead to the formation of black powdered PbS nanocrystals using cetyltrimethylammonium bromide and sodium dodecyl sulfate as a surfactant by thermal decomposition method. The synthesized PbS nanocrystals has been characterized by various techniques such as UV-visible spectroscopy, Raman spectroscopy, field emission scanning electron microscopy and energy dispersive X-ray analysis. The above characterizations confirm the formation of PbS nanocrystals. The star shape of PbS nanocrystals was clearly visible in the field emission scanning electron microscopy images. The modified electrode has been prepared using PbS nanocrystals by drop-casting method. Differential pulse anodic stripping voltammetry was used to detect the ppm levels of Cd(II) using the Hg-PbS modified graphite electrode which gave well defined peaks with low background current. The Hg-PbS modified graphite electrode was also used for simultaneous determination of Cd(II) and Sn(II). The Hg-PbS modified graphite electrode was able to detect Cd(II) in a wide concentration of 1.66 × 10^-6 to 4.54 × 10^-4 M. This present method is superior when compared to other methods of determining trace metal ions and it is easy reliable, highly sensitive and promising approach.