Syed Kashif Ali

This study is focused on synthesis of lead oxide (PbO) nanodots (quantum dots) via two methods viz. microwave-assisted (B) and solvothermal method (A). The results of microwave-assisted method are slightly different in comparison to the solvothermal method. Several techniques, such as Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and selective area electron diffraction (SAED) were used for characterizing PbO nanodots synthesized by both methods. The FTIR peak at 687 cm-1 indicated the formation of the Pb-O-Pb bond. The band gap, calculated with the help of UV data, was ~5.5 eV. The obtained PXRD pattern and miller indices suggested the formation of β-PbO and α-PbO nanoparticles with orthorhombic and tetragonal geometries. The crystallinity of PbO nanodots methods by A and B methods was 96% and 99%, respectively. The average crystallite size (for both samples synthesized by methods A and B) calculated by Debye-Scherrer’s equation was 42 and 38 nm, respectively. Sample A mostly contains α-type lead oxide nanodots, while sample B mainly contains mostly β-type lead oxide nanodots. The average size of nanodots observed from TEM images for samples A and B was 3.7 and 2.7 nm, respectively.