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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.

Nickel oxide (NiO) nanoparticles, using chemical reduction method, have been synthesized by the reaction of nickel chloride hexahydrate (NiCl2.6H2O) salt with triethylamine (Et3N) as a reducing agent at 700C and thermal decomposition of the precursor nickel hydroxide Ni(OH)2 nanoparticles from 3000C to 6000C at an increment of 1000C. The product was characterized by using X-Ray diffraction (sharp picks at 280,380,600), Scanning electron microscopy (average particle ranges between 1-100), UV-Vis spectrophotometer (absorption band at 320-350 nm), Fourier transform infrared spectroscopy (strong band at 750 cm-1), Energy dispersive X- ray spectroscopy (% weight of NiONPs is 12.73) analysis etc. The synthesized nanoparticles and nickel salt have been investigated for biophysical parameters like germination percentage, radical length (RL), Plumule length (PL) and seedling vigor index (SVI) on Vigna seed germination. The seeds treated with lower concentration show enhancement in germination% and SVI.