Unique and bio-inspired synthesis of nickel oxide nanoparticles by using an innocuous and ecofriendly waste material that is watermelon rind. In the reaction, watermelon rind recycled and used its extract as a solvent which act as a reductant for a synthesis of nickel oxide nanoparticle. The synthesized NiO NPs were analyzed by using X-ray Diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and UV-Vis spectroscopy. FTIR peak at 745 cm-1 and 671 cm-1 indicated that the formation of Ni-O bond. A prominent peak of UV-Vis spectra at 283 nm and band gap, calculated with the help of UV data, was ~3.3 eV. The obtained PXRD pattern and JCPDS data suggested the formation of nickel oxide nanoparticle and the average crystallite size calculated by Scherrer’s equation in between 30 to 150 nm. The average grain size of NiO NPs perceived from TEM images was 46.55 nm and polygonal barrel shape particles. Since, a simple, straightforward, pollutant-free, and economical technique for the synthesis of nickel oxide nanoparticles. However, the above synthesized nickel oxide nanoparticles have been explored for biophysical parameter vis. radicle length, plumule length and germination percentage on a Vigna radiata (moong) seed by the treatment of some concentration i.e. 25 ppm, 50 ppm, 100 ppm and 200 ppm in germination processes. At a low concentration of 25 ppm, a beneficial improvement in the germination process of Vigna radiata seed was observed.

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.

In this study, five complexes of the type [CrLCl2]Cl [where L = S4 macrocyclic ligands] were prepared and analyzed by elemental analysis, molar conductivity, infrared and X-ray photoelectron spectroscopy and their geometry was established as octahedral.