Nanoparticles of tin oxide (SnO₂) powders were prepared by co-precipitation method at 500 °C, 700 °C and 900 °C temperature. The sintered SnO₂ nanoparticles, structural, optical, magnetic, morphological properties and microbial activity have been studied. XRD studies reveals that sintered powder which exhibits tetragonal crystal structure and both crystallinity as well as crystal size increase with increase in temperature. The morphological studies reveal randomly arranged grains with compact nature grain size increases with sintering temperature. The compositional analyses of SnO₂ nanoparticles have been studied using X-ray photoelectron spectroscopy analysis. The optical band gap values of SnO₂ nanoparticles were calculated to be about 4.3 eV in the temperature 500 °C, comparing with that of the bulk SnO₂ 3.78 eV, by optical absorption measurement. Room temperature M-H curve for pure SnO₂ nanoparticles exhibits ferromagnetic behaviour. The tin oxide nanoparticles are acted as potential candidate material for bacterial and fungal activity.

Nanoparticles of Li, Mg and Sr doped and undoped zinc oxide was prepared by simple precipitation method. The structural, optical, and magnetic properties of the samples were investigated by the Powder X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), Fourier Transform Infrared (FTIR) spectroscopy, Ultra-violet Visible spectroscopy (UV-vis) spectra, Photoluminescence (PL) and Vibrational Sample Magnetometer (VSM). The Powder X-ray diffraction data confirm the formation of hexagonal wurtzite structure of all doped and undoped ZnO. The SEM photograph reveals that the pores availability and particles size in the range of 10 nm–50 nm. FTIR and UV-Visible spectra results confirm the incorporation of the dopant into the ZnO lattice nanostructure. The UV-Visible spectra indicate that the shift of blue region (lower wavelength) due to bandgap widening. Photoluminescence intensity varies with doping due to the increase of oxygen vacancies in prepared ZnO. The pure ZnO exist paramagnetic while doped (Li, Mg and Sr) ZnO exist ferromagnetic property. The photocatalytic activity of the prepared sample also carried out in detail.