In this work we have tried to prepare Ni and Ag doped ZnO nanopowders using the sol gel technique. The influence of Ni and Ag (1, 3 and 5 mol.%) on the crystalline structure and optical properties of ZnO was investigated. The samples were characterized by XRD, FTIR and UV–visible spectrophotometer. XRD patterns confirmed the wurtzite formation of doped and undoped ZnO nanopowders. The average crystallite sizes of the prepared samples found from XRD were 19 nm for undoped ZnO, from 17 to 22 nm for Ni-ZnO and from 19 to 26 nm for Ag-ZnO. The average crystallite size of Ag-ZnO increased with increasing Ag contents. Different optical properties of Ni-ZnO and Ag-ZnO nanopowders were observed for different Ni and Ag content. The band gaps of Ni-ZnO and Ag-ZnO nanopowders were lower than that of the undoped ZnO (3.1 eV). The band gaps of Ag-ZnO were lower than that of Ni-ZnO. The optical properties of ZnO were enhanced by Ni (mol.%) in the UV region and by Ag (3 and 5 mol.%) in the visible region.

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Copper doped  ZnS  nanoparticles (Zn1-xS:Cux  x =0,0.025,0.05,0.075) have been fabricated at room temperature without any capping agent by using chemical co- precipitation method. The prepared samples were analyzed by X-ray diffraction (XRD), a Scanning Electron Microscope (SEM), Energy Dispersive X-ray spectroscopy (EDS), and UV-Vis spectrophotometer. XRD studies confirmed  that crystalline  size of prepared nanoparticles are found between (2.034 -1.986 nm) and crystal  structure was cubic,  EDS spectra confirmed the presence of  Cu in the samples. UV-Vis studies confirmed  that the value of optical band gap has been found between (4.66 - 4.99 eV)  and the SEM images describe massive agglomeration of particles with more or less spherical morphology.

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