In this study preparation of Si and Zr doped CuO nanopowders have been investigated. The effects of Si and Zr doping and heat treatment temperature on the structural and optical properties of Nanopowders have been studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM-EDX), UV-Vis absorption and FTIR spectroscopy. Nanopowders were obtained by sol gel method under room conditions (temperature, 25–32 ◦C) and were subsequently calcined at different temperatures (400–700 ◦C). XRD results suggest that adding impurities has a significant effect on the crystallinity, and particle size of CuO. The patterns showed that CuO nanopowders calcined at different temperature were Tenorite structure. The optical absorption spectrum indicates that the CuO nanoparticles have a direct band gap of 1.78 eV. But optical band gap of the doped CuO (15%Si and 15%Zr) was found to be 3.75–3.95eV.
