The Effect of Different Dopants (Cr, Mn, ‎Fe, Co, Cu and Ni) on Photocatalytic ‎Properties of ZnO Nanostructures

   ZnO structures with different dopants (1mol% Cr, Mn, Fe, Co, Cu and Ni) have been synthesized via a simple hydrothermal method using sucrose as a template. These doped ZnO nanostructures characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL). The photocatalytic property of these synthesized materials was studied by a photocatalytic characterization system. The PL results confirmed that these dopants showed a significant effect on photoluminescence properties of ZnO structure. Among the synthesized photocatalysts, Ni doped ZnO showed a significant enhancement of photodecolorization capability (98.6 %) toward Congo red dye in UV irradiation. Also, it showed the highest dye adsorption (80%) at dark conditions. The improvement of decolorization of this photocatalyst might be attributed to enhancement the chance of the separation of electrons and holes, high capacity of dye adsorption and presence of defects in its structure. Preliminary experiment suggested Ni doped ZnO as effective photocatalyst for treating some pollution such as azo dyes.