[Retracted] Effect of Cu Doping on ZnO Nanoparticles as a Photocatalyst for the Removal of Organic Wastewater

Figure 7

(a) UV-Vis absorption spectrum in the 300–700  nm range for synthesized samples of pure and Cu-doped ZnO NPs. (b) The band gap of the as-obtained ZnO and Cu-doped ZnO.

(a)

(b)