In order to check if there is any peak shift with respect to doping concentrations

In order to check if there is any peak shift with respect to doping concentrations, the peak with highest intensity was considered and compared in Fig. 2. It was observed that peak position has slightly shifted to lower diffraction angle in the doped samples when compared to the pure ZnO. This explains that doped ions have been completely dissolved into the lattice of ZnO. This had resulted in the peak shift to lower diffraction angle. Recently, nanosized metal-oxide semiconductor materials have played an important role in the photo degradation of organic contaminants 10. Zinc oxide also has been considered as a suitable alternative for TiO2 due to its similar band (3.3eV), lower cost and better stability 11-12. However, the application of ZnO semiconductor is limited because of its higher charge carrier recombination rate 13. The presence of corrector ingredients in the ZnO crystals changes the coupling velocity of load carriers and relocation width of the band into visible area remarkably 14. Doping is a powerful way to enhance the separation of charge carries in semiconductor photocatalyst 15. Doping with metallic cations or non-metallic anions has been widely used for the modification of ZnO to improve its photocatalytic activity or to extend its light absorption into visible region 16.