A remarkable improvement in photocatalytic activity of ZnO nanoparticles through Sr doping synthesized by one pot flash combustion technique for water treatments

Abstract

Zinc oxide is well-known material and used in several applications. We have synthesized the good quality ZnO nanoparticles with different concentrations of Strontium (Sr) doping for photocatalytic applications. The elemental composition and homogeneous distribution of Sr doping in ZnO was investigated through EDX/SEM mapping. The morphology of synthesize products was studied through FE-SEM and grain size was estimated. X-ray diffraction (XRD) and FT-Raman spectroscopy analyses approves the single phase and purity of synthesized Sr:ZnO NPs as no additional peak in XRD and Raman was seen. The size of crystallites was estimated using Scherrer equation and noticed to be reduced from 24 to 16 nm with rising the Sr concentration. The energy gap was estimated using Kubelka-Munk function and noticed in range from 3.25–3.27 eV with Sr concentration. The photoluminescence spectra were recorded for all Sr:ZnO NPs at λexc =350 nm. The photocatalytic activity of Sr:ZnO NPs samples was investigation by decolourization of methylene blue (MB) dye under irradiation of black-light in an aqueous solution at ambient conditions. A remarkable improvement in photocatalytic activity was obtained for the entire prepared Sr:ZnO samples compared to that of neat ZnO. Such improvement in photocatalytic activity can be attributed to the effective photogenerated charges separating, in addition to the good adsorption of MB dye molecules over Sr:ZnO NPs surface.