Effects of metal-doping on zinc oxide nanoparticles synthesized via solvothermal method

Abstract

This research studies properties of metal-doped ZnO nanoparticles synthesized via solvothermal method, i.e. thermal decomposition of zinc acetate in 1, 4-butanediol, at 220 degree Celsius for 2 h. The physical properties of the product were investigated by XRD, SEM, XPS and UV/Vis. Doping of Ga, Cu, Al and Mg as the secondary metal at metal content 0 -12.5 at. % into ZnO crystals during solvothermal sysnthesis and calcinations at temperature 300-900 degree Celsius were also investigated. It was found that Ga and Al incorporated in ZnO crystal structure affected properties of ZnO nanoparticles. Blue-shift in UV absorption spectrum from Ga and Al doping indicated a change in electronic states of the product. An increase in the content of Ga and Al doping resulted in further shift in the UV absorption spectrum. Addition of the secondary metal also affected morphology of the synthesized particles. Calcination resulted in red-shift in UV absorption spectrum of Ga- and Al-doped zinc oxide. For Cu and Mg doping, the properties of as-synthesized samples were the same as undoped ZnO, but calcinations caused blue-shift in UV absorption spectrum of Mg-doped ZnO because ZnO was alloyed with Mg by calcinations at temperature higher than 700 degree Celsius. The photocatalytic degradation of methylene blue and the photoluminescence spectra were also employed to investigate properties of metat-doped ZnO.