Effect of zinc acetate dihydrate precursor concentration on the properties of TiO2-ZnO core-shell nanograss hetero-structure

TiO2-ZnO core shell nanograss (NG) hetero-structure was synthesized via two-step synthesis techniques, namely, liquid phase deposition (LPD) to prepare the TiO2 core nanograss and dip-coating technique to prepare the ZnO shell onto the core. The effect of the concentration of zinc acetate dehydrate (ZAD) precursor on the properties of TiO2-ZnO core shell has been investigated. The FESEM characterization reveals that the TiO2 NG has high density of nanobranch with sharp multiple arms. The morphological observation shows that 0.15 M is the optimum ZAD concentration in forming the TiO2-ZnO core-shell NG. It was found that the morphology changes from nanograss to nanoparticle as the concentration of ZAD is further increased to 0.20 M. The structural characterization by XRD confirms that the formation of anatase TiO2 and wurzite ZnO phases in the core-shell structure. The crystallite size of the TiO2 core decreases with the concentration of ZAD. The optical absorption of the sample increases with the concentration of ZAD in the wavelength range of 350-380 nm.