Synthesis of ZnO:TiO2 nanocomposites for photocatalyst application in visible light

xZnO:(1-x)TiO2 (x = 1.0, 0.6, 0.5, 0.4, 0.0) nanocomposites powder were synthesized by sol-gel method. The X-ray diffraction results have shown a mixed phase of titanium dioxide and zinc oxide. The average crystallite size was found in the range of 20-45 nm. The absorbance of ZnO:TiO2 nanocomposite powder was measured in the wavelength range from 350 to 800 nm and the optical bandgap was varied from 3.30 to 3.10 eV. The ZnO:TiO2 nanocomposites were investigated for their adaptability to degrade organic methyle blue dye under the influence of visible light. ZnO:TiO2 nanocomposite powder exhibit better absorption of visible light and generates more number of electron hole pairs. The photodegradation was increased from 75 to 90% with the varying of x from 1.0 to 0.4. For futher studies of the photocatalyst, biological oxygen demand and chemical oxygen demand were used for examining the consumption of oxygen in the dye with catalyst. The ZnO:TiO2 nanocomposites powder shows a better adaptability in photocatalytic applications under visible light as compared to other metal oxide nanocomposites.