Sunlight assisted photocatalytic degradation of different organic pollutants and simultaneous degradation of cationic and anionic dyes using titanium and zinc based nanocomposites

Abstract ZnO-TiO2 nanocomposites have been successfully synthesized by using simple hydrothermal method with various ZnO-TiO2 concentrations (such as 2:1, 1:1 and 1:2 ZnO-TiO2, pure ZnO and TiO2). The XRD, FT-IR, HR-TEM, FE-SEM with EDAX, XPS and UV–Visible spectroscopy were utilized for characterization of the as-prepared products. XRD revealed that samples are in nanocrystalline nature with formation of anatase TiO2, hexagonal ZnO, cubic Zn2TiO4 and other zinc titanates. The average crystallite size of the samples was between 8 and 36 nm. The photocatalytic activity has been demonstrated for the degradation of methylene blue (MB), tetracycline (TC) and mixture of dyes (includes methylene blue, rhodamine B and methyl orange) under sun light irradiation at room temperature. The degradation rate of methylene blue has been significantly enhanced with increase in percentage of ZnO. Nanocomposites with 2:1 concentration of Zn and Ti, has been more efficient than that of other composites. Also, effect of different parameters such as pH of dye solution, concentration of dye and amount of catalyst etc. has been evaluated.