Tamarindus indica mediated biosynthesis of nano TiO2 and its application in photocatalytic degradation of Titan yellow

Present article reports for the first time a simple, eco-friendly synthesis of nano TiO2 semiconductor photo - catalyst mediated by ethanolic Tamarindus indica leaf extract using titanium isopropoxide as precursor. XRD of the obtained product confirms the synthesis of anatase titania. Presence of aggregates of near spherical particles of size range 20-40 nm was revealed by SEM and TEM images. Purity of synthesised titania was verified by EDX and the surface area of the product determined by BET was 75 m(2)/g. The band gap estimated by UV spectroscopy was 3.21 eV. The photocatalytic activity of synthesised nano TiO2 was tested on photodegradation of Titan yellow dye by heterogeneous semiconductor photocatalysis process. The effect of TiO2 loading (0.25-1.0 g/l), initial concentration of Titan yellow (10-40 ppm), pH (3, 5, 7, 9 and 11) of the dye on photodegradation was studied in presence of UV light of 125 W. The percent degradation observed for 10 ppm dye at nano TiO2 loading of 0.75 g/l at pH 7.0 was 95% in 120 min. Effect of various light source and irradiation time were also studied. The degradation data was best fitted by Langmuir Hinshelwood kinetics with apparent rate constant of 0.015 min(-1) The photo degradation follows the pseudo first order kinetics.