Hydrothermally Grown ZnO Nanoparticles for Photodegradation of Textile Dye

Zinc oxide (ZnO) is one of the most investigated semiconductor material for photocatalytic applications such as solar cell, light emitting diode, photodiodes, photodetectors and sensors. Surface to volume ratio for nanoparticles increases with decrease in size and give rise to enhanced surface reactivity. Out of all available methods for the synthesis of ZnO nanoparticles hydrothermal method is one of the simplest methods with tolerable growth conditions. In the present work, hydrothermally grown ZnO nanoparticles have been demonstrated for photocatalytic degradation of direct violet dye, which is largely used in textile industries and hence can be found in industrial waste water. The synthesized ZnO nanoparticles have been characterized using SEM, X-ray diffraction, Raman and UV-Vis absorption spectroscopy. The average crystallite size as calculated using Scherrer formula comes out to be around 40 nm. The UV-Vis absorption spectrum of ZnO shows a sharp absorption band edge around 360 nm, indicating its UV responsive photocatalytic activity. Since direct violet dye is having an absorption in similar UV region, ZnO have been demonstrated for photocatalytic reduction of different concentrations of direct violet. It is observed that the photocatalytic process obey first order kinetics in the present work.