This research include, photocatalytic decolorization of an aqueous solution of 3
ppm of brilliant cresyl blue in a suspension of 0.11gm/100 ml of ZnO metal oxide
semiconductor as a catalyst, was carried out by using 125Watts mercury lamp from external
source inside a Pyrex photoreaction cell of 100 ml at room temperature 298 K. The effect
of various parameters, such as mass of catalyst, initial dye concentration, and light intensity
was studied. The disappearance of original colored dye concentration with irradiation time
was monitored by using UV-VIS spectrophotometer. The results indicate that this
photoreaction is a pseudo first order reaction according to the Langmuir -Hinshelwood
relationship. It has been observed that the increase of light intensity leads to the increase of
decolorization rate of brilliant cresyl blue.