Photocatalytic Degradation of Hazardous Safranin (O) Dye by Using Self Synthesized TIO2 Nanoparticles

Abstract

The textile industries generates extremely high amount of colour waste water, which are mainly poisons. A traditional biological treatment process is not helpful in treating the dye effluent because of low biodegradability of dyes. The presence of safranin (O) dye causes distinct acute impact on health therefore the removal of this dye from aqueous solution is highly desirable. The aim of this study was to assess the efficiency of photo-degradation of safanin (O) dye with application of nanoparticles of TiO2 as a photocatalyst. For this purpose nanoparticles of TiO2 were synthesized by a very simple sol-gel method with absence of additives and hydrolysing agents. The synthesized nanoparticles of TiO2 were characterized by FTIR, XRD, SEM, BET and UV-vis spectroscopy. It was found that change in polymorphic phase occurs as temperature changes from 600 to 800 0C and also the crystallinity of TiO2 increases with annealing temperature. The application of prepared TiO2 nanoparticles for photocatalytic degradation of safranin (O) dye from aqueous solution was explored. It was determined that anatase phase TiO2 shown highest photo-degradability of safranin (O) dye. The blank tests investigated for light irradiated to safranin (O) dye solution without TiO2 catalyst and for the suspension carrying TiO2 and safranin (O) dye in the dark that revealed both the photocatalyst and light energy were required for the photo-degradation of safranin (O) dye. The effect of several factors such as catalyst dose, initial concentration, pH of solution and temperature, was studied on the photocatalytic degradation of safranin (O) dye and optimized it. Results indicated that photo-degradation of safranin (O) dye increases at higher alkaline pH. The photo-degradation rate was strongly influenced by activation of TiO2 photocatalyst with photon and production of hydroxyl radicals’ hence suggested optimum catalyst dose and initial concentration of dye for photo-degradation process.