Synthesis characterization and testing of TiO2 reduced graphene oxide nanocomposites for the Photocatalytic removal of pollutants from water

Abstract

newlineWater resources all over the world are getting increasingly newlinecontaminated with toxic chemical pollutants such as pesticides, textile dyes, newlinepetrochemicals, heavy metals etc. as well as emerging contaminants like newlinepersonal care products, pharmaceuticals and endocrine disrupting newlinecompounds. Everyday anthropogenic activities introduce these contaminants newlineinto rivers, lakes, groundwater aquifers and oceans, deteriorating the newlinequality of water. As conventional methods for wastewater treatment are newlineineffective for the total removal of these pollutants, state of the art newlinetechnologies are the need of the hour. In this context, Advanced Oxidation newlineProcess (AOP) is identified as one among the most economically viable and newlineenvironmentally safe wastewater decontamination technologies. AOPs are newlinecharacterized by the in situ generation of highly reactive oxygen species newlineespecially hydroxyl radicals, which are very efficient for the destruction newlineand eventual mineralization of recalcitrant organic pollutants into carbon newlinedioxide, water and other innocuous products. AOPs for water and wastewater treatment include photolysis, newlineheterogeneous photocatalysis, ozonation, Fenton and photo-Fenton, newlineultrasound radiation, sonolysis, electrochemical oxidation and wet air newlineoxidation. Among these techniques, heterogeneous photocatalysis is newlineconsidered to be the most promising one for the degradation of organic newlinepollutants in water. Titanium dioxide (TiO2) is the most investigated newlinemetal oxide semiconductor photocatalyst due to its inherent properties newlinesuch as chemical inertness, photostability, non-toxicity and low cost. newlineHowever, TiO2 has photocatalytic activity in the UV region which limits newlineits efficient utilization of solar energy comprising only 3-5% UV newlineradiations. Also the quantum efficiency of TiO2 is low because of the fast newlinerecombination of photogenerated hole-electron pairs.