Advanced metal oxide nanocatalysts for efficient photocatalytic degradation of environmental pollutants

Abstract

Numerous sustainable water processing techniques have been widely investigated and are capable of boosting the quality of water. Among these techniques, photonanocatalysis has emerged as one of the most promising approaches in recent decades. However, a major challenge in the environmental remediation of photocatalyst technology is to develop an ideal photocatalyst which must have excellent photocatalytic efficiency, large specific surface area, maximum harvesting of solar energy, high durability and recyclability. Due to their stability, low toxicity, low cost and superhydrophilicity TiO2 has been used by researchers as an efficient photocatalyst for the degradation of organic pollutants. Unfortunately, it suffers greatly due to its high band gap with 3.2 eV, insufficient visible light response, fast photogenerated electrons and holes recombination rate and serious agglomeration. Also, the use of harsh, toxic chemicals in the synthesis process and improper disposal of such chemicals is causing serious impact on environment. Keeping these views, this thesis intends to provide a simple, environmentally safe and easy to scale up method for the synthesis of TiO2 nanoparticles. The main objective of this research is to provide an alternative environmentally benign routes for the synthesis of TiO2 nanoparticles and their application in the treatment of organic pollutants present in water. Understanding composition-activity relationship is another essential element in the exploitation for synergistic property of composite nanomaterials in catalytic processes. This thesis provides insight about the origin of synergistic effect in composite nanocatalyst by constructing different compositions of well define CoTiO3/TiO2 nanoparticles with various Ti to Co weight ratio of 2:1 (C1) and 1:1 (C2). An environmentally benign method utilizing aqueous extract of cinnamon was employed for the synthesis of the catalysts.