An Approach Towards Inactivation of Susceptible and Antibiotic Resistant Bacterial Contamination using Novel Photo electro catalysts

Abstract

Water in most rivers in India does not meet the standards for drinking and even for bathing purposes due to the high concentration of coliforms, organic and inorganic contaminants. Overuse, uncontrolled release and careless disposal of drug, pharmaceutical components from hospital and domestic waste imparts a crucial role in developing a resistance towards antibiotics in microbes over a period of time. The class of bacteria affected by antibiotics are hereby called susceptible bacteria and the class that shows resistance towards antibiotics are known as antibiotic resistant bacteria. Therefore, presence of both class of microbes in water pose a serious question on the public health. The conventional ways to remove microbes possess the limitations of generating harmful by-products, fouling, high energy requirement and so on. In this regard, heterogeneous photocatalysis eliminates all the above-mentioned limitations by providing ease of separation, energy and cost benefits. However, there are some limitations associated with it such as recovery of the catalyst, reusability of the catalyst, photo-corrosion in the semiconductor material and so on. In this work, efforts have been made to rectify the issues associated with the use of photocatalysts at a larger scale. Semiconductor based photocatalysis possesses capability to facilitate surface redox reaction for generation of highly oxidizing and reducing radicals for mineralization of contaminants into non-harmful by-products as a result of absorption of photons. Commercially available catalysts such as TiO2, ZnO are wide band gap semiconductors and are highly efficient under UV irradiation. However, their wide band gap limits their viable usage in visible/ longer wavelength light. Due to limited access of UV wavelength from solar light (3-4 %), there is extensive need to design visible light responsive semiconductors or composites...