Novel VIS Photoactive nanocatalyst for solar based water desinfection

The presence of pathogenic microorganisms in drinking water is a global concern since they may result in the risk of waterborne disease transmission such as typhoid, hepatitis, cholera, tuberculosis, and pneumonia. The WHO estimates that 884 million people lack access to improved water supplies, leading to millions of deaths and countless cases of disease and disability which is caused by microorganism-containing water in rural and isolated areas. Conventional inactivation methods are chlorination, ozonation, UV irradiation, and membrane technology. Among these methods chlorination is the most widely used inactivation method because of its low cost, high efficiency, and residual effect. Chloro-organic by-products which are highly carcinogenic would be generated during the chlorination process. Other frequently used processes are ozonation and UV irradiation, which also have drawbacks such as generation of toxic by-products, complicated and expensive equipment, and lack of residual effect. Membrane technology can only remove bacteria from water rather than kill them. Thus, alternative and low-cost methods of controlling pathogenic microorganisms with nontoxicity by-products such as nano-photocatalysts are intensively researched.Photocatalysts received wider attention when Matsunaga and al, reported the inactivation of 3 microbial cells (Lactobacillus acidophilus, Saccharomyces cerevisiae and Escherichia coli) through PEC process in 1985. TiO2 was the most promising photocatalyst. But due to its wide band (3.18 and 3.02 eV for anatase and rutile), TiO2 can only be activated in the near UV (? 400 nm). Thus, from viewpoint of efficient utilization of solar light, the development of efficient VISIBLE-light-driven photocatalysts for water disinfection is of a crucial issue. The VIS compound of choice is BiVO4.This project is geared towards green synthesis of effective nano-scaled Fe:BiVO4 using natural extracts as chelating agents and demonstrate their superior photocatalytic effectiveness.