Removal and real time determination of environmental pollutants using electrochemical photoassisted system

Abstract

In this project it is proposed the develop of photo-electrochemical system to remove and real-time monitoring of environmental contaminants in natural water samples. The pollutant removal system as well the real-time monitoring of the concentration of these substances will be based on the mechanism of a semiconductor-mediated photoelectro-oxidation of pollutants. For remediation methodology will be synthesized, characterized and applied photoanodes made of bismuth vanadate. This material, in the presence of light source and potential, have the ability to split the water molecule generating hydroxyl radicals, which oxidize the pollutants molecules, promoting the removal of these species. Subsequently it will be proposed a methodology for the real-time monitoring of pollutants using electrochemical sensors. The sensors are based on reduced graphene oxide-modified metal oxide semiconductors. The synergism between the reduced graphene oxide and the semiconductor nanoparticles will be interesting for the development of photoassisted electrochemical sensors. The gain in sensitivity is due to the fast charge transfer of the system graphene/semiconductor and the low rate of electron/hole recombination that occurs between these materials. In this case, it is possible to create a heterojunction process between the reduced graphene oxide, which can be modulated as a p-type semiconductor, and the semiconductor nanoparticles as n-type. Thus, combining the electrochemical and light energy is expected to increase the method sensitivity, consequently it will be possible the determination of substances with lower limits of detection. In this project the pollutants to be monitored are the endocrine disruptors (antibiotics, hormones, drugs and pesticides) in industrial and domestic effluent samples. Detection of these interferences will occur via direct electrochemical oxidation of the pollutants over the sensor surface. Thus, the development of an electrocatalytic system with highly sensitivity, accuracy, low cost, with potential for miniaturization, and that has the possibility for the implementation of methodology to detect in situ and in real time three endocrine disruptors in environmental matrices, it is very important. (AU)