Analytical detection of nitrate in aqueous solution for environmental monitoring: development and application of doped diamond electrode modified with metallic particles

• Grant number: 07/07385-4
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2008
• End date: April 30, 2010
• Field of knowledge: Interdisciplinary Subjects
• Principal Investigator: Maria Cristina Forti
• Grantee: Maria Cristina Forti
• Host Institution: Instituto Nacional de Pesquisas Espaciais (INPE). Ministério da Ciência, Tecnologia e Inovação (Brasil). São José dos Campos , SP, Brazil

Abstract

Nitrate (NO3-) is naturally found in waters and soils and is one component of the nitrogen cycle (N) therefore question related to the knowledge of the functioning and changes in the N cycle in different ecosystems natural or not are intimately linked with the amount of nitrate and its sources and sinks. In this project it is proposed the development, validation and operation of a sensor for nitrate in aqueous solution that will be build from diamond electrodes, and therefore leading to its nationalization as well as the patent of its characterization procedures. The electrodes will be prepared on silicon substrate doped with boron with variable concentrations. In order to improve the diamond electrode electro-catalytic activity the deposition of metallic nanoparticles will be carried on utilizing the technique of potential jump, varying some preparation conditions, such as, deposition potential, time and concentration of the metallic ions in the solution. The morphology, structure and electrochemical properties of the electrode will be characterized and applied to the study of the electrochemical nitrate reduction in aqueous media. The obtained products of the electrochemical nitrate reduction process will be quantified simultaneously with other analytical techniques such as flow injection analysis (FIA) and potentiometry. The use of doped diamond electrodes for analytical detention of nitrate will be validated against other techniques used for the same purpose. (AU)