Study of EC\' processes using Scanning Electrochemical Microscopy (SECM)

Author(s)

Fabiana Fanger Silva

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ)
• Defense date: 2021-10-08

Examining board members

Mauro Bertotti; Eduardo Mathias Richter; Maria Del Pilar Taboada Sotomayor

• Advisor: Mauro Bertotti; Alex da Silva Lima

Abstract

This work was based on the study of EC\' processes that occur in the ferrocenemethanol/ascorbate and iodide/thiosulfate systems and the use of the EC\' mechanism to increase the current from anodic oxidation processes involving ascorbate and iodide. Initially, investigations were carried out with macroelectrodes, and, in a subsequent step, microelectrodes were used. The influence of concentration, solution pH, and scan rate was studied to optimize the experimental conditions. Further experiments were carried out using Scanning Electrochemical Microscopy (SECM) as an attempt to confine the species involved in the system and to obtain a current increment because of the redox cycling effect. Juice fruit and synthetic urine samples were analyzed to evaluate the usefulness of the proposed approach. The determination of iodide and ascorbate can become more sensitive by taking advantage of the regeneration via the EC mechanism and the confinement of reagents and products established when a microelectrode is located close to a substrate (SECM configuration). (AU)

• FAPESP's process: 19/00889-4 - Electrochemical determination of iodate in urine samples by redox cycling with microelectrodes
• Grantee: Fabiana Fanger Silva
• Support Opportunities: Scholarships in Brazil - Master