Use of scanning electrochemical microscopy to investigate the effect of electrochemical treatments on the activity of boron-doped diamond electrodes towards different redox species

• Grant number: 16/03347-0
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: April 30, 2016
• End date: April 29, 2017
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Romeu Cardozo Rocha Filho
• Grantee: Ricardo Francisco Brocenschi
• Supervisor: Michael V. Mirkin
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Institution abroad: City University of New York, New York (CUNY), United States
• Associated to the scholarship: 14/11769-6 - Effect of electrochemical pretreatments on the superficial terminations of boron-doped diamond electrodes and influence of these terminations on the electrochemical response of different redox species, BP.PD

Abstract

Recently we have confirmed that the hydrogenation level on the surface of a highly doped boron-doped diamond (BDD) electrode could be increased by adequate electrochemical pretreatments. Additionally, we found that BDD surfaces do not need to be highly hydrogenated to attain high electron transfer (ET) rates with the [Fe(CN)6]3/4 redox system; in fact, there seems to be a threshold for the total relative level of oxidation of the BDD surface below which [Fe(CN)6]3/4 ET is no longer hindered. Using square-wave voltammetry, we also confirmed that the overpotential for ascorbic acid (AA) oxidation is very sensitive to the total relative level of oxidation of the BDD surface, decreasing as this level of oxidation is decreased. Thus, the objective of this BEPE research internship is to use scanning electrochemical microscopy (SECM) as a tool to understand how the level of oxidation of a highly doped BDD surface influences its electrochemical activity towards different redox systems, specially AA and [Fe(CN)6]3/4. The main focus will be on obtaining quantitative physico-chemical information by the combination of experiments with mathematical modeling and computer simulations. The electrochemical activity of the pretreated BDD surface for the redox systems will be assessed by SCEM at localized sites of the eletrode/solution interface (possibly at different crystallite facets of the BDD surface), complemented by voltammetric techniques and electrochemical impedance spectroscopy. The level of oxidation of the BDD surface attained after each specific electrochemical pretreatment will be determined by XPS, whereas morphological characterizations might be conducted using AFM, SEM, and SECM. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BROCENSCHI, RICARDO F.; SILVA, TIAGO A.; LOURENCAO, BRUNA C.; FATIBELLO-FILHO, ORLANDO; ROCHA-FILHO, ROMEU C.. Use of a boron-doped diamond electrode to assess the electrochemical response of the naphthol isomers and to attain their truly simultaneous electroanalytical determination. Electrochimica Acta, v. 243, p. 374-381, JUL 20 2017. (14/11769-6, 14/03019-7, 16/03347-0)

BAE, JE HYUN; BROCENSCHI, RICARDO F.; KISSLINGER, KIM; XIN, HUOLIN L.; MIRKIN, MICHAEL V.. Dissolution of Pt during Oxygen Reduction Reaction Produces Pt Nanoparticles. Analytical Chemistry, v. 89, n. 23, p. 12618-12621, DEC 5 2017. (16/03347-0)