Development of a versatile rotating ring-disc electrode for in situ pH measurements

Author(s)

Zimer, Alexsandro Mendes ^[1] ; da Silva, Marina Medina ^[1] ; Machado, Eduardo G. ^[2] ; Varela, Hamilton ^[2] ; Mascaro, Lucia Helena ^[1] ; Pereira, Ernesto Chaves ^[1]

Affiliation

^[1] Fed Univ Sao Carlos UFSCar, Dept Chem, Lab Interdisciplinar Eletroquim & Ceram LIEC, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Inst Chem Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Analytica Chimica Acta; v. 897, p. 17-23, OCT 15 2015.
• Web of Science Citations: 3

Abstract

There are some electrocatalytic reactions in which the key parameter explaining their behavior is a local change in pH. Therefore, it is of utter importance to develop an electrode that could quantify this parameter in situ, but also be customizable to be used in different systems. The purpose of this work is to build a versatile rotating ring/disc electrode (RRDE) with IrOx deposited on a glass tube as a ring and any kind of material as disc. As the IrOx is sensitive to pH variation, the reactions promoted on the disc can trigger proportional pH shifts on the ring. In such assembly, the IrOx ring presents a fast response time even during the pH transients due to the small thickness of the ring (approximately 10 mu m), which enables the detection of interfacial pH changes. The ring electrode was tested toward the interfacial pH shift observed during the electrolytic reduction of water on the disc and also characterized by acid-base titration to determine the response time. As the main conclusions, fast response and durable RRDE were obtained, and this assembly could be used to revisit many electrocatalytic reactions in order to test the importance of local pH on the process. (C) 2015 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 13/16930-7 - Electrocatalysis V: electrocatalytic processes of chemical and electrical energy interconversion
• Grantee: Edson Antonio Ticianelli
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/13503-0 - Development of sensor for interfacial-pH analysis during the pit corrosion observed in situ by temporal series micrographs
• Grantee: Marina Medina da Silva
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 12/07313-1 - Electro-oxidation of mixed fuels: kinetical instabilities and mechanism
• Grantee: Eduardo Giangrossi Machado
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 11/19430-0 - In situ investigation of carbon steel corrosion by means of temporal series micrographs coupled with electrochemical techniques
• Grantee: Alexsandro Mendes Zimer
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC