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

Autor(es)

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

Afiliação do(s) autor(es)

^[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

• Tipo de documento: Artigo Científico
• Fonte: Analytica Chimica Acta; v. 897, p. 17-23, OCT 15 2015.
• Citações Web of Science: 3

Resumo

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)

• Processo FAPESP: 13/16930-7 - Eletrocatálise V: processos eletrocatalíticos de interconversão entre as energias química e elétrica
• Beneficiário: Edson Antonio Ticianelli
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 13/13503-0 - Desenvolvimento de sensor para determinação de pH interfacial durante a corrosão puntiforme observada in situ por serie temporal de imagens
• Beneficiário: Marina Medina da Silva
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 12/07313-1 - Eletro-oxidação de misturas de combustíveis: instabilidades cinéticas e mecanismo
• Beneficiário: Eduardo Giangrossi Machado
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 11/19430-0 - Investigação in situ da corrosão do aço carbono por meio de series temporais de imagens acoplada a técnicas eletroquímicas
• Beneficiário: Alexsandro Mendes Zimer
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/07296-2 - CDMF - Centro de Desenvolvimento de Materiais Funcionais
• Beneficiário: Elson Longo da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs