pH measurement near the electrochemical reaction interface with the pH-sensing electrodes

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K14144
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Composite materials/Surface and interface engineering
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: TADA EIJI 東京工業大学, 物質理工学院, 准教授 (40302260)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 材料加工・処理 / 水素イオン濃度 / 金属酸化物電極 / 水溶液腐食 / カンチレバー / ケルビン法

Outline of Final Research Achievements

This study was designed to establish the technology to measure pH near the electrochemical reaction interface such as aqueous solution corrosion of metal. In particular, the pH measurement of the electrochemical reaction interface was attempted using a metal / metal oxide electrodes having pH response characteristics. As a result, we succeeded in measuring surface pH in a simulated corrosion system for iron using Sb / Sb oxide electrode. In addition, with the aim of measuring the local pH in the vicinity of the electrochemical reaction interface, W film produced using a sputtering method showed sub-Nernstian pH response and could be uniformly deposited on the cantilever for AFM.

Free Research Field

金属電気化学

Academic Significance and Societal Importance of the Research Achievements

現在溶液内のpH計測では，複合ガラス電極，IS-FET素子，蛍光による測定があるが，センサの体積や色素の空間的広がりなどの理由で，空間分解能が低く，電極反応界面近傍のpHの測定には適用でが困難である．本研究では，金属／金属酸化物電極のpH応答特性を利用することで，金属腐食反応界面のpH測定に成功した．また，W膜がpH応答特性に優れること，原子間力顕微鏡のカンチレバーに成膜できることを示したことは，今後電気化学反応界面の極近傍のpH測定への応用が期待される．本研究はナノ電気化学分野に対する学術的貢献があるといえる．