Electrochemical Behavior of Proton in Silicon Dioxide

Abstract

Electrodeposition, which is one of the process depositing materials onto surface of conducting material from solution consisting of ionic species, has emerged as a promising approach to yield metal chalcogenide nanomaterials in a scalable and cost-effective manner. Despite the practical aspects of depositing nanomaterials with an excellent control of electrical and optical properties, the electrodeposition has an underlying issue of exfoliating the electrodeposits affixed to a conductive substrate for precise characterization of deposited material and advanced device fabrication. Herein, by using a reconfigured structure, direct electrodeposition of low-dimensional metal-chalcogenide on a silicon dioxide (SiO2) was studied to overcome the limitation of electrodeposition which conducting material for a substrate is inevitable to transfer electrons. Electrochemically reduced hydrogen atom generated from abundant proton in acidic bath was sufficiently diffused within the SiO2 and allowed redox reaction directly on the surface of SiO2. By controlling the onset potential of proton reduction, more importantly, the applied potential is a main parameter governing the reduction of ions in the electrolyte. The study accounts for the growth mechanisms on the SiO2 through an understanding of morphological changes and electrochemical analysis. This finding dispels prejudice of the electrodeposition by a success of complex chalcogenide deposition on the insulating substrate that enlarges its applications in fields for advanced electronics.

pH meter has been widely used in various fields such as chemical and bio research laboratory, food and beverage industry, petrochemical and pharmaceutical industry and medical diagnosis. In recent years, miniaturization of pH electrode has drawn the attention of bio scientists to measure the pH of unknown area previously: brain, cell and tissues. Herein, novel pH sensor using metal-silicon-silicon dioxide structure was developed, which has high performance for stability, reliability, wide sensing range and fast response/recovery time. With this new pH sensor platform, the miniaturization of pH sensor would be possible by small pattern of metal electrodes on silicon dioxide.