Surface Hydrogenation of Boron-Doped Diamond Electrodes by Cathodic Reduction

• Published in: Analytical chemistry (Washington) Vol. 89; no. 21; pp. 11341 - 11347
• Main Authors: Kasahara, Seiji, Natsui, Keisuke, Watanabe, Takeshi, Yokota, Yasuyuki, Kim, Yousoo, Iizuka, Shota, Tateyama, Yoshitaka, Einaga, Yasuaki
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 07.11.2017
• Subjects: Analytical chemistry; Boron; Chemical reduction; Chemistry; Diamonds; Electrochemical analysis; Electrochemistry; Electrode materials; Electrodes; Hydrogen atoms; Hydrogen storage; Hydrogenation; pH effects; Protons; Sensitivity; Windows (computer programs)
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.7b02129

Boron-doped diamond (BDD) has attracted much attention as a promising electrode material especially for electrochemical sensing systems, because it has excellent properties such as a wide potential window and low background current. It is known that the electrochemical properties of BDD electrodes are very sensitive to the surface termination such as to whether it is hydrogen- or oxygen-terminated. Pretreating BDD electrodes by cathodic reduction (CR) to hydrogenate the surface has been widely used to achieve high sensitivity. However, little is known about the effects of the CR treatment conditions on surface hydrogenation. In this Article, we report on a systematic study of CR treatments that can achieve effective surface hydrogenation. As a result, we found that the surface hydrogenation could be improved by applying a more negative potential in a lower pH solution. This is because hydrogen atoms generated from protons in the CR treatment contribute to the surface hydrogenation. After CR treatments, BDD surface could be hydrogenated not completely but sufficiently to achieve high sensitivity for electrochemical sensing. In addition, we confirmed that hydrogenation with high repeatability could be achieved.