关键词: 掺硼金刚石膜, 氧化程度, 电荷转移速率, 平带电压

Abstract:

The boron doped diamond (BDD) with different oxidation extent was prepared through electrochemical anodic oxidation, followed by characterization with various methods. The electrochemical properties and charge transfer rates of boron doped diamond electrodes with different oxidation extent were investigated by cyclic voltammetry and Mott-Schottky plot. As results, BDD morphology and quality rarely changed after oxidation by scanning electron microscopy and Raman scattering spectroscopy techniques, while the O/C+O ratio obviously increased through EDX analysis. With the help of cyclic voltammetry and Mott-Schottky plot expressed by anodic current, it showed that the charge transfer rate enhanced with the increase of BDD oxidation extent. Moreover, the surface wettability decreased with the increasing oxidation extent, thus the hydrophilic property enhanced, suggesting the charge transfer rate expressed by anodic current increased. However, results from Mott-Schottky plot expressed by redox potential difference showed completely different result, i.e., the charge transfer rate increased and then decreased. This may be due to the kinds and ratios of functional groups on the BDD surface at different oxidation time, which may cause different charge transfer rates.

Key words: boron doped diamond, oxidation extent, charge transfer rate, flat band potential