掺硼浓度对金刚石薄膜电极电化学性能影响的研究

The Influences of Boron-doping Concentration on the Electrochemical Properties of Diamond Film Electrode

以不同掺硼浓度的金刚石薄膜作为电极材料,采用循环伏安法和交流阻抗法研究了电极的电化学性能,着重分析了掺硼浓度对金刚石电极电化学性能的影响。结果表明,随着掺硼浓度的增加,电极的电势窗口略微变小,背景电流也随之变大。在铁氰化钾电解液中,未掺杂金刚石薄膜的电极表面进行的不是可逆反应,而硼掺杂金刚石膜电极表面在反应过程中有着良好的活性和准可逆性;并且随着掺硼浓度的增加,其动力学过程主要受扩散过程控制。金刚石膜电极对苯酚模拟有机污染物的循环伏安实验表明,所考察的三个硼浓度不断增加的电极的氧化峰电流密度分别为0.8,1.9和5.1mA?cm?2,说明在本实验范围内,金刚石膜电极对苯酚催化氧化作用随着掺硼浓度的增加而增强。

In order to investigate the influences of boron-doping concentration on the electrochemical performances of diamond film electrode, the electrochemical behaviors of the boron-doped diamond film electrodes with different dopant densities were studied by the cyclic voltammetry and AC impedance. The results show that with the increase of the boron dopant density, the potential windows of the electrodes become narrower and the background currents become larger. In the electrolyte including ferri/ferrocyanide, the reaction performs on the electrode surface of the undoped diamond film is irreversible, while the reactions on the electrode surfaces of the B-doped diamond films show with good activity and are quasi-reversible. With the increase of boron-doping concentration, the electrochemical reaction carrying out on the electrode surface becomes a diffusion-controlled reaction. In the cyclic voltammetry experiments, during which the phenol simulated wastewater was treated by B-doped diamond film electrodes, the current densities of the oxidation peak of three B-doped diamond film electrodes prepared with increasing boron dopant densities are 0.8, 1.9 and 5.1 mA·cm^-2, respectively. It indicates that the electrochemical oxidation ability of the diamond film electrode increases with the increase of the boron-doping concentration.