Effect of Argon Addition on Properties of the Boron-Doped Diamond Electrode

Abstract

A boron-doped diamond(BDD) electrode is attractive for many electrochemical applications due to its distinctive properties: an extremely wide potential window in aqueous and non-aqueous electrolytes, a very low and stable background current and a high resistance to surface fouling. An Ar gas mixture of H2, CH4 and trimethylboron (TMB, 0.1% C3H9B in H2) is used in a hot filament chemical vapor deposition(HFCVD) reactor. The effect of argon addition on quality, structure and electrochemical property is investigated by scanning electron microscope(SEM), X-ray diffraction(XRD) and cyclic voltammetry(CV). In this study, BDD electrodes are manufactured using different Ar/CH4 ratios (Ar/CH4 = 0, 1, 2 and 4). The results of this study show that the diamond grain size decreases with increasing Ar/CH4 ratios. On the other hand, the samples with an Ar/CH4 ratio above 5 fail to produce a BDD electrode. In addition, the BDD electrodes manufactured by introducing different Ar/CH4 ratios result in the most inclined to (111) preferential growth when the Ar/CH4 ratio is 2. It is also noted that the electrochemical properties of the BDD electrode improve with the process of adding argon.