Electrochemical Properties of Boron-Doped Diamond Electrodes Prepared by Hot Cathode Direct Current Plasma CVD

Abstract

A series of boron-doped diamond (BDD) films were deposited by using a hot cathode direct current plasma chemical vapor deposition(HCDC-PCVD) system with different ratios of CH₄/H₂/B(OCH₃)₃ (trimethylborate) gas mixture. The morphology, structure and quality of BDD films were controled by SEM, XRD and Raman measurements. The electrochemical properties of the BDD films were investigated by electrochemical methods. Cyclic voltammetric performances of the BDD films indicated that the main determinant in the electrochemical characteristics of BDD films was the boron doping amount. The threshold potential for oxygen evolution increased from 1 V to 2.5 V. Meanwhile, the electrochemical potential window of BDD films was enlarged from 2.2 V to 4.5 V when the B content was increased from 1.75 × 10¹⁹cm^-3 to 2.4 × 10²¹ cm⁻³. The cyclic voltammograms of BDD films in K₄Fe(CN)₆ and K₃Fe(CN)₆ mixed solution indicated that the behavior of Fe(CN)₆^-3/-4 redox couple could be regarded as semi-reversible.

DOI: http://dx.doi.org/10.5755/j01.ms.22.2.12926