Abstract
Growing diamond film on a titanium substrate is a challenge. The major problem is the stability of the diamond film form. Since titanium metal is an ideal material for electrode fabrication, especially for DSA type electrodes, the research on the improvement of working life of boron-doped diamond film on titanium (Ti/BDD) remains a hot topic. By using proper pretreatment and a suitable combination of precursor gases, my research laboratory has been able to fabricate Ti/BDD electrodes using hot-filament chemical vapor deposition method with accelerated working life over 260 hours (measured under conditions of 10,000A/m2 in 3M H2SO4). The accelerated service life was further improved to 320 hours by deposition a layer of silicon between Ti and BDD layers. A recent innovation by having staged substrate temperatures lead to the producing of the Ti/BDD electrode with an accelerated service life over 800 hours. This great improvement was found to be attributed to the formation of a TiC layer at lower substrate temperature during the first stage of deposition, followed with a high quality BDD layer deposited at the latter stage at higher substrate temperature. The Ti/BDD electrodes can be utilized as electrochemical sensors of measuring pollutants, or work as anodic electrode in electro-oxidation of various pollutants such as acetic acid, maleic acid, dyes, phenols, etc.