Diamond electrodes dimensional stability

Conductive sp -bonded diamond is being developed as an advanced catalyst support material. Boron-doped diamond thin-film electrodes possess excellent properties for this application, such as electrical conductivity, chemical inertness, extreme corrosion resistance, and dimensional stability. Compared with more commonly used sp -bonded carbon materials, diamond is highly resistant to electrochemical corrosion. For exam-... 

Electrically conducting diamond is a new type of carlxm electrode material that is beginning to find widespread use in electroanalysis (86-88). The material possesses properties superior to other forms of carbon that include (i) low and stable background current over a wide potential range, (ii) wide working potential window in aqueous media, (iii) relatively rapid electron-transfer kinetics for several redox systems without conventional pretreatment, (iv) weak molecular adsorption, (v) dimensional stability and corrosion resistance, and (vi) optical transparency. The material is now available from several commercial sources and is not overly expensive, as commonly perceived (89). 

Diamond, due to its rigid crystalline network, is expected to be more stable than existing dimensionally stable anodes (DSAs). There are several reports on the stability and electrochemical treatment applications of diamond electrodes. Swain and coworkers have studied the morphological structural stability of diamond electrodes in both acidic and basic media [25,26]. The diamond films in their study were found to be dimensionally stable in both media, even at a current density of 0.5 A cm 2 for 20 h. However, when low quality diamond films, with significant sp impurities, were used, this harsh treatment resulted in the formation of pits at the grain boundaries. Ramesham and Rose [27] demonstrated the high corrosion resistance of diamond films in comparison to molybdenum, as well as noble metals such as Pt and Au. 

Conductive boron doped diamond is an alternative to traditional carbon electrodes that provides superior chemical and dimensional stability, low background currents, and a very wide potential window of water stability (Fig. l.l). In this Chapter we describe the historical development of these unique electrodes. 

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