Diamond electrodes: Diversity and maturity
- PDF / 629,512 Bytes
- 8 Pages / 585 x 783 pts Page_size
- 26 Downloads / 211 Views
Introduction Since the first publications on the basic electrochemical properties of diamond in the late 1980s and early 1990s,1–3 as well as the first patent on the application of diamond anodes for treating wastewater prior to discharge into the environment,4 interest in the use of electrically conducting diamond electrodes has steadily grown. Today, diamond electrodes find widespread use in electroanalysis, spectroelectrochemistry, neurochemistry (i.e., chemistry of neurotransmitters used for cellular communication), chemical/biological sensing, and water disinfection/purification. Diamond electrodes have attracted this level of interest due to their excellent electrochemical properties.5–10 These include (1) the ability to prepare the material in different architectures, (2) a wide working potential window, (3) enhanced signalto-background ratios due to the low background current, (4) good activity without conventional pretreatment, (5) weak molecular adsorption, and (6) optical transparency. It could be argued that chemical vapor deposited (CVD) diamond is the most versatile of all the different carbon electrode materials because it can be used in electroanalysis to provide low detection limits for analytes with superb precision and stability,11,12 for high-current density electrolysis (1–10 A/cm2) in aggressive solution environments without any microstructural or morphological degradation,13 as a corrosion-resistant electrocatalyst
support,14,15 and as an optically transparent electrode (visible and IR) for spectroelectrochemical measurements.16–18 This advanced carbon-based electrode provides researchers with a material that meets the requirements for a wide range of applications. In electroanalytical measurements, diamond electrodes generally provide significant improvements over conventional sp2 carbon electrodes in terms of linear dynamic range, limit of detection, response precision, and response stability. Broad application of this novel electrode material has been somewhat limited until recent years because there were no commercial suppliers. Today, the situation has changed, as there are multiple commercial suppliers of electrically conducting diamond thinfilm electrodes. Importantly, the cost of these materials is not high, as often perceived when one hears the word “diamond.”
Diamond materials and electrode architectures Several types of diamond electrodes can be prepared in different architectures. Single crystal diamond can be readily obtained and is most useful for fundamental studies of interfacial structure as well as grain boundary and crystallographic effects on rates of electrochemical reactions. Polycrystalline thin-film electrodes, deposited on properly pretreated substrates (e.g., Si, W, Mo, Nb, and Pt), are the most commonly utilized form of diamond. Sharpened metal wires can be coated with conducting diamond to form microelectrodes that are useful in
Yasuaki Einaga, Department of Chemistry, Keio University, Japan; [email protected] John S. Foord, Department of Chemistry, Chemistry Rese
Data Loading...
