DEVELOPMENT OF THIN-FILM ELECTRODES BASED ON SPUTTERED AMORPHOUS-CARBON

The fabrication of a novel thin film electrode based on radio frequenc y (RF) magnetron sputtered carbon 10 to 500 nm thick is reported. To m inimize problems arising from the ohmic resistance of carbon thin film s, a titanium nitride base layer is sputter-deposited onto a silicon s ubstrate. This carbon thin film electrode (CTE) compares very favorabl y with conventional carbon electrodes such as glassy carbon. The CTE e xhibits a low double-layer capacitance, a large electrochemical window , and a relatively high activity toward ferricyanide reduction. The fo rmation of surface functional groups and the resulting pH response Is discussed. Due to the smoothness of the surface, the CTE provides an e xcellent substrate for mercury films. The potentiometric stripping res ponse of the mercury-coated CTE toward cadmium, lead, and copper ions at the ppb concentration level in nondeoxygenated solutions is studied . Furthermore, a comprehensive evaluation of physicochemical propertie s of RF magnetron sputtered carbon films is presented.