Electrochemical studies of nano-structured diamond thin-film electrodes grown by microwave plasma CVD

In this paper, we report the investigation of the electrochemical properties of nano-structured diamond thin-film electrodes on porous silicon (PSi) synthesized by microwave plasma chemical vapor deposition (MPCVD). For the application, boron-doped and undoped diamond thin film has been performed and fabricated into an electrode device, and its microstructure, electrical and chemical properties have been studied. In order to enlarge the surface area of diamond electrodes, a negative bias was applied to the MPCVD process to deposit diamond thin film in a nano-structured form, so that its surface remained rough and nano-fine structured. Diamond thin films were analyzed by Raman spectroscopy and SEM. The morphology of boron-doped diamond thin films on PSi reveals nano-rods in the shape of diamond crystallites. Their electrochemical properties were evaluated by performing cyclic voltammetry (CV) measurement in inorganic K4[Fe(CN)6] in a K2HPO4 buffer solution. Boron-doped diamond thin film on PSi has demonstrated good electrochemical properties, with a larger redoxidation current of CV, due to its rough surface, which provides a more active electrochemical interface.