Fabrication of porous boron-doped diamond on SiO2 fiber templates

Boron-doped diamond (BDD) has become a well-established material in electrochemistry. Yet, many applications of BDD, especially thin films, would greatly benefit from an increase in specific surface area. This paper presents a simple and reproducible method for producing a stable BDD porous surface, which results in an increase in specific surface area. To fabricate porous films, BDD coated electrospun SiO2 fibers are prepared on top of planar BDD films using doctor blade and spin coating techniques. Deposition of BDD is performed using a microwave plasma enhanced chemical vapor technique. Grown porous BDD layers are characterized by scanning electron microscopy and Raman spectroscopy. In addition, specific surface area is determined using cyclic voltammetry and from Kr adsorption isotherms evaluated by the Brunauer-Emmett-Teller method. The highest capacitance value of ca. 7 mF/cm2 is found for the porous BDD prepared by doctor blade coating after removal of SiO2 fibers template by hydrofluoric acid. Electrochemical cycle stability is determined by galvanostatic charge/discharge. The charge retention is 85% after 3000 cycles.

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