Diamond foam electrodes for electrochemical applications

Nano-structured electrodes become promising materials for a vast number of applications such as bio-chemical sensing, supercapacitors, etc. We introduce a new concept to generate surface enlarged diamond electrodes, so-called "diamond foam". To obtain diamond foam electrodes, SiO2 spheres were used for heavily boron-doped (1021 cm-3) nano-crystalline diamond (B-NCD) overgrowth in a microwave plasma reactor. After overgrowth with B-NCD the SiO2 spheres were etched away with HF giving rise to diamond foam consisted of B-NCD shells accumulated on the substrate. This process has the advantage that the thickness of diamond foam can increase infinitely by repeating the growth and etching processes. Structural and electrochemical characterizations show that the diamond foam electrodes show a surface enlargement of around 40 while keeping good chemical stability as well as a diamond related structural properties.