Exploiting the Properties of Ti-Doped CVD-Grown Diamonds for the Assembling of Electrodes

A hybrid chemical vapor deposition (CVD)-powder flowing technique specifically developed in lab has been employed to produce high-quality polycrystalline diamond layers containing Ti inclusions. Morphology, structural features, and surface composition of nanocomposite diamond-based samples produced by different growth times have been analyzed by scanning electron microscopy, Raman and Auger spectroscopy, respectively. The CVD methodology adopted for the Ti incorporation in the diamond lattice does not perturb the crystalline quality of the diamond matrix, therefore maintaining the outstanding properties of the C-sp(3) phase. The functional properties of the nanocomposite layers have been tested by nanoindentation and I-V measurements. The electrochemical performance of the diamond/Ti electrodes is evaluated by performing cyclic voltammetry in different media, namely, acidic, neutral, and basic aqueous solutions, and by estimating the rate constant of heterogeneous electron transfer to diamond surface for the ferro/ferricyanide redox couple. The rather good electrochemical performances, the mechanical strength, and the chemical inertness of the Ti-doped diamond electrodes produced by the CVD approach, comply with the whole set of technological requirements, such as robustness, long durability, and biocompatibility, required for use in hostile environments or in biological systems.