Repozytorium publikacji - Politechnika Gdańska

The electrochemical active surface area (EASA) of polycrystalline boron-doped diamond (BDD) electrodes is heterogeneous and can be affected by numerous factors. There is a strong need for proper consideration of BDD heterogeneity in order to improve this material's range of application in electrochemistry. Localized changes in surface termination due to the influence of oxidation agent result in increased surface resistance. The observed behavior of this characteristic feature varies among individual grains, depending on their crystallographic orientation. Still, there is not much information about this key factor in terms of its influence on the electrochemical response of BDD. In this study we compared two approaches towards BDD surface oxidation, namely: anodic polarization at potentiostatic and potentiodynamic conditions. The surface impedance measurements via Nanoscale Impedance Microscopy (NIM) allowed the confirmation of diversified propensity for the modification of surface termination in BDD. We showed that the NIM studies provide a deep understanding on the electrical characterization and variation of surface resistance in BDD electrodes. In order to evaluate the actual heterogeneity of electrochemical activity distribution, voltammetry, dynamic electrochemical impedance spectroscopy (DEIS) and scanning electrochemical microscopy (SECM) studies were performed. For each investigated electrode, departure from the Randles-Sevcik equation was observed, with its level depending on the surface heterogeneity and oxidation treatment, justifying the standardization of pre-treatment procedure and development of non-standard model for diffusion transport in proximity of BDD electrode.

Autorzy

• dr hab. inż. Jacek Ryl link otwiera się w nowej karcie ,
• Łukasz Burczyk link otwiera się w nowej karcie ,
• dr hab. inż. Artur Zieliński link otwiera się w nowej karcie ,
• dr inż. Mateusz Ficek link otwiera się w nowej karcie ,
• Artur Franczak link otwiera się w nowej karcie ,
• dr hab. inż. Robert Bogdanowicz link otwiera się w nowej karcie ,
• prof. dr hab. inż. Kazimierz Darowicki link otwiera się w nowej karcie