Chemically Modified Electrodes
Current chemistries used to modify the surfaces of metal oxide semiconductor films are susceptible to hydrolysis and degrade at high, positive potentials. Amorphous carbon, aC, films are an attractive alternative to metal oxides for the preparation of chemically modified electrodes, with surfaces and surface chemistries that are stable under atmospheric conditions and in solution.
In work published in Applied Surface Science, Julia M. Fehr, an undergraduate student, and Catherine G. McKenas, a graduate student, both in the Matthew Lockett group, prepared azide-terminated aC films, which were further modified with a copper catalyzed azide‑alkyne click reaction. The team utilized X-ray photoelectron spectroscopy and cyclic voltammetry to show this modification strategy was selective to films containing azide group, enabling a new means of preparing modified aC electrodes.
The results presented by Julia and Catherine, suggest that these films will support the attachment of chromophores, providing a stable interface that can, unlike alkylphosphonate-metal oxide linkages, withstand the reaction conditions used in dye-sensitized solar cells and dye-sensitized photoelectron synthesis cells.