| Abstract
| - RuO2 thin film electrodes were synthesized by reactive radio-frequency magnetron sputtering at 40, 350, and 450 °C. Their characterization has been carried out ex situ by RBS, ERD, NRA, SEM, and WAXS, and CV was used for in situ studies. A comparison with the data previously obtained at thermally prepared oxide films points to some similarities as well as to some differences in electrochemical behavior.
- Ruthenium dioxide films were prepared by radio-frequency magnetron sputtering onto Siand Ti substrates. Films of different thicknesses (100−500 nm) were synthesized at substratetemperatures of 40, 350, and 450 °C. Their composition has been studied by Rutherfordbackscattering spectrometry, elastic recoil detection, and ion beam nuclear reaction analysis.Scanning electron microscopy and wide-angle X-ray scattering have been used for studyingthe surface texture of the samples and for their microstructural characterization, respectively.The electrochemical characterization by cyclic voltammetry has shown that, despite the highphysical density of the films, compared with that obtained by the thermochemical methods,they exhibit large charge-storage capacities. For the materials synthesized at 350−450 °C,an explanation of these results has been sought in specific features of the RuO2 rutile-typecell and columnar texture of the oxide film. The much higher capacity of the films synthesizedat 40 °C would be rather due to a poor sintering of the oxide phase. Study of the chlorineevolution reaction in the samples prepared at 350 and 450 °C points to a Volmer−Tafelmechanism, with a chemical desorption rate-determining step, and significant radicalintermediate coverage. Films deposited at 40 °C exhibited an unsatisfactory wear resistanceunder the anodic polarization required for the chlorine evolution reaction investigation.
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