Voltammetric characterization of ruthenium oxide-based aerogels and other RuO{sub 2} solids: The nature of capacitance in nanostructured materials
- Naval Research Lab., Washington, DC (United States)
Ruthenium dioxide is an important electrode material for applications in electrocatalysis and power sources. High surface areas are achieved in hydrous RuO{sub 2} precipitates and in mixed ruthenium oxide-titanium oxide, (Ru-Ti)O{sub x}, aerogels ( in which nanoscale domains are networked to form a highly porous structure). The electrochemical properties of (Ru-Ti)O{sub x} aerogels, RuO{sub 2}, and hydrous RuO{sub 2} are examined by direct pressing of sub-milligram quantities of the solid onto the surface of a conductive carbon/wax composite. Voltammetric measurements in acidic electrolyte confirm a pseudocapacitive response for all the RuO{sub x}-based materials. Despite an improvement in BET surface area, as compared with other RuO{sub 2} materials, the (Ru-Ti)O{sub x} aerogel displays a low specific capacitance, which correlated to the high degree of crystallinity of the aerogel. Nanocrystallites of rutile RuO{sub 2}, formed during thermal treatment of the sol-gel Ru/Ti precursors, deleteriously affect the specific capacitance of the material; however, all RuO{sub x} domains in the aerogel are voltammetrically addressable. The influence of proton-donating species on the observed capacitance for the (Ru-Ti)O{sub x} aerogel is evident from the dependence of the voltammetric charge in acidic electrolyte on the potential scan rate.
- OSTI ID:
- 680008
- Report Number(s):
- CONF-980314-; ISSN 0743-7463; TRN: IM9941%%49
- Journal Information:
- Langmuir, Vol. 15, Issue 3; Conference: American Chemical Society (ACS) meeting, Dallas, TX (United States), 26 Mar - 2 Apr 1998; Other Information: PBD: 2 Feb 1999
- Country of Publication:
- United States
- Language:
- English
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