10.1021/nl900528q.s001
Christopher N. Chervin
Christopher N.
Chervin
Alia M. Lubers
Alia M.
Lubers
Katherine A. Pettigrew
Katherine A.
Pettigrew
Jeffrey W. Long
Jeffrey W.
Long
Mark A. Westgate
Mark A.
Westgate
John J. Fontanella
John J.
Fontanella
Debra R. Rolison
Debra R.
Rolison
Making the Most of a Scarce Platinum-Group Metal: Conductive Ruthenia Nanoskins on Insulating Silica Paper
American Chemical Society
2009
Conductive Ruthenia Nanoskins
Insulating Silica PaperSubambient
SiO 2 substrates
electrochemical surface area
ruthenia phase
nanocrystalline RuO 2 coating
exhibit energy storage
electrochemical capacitive response
2009-06-10 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Making_the_Most_of_a_Scarce_Platinum_Group_Metal_Conductive_Ruthenia_Nanoskins_on_Insulating_Silica_Paper/2851120
Subambient thermal decomposition of ruthenium tetroxide from nonaqueous solution onto porous SiO<sub>2</sub> substrates creates 2−3 nm thick coatings of RuO<sub>2</sub> that cover the convex silica walls comprising the open, porous structure. The physical properties of the resultant self-wired nanoscale ruthenia significantly differ depending on the nature of the porous support. Previously reported RuO<sub>2</sub>-modified SiO<sub>2</sub> aerogels display electron conductivity of 5 × 10<sup>−4</sup> S cm<sup>−1</sup> (as normalized to the geometric factor of the insulating substrate, not the conducting ruthenia phase), whereas RuO<sub>2</sub>-modified silica filter paper at ∼5 wt % RuO<sub>2</sub> exhibits ∼0.5 S cm<sup>−1</sup>. Electron conduction through the ruthenia phase as examined from −160 to 260 °C requires minimal activation energy, only 8 meV, from 20 to 260 °C. The RuO<sub>2</sub>(SiO<sub>2</sub>) fiber membranes are electrically addressable, capable of supporting fast electron-transfer reactions, express an electrochemical surface area of ∼90 m<sup>2</sup> g<sup>−1</sup> RuO<sub>2</sub>, and exhibit energy storage in which 90% of the total electron−proton charge is stored at the outer surface of the ruthenia phase. The electrochemical capacitive response indicates that the nanocrystalline RuO<sub>2</sub> coating can be considered to be a single-unit-thick layer of the conductive oxide, as physically stabilized by the supporting silica fiber.