Final Technical Report on Contract N00014-87-K-0494, 1 September 1987 - 31 March 1991 (Minnesota University)
Abstract
In research funded by the ONR Young Investigator Award, our group was the first to investigate electrochemical reactions at solid electrodes of nanoscopic dimensions. The results have implications in redox chemistry of colloids and supported catalysts and in chemical analyses using miniaturized electrodes. Initial work using ultra thin platinum band electrodes demonstrated a departure of mass-transfer-limited voltammetric currents from predictions based on continuum fluid structure. We proposed an original model that described the dependence of molecular transport on near-surface diffusivity and the dimensions of the reacting electroactive molecule that quantitatively predicts the observed behavior. A detailed theoretical analysis of the effect of the electrical double layer on both electron-transfer kinetics and mass transfer at sub-micron electrode structures was developed that indicates that significant departure from the classical voltammetric waveshape and current magnitude is expected when one of the electrode dimensions is reduced below 10 nm. A new method of synthesizing Pt disk microelectrodes of nanometer dimensions was developed based on using a scanning tunneling microscope (STM) to induce localized dielectric breakdown on TiO2 coated Pt substrates.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 24, 1992
- Accession Number
- ADA246834
Entities
Organizations
- University of Minnesota