AVS 47th International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP8
Characterization of High Surface Area Platinum Black Electrodes for Electrochemical Sensing Applications

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: P. Neuzil, Institute of Microelectronics, Singapore
Authors: P. Neuzil, Institute of Microelectronics, Singapore
B. Ilic, Cornell University
D. Czaplewski, Cornell University
T. Stanczyk, Molex Incorporated
J. Blough, University of Illinois at Chicago
G.J. Maclay, University of Illinois at Chicago
Correspondent: Click to Email
The investigation of adsorbed high surface area noble metal nanoparticulates is important in medicine, nanotechnology, electrochemistry, microelectromechanical systems (MEMS) and sensors, biology, and in industry. In particular, high surface area noble metal electrodes have made a considerable impact in the field of microfabricated solid state, chemical and biological sensors. In our work, we investigate the properties of electrochemically deposited platinum black by atomic force and scanning electron microscopy. Initially the platinum electrodes were fabricated on various substrates utilizing developed silicon surface micromachining techniques. Platinum black was then electrochemically deposited on top of the microfabricated platinum electrodes. The platenized electrodes were subsequently used in an electrochemical cell for carbon monoxide detection (CO). The primary benefit of platinized electrodes is the increase in the surface area of the catalyst, which in turn causes an enhancement in the CO sensitivity by a few orders of magnitude. Deposition time and thermal conditioning were found to influence the quality and morphology of the platinum black layer. Methods of fractal analysis were employed to the acquired tapping mode atomic force micrographs in order to demonstrate the degree of roughness of the platinization. Morphological inclusions were readily observed in films deposited for duration of less than 60 seconds, at a bias of 1.5 V against a platinum counter electrode. Shorting of the microfabricated electrodes due to lateral outgrowth of high surface area platinum black was observed for various electrode geometries when current densities on the order of 100 mA cm@super -2@ were employed. We further show from out CO sensor performance that reproducibility of highly adherent platinized electrodes is achieved.