Summary: International Conference on Materials for Advanced Technologies (ICMAT 2007), Singapore, July 1-6, 2007.
A Novel Strategy of Surface Nanofication for Ceramic Gas Sensors
A.-M. Azad* and S.A. Akbar
Department of Chemical Engineering
The University of Toledo, Toledo, OH 43606, USA.
Department of Materials Science and Engineering
The Ohio State University, Columbus, OH 43210, USA.
High selectivity, enhanced sensitivity, short response time and long shelf-life are some of
the key features sought in the solid-state ceramic-based chemical sensors. Since the
sensing mechanism and catalytic activity of ceramics are predominantly surface-
dominated, benign surface features in terms of small grain size, large surface area and,
open and connected porosity, are required to realize a successful material.
In the case of oxide ceramics, we have developed a technique based on rigorous
thermodynamic consideration of the metal/metal oxide coexistence. In order to
incorporate the required nanoscale morphological features, a gas phase redox scheme was
adopted. By modulating the oxygen particle pressure below or above the theoretical meta
oxide/metal coexistence line, the formation and growth of new oxide surface on an
atomic/ molecular level, under conditions of `oxygen starvation' was achieved and,
novel microstructures in a host of oxide systems were incorporated. The presentation will