Summary: Sensors and Actuators B 120 (2006) 2534
Fine-tuning of ceramic-based chemical sensors via
novel microstructural modification
Part II: Low level CO sensing by molybdenum oxide, MoO3
Department of Chemical and Environmental Engineering, The University of Toledo, 3052 Nitschke Hall, Toledo, OH 43606-3390, USA
Received 2 November 2005; received in revised form 27 December 2005; accepted 23 January 2006
Available online 28 February 2006
Employing a buffer gas mixture of CO and CO2, the equilibrium oxygen partial pressure was varied across the Mo/MoO3 proximity line by
varying the ratio of concentration of the two gases, as described in an earlier communication. This led to the reduction of MoO3 in one case and
oxidation of the reduced phase (Mo or MoO2) in the other with a concomitant variation in the microstructural features of the resulting species.
The formation and growth of the new oxide surface under conditions of oxygen potential modulation has been found to impart enhanced sensing
characteristics to the MoO3-based chemical sensors for low levels of carbon monoxide (14100 ppm CO) in the ambient.
© 2006 Elsevier B.V. All rights reserved.
Keywords: Semiconducting oxides; MoO3; Chemical sensors; Microstructure; Carbon monoxide
Materials with nanofeatures are of immense relevance is
the field of solid-state ceramic-based chemical sensors. High
selectivity, enhanced sensitivity and short response time are