Mechanochemical Synthesis of TiO2-CeO2 Mixed Oxides Utilized as a Screen-Printed Sensing Material for Oxygen Sensor

Abstract

TiO2 and CeO2 are well known as oxygen sensing materials. Despite high sensitivity, the actual utilization of these materials in gas detection remains limited. Research conducted over the last two decades has revealed synergistic effects of TiO2-CeO2 mixed oxides that have the potential to improve some aspects of oxygen monitoring. However, there are no studies on the sensing properties of the TiO2-CeO2 obtained by mechanochemical treatment. We have tested the applicability of the mechanochemically treated TiO2-CeO2 for oxygen detection and presented the results in this study. The sensing layers are prepared as a porous structure by screen printing a thick film on a commercial substrate. The obtained structures were exposed to various O2 concentrations. The results of electrical measurements showed that TiO2-CeO2 films have a significantly lower resistance than pure oxide films. Mixtures of composition TiO2:CeO2 = 0.8:0.2, ground for 100 min, have the lowest electrical resistance among the tested materials. Mixtures of composition TiO2:CeO2 = 0.5:0.5 and ground for 100 min proved to be the most sensitive. The operating temperature can be as low as 320 °C, which places this sensor in the class of semiconductor sensors working at relatively lower temperatures.

Mechanochemical synthesis of nanostructured and composite oxide ceramics: From mechanisms to tailored properties

“…The respective properties and applications of TiO 2 and CeO 2 are well known and widely studied, and TiO 2 -CeO 2 hybrid systems have become an increasingly common research topic in the field of gas sensing and materials science. 46,47,52,79,81,82,[91][92][93] Stevanovic et al 94 combined CeO 2 and TiO 2 by mechanochemical method to form TiO 2 -CeO 2 composite powder. The addition of CeO 2 resulted in improved adhesion of TiO 2 films to alumina substrates and significantly improved oxygen reactivity stability.…”

Gas nanosensors for health and safety applications in mining

“…238 Among the other n-type MOS interfaces reported, CeO 2 is a well-researched material for O 2 sensing. 239 The Ce atoms inside the CeO 2 crystalline lattice possess variable oxidation states of Ce 3+ /Ce 4+ , which leads to oxygen storage capability and fast oxygen vacancy diffusion in CeO 2 . The latter feature was attributed to the signicant reduction in the response time of the O 2 sensor.…”