Mechanochemical Synthesis of TiO 2 -CeO 2 Mixed Oxides Utilized as a Screen-Printed Sensing Material for Oxygen Sensor.

TiO 2 and CeO 2 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 TiO 2 -CeO 2 mixed oxides that have the potential to improve some aspects of oxygen monitoring. However, there are no studies on the sensing properties of the TiO 2 -CeO 2 obtained by mechanochemical treatment. We have tested the applicability of the mechanochemically treated TiO 2 -CeO 2 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 O 2 concentrations. The results of electrical measurements showed that TiO 2 -CeO 2 films have a significantly lower resistance than pure oxide films. Mixtures of composition TiO 2 :CeO 2 = 0.8:0.2, ground for 100 min, have the lowest electrical resistance among the tested materials. Mixtures of composition TiO 2 :CeO 2 = 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.