Fast response of resistive-type oxygen gas sensors based on nano-sized ceria powder

The oxygen gas sensors based on cerium oxide porous thick film with the average particle size of 100 nm were fabricated by screen-printing method on alumina substrate using the powder of 100 nm prepared by mist pyrolysis. The sensor's response to the oxygen partial pressure drop from 10(5) to 10(3) Pa was compared with that of the sensors using films of larger particle sizes (200 and 2000 nm). Further, their fast response (in less than 8 s) was evaluated by periodic variation of oxygen partial pressure. The response time of sensors with the particle size of 100 nm was shorter than that of 200 and 2000 nm to the oxygen partial pressure drop from 10(5) to 10(3) Pa at 888 K. From the results obtained by the method of periodic variation of oxygen partial pressure, it became clear that the response times for the 100 nm particle sensor were less than 1 and 0.25 s at 1073 and 1173 K, respectively. Response time of oxygen gas sensor based on cerium oxide thick film could be reduced by decreasing the particle size of the thick film. (C) 2003 Elsevier Science B.V. All rights reserved.