Application of layered perovskite type proton conducting KCa2Nb3O10 in H2 sensors: Pt particle size and temperature dependence

• Published in: Sensors and actuators. B, Chemical Chemical, 2007-08, Vol.125 (2), p.435-440
• Main Authors: Sakthivel, M., Weppner, W.
• Format: Article
• Language: English
• Subjects: Electroless Pt deposition; Hydrogen sensor; Layered perovskite oxide; Proton conductivity
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2007.02.054

An all-solid-state ceramic hydrogen sensor working under short circuit amperometric conditions at low temperature has been developed. Ambient air was used as reference. The Dion-Jacobson (D-J) type layered perovskite KCa2Nb3O10 has been employed as electrolyte, studying the sensing response to 1–8% H2 concentrations in air. Thin films of platinum electrodes were deposited on the layered perovskite structured electrolyte by the multistep-impregnation-reduction (M-I-R) method. The electrochemically active particle size of 300–500nm was optimised by control of the reductant concentration. Electrodes with high porosities and Pt loading of 1.85mgcm−2 were obtained. The device was operated between 25 and 65°C. The response time was in the range of 8–15s and a stable current output was observed. The sensors were capable of detecting H2 with high reproducibility at 45°C with a maximum sensitivity of 11.7μAcm−2%−1. The structural and micro-structural characterizations were carried out with XRD and SEM, respectively.