Indium oxide thick-films decorated with PdO and PtO2 particles for oxygen detection in humid environments

Thick film indium oxide chemiresistive sensors decorated with PdO and PtO2 particles were investigated for oxygen detection under humid conditions (tested ranging from 20-80 RH) across a temperature range of 50 °C to 400 °C. The PtO2-decorated In2O3 sensors demonstrated a significantly higher response to oxygen, showing a 500 increase at 200 °C compared to the PdO-decorated sensors (response values of 41 and 8, respectively). Tests in dry air were conducted to assess the effect of humidity on sensor performance, revealing a maximum response of 74 for PtO2-In2O3 at 400 °C, more than three times higher than the response of 22 for PdO-In2O3. Selectivity tests confirmed that the sensors responded more strongly to oxygen than to interfering gases. The integration of an active carbon cloth (ACC) filter effectively reduced interferences from isobutylene and ethylene, enhancing sensor’s selectivity. A comparison of both sensors demonstrated that PtO2-decorated In2O3 has greater potential as an alternative to existing Pb-based electrochemical oxygen sensors, particularly in humid environments. © 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.