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Chemosensors, Vol. 12, Pages 238: CO2 Interaction Mechanism of SnO2-Based Sensors with Respect to the Pt Interdigital Electrodes Gap
Chemosensors doi: 10.3390/chemosensors12110238
Authors: Adelina Stanoiu Alexandra Corina Iacoban Catalina Gabriela Mihalcea Ion Viorel Dinu Ovidiu Gabriel Florea Ioana Dorina Vlaicu Cristian Eugen Simion
The tuning sensitivity towards CO2 detection under in-field-like conditions was investigated using SnO2-sensitive material deposited onto Al2O3 substrates provided with platinum electrodes with interdigital gaps of 100 µm and 30 µm. X-ray diffraction, low-magnification and high-resolution transmission electron microscopy, and electrical and contact potential difference investigations were employed to understand the sensing mechanism involved in CO2 detection. The morpho-structural analysis revealed that the SnO2 nanoparticles exhibit well-defined facets along the (110) and (101) crystallographic planes. Complex phenomenological investigations showed that moisture significantly affects the gas sensing performance. The experimental results corroborated the literature evidence, highlighting the importance of Pt within the interdigital electrodes subsequently reflected in the increase in the CO2 sensing performance with the decrease in the interdigital gap. The catalytic efficiency is explained by the distribution of platinum at the gas-Pt-SnO2 three-phase boundary, which is critical for enhancing the sensor performance.
