Effect of composition and temperature on conductive and sensing properties of CeO2 + In2O3 nanocomposite films
Abbreviated Journal Title
Sens. Actuator B-Chem.
Chemical gas sensor; Conductometric sensor; Mixed metal-oxide film; Nanocomposite sensor films; Sensor mechanism; SEMICONDUCTOR GAS SENSORS; THIN-FILMS; OXYGEN VACANCY; MIXED OXIDES; SNO2 FILMS; SURFACE; CERIA; CO; DEFECTS; GROWTH; Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation
The sensory response of nanostructured In2O3 + CeO2 composite films to hydrogen and carbon monoxide in air ambience is investigated for varying film composition and temperature ranging from 280 degrees C to 520 degrees C. The temperature dependence of the sensor responses S(S = R-0/R, where R-0 and R are respectively the film resistance in pure air and air containing the sample gas), exhibits the trend typical of such sensors, specifically, curves with maximum S-max at a certain temperature T-max. The values of Smax, characterizing the sensor response of the films significantly increase when a small amount of CeO2 is added to In2O3. Addition of CeO2 to In2O3 also results in a decrease in T-max. The measured XPS spectra show that at low CeO2 composition, the composite film structure is characterized by clusters with a high concentration of oxygen vacancies, which increase the chemisorption of reagents and oxygen. The maximum sensor response is observed in In2O3 + CeO2 composite films containing 3-10 wt.% CeO2. Further enrichment of the composite with CeO2 produces a sharp decrease in sensor response, which at 40 wt.% CeO2 is less than the response of pure In2O3. The response mechanism in the In2O3 + CeO2 composite is also investigated, considering the promotion of sensory reactions by small CeO2 nanoclusters located on the surface of the In2O3 nanocrystals. (C) 2014 Elsevier B.V. All rights reserved.
Sensors and Actuators B-Chemical
"Effect of composition and temperature on conductive and sensing properties of CeO2 + In2O3 nanocomposite films" (2015). Faculty Bibliography 2010s. 6839.