Trimethylamine sensing properties of CdO-Fe2O3 nano-materials prepared using co-precipitation method in the presence of PEG400

CdO-Fe2O3 precursors are prepared using co-precipitation method in the presence of PEG400. CdO-Fe2O3 nano-powders are obtained through heating the precursors under different conditions. CdO-Fe2O3 thick film sensors are fabricated using CdO-Fe2O3 nano-materials as sensing materials. The XRD analysis results reveal that CdO-Fe2O3 is mainly composed of CdFe2O4 when the precursor is heated at 700 degrees C for 2 h and the mole ratio of Cd/Fe is 1:2 in the starting materials. The TEM images show that the average particle sizes increase with heating temperature increasing, the particle sizes are in the range of 15-25 nm when heating temperature is 700 degrees C (2 h). The influence of the heating duration and heating temperature on the gas-sensing properties of the sensors based on CdO-Fe2O3 nano-materials are investigated. The responses to a few kinds of organic gases, such as (CH3)(3)N and C2H5OH are studied. It is found that the sensor based on CdO-Fe2O3 nano-material (700 degrees C, 2 h) exhibits high response to dilute trimethylamine when operating at 230 degrees C. The responses to 1000 ppm and 0.01 ppm (CH3)(3)N at 230 degrees C are 1527 and 2, respectively. The response time and recovery time for 1000 ppm trimethylamine are 70 and 170 S. (C) 2010 Elsevier B.V. All rights reserved.