Trimethylamine sensing properties of nano-SnO2 prepared using microwave heating method

The precursor was obtained through the reaction between SnCl4.5H(2)O and NaOH in the presence of PEG400 (polyethylene glycol, M = 400). Tin oxide (SnO2) nano-powders were prepared by heating the precursor with microwave method. SnO2 thick film sensors were fabricated using SnO2 nano-materials as sensing materials. The phase composition and morphology of the material particles were characterized through X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The average particle sizes of the samples obtained with 616 W microwave heating and 800 W microwave heating (20 min) are about 5 and 15 nm, respectively. The influence of the heating duration and heating power on the gas-sensing properties of sensors based on SnO2 nano-materials were investigated. The sensitivities of the sensors based on SnO2 nano-materials heated with 616 and 800W for 20 min were higher than those of the sensors based on SnO2 nano-materials heated with 136, 264 and 440 W for 20 min. When operating at 200-310 degrees C, the sensor based on SnO2 heated with 616 W for 20 min exhibits highest sensitivities in all sensors based on SnO2 heated with 616 W for different duration. The sensitivity to a few kinds of organic gases, such as (CH3)(3)N and (CH3)(2)CO were studied. It was found that the sensor based on SnO2 nano-materials (with 616 W microwave heating for 20 min) exhibited good performance characterized by high sensitivity and short response time to dilute trimethylamine when operated at 255 degrees C. The sensitivity to 0.001 ppm (CH3)(3)N at 255 degrees C was 3. The response time and recovery time were about 30 and 100 s, respectively. (C) 2010 Elsevier Ltd and Techna Group S.r.l. All rights reserved.