SnO2 doped MoO3 nanofibers and their carbon monoxide gas sensing performances

SnO2 doped MoO3 nanofibers with an average diameter of 100 nm were synthesized by a wet-chemical method, and sensors were fabricated by screen printing the nanofibers on alumina ceramic substrates. Structural characterizations were carried out using X-ray diffractometer, scanning electron microscope and transmission electron microscope, and chemical state analyses by energy dispersive X-ray spectroscope, X-ray photoelectron spectroscope and Diffuse Reflectance Infrared Fourier Transform Spectroscope. The carbon monoxide (CO) sensing properties were characterized in the temperature range of 200 to 400 °C; comparing with α-MoO3, both the sensitivity and the selectivity of the SnO2 doped MoO3 nanofibers were improved. The chemisorption and the oxidation of CO on the surfaces of the nanofibers are vital to the sensing performance; the addition of SnO2 to MoO3 enhanced the chemisorption and the oxidation of CO. The high sensitivity and vigorous repeatability demonstrate that the nanofibers are auspicious as sensitive and reliable chemical sensors.