Highly sensitive and fast responding CO sensor using SnO2 nanosheets

A highly sensitive and fast responding CO sensor was fabricated from a sheet-like SnO2. The SnO sheets were prepared by a room temperature reaction between SnCl2, hydrazine and NaOH, and they were subsequently oxidized into SnO, sheets at high temperature (600 degrees C). The morphology and size of the SnO2 sheets could be controlled during the formation of SnO, which influence the sensor response (R-a/R-g) and response time to a great extent. The sensor response of SnO nanosheets to 10 ppm CO was enhanced up to 2.34, and the 90% sensor response time could be reduced to 6s, which are significantly higher and shorter than those of SnO, powders (1.57 and 88 s), respectively. The realization of both a high sensitivity and rapid response were explained in terms of rapid gas diffusion onto the entire sensing surface due to the less-agglomerated and very thin structure of SnO2 nanosheets and the catalytic effect of Pt. (c) 2007 Elsevier B.V. All rights reserved