Fast response chlorine gas sensor based on mesoporous SnO2

Mesoporous SnO2 is obtained through a simple hydrothermal process by using tin chloride as a raw material, urea as a pore-forming agent and pH regulator. X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) nitrogen adsorption-desorption measurements are employed to characterize the obtained mesoporous structures. The results show that the as synthesized material after calcination can be well indexed to tetragonal phase SnO2 with a mesoporous structure. The sensing properties of the sensor based on mesoporous SnO2 are investigated. The results reveal that the response to dilute Cl-2 gas of the materials is very high and fast. The short recovery time mainly attributes to the bigger pore size of mesoporous SnO2. Finally, the reaction mechanism is proposed. (C) 2009 Elsevier B.V. All rights reserved.