Mesostructured SnO2 as sensing material for gas sensors

Mesostructured tin oxide with high specific surface area was synthesized using a cationic surfactant (cetyltrimethylammonium bromide, CTAB: CH3(CH2)(15)N+(CH3)(3)Br-) as the organic template and the hydrous tin chloride (SnCl4 . 5H(2)O) and NH4OH as the inorganic precursor and alkali source under acidic conditions at ambient temperature. The surface areas of mesostructured tin oxides are about 368, 343 and 134 m(2)/g for calcination at 300, 350 and 400 degreesC, respectively. The tin oxides used as sensitive materials of indirect heating structure sensors were fabricated on an alumina tube with Au electrodes and platinum wires. Electrical and sensing properties of the sensors based on mesostructured tin oxide were investigated. It was found that the materials with high surface area had higher sensitivity to C2H5OH and H-2 and selectivity to other interferential gases (such as methane, butane, CO and gasoline) than commercial sample of polycrystalline tin (IV) oxide. (C) 2003 Elsevier Ltd. All rights reserved.