浸漬法で形成したSiO_2被膜によるPd/SnO_2ガスセンサーの特性改善

概要

論文の詳細を見る
A sintered 0.5 mass% Pd/SnO_2 sensor was coated with SiO_2 films to improve the gas-sensing properties. The SiO_2 films were prepared by a simple dip-coating method of three kinds of alkoxysilane solutions of Si(OC_2H_5)_4, CH_3Si(OC_2H_5)_3 and(CH_3)_2Si(OC_2H_5)_2, followed by calcination at 600℃. A uniform, crack-free, but still porous SiO_2 film was obtained only from CH_3Si(OC_2H_5)_3. The use of Si(OC_2H_5)_4 resulted in a film with many cracks, probably because of too much three-dimensional polymerization of the precursor up to 400℃. On the other hand, the alkoxylsilane with two methyl groups left no effective SiO_2 film behind, because a large portion of it decomposed into volatile matters upon heating. The H_2 sensitivity of the Pd/SnO_2 sensor markedly increased with the coating of a crack-free SiO_2 film from CH_3Si(OC_2H_5)_3, especially at 300℃, whereas the sensitivity to CH_4, C_3H_8 and C_2H_5OH decreased. Thus, the SiO_2 coating resulted in a highly sensitive and selective H_2 sensor, though the response and recovery time get prolonged by the coating. In contrast, the coating of a SiO_2 film with many cracks from Si(OC_2H_5)_4 showed no significant effect on the gas-sensing properties.
社団法人日本セラミックス協会の論文
1998-01-01