Meso- to macro-porous oxides as semiconductor gas sensors

摘要

The present article reviews our latest studies directed to improving gas sensing properties of semiconductor metal oxides, SnO_2 and TiO_2, by controlling their porous structure in the range of nano- to micro-meter size. Thermally stable mesoporous oxide powders and submicron-size porous thick films were fabricated by a templating method employing supramolecular surfactants or polymethylmethacrylate microspheres and also by a sol-gel process in a polyethylene glycol matrix. Advantages of these methods in improving the sensing properties are overviewed and then remaining problems are discussed.