Gas sensing properties of a stabilized zirconia-based sensor with a porous MoO3 electrode prepared from a molybdenum polyoxometallate–alkylamine hybrid film

Mo7O246−–hexylamine hybrid films have been deposited on an yttrium stabilized zirconia (YSZ) tube from an aqueous solution containing Mo7O246− and hexylamine by using the simple dip-coating method. An XRD analysis of the inorganic–organic hybrid film confirms a well-ordered regular multilayer structure. Calcination of the hybrid film at 500 °C results in the formation of a porous electrode consisting of nanosized MoO3 particles, as revealed by AFM and SEM. A zirconia-based device fitted with the porous MoO3 electrode shows higher sensitivity towards H2 (50–500 ppm) and NH3 (10–100 ppm) in air at 500 °C, as compared with a zirconia-based device fitted with an electrode prepared from reagent MoO3 powders. This study demonstrates that a molybdenum polyoxometallate–alkylamine hybrid film is a useful precursor for preparing porous MoO3 electrodes with high gas sensitivity.