Gas sensing properties of a stabilized zirconia-based sensor with a porous MoO_3 electrode prepared from a molybdenum polyoxometallate-alkylamine hybrid film

摘要

Mo_7O_(24)~(6-)-hexylamine hybrid films have been deposited on an yttrium stabilized zirconia (YSZ) tube from an aqueous solution containing Mo_7O_(24)~(6-) 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℃ results in the formation of a porous electrode consisting of nanosized MoO_3 particles, as revealed by AFM and SEM. A zirconia-based device fitted with the porous MoO_3 electrode shows higher sensitivity towards H_2 (50-500 ppm) and NH_3 (10-100 ppm) in air at 500℃, as compared with a zirconia-based device fitted with an electrode prepared from reagent MoO_3 powders. This study demonstrates that a molybdenum polyoxometallate-alkylamine hybrid film is a useful precursor for preparing porous MoO_3 electrodes with high gas sensitivity.