Study On Preparation And Gas Sensing Property Of Water-soluble Polyaniline/SmBaCuMO_5+δ（M=Cu, Zn, Fe, Co, Ni, V, Cr, Mn） For Nh₃

With the environmental pollution getting more serious, it is very important todevelop new types of gas sensors with low operating temperature, high sensitivity,good selectivity and rapid response and recovery properties.In this paper, the water-soluble polyaniline/SmBaCuMO_5+δ（M=Cu, Zn, Fe, Co,Ni, V, Cr, Mn） composite materials were prepared with the powders of water-solublepolyaniline and SmBaCuMO_5+δ（M=Cu, Zn, Fe, Co, Ni, V, Cr, Mn） through the directoxidation method with water as dispersion medium. The powders of water-solublepolyaniline were synthesized by chemical-oxide method and the powders ofSmBaCuMO_5+δ（M=Cu, Zn, Fe, Co, Ni, V, Cr, Mn） were prepared by sol-gel method.The structures of inorganic composite oxide were analyzed by XRD, absorptionspectrum of organic powders were analyzed by FT-IR respectively, and microstructureof composite materials were analyzed by TEM. The gas sensing properties ofcomposite materials and single material were tested by static test system of gassensors.The water-soluble polyaniline/SmBaCuMO_5+δ（M=Cu, Zn, Fe, Co, Ni, V, Cr, Mn）composite materials can present gas sensing properties to ammonia gas under theconditions of room temperature. Composite materials gas sensors present highselectivity to ammonia compared to ethanol, hydrogen, methanol, methane, tolueneand nitrogen dioxide. Compared to work temperature （300oC） and selectivityproperties of inorganic oxide gas sensors, composite materials gas sensors can workin normal temperature and present high selectivity to ammonia gas.Above all， the new type of composite materials gas sensors based onorganic/inorganic with normal temperature as operating temperature, high selectivityand rapid response and recovery properties were manufactured. The mechanism ofgas sensing of organic/inorganic materials and the law of gas sensitive effect on the performance with the fourth cycle M element doping SmBaCuMO_5+δ（M=Cu, Zn, Fe,Co, Ni, V, Cr, Mn） were preliminary discussed. And it laid the foundmion for theresearch on the application of these materials.