The synthesis of noble metal and metal contained Tin Oxide nano powder for thick and thin film gas sensors

摘要

PURPOSE: Nano-sized SnO2 powders containing precious metals(Pt, Au, Pd) or metals(W, Mo, Ca) for thick and thin film type gas sensors with high sensitivity and excellent selectivity by adding polyvinyl pyrrolidone(PVP) polymer to reactants of conventional coprecipitation method. CONSTITUTION: The preparation method of SnO2 powder with a 5-15nm size comprises the steps of: mixing tin chloride solution with chloride solution of precious metal; adding 0-20wt.%(based on Sn) of polyvinyl pyrrolidone(PVP)-based polymer dissolved in alcohols and stirring strongly; heating the mixed solution to higher temperature than boiling point of alcohol and refluxing; adding NaOH or NH4OH and aging; washing precipitates with NH4NO3, acetone and alcohol, dehydrating and drying; calcining at 650deg.C and ball-milling.