Synthesis, structure and gas sensitivity properties of pure and doped SnO 2

Abstract

Polycrystalline SnO 2 showing small particle size has been synthesized by means of pyrolysis in a tubular furnace of an aerosol produced by ultrahigh-frequency spraying of a solution. Pd nanoparticles have also been dispersed on the surface of cassiterite grains. In both cases, three solution precursors have been used: chloride, oxalate and sulfate. An SEM study indicates that two kinds of textures are obtained depending on the precursor solution: hollow spherical particles or quasi-spherical grain agglomerates. Cold pressing and annealing modify such morphologies. Conductance G = f( T) curves were studied from 50 to 500 °C under pure air ( G = G 0), 80 ppm ethanol or 300 ppm CO. G = f( T) curves under polluted air show different behaviors. Most of them show a pronounced maximum and corresponding sensitivity S = ( G - G 0)/ G 0 varies between 10 and 390.