We report the microstructure and gas-sensing property of TiO2 ZnSnO3 prepared by three different addition methods. We find that the loading of TiO2 enables a significant improvement of sensor response and selectivity to ethanol and that the wet process, which is defined as the introduction of TiO2 gel to ZnSnO3 precipitants, is most efficient to enhance the gas-sensing behaviors. Microscopically, surface characterizations suggest that the improved sensing properties for the TiO 2 ZnSnO3 can be attributed qualitatively to its large specific surface area and porous morphology. A gas adsorption model based on surface physics is proposed to discuss further the mechanism behind the sensing property enhancement. This study may open up an avenue for effectively tuning gas-sensing character of ZnSnO3 which is important for modifying functionality of other sensing materials.
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