Yellow nano tungsten oxide is prepared by hydrothermal method using tungstic acid as precursor and thiourea as basic adjuvant. The influence of different reaction conditions on the morphology and gas sensitivity of yellow tungsten oxide can be studied by changing the preparation temperature of the precursor and the content of thiourea.
Transmission electron microscope (TEM) is used to characterize the synthesized product. The preparation temperature of precursor tungstic acid has important influence on yellow tungsten oxide synthesis. The spherical structure with nanostructure could be synthesized when the preparation temperature of tungstic acid is 25°C. And the diamond structure with nanostructure could be synthesized when the preparation temperature of tungstic acid is 60°C.
Output voltage of yellow tungsten oxide whose precursor is prepared at 80°C is higher than those of the ethanol and acetone, and the tungstic acid hydrothermally prepared yellow tungsten oxide do not have a stable voltage, the nano yellow tungsten oxide material with a diamond structure and has excellent gas-sensing property.
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