Hydrothermal method refers the use of aqueous solution as reacting system, by heating the reaction system and add pressure in a special closed reactor such as autoclave to set up a relative reaction atmosphere with high temperature and high pressure to dissolve and re-crystallize material so as to processing inorganic synthesis and material treatment. There are three main characteristics for hydrothermal method:
1.Accelerate reacting between complex ions.
2.Accelerate hydrolysis reaction.
3.Accelerate the oxidation reduction electrical potential to have obvious change.

Ammonium Paratungstate Hydrothermal Method Producing Tungsten Trioxide

Use 310g APT as raw material, 100ml deionized water as solvent, heat and let them dissolve. The reaction product was taken out from the reaction kettle and cooled to room temperature for 4 to 14 hours under the hydrothermal condition of 100-180e according to orthogonal design. The product is washed repeatedly with deionized water and ethanol, dried in air and calcined at a certain temperature for 2 h to obtain WO3 powder.