Hydrothermal Synthesis Preparation of Pyrochlore Tungsten Oxide

Pyrochlore-type tungsten oxide is a special form of tungsten trioxide, which uses the WO₆ octahedron as the structural unit to form a layered structure with circular tunnels through the corner top of the rigid skeleton of W-O. Due to its special physical and chemical properties, it is widely used in the fields of catalysis, sensing, electronics and other materials science.

Hydrothermal reduction of pyrochlore tungsten oxide process is as follows:

1)Ammonium paratungstate conversion solution: a certain amount of water or a certain concentration (ammonium or sodium salt solution or lithium salt solution or silver salt solution), ammonium paratungstate added quality (APT - nH₂O), proper control of the liquid-solid ratio, temperature, pressure, stirring speed and reaction time of hydrothermal reaction, which control the gas timed release amount, and the gas with deionized water absorption, after the reaction, filtering to obtain filtrate and transition materials of filter cake, the filtrate can be recycled after simple treatment; Proper control of the liquid-solid ratio, temperature, pressure, stirring speed and reaction time of hydrothermal reaction, which control the gas timed release amount, and the gas with deionized water absorption, after the reaction, filtering to obtain filtrate and transition materials of filter cake, the filtrate can be recycled after simple treatment;

2)Transformation of material purification: take a certain quality of transformation material, add a certain amount of deionized water, control the appropriate liquid solid ratio, temperature, pressure, stirring speed and reaction time to react. After the reaction, the filtrate and filter cake were filtered, the filtrate can be used repeatedly, the filter cake is pure pyrochlore-type tungsten oxide products;

3)Take the transformation material and deionized water, the ratio of liquid to solid is 10:1, put it in the beaker, keep the temperature 70 degrees, the magnetic force stirred 2h, the stirring intensity is set to 1000 rpm, and the final product is filtered and dried.

Preparation of pyrochlore tungsten oxide by hydrothermal method, according to the solution obtained pyrochlore tungsten oxide with different impurities, impurity content and controllable, compared with other products prepared by hydrothermal method with sodium tungstate solution as raw material, the interference of Na impurities can be eliminated and the ultrafine WO₃ powder can be prepared. The reaction rate can reach over 99%. The reagents used are convenient and easy to get, and can be recycled. Gas is easy to recycle, no pollutants are discharged, and the environment is friendly. The device is simple and easy to operate.

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