Mesoporous Tungsten Trioxide Preparation

Mesoporous material is a great aperture ratio between surface area and pore structure of the new three-dimensional microporous material that with a large hole. It has excellent properties of other porous materials are short of: a highly ordered pore structure; pore single distribution, and pore size may vary widely. Mesoporous material is diverse in shape, composition and properties of the cell wall can be regulated. We can obtain high thermal stability and hydrothermal stability by optimizing the synthesis conditions. Its allure is still in its catalysis, adsorption, separation and potential applications in many fields of light, electricity and magnetism and so on. Mesoporous material is classified according to chemical composition: silicon and non-silicon-based two categories.

Preparation of Tungsten Trioxide Mesoporous Materials
1. Hydrothermal
The calcination or solvent extraction remove the organic templating agent to prepared mesoporous tungsten oxide by mainly by the long-chain organic compounds as a template, a tungsten source is tungsten hexachloride. However, it is easier for tungsten oxide to collapse. And the use of an organic template was removed and extracted; it is difficult to be repeated extraction. Anhydrous ethanol as the reaction medium, a non-ionic surfactant p123 as templates, ethanol as a reactant, the use of sol-gel method, calcination at 400 ℃ 5h after preparing the mesoporous tungsten trioxide, a pore diameter of 125m / g porosity 48%.

2. Hardboard Template
We use mesoporous silica as template, make tungsten oxide remove the template with HF in its crystalline after high temperature, such methods are relatively mild conditions when removing the template, and the template is removed completely. The prepared mesoporous tungsten trioxide structure is better because the silica support as a skeleton. The template method is prepare tungsten oxide mesoporous materials that using mesoporous silica material as the template, using phosphotungstic acid as a tungsten source.

Non-mesoporous material from the synthesis, synthesis mechanism to practical applications such as synthetic technology remains immature (the collapse in the process of removing the templating agent), not green, repeatability and so on.

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