Preparation method of monoclinic system tungsten trioxide

A technology of tungsten trioxide and sodium tungstate, applied in chemical instruments and methods, tungsten oxide/tungsten hydroxide, metal/metal oxide/metal hydroxide catalysts, etc., can solve the problem of poor dispersion and change of crystal shape Improve the hydrogen production activity, ensure the integrity, and achieve the effects of excellent photocatalytic performance

Inactive Publication Date: 2017-06-13
HEBEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the literature, in many cases, the prepared tungsten trioxide precursor needs to be treated at a high temperature above 600 °C to achieve the purpose of converting the crystal form and improving the crystal integrity of the sample, but the high temperature treatment will change the crystal morphology and make the crystal particles The particle size increases and the dispersion becomes poor

Method used

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  • Preparation method of monoclinic system tungsten trioxide
  • Preparation method of monoclinic system tungsten trioxide
  • Preparation method of monoclinic system tungsten trioxide

Examples

Experimental program
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Effect test

Embodiment 1

[0029] (1) Weigh 5gNa 2 WO 4 .2H 2 O, add deionized water to prepare an aqueous solution with a mass concentration of 10%, according to NHO 3 Add nitric acid solution with a mass concentration of 63% at a molar ratio of 2:1 to tungsten atoms to obtain a light yellow precipitate, stir for 0.5 hours, and the precipitate turns into bright yellow. After centrifugation, a yellow precipitate was collected.

[0030] (2) Transfer the yellow precipitate obtained in (1) into a beaker, add deionized water with a mass ratio of 6:1 to the precipitate, and stir to form a slurry. Simultaneously weigh citric acid at a ratio of 2:1 to tungsten atom molar ratio, add water to prepare an aqueous solution with a mass concentration of 20%; weigh polyethylene glycol 2000 at a ratio of 0.5:1 to tungsten atom mass ratio, add water It is prepared into an aqueous solution with a mass concentration of 20%, and the two are sequentially added to the aforementioned slurry.

[0031] (3) Press NHO 3 The...

Embodiment 2

[0035] (1) Weigh 5gNa 2 WO 4 .2H 2 O, add deionized water to prepare an aqueous solution with a mass concentration of 10%, press HNO 3 Add nitric acid solution with a mass concentration of 63% at a molar ratio of 2:1 to tungsten atoms to obtain a light yellow precipitate, stir for 0.5 hours, and the precipitate turns into bright yellow. After centrifugation, a yellow precipitate was collected.

[0036] (2) Transfer the yellow precipitate obtained in (1) into a beaker, add deionized water with a mass ratio of 6:1 to the precipitate, and stir to form a slurry. At the same time, weigh L-tartaric acid in a ratio of 1:1 to the tungsten atom molar ratio, add water to prepare an aqueous solution with a mass concentration of 20%; weigh polyethylene glycol 2000 in a ratio of 0.3:1 to the tungsten atom mass ratio, add water It is prepared into an aqueous solution with a mass concentration of 20%, and the two are sequentially added to the aforementioned slurry.

[0037] (3) Press HN...

Embodiment 3

[0041] Take by weighing 4g copper nitrate, be mixed with deionized water and be that mass concentration is the aqueous solution of 10%, be 1.1:1 to take by weighing oxalic acid by the mol ratio of oxalic acid and copper, be mixed with deionized water that mass concentration is the oxalic acid aqueous solution of 15%, The latter was added to the former to form a copper oxalate precipitate, which was deposited for 20 minutes and then filtered. Weigh chromium nitrate according to the molar ratio of chromium to copper as 1:1, prepare a chromium nitrate aqueous solution with a mass concentration of 10% with deionized water, add copper oxalate precipitate to it, stir mechanically to form a slurry, and stir At the same time, heat it on a water bath at 85°C to dehydrate the slurry, and then move it into an oven to dry after it becomes thick. Grind the dried powder with a mortar, roast in a nitrogen atmosphere at 600°C for 5h, at 800°C for 3h, at 950°C for 3h, and at 1000°C for 3h to o...

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Abstract

The invention relates to a preparation method of monoclinic system tungsten trioxide. The preparation method of the monoclinic system tungsten trioxide comprises the following steps: (1) while stirring, adding nitric acid into sodium tungstate solution, stirring, then carrying out centrifugal separation, and collecting to obtain yellow precipitate; (2) transferring the yellow precipitate into a reactor, and adding deionized water, organic acid solution and polyethylene glycol solution; (3) then adding the nitric acid, and stirring for 0.5-2 hours; and (4) transferring the obtained slurry into an autoclave, sealing, then heating to the temperature of 160-250 DEG C, and continuously reacting for 8-20 hours, so that monoclinic system tungsten trioxide powder is obtained. The preparation method provided by the invention has the advantages that uniformly dispersed micro-nano tungsten trioxide crystal particles are obtained, and the obtained tungsten trioxide crystal particles have excellent photocatalytic performance.

Description

[0001] Technical field: [0002] The invention belongs to the technical field of tungsten trioxide preparation, in particular to a preparation method of monoclinic tungsten trioxide. [0003] technical background: [0004] Tungsten trioxide is a semiconductor oxide with N-type conductivity characteristics. Due to its more suitable forbidden band width and relatively positive valence band potential, it shows good performance in the process of photocatalytic water splitting. As a catalyst for photocatalytic water splitting, the crystal phase composition, particle size and dispersion of tungsten trioxide have an important impact on its performance. A large number of experimental results show that monoclinic tungsten trioxide has better photocatalytic performance than tungsten trioxide in other crystal phases. The reduction of the particle size and the improvement of crystallization integrity of tungsten trioxide are beneficial to the improvement of its photocatalytic activity. A...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01G41/02B01J23/30C01B3/04
CPCB01J23/002B01J23/30B01J35/004B01J2523/00C01B3/042C01G41/02C01P2002/72C01P2004/03C01P2004/38C01P2004/62B01J2523/69B01J2523/67B01J2523/17Y02E60/36
Inventor 王桂赟杨欢宋立佳王延吉赵新强
Owner HEBEI UNIV OF TECH
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