CN101234782A - Preparation method of high-purity large-particle anatase titanium dioxide - Google Patents

Abstract

The invention provides a method for preparing big-particle anatase-type titanium dioxide of high-purity; titanium dioxide of 0.5-2g and alkaline solution of 10-15mol/L with density of 40-60ml are evenly mixed in a stainless steel autoclave or a tetrafluoroethylene vessel; the mixture reacts for 60-100 hours under 453-493 K; pH value of the generated product is regulated to 9-11; and after the product reacts for 2-3 days under 453-493 K in the stainless steel autoclave or the tetrafluoroethylene vessel; after being fully washed by distilled water, the high-purity big-particle anatase-type titanium dioxide is finally obtained by ambient drying for 1-40 hours under 323-373 K. The method for preparing the high-purity big-particle anatase-type titanium dioxide has the advantages of simple operation, low cost, high purity, stable performance and mass synthesis; furthermore, the biggest particle of the prepared big-particle anatase-type titanium dioxide is up to 3.6 micrometers with high purity.

Description

Preparation method of high-purity large-particle anatase titanium dioxide

technical field

The invention belongs to the field of nanomaterial preparation, and more specifically relates to a preparation method of high-purity large-particle anatase titanium dioxide.

Background technique

The refractive index of large-particle anatase titanium dioxide is 2.52, which is higher than that of diamond, which is 2.42. It is a very good optical material. High-purity large-particle anatase titanium dioxide is a good optical material and can be widely used in the manufacture of optical devices such as laser transmitters. However, according to theoretical calculations, when the anatase titanium dioxide particles are larger than a dozen nanometers, a crystal phase transition from anatase phase to rutile phase will occur. Therefore, it is difficult to synthesize pure-phase anatase-type titanium dioxide with large particles. Neither the traditional sulfuric acid method nor the method of adding crystal nuclei can obtain large-particle pure phase anatase titanium dioxide. At present, there is no relevant report on the preparation of high-purity large-particle anatase titanium dioxide.

purpose of invention

The purpose of the present invention is to provide a method for preparing high-purity large-particle anatase-type titanium dioxide, which is not only easy to operate, low in cost, high in purity, stable in performance, and can be synthesized in large quantities, but also the prepared large-particle anatase-type titanium dioxide The largest particles reach 3.6 microns and are of high purity.

The preparation method of the present invention is as follows: 0.5-2 grams of titanium dioxide and an alkali solution with a concentration of 40-60 milliliters of 10-15 mol/liter are fully mixed in a stainless steel autoclave or a polytetrafluoroethylene container, and the mixture is reacted at 453-493K 60~100h; the pH value of the generated product is adjusted to 9~11, and then placed in a stainless steel autoclave or a polytetrafluoroethylene container at 453~493K for 2~3 days, after being fully washed with distilled water, the Dry at 373K under normal pressure for 1-40 hours to obtain the final high-purity large-particle anatase titanium dioxide.

The remarkable advantage of the present invention is: the present invention prepares high-purity large-particle anatase titanium dioxide with a simple method at relatively low temperature and without adding any surfactant and template. The largest particle reaches 3.6 microns, which is the largest anatase titanium dioxide synthesized so far, and this method is not only easy to operate, low cost, high purity, stable performance, and can be synthesized in large quantities, but also the prepared large particle anatase titanium dioxide The largest particles reach 3.6 microns and are of high purity. First, the presence of hydroxide ions can change the surface energy of anatase titanium dioxide to form high-purity large-particle bipyramids. Secondly, the precursor titanate is a layered structure composed of TiO6 octahedrons combined by edge sharing. Under hydrothermal conditions, the basic structure of titanate shrinks at fixed positions, reduces its interlayer spacing, and transforms into an anatase-type titania structure. The formation process of large particle anatase bipyramids includes two steps of precursor fragmentation and dissolution and nucleation. The nucleated anatase TiO2 resembles a truncated octahedral biconical seed consisting of eight equal {101} faces and two equal {001} faces. The surface free energy of the {001} plane is 1.4 times that of the {101} plane, and the plane with high free energy will disappear first during the growth process. According to the Ostwald ripening mechanism, the system with lower free energy is more stable, and the growth of large particles is completed by consuming small particles. Due to the high free energy of the {001} plane, the growth rate is fast and the disappearance is the fastest, so biconical anatase titanium dioxide large particles are formed.

Description of drawings

Fig. 1 is the electron micrograph of product of the present invention, wherein (a) part is scanning electron micrograph, (b) part is transmission electron micrograph.

Fig. 2 is the X-ray powder diffraction pattern of the product of the present invention.

Detailed ways

First, 0.5-2 grams of titanium dioxide and 40-60 ml of alkali solution with a concentration of 10-15 mol/liter are fully mixed in a stainless steel autoclave or a polytetrafluoroethylene container, and the mixture is reacted at 453-493K for 60-100 hours; Adjust the pH value of the product to 9-11, then place it in a stainless steel autoclave or a polytetrafluoroethylene container and react at 453-493K for 2-3 days. After being fully washed with distilled water, dry it under normal pressure at 323-373K 1 to 40 hours to obtain the final high-purity large-particle anatase titanium dioxide.

The alkaline solution is caustic soda solution.

The pH value of the generated product is adjusted using 0.1-0.5 mol/liter of hydrochloric acid or nitric acid.

Described drying adopts normal pressure drying.

The largest particle of the anatase titanium dioxide prepared by the invention reaches 3.6 microns, and the purity is over 99%. The following examples illustrate the invention in detail, but are not limited thereto.

Example 1

First, 1 gram of titanium dioxide and 50 milliliters of caustic soda with a concentration of 10 mol/liter are fully mixed in a stainless steel autoclave or a polytetrafluoroethylene container, and the mixture is reacted at 473K for 72 hours; the pH value of the generated product is adjusted to 10.5, and then the Put it in a stainless steel autoclave or a polytetrafluoroethylene container and react at 473K for 2 days, wash thoroughly with distilled water, and dry at 373K for 6 hours to obtain the final high-purity large-particle anatase titanium dioxide. The alkaline solution is caustic soda solution.

The pH value of the generated product is adjusted using 0.1 mol/L hydrochloric acid. Described drying adopts normal pressure drying. The largest particle of the prepared large-particle anatase titanium dioxide reaches 3.6 microns, and the purity is over 99%.

Example 2

First, 0.5 grams of titanium dioxide and 40 milliliters of caustic soda with a concentration of 10 mol/liter are fully mixed in a stainless steel autoclave or a polytetrafluoroethylene container, and the mixture is reacted at 453 K for 60 hours; the pH value of the generated product is adjusted to 9, and then the Put it in a stainless steel autoclave or a polytetrafluoroethylene container and react at 453K for 2 days, wash thoroughly with distilled water, and dry at 323K for 1 hour to obtain the final high-purity large-particle anatase titanium dioxide. The alkaline solution is caustic soda solution.

The pH value of the generated product is adjusted using 0.1 mol/liter of nitric acid. Described drying adopts normal pressure drying. The largest particle of the prepared large-particle anatase titanium dioxide reaches 3.6 microns, and the purity is over 99%.

Example 3

First, 2 grams of titanium dioxide and 60 milliliters of caustic soda with a concentration of 15 mol/liter are fully mixed in a stainless steel autoclave or a polytetrafluoroethylene container, and the mixture is reacted at 493K for 100 hours; the pH value of the generated product is adjusted to 11, and then the Put it in a stainless steel autoclave or a polytetrafluoroethylene container and react at 493K for 3 days, wash thoroughly with distilled water, and dry at 373K for 40 hours to obtain the final high-purity large-particle anatase titanium dioxide. The alkaline solution is caustic soda solution.

The pH value of the generated product is adjusted using 0.5 mol/liter of nitric acid. Described drying adopts normal pressure drying. The largest particle of the prepared large-particle anatase titanium dioxide reaches 3.6 microns, and the purity is over 99%.

Example 4

First, 1.5 grams of titanium dioxide and 50 milliliters of caustic soda with a concentration of 12 mol/liter are fully mixed in a stainless steel autoclave or a polytetrafluoroethylene container, and the mixture is reacted at 470K for 70 hours; the pH value of the generated product is adjusted to 10, and then the Place it in a stainless steel autoclave or a polytetrafluoroethylene container and react at 470K for 3 days, wash thoroughly with distilled water, and dry at 353K for 20 hours to obtain the final high-purity large-particle anatase titanium dioxide. The alkaline solution is caustic soda solution.

The pH value of the generated product is adjusted using 0.5 mol/L hydrochloric acid. Described drying adopts normal pressure drying. The largest particle of the prepared large-particle anatase titanium dioxide reaches 3.6 microns, and the purity is over 99%.

Example 5

First, 1.5 grams of titanium dioxide and 45 milliliters of caustic soda with a concentration of 13 mol/liter are fully mixed in a stainless steel autoclave or a polytetrafluoroethylene container, and the mixture is reacted at 483K for 80 hours; the pH value of the generated product is adjusted to 10.5, and then the Put it in a stainless steel autoclave or a polytetrafluoroethylene container and react at 483K for 2 days, wash thoroughly with distilled water, and dry at 373K for 30 hours to obtain the final high-purity large-particle anatase titanium dioxide. The alkaline solution is caustic soda solution.

The pH value of the generated product is adjusted using 0.3 mol/L hydrochloric acid. Described drying adopts normal pressure drying. The largest particle of the prepared large-particle anatase titanium dioxide reaches 3.6 microns, and the purity is over 99%.

the summary of instruction

The invention provides a method for preparing high-purity large-particle anatase-type titanium dioxide. 0.5-2 grams of titanium dioxide and an alkali solution with a concentration of 40-60 ml of 10-15 mol/liter are placed in a stainless steel autoclave or a polytetrafluoroethylene container. Mix well, and react the mixture at 453-493K for 60-100 hours; adjust the pH value of the product to 9-11, then place it in a stainless steel autoclave or a polytetrafluoroethylene container and react at 453-493K for 2-3 hours Days later, after fully washing with distilled water, drying under normal pressure at 323-373K for 1-40 hours to obtain the final high-purity large-particle anatase titanium dioxide. The method not only has the advantages of simple operation, low cost, high purity and stable performance, and can be synthesized in large quantities, but also the largest particle of the large-particle anatase titanium dioxide prepared reaches 3.6 microns, and has high purity.

Claims (5)

1. A preparation method for high-purity large-particle anatase titanium dioxide, characterized in that: the preparation method is: 0.5 to 2 grams of titanium dioxide and a concentration of 40 to 60 milliliters of 10 to 15 mol/liter of alkali solution in stainless steel Mix well in an autoclave or a polytetrafluoroethylene container, react the mixture at 453 ~ 493K for 60 ~ 100h; adjust the pH value of the generated product to 9 ~ 11, and then place it in a stainless steel autoclave or polytetrafluoroethylene container After reacting at 453-493K for 2-3 days, after fully washing with distilled water, drying under normal pressure at 323-373K for 1-40 hours to obtain the final high-purity large-particle anatase titanium dioxide. 2. The method for preparing high-purity large-particle anatase-type titanium dioxide according to claim 1, characterized in that: the alkaline solution is a caustic soda solution. 3. The method for preparing high-purity large-particle anatase-type titanium dioxide according to claim 1, characterized in that 0.1-0.5 mol/liter of hydrochloric acid or nitric acid is used to adjust the pH value of the generated product. 4. The method for preparing high-purity large-particle anatase-type titanium dioxide according to claim 1, characterized in that: said drying adopts normal pressure drying. 5. The method for preparing high-purity large-particle anatase-type titanium dioxide according to claim 1, characterized in that: the largest particle of the prepared large-particle anatase-type titanium dioxide reaches 3.6 microns.

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