CN1147431C

CN1147431C - Process for preparing anatase-phase nano TiO2

Info

Publication number: CN1147431C
Application number: CNB021155070A
Authority: CN
Inventors: 菱昝; 昝菱; 钟家柽; 罗其荣; 龚楚清
Original assignee: Wuhan University WHU
Current assignee: Wuhan University WHU
Priority date: 2002-02-01
Filing date: 2002-02-01
Publication date: 2004-04-28
Anticipated expiration: 2022-02-01
Also published as: CN1373089A

Abstract

The present invention relates to a preparation method of high-temperature stable anatase-phase nanometer TiO2. The method comprises the following steps that metatitanic acid with low price is used as raw materials, dissolved in sulfuric acid to obtain titanyl sulfate solution, ammonia, sodium hydroxide or mixed solution of ammonia and ammonium carbonate is dripped in a certain concentration, and thus, titanic acid is obtained; the titanic acid is washed, dried, calcined at different temperatures, and thus, nanometer anatase TiO2 within a range of 30 to 80 nm can be obtained. The method has the characteristics that the price of the raw materials is low, the products can maintaine anatase phase at a temperature of 800 DEG C and can not convert into rutile, the crystal grains can not grow rapidly at high temperatures, can maintain less than 100 nm and has good dispersibility, and the method has low cost and simple technological condition, and is favorable to mass production.

Description

A kind of anatase-phase nano TiO 2The preparation method

Technical field

The present invention relates to anatase-phase nano TiO ₂Preparation, belong to field of fine chemical, use present method can prepare at the high temperature nano-anatase phase TiO of stable existence still ₂

Background technology

Nano-TiO ₂Be meant the titanium dioxide product of grain-size less than 100 nanometers, because its particle is little, specific surface area is big, thereby higher chemically reactive is arranged, and is widely used in the Chemical Manufacture.Titanium dioxide has three kinds of crystal formations: sharp titanium, and rutile and brookite, the front is the kind of present widespread use for two kinds.Rutile is widely used in coating, makeup, and sunscreen, in the high-grade paint, its tinting strength is better than anatase octahedrite.Anatase octahedrite then is widely used in the chemical fibre delustring mutually, the photochemical catalysis decontamination, and photo-catalyst, its photochemidal activity is better than rutile TiO ₂Anatase octahedrite is at cryostatic stabilization, generally just begin to transform but arrived high temperature to rutile at 600 ℃, 800 ℃ mostly with rutile mutually for mainly there being crystalline phase, and this crystal transition is a non-reversible process.In order to utilize the photochemical catalysis stain removal bactericidal of anatase octahedrite phase, need it is solidificated in the surface of glass and pottery and plays easy to clean and the antimicrobial characteristics, but with TiO ₂Be solidificated in the surface of glass or pottery, particularly to pottery, its glaze temperature of fusion is generally more than 800 ℃, therefore requires at high-temperature stable and keeps nanocrystalline anatase octahedrite phase TiO ₂Prepare TiO at present ₂Method generally be to take TiCl ₄Hydrolysis or thermal-flame method obtain, and are TiCl as the P25 product of Germany ₄Flame method preparation, particle diameter is 30nm, anatase octahedrite and rutile mutually and save as sharp titanium: rutile=80: 20, TiCl ₄The TiO of hydrolysis method preparation ₂In the time of 700 ℃, begun to transform and granularity＞100nm to rutile.The TiO of traditional sulfuric acid process preparation ₂Still can keep most of anatase octahedrite phase at 800 ℃, but its particle diameter is bigger,, does not belong to nanocrystalline greater than 0.5 μ m.The sharp titanium nano-TiO of useful Prepared by Sol Gel Method ₂, quality is better but cost is too high, only suitable prepared in laboratory and use.

Summary of the invention

It is lower and at the anatase-phase nano TiO of high-temperature stable that problem to be solved by this invention provides a kind of cost ₂The preparation method.

Technical scheme provided by the invention is a kind of anatase-phase nano TiO ₂The preparation method:

(1) uses H ₂SO ₄The dissolving metatitanic acid obtains titanyl sulfate;

(2) dilute sulphuric acid oxygen titanium solution concentration is at 0.05～0.5mol/L;

(3) use ammoniacal liquor, (NH ₄) ₂CO ₃Regulate PH to 8-11 with the mixed solution of NaOH or ammoniacal liquor;

(4) the positive metatitanic acid of washing with 3% Ba (NO3), 2 mensuration to there not being SO ₄ ^-

(5) to the positive metatitanic acid calcination after the washing, calcination temperature is controlled at 500～800 ℃, and the treatment time is 1～2 hour;

Can obtain evenly by above-mentioned steps, disperse the TiO of 30～80nm of pure preferably sharp titanium phase ₂

Outstanding feature of the present invention:

1. technology is simple, and raw material is cheap, is easy to scale operation.

2. temperature controllable obtains different big or small anatase octahedrite nano titanium oxides.

3. still be stable pure sharp titanium at 800 ℃ high temperature, and crystal grain only is the 80nm size.

Description of drawings:

Fig. 1 is the TEM photo of the present invention at 500 ℃ of calcining products obtained therefroms, magnification 33000;

Fig. 2 is the TEM photo of the present invention at 800 ℃ of calcining products obtained therefroms, magnification 33000;

Fig. 3 is a process flow sheet of the present invention.

Embodiment

Preparation flow of the present invention is as shown in Figure 3:

1, metatitanic acid and sulfuric acid are the commercially available prod, can obtain titanyl sulfate solution through heating for dissolving.

2, titanyl sulfate is diluted to 0.05～0.5mol/ and rises concentration, dropping ammonia then, 10% NaOH or ammoniacal liquor and 10-20% (NH ₄) ₂CO ₃Mixed solution, slowly drip and stir, a large amount of CO will be arranged ₂Gas produces, and regulates PH to 8-11.

3, with a large amount of water washing precipitations, to SO ₄ ^-Clean.

4, the dry precipitation of cleaning is removed surface water.

5, intensification calcination, constant temperature in 500 ℃～800 ℃ intervals as required.The setting of warm area is relevant with nanocrystalline size, can obtain the TiO of about 30nm at 500 ℃ of constant temperature ₂Crystal grain.Grow up at 800 ℃ of constant temperature crystal grain, about 80nm, but be all pure anatase octahedrite phase, Fig. 1 is the TEM photo of 500 ℃ product, the TEM photo when Fig. 2 is 800 ℃, and as seen from the figure, the dispersiveness of sample is better, uniform crystal particles.The X-ray diffraction figure main diffraction peak of 800 ℃ of constant temperature after 1 hour is: 25.28 ° (100), 48.09 ° (29), 37.85 ° (20), ° 53.90 (18), 55.06 ° (17) are the characteristic peaks of anatase octahedrite phase, and do not find the characteristic diffraction peak [27.45 ° (100)] of any rutile.

Embodiment 1: the dense H of metatitanic acid ₂SO ₄Dissolving obtains titanyl sulfate solution, and thin up is to the 0.4mol/ liter, and control drips the (NH of 10%NaOH and 10% down ₄) ₂CO ₃Mixing solutions, the limit edged stirs, and up to PH=8, drips off through 1 hour approximately, filtering reaction thing, and washing precipitation then is washed till 3% Ba (NO ₃) ₂Inspection is less than SO ₄ ^-, 100 ℃ of dryings are sloughed surface water then, calcine 1 hour for 500 ℃, obtain product, and its big or small pattern is seen Fig. 1, and particle is even, and size is about 30nm.

Embodiment 2: the dense H of metatitanic acid ₂SO ₄Dissolving obtains titanyl sulfate solution, and thin up is controlled down the slowly ammoniacal liquor of dropping 10% and 20% (NH to the 0.06mol/ liter ₄) ₂CO ₃Mixed solution, the limit edged stirred, and, dripped off filtering reaction thing, and washing precipitation then, the Ba (NO to 3% approximately up to PH=10 through 1 hour ₃) ₂Inspection is less than SO ₄ ^-, 100 ℃ of dryings are sloughed surface water then, calcine 1 hour for 800 ℃, obtain product, and its big or small pattern is seen Fig. 2, and particle is even, and size is 50nm～80nm, its x-ray diffraction pattern is the characteristic peak of anatase octahedrite phase entirely, does not have the signal of any rutile.

Embodiment 3: the dense H of metatitanic acid ₂SO ₄Dissolving obtains titanyl sulfate solution, and thin up is to the 0.2mol/ liter, and control drips 10% ammoniacal liquor down, and the limit edged stirs, and up to PH=9, drips off through 1 hour approximately, and filtering reaction thing, and washing precipitation then is washed till 3% Ba (NO ₃) ₂Inspection is less than SO ₄ ^-, 100 ℃ of dryings are sloughed surface water then, calcine 1 hour, and obtain product for 700 ℃.

Claims

A kind of anatase-phase nano TiO ₂The preparation method, it is characterized in that:

(1) uses H ₂SO ₄The dissolving metatitanic acid obtains titanyl sulfate;
(2) dilute sulphuric acid oxygen titanium solution concentration is at 0.05～0.5mol/L;
(3) use ammoniacal liquor, (NH ₄) ₂CO ₃Regulate PH to 8-11 with the mixed solution of NaOH or ammoniacal liquor;
(4) the positive metatitanic acid of washing is to there not being SO ₄ ^-
(5) to the positive metatitanic acid calcination after the washing, calcination temperature is controlled at 500～800 ℃, and the treatment time is 1--2 hour;

Can obtain evenly by above-mentioned steps, disperse the TiO of 30～80nm of pure preferably sharp titanium phase ₂