Preparation method of mixed crystal nano-TiO2

A method for preparing a mixed crystal nano-titanium dioxide

TECHNICAL FIELD

[0001] The present invention relates to the field of nano-materials, and more particularly, to a method for preparing a mixed crystal titania nanoparticles.

Background technique

[0002] In recent years, environmental and energy issues has aroused great concern. In the huge textile industry in the production process, the dye becomes a very serious ecological organic pollutants, it is difficult to remove the biological and physical methods, photocatalytic degradation of pollutants has been considered effective. Nano titanium dioxide as a non-toxic, inexpensive and stable nature of nanomaterials is expected to become the most promising photocatalyst.

[0003] The nanoscale titanium dioxide, also known as titanium dioxide, a diameter of 100 nm or less, the product appearance is white loose powder. Ti02 nanoparticles stable, good light-harvesting performance, recyclable. 1102 applications is very broad, widely used in terms of energy and the environment, biological, medical and other health, has the following advantages:

[0004] 1, photocatalytic degradation of pollutants: Nano Ti02 as a catalyst, there is no secondary pollution, and not selective, widely used in environmental pollution. Can degrade dye wastewater, insecticides, pesticides wastewater, surface active agents, as well as industrial waste containing heavy metals, can be oxidative degradation;

[0005] 2. Application dye-sensitized solar cell areas: semiconductor nano-Ti02 has a relatively wide band gap, and good lightfastness properties. Photosensitive dye molecules adsorbed on the surface of semiconductor nano-hit 02 to improve the photoelectric conversion efficiency;

[0006] 3, the shielding effect of UV nano-Ti02: Nano T1 2 have a UV shielding effect, plus it is non-toxic, stable, etc., used in cosmetics Ti02 nano sunscreen, paint, chemical fiber, various aspects of rubber, plastics and the like.

[0007] There are two main titanium dioxide crystalline forms: anatase (Anatase) and rutile (Rutile). Rutile than anatase titanium dioxide stable and dense, with high hardness, density, dielectric constant and refractive index, its opacity and tinting strength is also high. The anatase titanium dioxide in the visible short-wave part of the reflectance higher than rutile titanium dioxide, bluish tint, and UV absorption capacity is lower than rutile, photocatalytic activity than rutile. Under certain conditions, anatase titanium dioxide can be converted to rutile titanium dioxide.

[0008] In the mixed crystal nano-titanium dioxide existing in the preparation process, in order to prepare qualified titanium dioxide products, often adding a precipitating agent in the preparation process and heat treatment, such as: Wang Wei et al. (Wang Wei, Ruancheng Dong, Ru red strong A mesoporous titania color material and a preparation method referral, China, patents, 201410231843.2,2014.08.13) titanium source (titanium tetrachloride, titanium trichloride, titanate one or two) and water reacting titanate, titanate and hydrogen peroxide were mixed to prepare a titanium peroxide acid, non-ionic surfactant and an acid to form a composite titanium peroxide and baking mesoporous titania composites. Bing, etc. (Bing, Yang Zewei, Ann Ho, etc. One brookite and rutile titanium dioxide nano mixed crystal cryogenic preparation. Chinese invention patents, 201410629923.3,2015.03.25) ultra-pure water, tetraethyl titanate and ethanol by mixing prepared and dried to obtain hydrous titanium oxide, obtained by adding hydrogen peroxide peroxide titanate sol, the sol at 40~60 ° C water bath, and finally at 160~200 ° C water conditions thermal reaction, the product obtained after washing and drying the mixed crystal. Wang Zhenxing, etc. (Wang Zhenxing, Ding Shiwen, Zhang Mei-hong Synthesis of highly dispersed nano-titanium dioxide mixed crystal! Structures and photocatalytic properties of Inorganic Chemistry, 2005,3,21) fume hood in a dry measuring cylinder with titanium tetrachloride was added slowly the hydrochloric acid solution. The mixed solution is rapidly heated to a constant temperature reaction 10~60min 100 ° C and then the amount of urea solution of the aqueous solution was added quickly. Under alkaline conditions at 100 ° c reflux 2h vacuum filtration and washed. Then dried, and finally placed in a muffle furnace burning 30min sample was taken. In order to prevent the occurrence of hard agglomerates of nanoparticles, adding a certain amount in the mixed solution of nanoscale carbon black in the drying process. Ding Shiwen, etc. (Ding Shiwen, Dong Wei, Wang Liyong, etc. Preparation of Crystal Nano Ti02 and Degradation of wastewater containing cyanide mixed, Natural Science, Xiangtan University, 2008,2,30.) Will llmL TiCl slowly added dropwise 200mL distilled water , keeping the drip ld / s, titration process to maintain the solution is clear. The clear solution was transferred to a beaker of 500mL three-necked flask, heated to boiling under acidic conditions, until the solution appears cloudy after the reaction was continued 10~60min, then 1ml of aqueous ammonia was added to adjust the pH to weakly alkaline, reaction was continued for 60min. After filtration, washing reduced pressure at 80~90 ° C and dried to obtain a powder sample to release a muffle furnace firing 60min. Wang Liyong like (Wang Liyong, FOR THERMAL DONG Wei, etc. synthetic nano-titanium dioxide mixed crystal and light Degradation of Acid Red 3R research, Hebei University (Natural Science), 2007,3,27) will TiCl4 rate dropped to 1 per drop 200mL deionized water, rapid heating, to a large number of white turbidity system, at 100 ° C after the reaction period, the volume fraction of 50% aqueous ammonia and to weakly alkaline, the reaction was continued at 100 ° C after 3h, the product was filtered deionized water to remove impurity ions NH4 + and C1, then ethanol wash away residual moisture in the sample, vacuum-dried, finely prepared nanometer mixed crystal powder. Gou Ji Kim et al. (Quarter gold Gou, Guo, Shi Zhaohui, etc. Preparation and photocatalytic properties of titanium dioxide mixed crystal nano suspensions Materials Review B:.. Research papers, 2012,7,26) in ammonia and water TiCl4 solution was added dropwise a mixed solution, high-temperature heating oil bath, the pH was adjusted with concentrated hydrochloric acid, to obtain a white precipitate T1 2. Du Jin Ge et al. (Du Jin Ge, Yao Chaozong. Preparation and photocatalytic properties of titanium dioxide chemistry, 2012,4,23) titanium tetrachloride was added to distilled water and ethanol mixed solution, stirring slowly dropped urea solution, After stirring at room temperature uniform 2h, transferred to a Teflon-lined autoclave, in a forced air oven 180 ° C thermostat handle 16h. It cooled to room temperature, filtered, washed, 60 ° C drying to obtain Ti02 nano powder. In preparing the mixed crystal of titanium dioxide, acids and bases are involved in the preparation process as a precipitating agent, a subsequent heat treatment process increases the complexity of the manufacturing process. The present case by the reaction temperature and reaction time is controlled without adding a subsequent heat treatment of precipitation agent prepared crystal ratio of controllable nano-silica mixed crystal, reducing the complexity of the manufacturing process.

SUMMARY OF THE INVENTION

[0009] In view of the above problems, the present invention provides a method for preparing a mixed crystal titanium dioxide can be obtained anatase and rutile titanium dioxide mixed crystal type at the same time in a single manufacturing process. Specific technical programs are as follows:

[0010] - the kind of mixed crystal titanium dioxide production method, the method comprising the steps of:

[0011] First, TiCl4 dissolved in deionized water to prepare a solution of a certain concentration of TiCljK; then, at 30~60 ° C in temperature aging 2~8h and / or aged at an elevated temperature of 60~90 ° C 2 ~8h, the resulting precipitate was filtered, washed, and dried, in this process, without adding any reagents and adjusting the pH value; Finally, the resulting mixed crystal titanium dioxide;

[0012] The 11 (: 14 with deionized water volume ratio of 1: 100~1: 30.

[0013] The mixed crystal refers to a mixture of the two polymorphs anatase and rutile.

[0014] The anatase and rutile in a weight ratio of 10~80: 20~90.

[0015] The present inventors have been found that the reason may be a mixed crystal produced two crystal at different temperatures to generate speed is not the same: the low temperature, the faster the growth of rutile; high temperature, anatase growth faster. So generated at low temperature mixed crystal rutile content, high temperature synthesis after anatase content. In order to adjust the proportion of mixed crystal used in low temperature two temperature ranges, different growth time to achieve the purpose of adjusting the proportion of mixed crystal.

[0016] advantages of the present invention and the beneficial effects of the following: nano-titanium dioxide is an excellent photocatalytic material, especially those with a certain proportion of mixed crystal titanium oxide, the traditional method is by changing the calcination temperature and calcination time or by adding some the proportion of mixed crystal polymorph control agent regulation method, calcination likely to cause sintering and agglomeration of particles, process control agent method to add operational complexity; the preparation method of the present invention provides, simply TiCl4 dissolved into the water, dubbed a certain percentage aqueous solution at different temperatures at different times of aging, we can regulate the proportion of products anatase and rutile. The preparation process is simple, the resulting slurry can be directly supported on a carrier, avoiding the calcination process of reunion.

Brief Description

[0017] FIG. 1 is a titanium dioxide mixed crystal X-ray diffraction pattern of implementation;

[0018] FIG. 2 is a titanium dioxide mixed crystal X-ray diffraction pattern of Example 1 of the fitting;

[0019] FIG. 3 is an embodiment 2 mixed crystal titanium dioxide X-ray diffraction pattern;

[0020] FIG. 4 is an embodiment of the titanium dioxide mixed crystal X-ray diffraction pattern 2 is fitted;

[0021] FIG. 5 is a mixed crystal of titanium dioxide 3 X-ray diffraction pattern of implementation;

[0022] FIG. 6 is an embodiment 3 of the titanium dioxide mixed crystal X-ray diffraction pattern fitting;

[0023] FIG. 7 is a fourth embodiment titanium dioxide mixed crystal X-ray diffraction pattern;

[0024] FIG. 8 is an embodiment of the titanium dioxide mixed crystal X-ray diffraction pattern fitting 4;

[0025] Example 5 FIG. 9 is a titanium dioxide mixed crystal X-ray diffraction pattern;

[0026] Example 5 FIG. 10 is a titanium dioxide mixed crystal X-ray diffraction pattern fitting;

[0027] FIG. 11 is a titanium dioxide mixed crystal X-ray diffraction pattern of the sixth embodiment;

[0028] FIG. 12 is a titanium dioxide mixed crystal X-ray diffraction pattern fits 6 implementation.

detailed description

[0029] The following examples of the present invention will be described in detail. It is necessary to point out that the following examples of some cases of non-essential improvements and adjustments only for the present invention is further illustrated, can not be construed as limiting the scope of the present invention, the field of professional and technical personnel to make based on the content of the present invention, still belong to the scope of the invention.

[0030] Example 1

[0031] A 3.5mL of TiCl4 dissolved in 100mL deionized water. The solution was heated in a thermostat placed in 45 ° C water bath 6h0 then the resulting slurry was filtered, washed, and dried, to give the mixed crystal titanium oxide powder. The resulting product measured diffraction pattern and fit the pattern shown in Figure 1 and Figure 2 respectively. Correlation calculation data as follows:

[0032] calculated content anatase titanium oxide phase of the sample was 24.4% and an average particle size of 1.10nm. Rutile content was 75.6%, an average particle size of less than lnm0

[0033] Example 2

[0034] A 2.5mL of TiCl4 dissolved in 100mL deionized water. The solution was heated 2h into the 35 ° C water bath, then removed and the solution was placed in a 85 ° C water bath heated 6h. The resulting slurry was then filtered, washed, and dried, to give the mixed crystal titanium oxide powder. The resulting product measured diffraction pattern and fit the pattern shown in Figure 3 and Figure 4, respectively. Correlation calculation data as follows:

[0035] calculated content anatase titanium oxide phase of the sample was 72.3%, an average particle size of less than lnm. Rutile phase content of 27.7% and an average particle size of 1.06nmo

[0036] Example 3

[0037] A 2mL of TiCl4 dissolved in 100mL deionized water. 4h the solution is heated to 55 ° C into a water bath, then removed and the solution was placed in a 80 ° C water bath heated 4h. The resulting slurry was then filtered, washed, and dried, to give the mixed crystal titanium oxide powder. The resulting product measured diffraction pattern and fit the pattern shown in FIG. 5 and 6, respectively. Correlation calculation data as follows:

[0038] calculated the content of titanium dioxide anatase phase of the sample was 66.7% and an average particle size of less than lnm. Rutile phase content of 33.3% and an average particle size of 1.34nm.

[0039] Example 4

[0040] A 3.5mL of TiCl4 dissolved in 100mL deionized water. The solution was heated to 80 ° C placed in a constant temperature water bath 8h0 resultant slurry was then filtered, washed, and dried, to give the mixed crystal powder. The resulting product measured diffraction pattern and fit the pattern as shown in Figures 7 and 8 respectively. Correlation calculation data as follows:

[0041] calculated content anatase titanium oxide phase of the sample was 83.2%, an average particle size of less than lnm. Rutile phase content of 16.8% and an average particle size of 1.51nm.

[0042] Example 5

[0043] The 3mL of TiCl4 dissolved in 100mL deionized water. The solution was heated 2h into 70 ° C water bath thermostat, remove and then the solution was placed in a 45 ° C water bath heated 6h. The resulting slurry was then filtered, washed, and dried, to give the mixed crystal titanium oxide powder. The resulting product measured diffraction pattern and fit the pattern as shown in Figures 9 and 10 respectively. Correlation calculation data as follows:

[0044] calculated the content of titanium dioxide anatase phase of the sample was 78.7%, an average particle size of less than lnm. Rutile phase content of 21.3% and an average particle size of less than lnm.

[0045] Example 6

[0046] A 1.5mL of TiCl4 dissolved in 100mL deionized water. Aging 4h the solution was put in a constant temperature water bath at 80 ° C, and then the solution was taken into a 45 ° C water bath aging 4h. The resulting slurry was then filtered, washed, and dried, to give the mixed crystal titanium oxide powder. The resulting product measured diffraction pattern and fit the patterns 11 and 12, respectively. Correlation calculation data as follows:

[0047] calculated the content of titanium dioxide anatase phase of the samples was 80%, an average particle size of less than lnm. Rutile phase content of 20% and an average particle size of 1.42nm.