Preparation method of high-activity mesoporous hydrated titanium oxide powder

Method for preparing highly active mesoporous hydrous titanium oxide powder

TECHNICAL FIELD

[0001] The present invention relates to a method used in catalytic activity in the field of high technology mediated prepared hole hydrous titanium oxide, belonging to the field of inorganic nanomaterials.

Background technique

[0002] In the catalytic light, electricity and other methods to remove the degradation of toxic and hazardous substances are typical pollutants carbon treatment. Titanium dioxide nanoparticles use of light catalytic degradation of organic matter, with a stable, non-toxic, organic matter degradation can be completely mineralized, no secondary pollution, etc., is recognized as the best light catalyst, its existing form, anatase type, rutile, brookite, orthorhombic type and hydrated type, etc., wherein the hydration type titanium oxide has broad application prospects (Kim SK, Park HJ, Kwak CG in terms of water treatment, solar cells, solid super acid catalyst, etc., et al "Characterization of pore structure of mesoporous hydrogen titanium oxide hydrates" · Journal of Physics and Chemistry of Solids 2008, 69,1139-1141;... Li Shuang, Xu Jiandong, Xu Bin, and other "meta-titanic acid catalyzed hydrolysis of the epoxy ring Preparation of trans-1,2-hexane-cyclohexanediol. "Nanjing University of Technology (Natural Science) .2014, 3 (36), 111-114 .; Hanshi Qi, Secretary Chao is, Yanheng Bo, and so on." skewness mechanism of acid potassium titanate whiskers as a raw material for preparing functional materials .2012,14 (43), 1829-1832.). mesoporous hydrous titanium oxide because of its larger surface area, developed pore structure, not only through adsorption provide photocatalytic reaction of high concentrations of the reactants, and can produce more active sites, thereby significantly improving the photocatalytic activity; at the same time, since the titanium oxide nano-sized aggregates, both good flowability and deposition can be easily recovered and reused, in terms of water treatment, air purification, solar cells, and other biological materials exhibit broad application prospects.

[0003] The present method of preparing mesoporous on hydrous titanium oxide powder has been reported, resulting morphologies substantially mesoporous titania nanotubes, and mainly non-mesoporous titanium oxide powder is titanium source, heated at a high concentration of NaOH in the reaction solution obtained by a certain time. For example, research literature [Kim SK, Park HJ, Kwak CG, et al. "Characterization of pore structure of mesoporous hydrogen titanium oxide hydrates '' · Journal of Physics and Chemistry of Solids. 2008, 69, 1139-1141.] Mentioned , titanium dioxide is a titanium source powder, the NaOH solution 10m〇l / L 90-210 ° C in a certain reaction time, washed with HCl after the availability of a range of different composition hydrous titanium oxide nanotubes; literature [a Nakahira, W kato, M Tamai, et al. "Synthesis of nanotube from a layered H2T14O9 · H2O in a hydrothermal treatment using various titania sources '' · Journal of Materials Science, 2004, 39,4239-4245.] respectively anatase Ti 〇2, rutile Ti〇2 commodity P25 titanium source, lOmol / L of NaOH, KOH solution 110-150 ° C hydrothermal reaction at different times to give the composition SH2Ti4O9 · H2O in hydrous titanium oxide nanotubes. Hydrous titanium oxide nanotubes, while having a high specific surface area and pore better, but there are narrow channels to the detriment of organic matter (or photocatalytic degradation) issue adsorption and diffusion in the pores, so the photocatalytic activity is not very good ; and, the use of such goods Ti0 2 (such as the German Degussa produced P25, anatase TiO2, etc.) as raw materials in an autoclave hydrothermal reaction is, expensive raw materials, equipment requirements, there is currently producing high active mesoporous hydrated titanium technology still to be improved.

[0004] ethylene diamine small molecule organic amine having a structure-directing role of linear growth, research literature [Zhao PT, Huang K X. "Preparation and Characterization of Netted Sphere-like CdS Nanostructures". Crystal Growth & Design, 2008,2,717-722 *] referred to Cys and cadmium nitrate tetrahydrate as a precursor in ethylenediamine solvent 150 ° C reaction 8h, generated by CdS nanowires woven into a mesh sphere. In the preparation of titanium oxide, ethylene diamine nitrogen is used as a dopant, such as literature [Zheng J, Liang Kong, Feraih SA, et al. "Enhanced visible-light-driven photocatalytic activity of mesoporous Ti02-xNx derived from the ethylenediamine-based complex ". Nanoscale, 2013,5,5396-5402.] tetrabutyl titanate as titanium source, dodecylamine as template, ethylenediamine nitrogen, by solvent evaporation induced self-assembly method to prepare ago rear-wheel drive body, 450 ° C calcined mesoporous nitrogen-doped anatase titanium dioxide; Venant dog [George H, Tatsuya S, Kazuyoshi K, et al "Synthesis and electrochemical performance of hierarchically porous N-doped. Ti02 for Li-ion batteries'NewJ.Chem, 2014,38,1380-1384 ·] with titanium tetra-propyl source, templating agent polyethylene glycol, ethylene diamine as nitrogen source, using the sol-gel method after preparation precursor at 300 ° C-70 (TC after firing has been nitrogen-doped porous anatase type titanium dioxide; literature [Zhou W, Yu C, Fan Q, et al "Ultrasonic fabrication of N-doped. Ti02 Nanocrystals with mesoporous structure and enhanced visible light photocatalytic activity '' · Chinese Journal of Catalysis, 2013, 34, 1250-1255.] titanium tetrachloride titanium source, ethylene oxide / propylene oxide block copolymer after the template agent, ethylenediamine nitrogen generated by ultrasound precursor reaction, put teflon lined autoclave 180 ° C hydrothermal reaction 24h, 350 ° C was calcined nitrogen-doped mesoporous anatase mine-type titanium dioxide. these ethylenediamine as nitrogen doping, although improved activity, but they must add the template to generate mesoporous structure and a firing step to obtain anatase titanium oxide, increasing the cost of the key issues They are: roasting process is likely to cause the collapse of hard agglomerates and particles between the pore structure, thereby reducing activity.

SUMMARY

[0005] The object of the present invention is to provide a highly active mesoporous hydrous titanium oxide preparation. The resulting product of the present invention is a particulate titanium dioxide nanoparticles aggregates have mesoporous structure, degradation in the pores of the adsorption and diffusion of easy, not easy to overcome the problems of the prior adsorption and diffusion of nanotubes exist and overcome the product has been announced technical defects, such as raw materials to expensive TiO 2 powder is titanium source, equipment requirements, the need in an autoclave hydrothermal reaction, the process is more complex, the need to improve the activity of the product and the need to increase the cost of other defects.

[0006] The present invention uses a simple one-pot, with readily available and inexpensive industrial raw material titanium tetrachloride titanium source, the process is simple, easy operation, short process, reduce costs, and the resulting product is granular aggregates of nano-TiO 2 with high photocatalytic activity, protect the environment, it is a new method for preparing easy industrial production and promotion applications.

[0007] Technical Solution to a certain volume of pure ethylene diamine (AR), and then press the titanium tetrachloride with ethylene diamine 1: 2-16 molar ratio of titanium tetrachloride and ethylene diamine, the reaction is complete the mixture was placed in a 65 ° C water bath, to 65r / min speed rotary evaporation in vacuo 3h, remove excess ethylenediamine, titanium tetrachloride with water then 1: 10-30 ratio by volume with purified water, and then at a temperature of 30-98 ° C was heated at reflux for 24-96 hours. the product was centrifuged and washed first with purified water three times, dried over anhydrous washed with ethanol three times, dried at a temperature of 45 ° C for 12 hours, to obtain a highly reactive mesoporous hydrous titanium oxide.

[0008] to take the first 24. OmL pure ethylene diamine (AR), and then press the titanium tetrachloride with ethylene diamine 1: 8 molar ratio of titanium tetrachloride 5. OmL added dropwise 24.Oml ethylenediamine during and after completion of the reaction, the mixture was placed in a water bath at 65 ° C to 65r / min speed rotary evaporation in vacuo for 3 hours to remove excess ethylenediamine, titanium tetrachloride with water then 1: 20 ratio by volume with purified water IOOmL , at 98 ° C and then boiled under reflux for 72-96 hours. the product was centrifuged and washed first three times with purified water, washed with ethanol 3 times and dried over anhydrous baked at a temperature of 45 ° C for 12 hours, to obtain a high- activity mesoporous hydrous titanium oxide.

[0009] The resulting product of the invention for the nano-sized titanium dioxide granular aggregates of organic matter in favor of the move and its Gan surface diffusion, while convenient recycling than conventional mesoporous hydrated titania nanotubes and the commodity P25 photocatalytic activity are high, showing broad application prospects in water treatment. The process of the present invention is simple, easy to operate, in water treatment, air purification, aspects, solar cells, and other biological materials having a wide range of uses, easy industrialization and application.

BRIEF DESCRIPTION

[0010] FIG. 1 is an embodiment in which a mesoporous titanium dioxide nanoparticles isothermal adsorption / desorption curves.

[0011] Figure 2 is an embodiment in which titanium dioxide nanoparticles mesoporous pore volume - size distribution curve.

[0012] FIG. 3 is an embodiment in which a mesoporous titanium dioxide nanoparticles of X-ray diffraction pattern.

[0013] FIG. 4 is an embodiment of the TEM photograph as a mesoporous nano-TiO2.

[0014] FIG. 5 is Embodiment 2 of the titanium dioxide nanoparticles prepared mesoporous pore volume - size distribution curve.

detailed description

[0015] Example One: First take 24.0 mL of pure ethylene diamine (AR), and then press the titanium tetrachloride with ethylene diamine 1: 8 molar ratio of 5. OmL titanium tetrachloride was added dropwise to 24.0 mL ethylenediamine, until the reaction was complete, the mixture was placed in a water bath at 65 ° C to 65 r / min speed rotary evaporation in vacuo 3 h, then titanium tetrachloride and the water volume ratio of 1:20 was added 100 mL of pure water, and then the system at 98 ° C temperature was heated to reflux 72 h (hours), the product was centrifuged, pure water 3 times, washed three times with ethanol at 45 ° C temperature drying 12 hours, that is, obtain a high activity of mesoporous hydrous titanium oxide catalyst. Figure 1 isothermal absorption / desorption curve shows that it belongs to IUPAC classification type IV isotherm and H3 hysteresis loop, you can see a sample of mesoporous catalyst. The catalyst is prepared by Method BET specific surface area of ​​432.7 m2 / g, a total pore volume of the adsorption of 0.731 m3 / g, pore volume of 0.151 m3 / g. Figure 2 shows pore size mainly distributed in the 3-4 nm. As shown in Figure 3 XRD test results, the catalyst is prepared by the hydrous titanium oxide. Figure 4 is a TEM photograph of the catalyst prepared.

[0016] Determination of the photocatalytic activity: Take catalyst 5.0 mg, was added 50mL concentration of 2.0 X l (T5g / mL of methylene blue solution as degradation by 100 Hz ultrasonic dispersion after standing at 40 W UV lamp ( at 10 cm) irradiated to degrade methylene blue, methylene blue solution is then measured removal order and there are mesoporous hydrated titania (Ref. [Kim SK, Park HJ, Kwak CG, et al. "Characterization of pore structure of mesoporous hydrogen titanium oxide hydrates "· Journal of Physics and Chemistry of Solids. 2008, 69, 1139-1141 · photocatalytic activity] preparation) and commodities P25 do comparison, were taken 5.0 mg TiO2 nanotubes and P25 in the same operation measuring its removal, both catalysts are photodegradation 100 minutes after the results are as follows:

<img id="idf0001" file="CN105618022AD00051.tif" img-content="drawing" img-format="tif" />

COD Detection The Photocatalytic Performance: Take catalyst 5.0 mg, was added 50 mL concentration 2.OX KT5 g / mL methylene blue solution for degradation by 100 Hz after ultrasonic dispersion placed under ultraviolet light 40W (10 cm at) 2h irradiation to degrade methylene blue. Respectively, according to the national standard method for the determination of chemical oxygen demand before and after the photocatalytic (C0D), the difference shall photocatalytic effect produced. And P25 for the photocatalytic activity to do comparison, taking 5.0 mg P25 measured by the same manner as the COD change, results are as follows:

<img id="idf0002" file="CN105618022AD00061.tif" img-content="drawing" img-format="tif" />

Example Two: Effect of hydrothermal time to take 24.0 mL of pure ethylene diamine (AR), and then press the titanium tetrachloride with ethylene diamine 1: 8 molar ratio will be 5.0 mL of titanium tetrachloride was added dropwise to 24.0 mL ethylenediamine, until the reaction was complete, the mixture was placed in a water bath at 65 ° C to 65 r / min speed rotary evaporation in vacuo 3.0 h, then titanium tetrachloride and the water volume ratio of 1:20 was added 100 mL of pure water, and then the system was heated to reflux, respectively 0 h, 6 h, 12 h, 24 h, 48 h, 72 h, 96.0 h, the product was centrifuged, pure water 3 times, washed three times with ethanol at a temperature of 45 ° C after drying at 12 h, to obtain a series of catalysts. Figure 5 is a series of prepared catalyst pore volume - size distribution curve. We prepared a series of a specific surface area and pore volume results are as follows:

<img id="idf0003" file="CN105618022AD00062.tif" img-content="drawing" img-format="tif" />

= Total pore volume of mesoporous adsorption single point total pore volume - measured total pore volume of porous photocatalyst on a case by methylene blue removal process, results are as follows:

<img id="idf0004" file="CN105618022AD00063.tif" img-content="drawing" img-format="tif" />

Example Three: Influence of the amount of titanium tetrachloride was added to take 24.0 mL of pure ethylene diamine (AR), and then press the titanium tetrachloride with ethylene diamine 1: 16 molar ratio, respectively: 4,1: 8,1 10.0 mL, 5.0 mL, 2.5 mL of titanium tetrachloride was added dropwise to 24.0 mL ethylenediamine, until the reaction was complete, the mixture was placed in a water bath at 65 ° C to 65 r / min speed rotary evaporation in vacuo 3 h, press ethylenediamine and water volume ratio of 6:25 was added 100 mL of pure water, and then the system was heated to reflux for 72 h, the product was centrifuged, pure water 3 times, washed three times with ethanol at 45 ° C temperature bake dry for 12 hours to obtain a series of catalysts. Prepared catalyst specific surface area and pore volume results are as follows:

<img id="idf0005" file="CN105618022AD00064.tif" img-content="drawing" img-format="tif" />

Determination of photocatalytic removal of methylene blue by the case of a process with the following results:

<img id="idf0006" file="CN105618022AD00065.tif" img-content="drawing" img-format="tif" />

Example IV: Effect of the amount of ethylenediamine is added 5.0 mL of titanium tetrachloride was taken, respectively, according to ice-water bath of pure titanium tetrachloride with ethylene diamine (AR) 1: 1,1: 2,1: 4,1 : 8, the molar ratio of 1:16 ^ 5.〇1 titanium tetrachloride was added dropwise to 3.〇11 ^, ^ 6.〇11, 12.〇11 ^, ^ 24.〇11, 48.〇 11 ^ ethylenediamine, after completion of the reaction, titanium tetrachloride and then water volume ratio of 1:20 was added 100 mL of purified water, and then the system was heated at reflux for 72 h, the product was centrifuged, pure water 3 times, no after the ethanol wash water three times, dried at 45 ° C temperature for 12 hours, to obtain a series of catalysts. Catalyst specific surface area and pore volume results are as follows:

<img id="idf0007" file="CN105618022AD00071.tif" img-content="drawing" img-format="tif" />

Example five: the effects of different water requirements to take 24. OmL pure ethylene diamine (AR), and then press the titanium tetrachloride with ethylene diamine 1: 8 molar ratio will be 5.0 mL of titanium tetrachloride was added dropwise to 24.0 mL ethylenediamine, until the reaction was complete, the mixture was placed in a water bath at 65 ° C to 65 r / min speed rotary evaporation in vacuo 3h, then titanium tetrachloride with water 1: 10,1: 20,1: the volume ratio of 30 were added to 50 mL, 100 mL, 150 mL purified water, and then the system was heated at reflux for 72 h, the product was centrifuged, pure water 3 times, washed three times with ethanol, at a temperature of 45 ° C drying 12 hours later, that was a series of catalysts. Prepared catalyst specific surface area and pore volume results are as follows:

<img id="idf0008" file="CN105618022AD00072.tif" img-content="drawing" img-format="tif" />

Case discussion by a stalk measuring the universe photocatalyst removal of methylene blue, as follows:

<img id="idf0009" file="CN105618022AD00073.tif" img-content="drawing" img-format="tif" />

Example VI: influence of hydrothermal temperature to take 24.0 mL of pure ethylene diamine (AR), and then press the titanium tetrachloride with ethylene diamine 1: 8 molar ratio of 5. OmL titanium tetrachloride was added dropwise to 24.0 mL ethylenediamine, until the reaction was complete, the mixture was placed in a water bath at 65 ° C to 65 r / min speed rotary evaporation in vacuo 3h, then titanium tetrachloride and the water volume ratio of 1:20 was added 100 mL of pure water, and then the system were placed in 30 ° C, 60 ° C, 98 ° C (boiling under reflux), 120 ° C (120 ° C reaction reaction in Teflon-lined autoclave) for 72 hours. the product was centrifuged, pure water 3 times, washed three times with anhydrous ethanol, dried at 45 ° C temperature for 12 hours, to obtain a series of catalysts. Catalyst specific surface area and pore volume results are as follows:

<img id="idf0010" file="CN105618022AD00081.tif" img-content="drawing" img-format="tif" />

Example VII: Effect of catalyst by washing in case of a sample preparation method, but after a hydrothermal synthesis but no longer direct drying washing, washing another two catalyst specific surface area and pore volume results are as follows:

<img id="idf0011" file="CN105618022AD00082.tif" img-content="drawing" img-format="tif" />

Determination of the Methylene Blue photocatalyst removal cases by a procedure, the results are as follows: Example Eight:

<img id="idf0012" file="CN105618022AD00083.tif" img-content="drawing" img-format="tif" />

Effect of order of addition of reactants by titanium tetrachloride: Pure ethylenediamine (analytical): Volume of pure water ratio of 1: 4.8: 20 was added to the reaction. 1 order of addition: first 5.0 mL of titanium tetrachloride was added 24.0 mL of ethylenediamine, after completion of the reaction adding 100 mL of water, was refluxed for 72h, the sample, successively washed with water and purified with absolute ethanol, at a temperature of 45 ° C drying after 12 hours standby. Order of addition 2: In the same volume ratio of the first 5.0 mL of titanium tetrachloride was added 100 mL of water, was added 24.0 mL of pure ethylenediamine (AR), water and heat at reflux for 72 h, the sample in the same manner, washed, and dried at . Different order of addition obtained catalyst specific surface area and pore volume results are as follows:

<img id="idf0013" file="CN105618022AD00084.tif" img-content="drawing" img-format="tif" />

Determination of the Methylene Blue photocatalyst removal cases by a process with the following results:

<img id="idf0014" file="CN105618022AD00085.tif" img-content="drawing" img-format="tif" />