CN104445387A

CN104445387A - Method for preparing photo-catalytic active titanium dioxide nano material

Info

Publication number: CN104445387A
Application number: CN201410617934.XA
Authority: CN
Inventors: 华文蔚
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-11-05
Filing date: 2014-11-05
Publication date: 2015-03-25

Abstract

The invention discloses a method for preparing a photo-catalytic active titanium dioxide nano material. The method is characterized by comprising the following steps: 1) dissolving an organic compound of titanium, zinc, cadmium, tungsten or tin into an aqueous solution, stirring, and generating a white sediment after sufficient mixing, wherein the organic compound of titanium, zinc, cadmium, tungsten or tin is a corresponding acid ester or a mixture of titanium, zinc, cadmium, tungsten or tin; 2) drying and pulverizing the sediment obtained in step (1) to obtain solid powder, wherein the drying temperature is 80-120 DEG C and the drying time is 5-12 hours; and 3) adding starch into the solid powder, thermally treating the powder mixture with oxygen-free equipment, and washing and drying by the end of the reaction to obtain the active semiconductor photo-catalytic nano material. The method reduces the production cost and simplifies the production process.

Description

A kind of preparation method of photocatalytic activity titanium dioxide nano material

Technical field

The present invention relates to a kind of preparation method of photocatalytic activity titanium dioxide nano material.

Background technology

Since rising of Tokyo Univ Japan in 1972 has been led since the strong professor of clear and tutor Duo Ben finds photocatalysis principle and effect for the first time, the research of optically catalytic TiO 2 is always very active, be widely used in the exploitation of solar cell, gas sensor, sun power preparing hydrogen by decomposing, the photocatalytic degradation of sewage and waste water, photo-catalyst, self-cleaning and antifog etc.But the forbidden band of TiO 2 wider (Eg=3.2eV), only can only be accounted in sunlight about 5% (λ≤387.5nm) UV-light excite.Thus, improve its quantum yield, widen TiO 2 to the response of visible ray accounting for solar radiation 46%, thus full range utilizes sun power, is the developing direction of TiO 2 photocatalyst material.The spectral sensitization of organic dye, precious metal support and transient metal doped, although can improve the utilization ratio to sunlight, also make photocatalytic titania film UV-light light reaction reduce, photo-catalysis capability is weak, photo and thermal stability be deteriorated, cost improve.Asahi etc. calculate the state density (DDSs) of the rear TiO 2 of C, N, F, P or S doping respectively, after showing that TiO 2 is anion doped, its photoabsorption edge can be made to be shifted to lower level, exciting light threshold values can be expanded to visible region (Science 2001,293,269).Because carbon has suitable specific conductivity, density is very low, and carbon can enter in titanium dioxide by the organic carbon of optimal temperature, changes the absorption of visible ray, thus obtains good photocatalysis effect.Khan etc., by controlling methane and oxygen flow, the flame calcination titanium sheet of 850 degree, obtain the titanium dioxide (Science 2002,297,2243) of carbon doping.But mainly the form of rutile exists after the titanium dioxide high-temperature roasting of carbon doping, and the reunion of TiO 2 nanocrystal may be caused to grow up.Irie etc. to TiC 600 degree of oxidizing annealings in Oxygen Flow, the Carbou doped titanium-oxide obtained

Under visible ray (400-530nm) radiation, Virahol is decomposed and become display light catalytic activity in the reaction of CO2 (Chem.Lett.2003,32,772) through acetone.Li Yuanzhi etc. contain K Anatase in hexanaphthene air-flow Program intensification carbonization to TiCl 4 hydrolysate, obtained Carbou doped titanium-oxide (Chem.Phys.Lett.2005,404,25).After titanium isopropylate hydrolysate in the mixture of the KCl aqueous solution and ethanol mixes with glucose by Ren Wenjie etc., 160 degree of hydrothermal treatment consists obtain Carbou doped titanium-oxide, have particulate interspaces mesoporosity (Appl.Catal.B2007,69,138).Ye Qin etc. adopt the method for gas reaction magnetron sputtering to prepare carbon doping TiO2 film (artificial lens journal, 2006,35,1257) at 350 degree.Above-mentioned carbon doping TiO2 is prepared mostly under the high temperature conditions, and a small amount of low temperature synthesis report needs the participation of potassium ion, and preparation condition is harsh, complex process, and the carbon doping TiO2 of preparation is dense non-porous mostly, occasionally has report to have mesoporosity.If introduce mesopore-macropore hierarchical porous structure in the catalyst, then can the diffusion of effectively intensified response thing and product molecule, reduce resistance to mass transfer, raising catalytic activity.The introducing of the macropore that aperture is identical with the wavelength of light, is also conducive to the transmission of light at catalyst particles intragranular, and then improves active.

Existing is that the Photocatalitic Technique of Semiconductor of representative demonstrates wide application prospect in organic pollutant degradation, hydrogen production by water decomposition, self-cleaning surface, anti-bacteria ceramic etc. with titanium dioxide.The mechanism of conductor photocatalysis reaction is the photon exceeding the corresponding energy of band gap by absorbing energy, the valence-band electrons of photocatalyst excites and generates photohole and electronics, and then moves to the process that the organic pollutant of catalyst surface and absorption or water molecules carry out redox reaction.This method has many advantages such as energy consumption is low, reaction conditions is gentle, easy and simple to handle.But the wide band gap semiconducter compounds such as the TiO2 that application is more at present only work in ultraviolet light range, and solar energy mainly concentrates on the visible-range of 400-700nm, additional ultraviolet source is very unfavorable for the photocatalysis purifying technology of open environment system, both add cost and also bring safety problem, so be infeasible simultaneously.Natural photodegradation toxic organic pollutant or photolysis water hydrogen is utilized to be significant for environmental protection and energy development.

Have developed hundreds of visible light-responded novel semi-conductor photocatalyst material in the recent period, but the metallic element relating to some costlinesses in these structures is as niobium, bismuth, tantalum etc., makes these novel semi-conductor photocatalyst materials not possess competitive power in price in the large-scale application such as environmental purification.Adopt cheap titanium dioxide product, introduce the cheap element such as nitrogen, carbon, sulphur by simple method and carry out nonmetal doping, form the titania-doped product of the efficient stable that band gap reduces, wide range responds, such nano material will have wide market in environmental purification field.Large quantifier elimination shows by nonmetal doping titanium dioxide, intermediate level is formed between the valence band and conduction band of semi-conductor, such electronics can transit to intermediate level and arrive conduction band again, required excitation energy reduces, so the optical wavelength of its response can be extended to visible region always, to the energy of sunlight wide spectrum more than 90% be made full use of, promote the large-scale application of photochemical catalysis environmental purification technology.

There are the paper of some carbon doping titanium dioxide and the report of patented technology at present, such as document " German applied chemistry " magazine 2003,42, " carbon modifies the daylight photocatalysis of TiO2 " (S.Sakthivel that 4908-4911 delivers, H.Kisch, Daylight Photocatalysis by Carbon-Modified TitaniumDioxide, Angew.Chem.Int.Ed.), report and add TBAH hydrolysis titanium tetrachloride, roasting obtains the carbon doping titanium dioxide of highlight catalytic active at low temperatures.And document " applied catalysis B: environment " magazine 2001, 32, " adopting carbon containing titanium dioxide optical catalyst Visible Light Induced Photocatalytic 4-chlorophenol " (C.Lettmann that 215-227 delivers, K.Hildenbrand, H.Kisch, et al., Visible light photodegradationof4-chlorophenol with a coke-containing titanium dioxide photocatalyst, AppliedCatalystsB:Environmental), report the carbon containing titanium dioxide adopting the method for acid lower hydrolysis alkyl titanium precursor thing to prepare highlight catalytic active.Patent CN100375650C " low temperature process of preparing carbon-doped mesoporous TiO 2 visible light photocatalyst ", adopts saccharide compound as carbon source, prepares mesoporous carbon doping titanium dioxide by low-temperature hydrothermal or solvent-thermal method.The method major part preparing carbon doping titanium dioxide of these bibliographical informations relates to complicated technique, or high-temperature calcination under logical nitrogen or vacuum condition, be unfavorable for large-scale preparation, or need to add special chemical substance, add the production cost of product.

CN101024168A discloses with titanic acid ester (comprising other various alkoxide etc.), lauryl amine (DDA), and vitamin B6 etc. are raw material, the titanium-oxide graded Porous materials of one-step synthesis method carbon doping.This preparation method comprises the following two kinds scheme: at (1) 80 DEG C by titanic acid ester and carbon source (as lauryl amine DDA, the ratio 0.05 ~ 1 of DDA/TiO 2 amount) mix in Erlenmeyer flask, the mixed solution (volume ratio is 10: 1 ~ 5: 1) of ethanol and deionized water is joined in reaction solution fast, stir, aging, washing, suction filtration, drying, obtains white powder.White powder solid in tube furnace under nitrogen protection at 300 ~ 600 DEG C roasting 2-8h namely obtain the porous oxidation ti powder of yellowish carbon doping.(2) under room temperature, 5.8 ~ 8.0g titanic acid ester, 15 ~ 30ml deionized water, 4.0 ~ 8.0g carbon source (as vitamin B6) are mixed; stir; aging; dry at 60 DEG C; white powder, white powder under the condition of nitrogen protection at 300 ~ 600 DEG C roasting 2-8h namely obtain the porous oxidation ti powder of yellowish carbon doping.Described titanic acid ester can be titanium ethanolate [Ti (OC 2 H 5) 4], metatitanic acid n-propyl [Ti (OC 3 H 7) 4], isopropyl titanate [Ti (iso-OC 3 H 7) 4] or butyl (tetra) titanate [Ti (OC 4 H 9) 4].Described carbon source can be lauryl amine, urea, tetrabutylammonium, hexahydroaniline, vitamin B6.Adopt above formula and reaction conditions, through above-mentioned processing step, can prepare and have foramen magnum-mesoporous hierarchical porous structure, single anatase phase, absorption spectrum expansion is wide, has the titania meterial of ultraviolet and the highly active carbon doping of visible light catalytic.

Summary of the invention

The object of the invention is to the preparation method proposing a kind of photocatalytic activity titanium dioxide nano material.

For reaching this object, the present invention by the following technical solutions:

A preparation method for photocatalytic activity titanium dioxide nano material, is characterized in that comprising the steps: 1) organic compound of titanium is slowly added in the aqueous solution, be fully uniformly mixed, produce white precipitate material; Wherein the volume ratio of titanium organic compound and water is 1:0.1 ~ 5, and the organic compound of titanium is the mixture mixed with 1:1:1 of tetrabutyl titanate, titanium isopropylate and tetraethyl titanate; 2) by white precipitate material 80 ~ 120 DEG C of dryings, time of drying is 5 ~ 12 hours, subsequently grinding obtain pressed powder; 3) in pressed powder, add starch, and powdered mixture is placed in hypoxia device heat-treats, heat-up rate is 1 ~ 40 DEG C/min, in 300-450 DEG C of air atmosphere, calcine 1-5 hour; After product collection, through washing and alcohol wash, drier at 60 ~ 80 DEG C, namely obtain and there is titanium dioxide nano material.

Embodiment

Embodiment 1

A preparation method for photocatalytic activity titanium dioxide nano material, is characterized in that comprising the steps: 1) organic compound of titanium is slowly added in the aqueous solution, be fully uniformly mixed, produce white precipitate material; Wherein the volume ratio of titanium organic compound and water is 1:1, and the organic compound of titanium is the mixture mixed with 1:1:1 of tetrabutyl titanate, titanium isopropylate and tetraethyl titanate; 2) by white precipitate material 80 DEG C of dryings, time of drying is 5 hours, subsequently grinding obtain pressed powder; 3) in pressed powder, add starch, and powdered mixture is placed in hypoxia device heat-treats, heat-up rate is 1 ~ 40 DEG C/min, in 300-450 DEG C of air atmosphere, calcine 1-5 hour; After product collection, through washing and alcohol wash, drier at 60 ~ 80 DEG C, namely obtain and there is titanium dioxide nano material.

Embodiment 2

A preparation method for photocatalytic activity titanium dioxide nano material, is characterized in that comprising the steps: 1) organic compound of titanium is slowly added in the aqueous solution, be fully uniformly mixed, produce white precipitate material; Wherein the volume ratio of titanium organic compound and water is 1:2, and the organic compound of titanium is the mixture mixed with 1:1:1 of tetrabutyl titanate, titanium isopropylate and tetraethyl titanate; 2) by white precipitate material 120 DEG C of dryings, time of drying is 12 hours, subsequently grinding obtain pressed powder; 3) in pressed powder, add starch, and powdered mixture is placed in hypoxia device heat-treats, heat-up rate is 1 ~ 40 DEG C/min, in 300-450 DEG C of air atmosphere, calcine 1-5 hour; After product collection, through washing and alcohol wash, drier at 60 ~ 80 DEG C, namely obtain and there is titanium dioxide nano material.

Embodiment 3

A preparation method for photocatalytic activity titanium dioxide nano material, is characterized in that comprising the steps: 1) organic compound of titanium is slowly added in the aqueous solution, be fully uniformly mixed, produce white precipitate material; Wherein the volume ratio of titanium organic compound and water is 1:5, and the organic compound of titanium is the mixture mixed with 1:1:1 of tetrabutyl titanate, titanium isopropylate and tetraethyl titanate; 2) by white precipitate material 80 ~ 120 DEG C of dryings, time of drying is 12 hours, subsequently grinding obtain pressed powder; 3) in pressed powder, add starch, and powdered mixture is placed in hypoxia device heat-treats, heat-up rate is 40 DEG C/min, calcines 5 hours in 450 DEG C of air atmospheres; After product collection, through washing and alcohol wash, drier at 80 DEG C, namely obtain and there is titanium dioxide nano material.

Obviously, the above embodiment of the present invention is only for example of the present invention is clearly described, and is not the restriction to embodiments of the present invention.For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description.Here exhaustive without the need to also giving all embodiments.And these belong to spirit institute's apparent change of extending out of the present invention or change and are still among protection scope of the present invention.

Claims

1. the preparation method of a photocatalytic activity titanium dioxide nano material, it is characterized in that comprising the steps: 1) by water-soluble for the organic compound of titanium, zinc, cadmium, tungsten or tin solution, stir, generate white precipitate after abundant mixing, the organic compound of titanium, zinc, cadmium, tungsten or tin is selected from corresponding acid esters or its mixture of titanium, zinc, cadmium, tungsten or tin; 2) precipitation that step (1) obtained is dry, grind, and obtain pressed powder, described drying temperature is 80 ~ 120 DEG C, and time of drying is 5 ~ 12 hours; 3) in pressed powder, starch is added, and at anaerobic equipment, powdered mixture is heat-treated, reaction terminates rear washing, drying, obtain active semiconductor photocatalysis nano material, wherein step (3) described thermal treatment is that drying temperature is 60 ~ 80 DEG C at 300-450 DEG C of calcining 1-5 hour.

2. the preparation method of photocatalytic activity titanium dioxide nano material as claimed in claim 1, is characterized in that the mass ratio of the water in the organic compound of titanium, zinc, cadmium, tungsten or tin in step (1) and the aqueous solution is 5-10:1.