CN1930250B

CN1930250B - Carbon-containing, titanium dioxide-based photocatalyst, and process for producing the same

Info

Publication number: CN1930250B
Application number: CN2005800078607A
Authority: CN
Inventors: J·奥斯-格伯; H·基什; S·萨克斯威尔
Original assignee: Kronos International Inc
Current assignee: Kronos International Inc
Priority date: 2004-04-07
Filing date: 2005-04-06
Publication date: 2011-05-18
Anticipated expiration: 2025-04-06
Also published as: CN1930250A; UA90270C2; ZA200606740B

Abstract

The invention relates to a titanium dioxide-based photocatalyst containing carbon that is highly photoactive in visible light (vlp-TiO2) and to a method of manufacture. The vlp-TiO2 is manufactured by mixing a fine grained titanium compount (BET>=50m<2>/g) with an organic carbon compound and subsequent thermal treatment at temperatures up to 400 DEG C. The carbon content amounts to 0.05 to 4% by weight, preferably 0.4 to 0.8% by weight. The product is characterized by an ESR spectrum which displays only one significant signal in the g value range from 1.97 to 2.05 at g about 2.003. The inventive photocatalyst can be used for to degrade contaminants and pollutants in liquids and gases.

Description

Carbonaceous titanium dioxide optical catalyst and preparation method thereof

The present invention relates to a kind of carbonaceous photocatalyst based on titanium dioxide, it is photoactive at visible region, below is also referred to as vlp-TiO ₂

The invention still further relates to the carbonaceous titanium dioxide (vlp-TiO of a kind of preparation ₂) method, it plays the photocatalyst effect under radiation of visible light.

Light-catalysed material is the semi-conductor that wherein forms electron-hole pair under light action, and this electron-hole pair produces highly reactive free radical on material surface.Titanium dioxide is a kind of such semi-conductor.Known, titanium dioxide can be removed nature and artificial impurity in the sky G﹠W by uviolizing, wherein be reduced by atmospheric oxygen, and impurity oxidized (mineralising) end product that is environment friendly.And the surface of titanium dioxide becomes Superhydrophilic owing to absorbing ultraviolet ray.The antisedimentation of titanium deoxid film based on this promptly on mirror and the window.

A critical defect of titanium dioxide is the following fact, has only the ultraviolet part of sunlight, promptly has only 3～4% light to utilize, and in the available light of diffusion, does not have or have only very weak catalytic activity fully.

For this reason, people modify titanium dioxide with regard to research for a long time, thereby also can utilize the described phenomenon in the visible range of major portion-Yue 400～about 700nm of the sunlight of photochemical effect-produce.

Make TiO ₂A kind of approach for available light display light catalytic activity is a doped metal ion, as V, Pt, Cr, Fe etc.Another kind of possibility is by reduction Ti ⁴⁺And at TiO ₂Produce the oxygen room in the lattice.Two kinds of development all need wasteful production technology, implant or Cement Composite Treated by Plasma as ion.A lot of patents have been described the titanium dioxide that nitrogen is modified, and it has photocatalysis (for example EP 1 178 011 A1, EP 1 254 863 A1) under the visible region irradiation.

Known in addition, by modifying with carbon, the photocatalytic activity of titanium dioxide is improved under radiation of visible light.For example JP 11333304 A disclose a kind of titanium dioxide, and its surface to small part has the precipitation of graphite, amorphous carbon, diamond class charcoal or hydrocarbon.EP 0 997 191A1 relate to a kind of titanium dioxide, and its surface is gone up and is coated with titanium carbide by vapour deposition.Wherein titanium dioxide contains nitrogen, sulphur, carbon or other elements especially and for example is disclosed among EP 1 205 244 A1 and EP 1 205 245 A1 as anionic photocatalyst material.These negatively charged ion are positioned at position or crystal grain boundary between the oxygen position, lattice of polycrystalline titanium oxide particle.There are not illustrative material characteristic or catalysis or physical properties.

Also known, by ℃ can making titanium dioxide from the alcoholization titanium with hydrochloric acid hydrolysis and postheating to 350, it contains carbon people such as (, AppliedCatalysis B 32 (2001) 215) C.Lettmann of 1.0～1.7 weight %.Here, carbon is from the part of titanium compound.

Find that according to another publication titanium tetrachloride and TBAH are hydrolyzed, calcined one hour down at 400 ℃ then, produce titanium dioxide goods (the S.Sakthivel ﹠amp that contains 0.42 weight % carbon; H.Kisch, Angew.Chem.Int.Ed.42 (2003) 4908).In the case, carbon is from precipitation agent, and is evenly distributed in (volume-doping) in the volume mostly.

The shortcoming of known photocatalyst material is that its preparation method is not suitable for big industrial production.These methods or because technical reason and can not use on a large scale or uneconomic.In addition, aspect the degraded objectionable impurities, products therefrom shows not enough photocatalytic activity mostly in the visible region of λ 〉=400nm, and the wetting ability of having only less photoinduction to cause raises.And, this product is just optimized its photocatalysis performance so far.Color and brightness, promptly optical property does not also arouse attention so far.By contrast, can only stand less vlp-TiO being impatient at maybe ₂The all areas of inherent colour as at coating, when particularly using, uses the very bright vlp-TiO that inherent colour is less and photocatalytic activity is higher in printing ink, lacquer and plaster ₂Has advantage.

The objective of the invention is to, provide a kind of available light active and photocatalyst efficiently, it is based on the titanium dioxide of modifying with carbon, and a kind of economic means for preparing this catalyzer is provided.

According to the present invention, this purpose realizes that by a kind of carbonaceous titanium dioxide it is with respect to pure titinium dioxide, at λ 〉=400nm (vlp-TiO ₂) zone has tangible photoabsorption, in its electron spin resonance spectroscopy that records under the 5K temperature (ESR), has only a tangible signal in the g value is 1.97～2.05 scopes.This purpose also realizes in this method, having 50m at least by a kind of preparation method ²The titanium compound of/g BET (Brunauer-Emmett-Teller) specific surface area mixes closely with carbonaceous material, and under the temperature of height to 400 ℃ mixture is heat-treated.Other favourable embodiments of the present invention provide in the dependent claims.

Product

According to vlp-TiO of the present invention ₂Type list than description of the Prior Art reveals higher photocatalysis efficiency.With the rayed of wavelength 〉=455nm 120 minutes, by true quantitative vlp-TiO ₂The 4-chlorophenol degradation amount that is caused is as the yardstick of photocatalysis efficiency (hereinafter referred to as " photolytic activity ").Below describe this measuring method in detail.Under described measuring condition, vlp-TiO of the present invention ₂Photolytic activity be at least 20%, preferably at least 40%, especially at least 50%.

Carbon content accounts for TiO ₂0.05～4 weight %, preferred 0.05～2.0 weight %, preferred especially 0.3～1.5 weight %.Carbon content reaches best result when being 0.4～0.8 weight %.

Titanium dioxide granule only contains carbon at upper layer, and therefore hereinafter referred to as " carbon is modified ", titanium dioxide adulterated with volume, that make according to Sakthivel and Kisch (2003) is different.Vlp-TiO of the present invention ₂Carbon or carbon compound may at first be combined in TiO by the oxygen conjugated link(age) ₂On the surface, and theobromine is washed off.

This photocatalyst can be additionally or selectivity contain nitrogen and/or sulphur.TiO with unmodified ₂Difference, vlp-TiO of the present invention ₂The visible light of absorbing wavelength λ 〉=400nm.With the proportional Kubelka-Munk function F of specific absorption (R _∞) be about 50% of 400nm duration at the 500nm place, be about 20% of 400nm place value at the 600nm place.

The vlp-TiO of the present invention that records in the 5K temperature ₂Electron spin resonance spectroscopy (ESR) be characterised in that, be 2.002～2.004 in the g value, strong signal was especially arranged in 2.003 o'clock.Other signals do not appear in the g value is 1.97～2.05 scopes.By be about the intensity enhancing of measuring under 2.003 the signal intensity ratio dark at g with the rayed of wavelength X 〉=380nm (not having ultraviolet 100W halogen lamp, cold light strainer KG5).

Vlp-TiO of the present invention ₂X-ray photoelectron spectroscopy (XPS) be characterised in that strong absorption band appears in the place at the 285.6eV bond energy, in the 01s-bands of a spectrum at 530eV place.

Another feature is, and is different with the photocatalyst that makes according to Sakthivel and Kisch (2003), vlp-TiO ₂Not only do not have in x-ray photoelectron spectroscopy (XPS) but also in infrared spectra, show the carbonate bands of a spectrum.

Under radiation of visible light, vip-TiO ₂Water contact angle be about 8 °, and the TiO of unmodified ₂The contact angle that shows is about 21 °.

This novel photocatalysis agent makes not only can use the artificial visible light, and the available light of the enough indoor diffusions of energy makes the objectionable impurities degraded.Can be used for impurity and objectionable impurities in degradation liquid or gas, the especially water and air.

This photocatalyst can advantageously be coated in different carriers as glass (normal and minute surface), timber, fiber, pottery, concrete, material of construction, SiO with thin layer ₂, on metal, paper and the plastics.With easy manufacture, use possibility in various fields is also disclosed thus, the surface that for example in construction industry, ceramic industry and automotive industry, is used for self-cleaning property, perhaps at environmental technology (air regulator, the device that is used for purifying air and sterilizing air, and water-purification plant, especially tap water, for example for antibiotic and antiviral purpose) the middle use.

This photocatalyst can be used for the coating that indoor and outdoors is used, for example printing ink, plaster, lacquer and glaze (Lasuren), in order to coating body of wall, stucco surface, tectum, wallpaper and wood surface, metallic surface, glass surface or ceramic surface, perhaps coated member, as the first surface decorating spare of heat insulation composite material system and suspension, and be used for road surface and plastics, plastics film, fiber and paper.This photocatalyst can also be used to auxilliary lining (Verkleidung) part producing concrete product, concrete-paving brick, roof brick, pottery, ceramic tile, wallpaper, fabric, refractory brick and be used for indoor and outdoors roof and wall.

By photoinduced TiO ₂The wetting ability on-surface raises and also brings other to use, as no sedimentary mirror and the window in health field or automotive industry and the construction industry.

This photocatalyst also is suitable for photocell and in order to water of decomposition.

Followingly describe in detail according to vlp-TiO of the present invention with reference to Fig. 1～9 ₂

Fig. 1 represents and the proportional Kubelka-Munk function F of relative specific absorption (R _∞) (unit arbitrarily), the TiO of expression unmodified ₂With the TiO that modifies with C ₂(vlp-TiO ₂) as the function of wavelength, can see, different with the titanium dioxide of unmodified, vlp-TiO ₂Absorb visible spectrum district.F (R _∞) value is about 50% of 400nm place value at the 500nm place, be about 20% of 400nm place value at the 600nm place.

Fig. 2 is illustrated in the vlp-TiO of the present invention that writes down under dark and the 5K temperature ₂(spectrum A) and the TiO that makes according to Sakthivel and Kisch ₂The electron resonance spectrum (ESR) of (spectrum B).Spectrum A is only to show a tangible signal at 2.003 o'clock in the g value.Spectrum B shows other three signals in the g value is 1.97～2.05 scopes except the master signal that is about demonstration in 2.003 o'clock at g.

Fig. 3 comprises vlp-TiO of the present invention ₂(spectrum A) and known, according to Sakthivel and Kisch by the sedimentary TiO of titanium tetrachloride usefulness TBAH ₂X ray-the photoelectron spectrum (XPS) of (spectrum B).Vlp-TiO ₂Spectrum an outstanding Cls-signal is arranged at 285.6eV bond energy place, in the 0ls-absorption band at 530eV place, confirmation is an elemental carbon.Otherwise spectrum B is presented at the Cls-signal that bond energy is a 284.5eV place elemental carbon, and at the bands of a spectrum of 289.4eV and 294.8e.V, explanation is a carbonate.Corresponding IR-spectrum is 1738,1096 and 798cm ^-1Typical carbonate bands of a spectrum are also arranged.

Fig. 4 illustrates vlp-TiO ₂TiO with respect to unmodified ₂Passing through artificial visible light (λ 〉=455nm) degrade the 4-chlorophenol (as 2.5 * 10 ^-4The M aqueous solution) photocatalysis efficiency the time.Figure demonstrates, organic carbon (TOC in the solution _t) total content with respect to initial value (TOC ₀) descend.Use vlp-TiO ₂Degraded fully after 3 hours.

Fig. 5 explanation is with the TiO of unmodified ₂Compare vlp-TiO ₂Degrade the 4-chlorophenol (as 2.5 * 10 by the available light of indoor diffusion ^-4The M aqueous solution) photocatalysis efficiency the time.Figure demonstrates, organic carbon (TOC in the solution _t) total content with respect to initial value (TOC ₀) descend.Even available light (7～10W/m in 400～1200nm scope in the diffusion of weak intensity ²) under, vlp-TiO ₂In six hours, cause 80% degraded.Even at the available light of the very weak diffusion of intensity (1.6 to＜1W/m ²) under, be different from commercial TiO ₂Photocatalyst (Degussa P25, Kemira UV-Titan, Sachtleben Hombikat, Tayca MT-100SA), vlp-TiO ₂Also show tangible photolytic activity.As mentioned above, measure 2.5 * 10 ^-4The degradation rate of M 4-chlorophenol solution.

A) light intensity: 1.6W/m ²Time: 12h

Catalyzer The BET surface-area Degradation rate

vlp-TiO ₂ 170m ²/g 16％

P25 50m ²/g 4％

UV-titanium 20m ²/ g 5%

Hombikat 240m ²/g 9％

MT-100SA 50m ²/g 5％

B) light intensity:＜1W/m ²Time: 24h

Catalyzer The BET surface-area Degradation rate

vlp-TiO ₂ 170m ²/g 18％

Hombikat 240m ²/g 3％

Fig. 6 explanation is with the TiO of unmodified ₂Compare vlp-TiO ₂Photocatalysis efficiency when degrading benzene (5 volume %), acetaldehyde (2 volume %) and carbon monoxide (5 volume %) by the available light of indoor diffusion.Use 1 liter of round-bottomed flask as reactor, be equipped with a paper-circle filter (d=15cm) that scribbles 12mg titanium dioxide.Figure demonstrates, organic carbon (TOC in the atmosphere _t) total content with respect to initial value (TOC ₀) descend.Curve shows that benzene, acetaldehyde and carbon monoxide are by vlp-TiO of the present invention ₂Degraded and acetaldehyde are by the TiO of unmodified ₂Degraded.

Fig. 7 represents vlp-TiO ₂X-ray powder diffraction figure, have only anatase octahedrite reflection.The crystalline size that calculates according to the Scherrer method is 10nm.

Fig. 8 represents the vlp-TiO by high-resolution electron microscope (HTEM) generation ₂Figure has crystalline lattice line.Can estimate that crystalline size is in the 10nm magnitude.

Fig. 9 provides the vlp-TiO than expression with C/Ti ₂Carbon-depth curve.By ion bombardment (Ar ⁺) and esca analysis mensuration.The bombardment time 5 * 10 that is marked ³Second is corresponding to the about 5nm of the degree of depth.

Preparation

The inventive method is from titanium compound, and this titanium compound exists with amorphous, partial crystallization or crystalline titanium oxide or aqueous titanium oxide and/or with the form of titanyl hydrate and/or titanyl hydrate, hereinafter referred to as initial titanium compound.

Initial titanium compound for example forms according to sulphate process or according to chloride process when preparation titanium dioxide.Titanyl hydrate or titanyl hydrate or metatitanic acid for example produce when hydrolysis titanyl sulfate or chlorination oxygen titanium.

Initial titanium compound can be used as fine-grained solids and exists, and perhaps is present in the suspension that corresponding solids content is at least 15 weight %, and solid BET specific surface area is at least 50m ²/ g, the preferred about 150～350m of BET ²/ g, especially BET are 150～250m ²/ g.

For industrial use the inventive method, for reason economically, as initial titanium compound preferably from the titanyl hydrate of sulphate process.This titanyl hydrate is advantageously at first removed the sulfuric acid of adhesion by neutralization and washing, and feasible dry back solid sulphate content＜1 weight % is with SO ₃Meter.

The decomposition temperature of carbonaceous material is the highest 400 ℃, and best＜350 ℃ are preferred＜300 ℃.The carbonaceous material of prove out for example is timber, carbon black or gac, especially organic carbon compound, as contain the hydro carbons of at least one functional group.Functional group can be: OH; CHO; COOH; NH _xSH _xCOOR, wherein R is an alkyl or aryl.Suitable for example have succsinic acid, glycerine or ethylene glycol.Sugar or other carbohydrate can also be used, organic hydroxide ammonium, especially tetra-allkylammonium can be used equally.The mixture of described compound also is suitable.The water miscible polyvalent alcohol of preferred use, the ratio of its carbon/oxygen is about 0.7～1.5, preferably is about 1, especially tetramethylolmethane.This carbon compound can use with solid or solution or suspension.

Organically carbon compound should have high as far as possible affinity to initial titanium compound surface, thereby can produce close combination with it.

Initial titanium compound and organic so close mixing of carbon compound make initial titanium compound surface scribble carbon compound.Organically carbon compound can physical adsorption or chemisorption and being present on the initial titanium compound surface.Applying initial titanium compound surface can realize by mixing with the suspension of initial titanium compound in the suspension that carbon compound is dissolved in initial titanium compound or by the suspension that makes carbon compound.Can make carbon compound and the prior dry Powdered initial titanium compound of crossing carry out intense mixing equally.Using under the titanyl hydrate situation, perhaps, also can when being prepared into water-disintegrable solution, mix titanyl hydrate this carbon compound.In the mixture of initial titanium compound that makes and carbon compound, the amount that carbon compound accounts for initial titanium compound (as solid) is 1～40 weight %.

If the mixture of making exists with suspension, before further handling, be pulverulent solids then with it drying.Use currently known methods, as spraying drying or fluidised bed drying for this reason.

Pre-dried mixture that make, optional is heat-treated under the highest 400 ℃ temperature.Thermal treatment is in oxidizing atmosphere, preferably carry out in air or oxygen-air mixture.At this moment, organically carbon compound decomposes on initial titanium compound surface, and discharges H ₂O, CO ₂And CO.Though thermal treatment also can for example be carried out in commercial lab oven in (discontinuous) batchwise operation, for reason economically, the preferred continuous processing that can carry out with the temperature profile of determining.Can consider to realize all methods of relevant temperature feature and necessary retention time as continuation method.Specially suitable equipment is indirect and direct-fired rotary kiln.Also can use the plough shovel form mixing tank of fluidized-bed reactor, fluidized bed dryer and the heating of continuous operation.Described back three kinds of devices also can be with discontinuous operation scheme operation.

Preferably heat-treat like this, make that forming carbon content is 0.05～4.0 weight %, preferred 0.05～2.0 weight %, preferred especially 0.3～1.5 weight %, the especially product (vlp-TiO of 0.4～0.8 weight % ₂).In heat treatment process, colour-change arrives cream-coloured from white to the grey then.End product demonstrates cream-coloured to ecru.Be characterised in that, in the amorphous of upper layer and polycrystalline scope and on the surface, itself can detect carbon.Product is photoactive in visible light.

After the thermal treatment, make product go to reunite with currently known methods, for example at rod mill, injector-type mill or anti-injector-type mill.For Powdered pre-dried mixture, thermal treatment in most cases causes not having the product of aggregate, and it need not further grinding.The grain fineness that reaches depends on the particle diameter of initial titanium compound.The grain fineness or the specific surface area of product are very little, but with educt in same magnitude.The grain fineness that photocatalyst will reach depends on the use field of this photocatalyst.Usually as TiO ₂In the such scope of pigment, but also can be beneath or on.Specific surface area according to BET is 100～250m ²/ g, preferred 130～200m ²/ g, especially 130～170m ²/ g.

Embodiment

Describe the present invention in detail by following examples, but the scope of the invention is not limited to this.

Embodiment 1:

Prepare aqueous titanyl hydrate pulpous state thing (35 weight % solid) according to sulphate process, at room temperature the suspension that can stir to formation with distilled water diluting.Solids content is 20～25%.Add NaOH solution (36 weight %), up to the pH value is adjusted to 6.0～7.0.Filter and use distilled water wash suspension then, up to the SO that records with the exsiccant residue ₃Content is less than 1 weight %.

Next the titanyl hydrate that neutralizes in this way and wash is the suspension (25% solid) that can stir with distilled water diluting once more, and adds the succsinic acid of 12 weight %, in solid.Succsinic acid adds in the suspension with solid, and stirred suspension, dissolves fully up to succsinic acid.In order to improve the solvability of succsinic acid, suspension is heated to about 60 ℃.Pei Zhi suspension under agitation carries out drying under baudelot evaporator (IR light source) in this way, forms pasty material up to suspension.This pasty material is dry under 150 ℃ in the loft drier of laboratory then, up to solids content＞98%.

With 300g exsiccant titanyl hydrate/succsinic acid mixture fine powder broken (for example by mill and sieve), and the powder of gained is placed in the quartz curette with cover in 290 ℃ of following lab oven at.Between after 1～2 hour quartz curette is taken out and mixed powder once more.After 13～15 hours, the powder color becomes lark by initial yellow through grey black in lab oven at.Last thermal treatment is vlp-TiO ₂, carbon content drops to about 0.65～0.80 weight % by 5～5.5 initial weight %.

Make this photocatalyst go to reunite then, and analyze carbon content, optical property, BET surface-area and photolytic activity.

Embodiment 2

The process that is similar to embodiment 1 is carried out, and difference is that 12 weight % tetramethylolmethanes add in titanyl hydrate-suspension as solid.

Embodiment 3

The process that is similar to embodiment 2 is carried out, and difference is that 5 weight % tetramethylolmethanes add in titanyl hydrate-suspension as solid.

Embodiment 4

As described in embodiment 1, use 5 weight % tetramethylolmethanes to prepare titanyl hydrate/tetramethylolmethane-suspension.As different from Example 1, in the rotary kiln of operation continuously, heat-treat the suspension that obtains like this is following:

This rotary kiln moves with reflux type, and through the gas burner direct heating.The flame that gas burner opens wide is protected by flame tube, therefore prevents and product (vip-TiO ₂) directly contact.The furnace length of heating is 7m, and internal diameter is 0.3m.Suspension carefully is sprayed at the inlet of this stove.The feeding amount of suspension is 40kg/h.The chain type internals of stove inlet provides good vortex, thereby carries out rapid drying, then the exsiccant material is pulverized.Be 1 hour the working time of the rotary kiln of operation continuously.Gas volume by burner with the Control for Kiln Temperature of outlet area at 260 ℃.Produce the vlp-TiO of lark fine powder at the outlet of still place ₂This vlp-TiO then ₂In laboratory blender (Braun, MX 2050), go to reunite, and analyze carbon content, optical property, BET surface-area and photolytic activity.

Embodiment 5

The process that is similar to embodiment 4 is carried out, and difference is, the gas volume by burner with the Control for Kiln Temperature of outlet area at 280 ℃.

Embodiment 6

As described in embodiment 1, use 5 weight % tetramethylolmethanes to prepare titanyl hydrate/tetramethylolmethane-suspension.As different from Example 1, in electrical heater with this suspension predrying be 22% pulverulent solids for residual moisture content.In the rotary kiln of the continuous indirect heating of operation, to following the heat-treating of this pre-dried Powdered materials used:

This rotary kiln moves with concurrent, and electrically heated in three districts.The furnace length of heating is total up to 2700mm, and internal diameter is 390mm.Pulverulent solids infeeds the inlet of stove by quantitative helical feed.The chain type internals is provided at the uniform distribution in the stove on the whole length of tube, and prevents attached on the furnace wall.The feeding amount is 25kg solid per hour.Be 0.5 hour the working time of the rotary kiln of operation continuously.The furnace temperature of three heating zone of electric control.The temperature separately of three heating zone can be regulated separately.Produce cream-coloured fine powder vlp-TiO at the outlet of still place ₂This vlp-TiO then ₂In laboratory blender (Braun, MX 2050), go to reunite, and analyze carbon content, optical property, BET surface-area and photolytic activity.

Counter-example

Be similar to embodiment 2, the BET surface-area is about 10m ²The TiO of/g ₂Pigment (anatase octahedrite) (commodity Kronos 1000) mixes with 12% tetramethylolmethane, and heat-treats.

Embodiment	Organism	Thermal treatment		vlp-TiO ₂Analyze					Photolytic activity
										℃	Time (h)	C content	The PLV test			BET	The degraded of 4-CP (%) in 120 minutes
		(％)	L*	b*	a*	m ²/g
								1	Succsinic acid			290	13	0.79	85.4	9.85	1.63	164	48
2	Tetramethylolmethane	290	28	0.75	86.9	10.08	1.53			158	50
								3	Tetramethylolmethane			290	10	0.76	83.7	10.03	1.59	140	63
4	Tetramethylolmethane	260*	1**	0.92	85.1	11.7	1.2			152	58
								5	Tetramethylolmethane			280*	1**	0.50	85.8	9.4	2.2	160	68
6	Tetramethylolmethane	300***	0.5**	0.78	83.0	11.0	2.6			167	86
								Counter-example	Tetramethylolmethane				290	42	0.82	74.7	9.12	2.50	11.6	＜5

* export the maximum temperature that records at rotary kiln

* is by the working time of sending into material of rotary kiln

The temperature of three heating zone that * * records in the thermoelectric converter scope

Summarized vip-TiO of the present invention in the table ₂Analytical value and photolytic activity.

The vlp-TiO that makes by titanyl hydrate ₂(embodiment 1～6) also shows excellent photocatalysis efficiency in the visible range when showing good optical value (PLV test).Use anatase pigment and can produce the photoactive product (counter-example) that void value must be mentioned as initial titanium compound without titanyl hydrate.

Embodiment 7

5g titanium dioxide (commodity of the commodity TRONOXTitanhydrat-0 of Kerr-McGee Pigments GmbH company) at room temperature is suspended in the 20ml distilled water, mix with 5ml ethylene glycol (commodity of FLUKA AG company), and at ultra sonic bath (the Sonorex Super RK 106 of Berlin BandelinElectronic company; 35kHz, 120W eff.Hf-Leistung) handled 30 minutes.After magnetic stirs and to spend the night, preferably remove in a vacuum and desolvate, residue is at 100～200 ℃, preferably about 200 ℃ of following dryings at least 12 hours, then in one hour in the vessel in heating to 300 of sealing ℃, and under this temperature, kept again three hours.Find that the powder color becomes cream-coloured from white through lead.Longer time adds colourless, the inactive powder of thermogenesis.

The results of elemental analyses of product is the carbon of 2.58 weight %, the nitrogen of 0.02 weight % and the hydrogen of 0.40 weight %.The TiO of unmodified ₂The C and the N of 0.0 weight % and the H of 0.0 weight % that contain 0.07 weight %.

Embodiment 8

For the carbon compound of release surface, with 5g vlp-TiO ₂In 100ml 2M sodium hydroxide solution (pH12), stir and spend the night.By the centrifugal extracting solution of lark and the almost colourless white residue of obtaining, the latter is dry down at 100 ℃.The powder of gained does not show activity to degraded 4-chlorophenol under visible light.If this powder and this extracting solution merge once more, and heating a little, preferably be heated to about 200 ℃, then in DeR, have and untreated (not alkali cleaning) vlp-TiO ₂Identical activity.

Embodiment 9

For the applied plastic film, will in ultra sonic bath, be suspended in liquid such as methyl alcohol or the ethanol according to the powder that embodiment 6 makes, and with the suspension of gained by the spray bottle as far as possible unfertile land be coated on the film.Under 343K, after the drying, repeat coating, subsequently up to reaching desirable layer thickness.

Without plastics film, also can use other carriers) as paper (referring to the experiment of Fig. 6) or aluminium (referring to following testing method h): " dip coated ".

Measuring method

A) mensuration of optical value (PLV-test)

This method is used to find out vlp-TiO ₂Optical value brightness L*, tone a* and tone b*.Under the condition of determining, with the micro hydraulic machine of Frankfort MATRA company by the vlp-TiO that will test ₂Preparation powder compression thing.Measure the emission value of powder compression thing then with HUNTERLAB trichromatic chromascope.

Before preparation compacting thing, grind vlp-TiO ₂For this reason, with the vlp-TiO of 100g gained ₂Add commercial mixing tank (manufacturer: Braun, model: MX2050), and ground 12 times * 5 seconds.Between each grinding steps, opening mixing tank, and mixed powder once more.Have all lacklustre blank sheet of paper in both sides of lay on the base plate of annular recess, and encircling (high 4cm, diameter 2.4cm) with press pressed metal in groove.Slightly shaking and knocking down the vlp-TiO that will about 25g grinds ₂Add in this metal ring.With 2-3kN pressure powder is compressed.For the second time repeat pressing process, up to reaching the 15kN working pressure of wanting.

By careful rotation and pull metal ring, it is separated with base plate.Paper between base plate and the ring is removed.The compacting thing is arranged in ring now, be used for the measuring process on the HUNTERLAB chromascope.

Observed value L*, a*, b* directly read on chromascope.

B) mensuration of photolytic activity (objectionable impurities degraded)

Under artificial visible light:

In ultra sonic bath, 15mg vlp-TiO ₂At 15ml 2.5 * 10 ^-4 Disperseed 10 minutes in the 4-chlorophenol solution of M, in water-cooled round sample pool, on optical bench, expose then.In order to measure photolytic activity, expose with being installed in the Osram XBO 150W xenon Jupiter that focuses in the lampshade (AMKO model A1020, focal length 30cm).The spectrum of this lamp draws in Figure 10.Be reflected in that 15ml embeds, the water-cooled round sample pool (internal diameter 30mm, bed thickness 20mm) and carry out.Stirring electric motor and the magnetic stirrer stirring reaction suspension that can install with a side.The circle sample pool draws in Figure 11.Sample pool is fixed on the focus place of lamp.Light is focused on the feasible reaction chamber that only shines sample pool.All component is fixedly mounted on the optical bench.In order to eliminate ultraviolet ray, split strainer (Schott company) is installed in light path, its penetrance is λ 〉=455nm.In order to prevent that reaction chamber may be heated owing to exposure, also installs an IR strainer in light path.Here be a cylinder (diameter 6cm, length 10cm) of filling water.

(λ=224nm) reduction of tracking 4-chlorophenol concentration perhaps under degraded (oxidation) situation, follows the tracks of by the total content (TOC value) of measuring organic carbon by UV spectrum.

In the available light of indoor diffusion:

In ultra sonic bath, 50mg vlp-TiO ₂At 50ml 2.5 * 10 ^-4Disperse 10 to disperse in the 4-chlorophenol solution of M, in Erlenmeyer flask (100ml), under agitation be subjected to the irradiation of indoor natural light line then.

The degraded of aldehydes gas, benzene vapor and carbon monoxide:

In the round-bottomed flask (1 liter) of an aldehydes gas (2 volume %) that is full of air saturation or benzene vapor (5 volume %) or carbon monoxide, put into two bilaterals and scribble vlp-TiO ₂Round filter (paper, d=15cm, 12mg catalyzer/strainer).

This flask is subjected to the available light irradiation in the laboratory then, and follows the tracks of the minimizing of objectionable impurities and the formation of carbonic acid gas by IR spectrum.

C) mensuration of carbon content

Measure total content of organic carbon (TOC) with carbon analyzer LECO C-200.This measuring method is based on the TiO that burns under oxygen in induction furnace ₂In contained organic substance, detect by IR then and measure formed carbonic acid gas.TiO ₂The about 0.4g of starting weight.

D) mensuration of BET (Brunauer-Emmett-Teller) specific surface area

According to statistical volume theory, with the Tristar3000 mensuration BET surface-area of Micromeritics company.

E) XPS measuring

In order to measure bond energy, (23.50eV pass through energy (pass energy) to use instrument Phi 5600 ESCA spectrographs; The A1 standard substance; 300.0W; 45.0 °).

F) ESR measures

In order to measure the electron resonance spectrum, use Bruker Elexys 580 spectrograph X-bands of a spectrum (9.5GHz).Sample is evacuated and reaches 10 ^-5Torr is filled helium, is 10 up to pressure ^-2Torr, fusing then.Measure under the following conditions:

Adjustment magnetic field is 100Hz.RF power: 0.0002-1mW.: 3340-3500G.Sweep length: 100-500G.Switching time: 81.92ms.Time constant: 40.96ms.The fabric width of modifying: 0.2-13G, temperature: 5K.Measure the g value by Hall-Sonde.

G) measurement of the reflection spectrum of diffusion (Kubelka-Munk-function)

Measure the reflection spectrum of powder diffusion with the Shimadzu UV-2401 PC UV/visible spectrophotometer that is equipped with the Wu Bulixi ball.Use barium sulfate as the white standard thing, before measurement in mill abrasive flour and barium sulfate together.Kubelka-Munk-function and specific absorption are proportional.

H) super hydrophilicity

In order to measure the contact angle of water, with vlp-TiO ₂TiO with unmodified ₂Be suspended in respectively in the distilled water, be coated in by " dip coated " on the aluminium sheet of 5 * 5cm size, and 400 ℃ of calcinings 1 hour.After preserving under available light, the contact angle of measuring the titanium dioxide of unmodified is 21 °, and the contact angle of vlp-Ti02 has only 8 °.The contact angle of the aluminium sheet of uncoated is 91 °.

Claims

1. based on the carbonaceous photocatalyst of titanium dioxide, it is with respect to pure titinium dioxide, has tangible photoabsorption in λ 〉=400nm zone, it is characterized in that, an electron spin resonance spectroscopy ESR who records under the 5K temperature is arranged, and it has only a tangible signal in the g value is 1.97～2.05 scopes, and carbon only is arranged in the upper layer of titanium dioxide granule, it is characterized in that its carbon content is 0.05～4 weight %.

2. according to the photocatalyst of claim 1, it is characterized in that in the ESR spectrum, it is 2.002～2.004 places that this signal appears at the g value.

3. according to the photocatalyst of claim 1, it is characterized in that in x-ray photoelectron spectroscopy XPS, there is strong absorption band at the place at the 285.6eV bond energy, in the O1s-bands of a spectrum at 530eV place.

4. according to the photocatalyst of claim 1, it is characterized in that, with the proportional Kubelka-Munk function F of specific absorption (R _∞) be 50% of 400nm place value to be 20% of 400nm place value at the 600nm place at the 500nm place.

5. according to the photocatalyst of claim 1, it is characterized in that photolytic activity is at least 20%.

6. according to the photocatalyst of claim 1, it is characterized in that its carbon content is 0.3～1.5 weight %.

7. according to the photocatalyst of claim 1, it is characterized in that not only not having in x-ray photoelectron spectroscopy XPS but also in infrared spectra, show the carbonate bands of a spectrum.

8. according to the photocatalyst of claim 1, it is characterized in that the BET specific surface area is 100～250m ²/ g.

9. preparation has the method based on the carbonaceous photocatalyst of titanium dioxide of tangible photoabsorption with respect to pure titinium dioxide in λ 〉=400nm zone, it is characterized in that having 50m at least ²The titanium compound of/gBET specific surface area and carbonaceous material uniform mixing, and under the temperature of height to 400 ℃, mixture is heat-treated, carbon only is arranged in the upper layer of titanium dioxide granule, it is characterized in that, and its carbon content is 0.05～4 weight %.

10. according to the method for claim 9, it is characterized in that this titanium compound is amorphous, partial crystallization or crystalline titanium oxide or aqueous titanium oxide or titanyl hydrate or titanyl hydrate.

11. the method according to claim 10 is characterized in that, this titanium compound is the titanyl hydrate that is produced by sulphate process.

12. the method according to claim 11 is characterized in that, this titanyl hydrate at first is neutralized and washs, feasible dry back solid SO ₃Content is less than 1 weight %.

13. the method according to claim 9 is characterized in that, the decomposition temperature of carbonaceous material is the highest 400 ℃.

14. the method according to claim 9 is characterized in that, this carbonaceous material is the hydro carbons that contains at least one functional group.

15. the method according to claim 14 is characterized in that, functional group is one of following group: OH, CHO, COOH, NH _x, SH _x, COOR, wherein R is an alkyl or aryl.

16. the method according to claim 9 is characterized in that, uses compound or its mixture that is selected from ethylene glycol, glycerine, carbohydrate, organic hydroxide ammonium as carbonaceous material.

17. the method according to claim 9 is characterized in that, this carbonaceous material is timber, gac or carbon black.

18. the method according to claim 9 is characterized in that, thermal treatment is carried out in the calciner of operation continuously.

19. the method according to claim 9 is characterized in that, thermal treatment is carried out at rotary kiln or in fluidized-bed.

20. the method according to claim 9 is characterized in that, thermal treatment is carried out in oxidizing atmosphere.

21. the method according to claim 9 is characterized in that, thermal treatment is carried out at air or in oxygen-air mixture.

22. the method according to claim 9 is characterized in that, carries out independent predrying before thermal treatment.

23. the method according to claim 22 is characterized in that, described predryingly carry out in spray-dryer or fluidized bed dryer.

24. photocatalyst according to the preparation of the method for claim 9.

25., be used for plastics, fiber, paper and road surface according to claim 1～8 or 24 each the purposes of photocatalyst.

26., be used for plastics film according to claim 1～8 or 24 each the purposes of photocatalyst.

27., in construction industry, be used to produce member, and be used for automotive industry according to claim 1～8 or 24 each the purposes of photocatalyst.

28. according to the purposes of claim 27, it is used to the auxilliary backing member producing concrete product, pottery, wallpaper, fabric and be used for indoor and outdoors roof and wall.

29. according to the purposes of claim 27, it is used to produce concrete-paving brick, roof brick, ceramic tile, refractory brick.

30., be used for air regulator according to claim 1～8 or 24 each the purposes of photocatalyst, be used for the device of purifying air and sterilizing air, and water-purification plant.

31. according to the purposes of claim 30, it is for antibiotic or antiviral purpose.

32., be used for photocell and in order to water of decomposition according to claim 1～8 or 24 each the purposes of photocatalyst.