A kind of preparation method of silver/cadmium sulfide/titanic oxide composite photochemical catalyst material
Technical field
The present invention relates to a kind of preparation method of silver/cadmium sulfide/titanic oxide composite photochemical catalyst material, belong to optic catalytic composite material preparation field.
Background technology
TiO
2be the catalyst of heterogeneous catalytic reaction, valence-band level is comparatively dark, has nontoxic, corrosion resistance, high stability, reaction condition is gentle, to organic matter degradation non-selectivity in water pollutant, mineralising thoroughly, non-secondary pollution, the advantage such as cheap is the generally acknowledged photochemical catalyst most with practical application foreground.Disposing of sewage, improving drinking water quality, controlling atmosphere pollution, purify the air of a room, catalyzing hydrolysis hydrogen manufacturing, sterilization and prepare the aspects such as solar energy sensitized cells and be all widely used.Particularly in environmental protection, TiO
2wide application prospect is presented especially as photochemical catalyst.
But the photosensitized reaction of TiO2 is confined to ultraviolet region, this occupies 5% of solar spectrum, in addition, due to the right height recombination rate again of light induced electron and hole, thus limits photocatalytic activity and the application prospect of TiO2.Therefore, expand absorption region and promote that being separated of photo-generated carrier is the two large effective measures strengthening TiO2 photocatalytic activity.So scientific worker begins one's study doping vario-property to construct hetero-junctions to improve the photocatalytic activity of TiO2 both at home and abroad, why welcome structure hetero-junctions is is because it can not only improve the performance of single material, and can introduce the property that homogenous material do not have.But be confined to synthesize binary composite, trielement composite material just started to be studied by people in recent years.
Summary of the invention
The object of this invention is to provide a kind of preparation method of silver/cadmium sulfide/titanic oxide composite photochemical catalyst material, attempt a kind of synthetic method of trielement composite material, in titanium dioxide, add cadmium sulfide simultaneously, silver, CdS energy gap is less, its band-gap energy is 2.5eV, with band-gap energy 3.2eVTiO2 compound, when excitation energy is not enough to the TiO2 in exciting light catalyst, but CdS can be excited, because TiO2 conduction band is higher than CdS, the electronics produced that makes CdS is stimulated more easily moves on TiO2 conduction band, the hole of generation is excited still to stay CdS valence band, this electronics is conducive to the separation of electric charge to the migration of TiO2 from CdS.When penetrating with the illumination of enough excitation energies, there is electron transition in CdS and TiO2 simultaneously, due to energy level difference, electron-collection is at the conduction band (CB) of TiO2, and void coalescence is in the valence band (VB) of CdS, light induced electron and hole can freely carry out with adsorption matter exchanging the separation of charge effect that CdS/TiO2 improves system.Ag in addition
+doping change TiO2 surface cleanliness and add blemish.Be entrained in the Ag on TiO2
+, accept electronics under light illumination and be reduced to simple substance Ag.Metal A g constitutes a large amount of micro cells on TiO2 surface, the electronics that illumination excites rear TiO2 surface to produce moves to the anode (Ag) of micro cell, anode (TiO2) surface is then stayed in hole, thus also achieves electronics and is separated with the effective of hole.Therefore this composite has excellent photocatalysis performance, prepares the catalysis material that combination property is superior.
A preparation method for silver/cadmium sulfide/titanic oxide composite photochemical catalyst material, concrete grammar is as follows:
(1) CdO/TiO
2preparation:
Take the triblock copolymer pluronic P123 of 1.0g, be dissolved in 15ml absolute ethyl alcohol, stirred at ambient temperature 0.5h, then ultrasonic process 10min is P123/EtOH mixed solution, simultaneously, the concentrated hydrochloric acid of 3.2ml is dropwise added in the tetra-n-butyl titanate of 4.0g, and adds Cd (NO
3)
24H
2o, makes the CdO/TiO obtained
2mass ratio be 1%, 2%, 4% or 8%, P123/EtOH mixed solution mixes with above-mentioned solution after stirring 0.5h, stirred at ambient temperature is 3h at least, the sol solution of synthesis is poured in a unlimited culture dish, maintenance ambient humidity, light and temperature is 50%-60%, in left at room temperature 2-4 week, become after wet powder until it, grind calcine 4h at 200 DEG C after, powder is refluxed 48h in the ethylenediamine solution of pH11-12, temperature remains on 125 DEG C, pH regulates at 11-12, reflux complete, suction filtration also spends deionized water, by product at 60 DEG C of dry 10h, finally, gained powder is first ground, then N at 350 DEG C
2middle calcining 3h, calcines 2h in air subsequently and namely obtains CdO/TiO at 500 DEG C
2,
(2) CdS/TiO
2the preparation of middle composite granule:
Use Na
2s9H
2o is made into 100ml0.2mol/LNa
2s solution, takes the CdO/TiO that 0.6g has been prepared
2, be dispersed in 100mlNa
2in S solution, in stirred at ambient temperature 6h.Last suction filtration, by gained powder at 80 DEG C of dry 10h, through grinding and obtain middle composite granule;
(3) preparation of silver/cadmium sulfide/titanic oxide composite photochemical catalyst material:
Take 0.3g made CdS/TiO
2, 0.0094gAgNO
3be added in there-necked flask, make Ag/(CdO/TiO
2) mass ratio be 2%, add 45mlH simultaneously
2o and 5mlCH
3oH, by above-mentioned solution high-purity Ar or N
2purify away O
2, after purification 30min, open UV, visible light light source and irradiate 1h, then centrifugal and 80 DEG C of dry 10h will be deposited in obtain silver-colored/cadmium sulfide/titanic oxide composite photochemical catalyst material.
From Figure of description 1, the compound catalyze material that the present invention obtains is in UV-vis DRS spectrogram, and absorbing wavelength reaches 500nm.
Advantage of the present invention: the present invention is from the angle of composite, and by silver, cadmium sulfide and titanium dioxide are combined with each other, and prepare a kind of catalysis material.This composite photocatalyst material is compared with pure titinium dioxide, and in UV-vis DRS spectrogram, absorbing wavelength is greater than 400nm.There is higher refraction coefficient and stable physical and chemical performance, and chemical resistance and photoetch, photocatalytic activity are higher.Therefore, this composite is in photocatalytic water, sterilization and prepare in solar energy sensitized cells etc., particularly in environmental protection, has broad application prospects.
Accompanying drawing explanation
Fig. 1 is the UV-vis DRS spectrogram of the compound catalyze material that the present invention obtains.
Reference numeral:
Fig. 2 is the CdS/TiO of four different proportions that embodiment 1-4 is corresponding
2intermediate product and CdS and TiO
2photocatalysis effect.
Reference numeral:
Detailed description of the invention
Below by embodiment, the invention will be further described.
Embodiment 1
(1) CdO/TiO
2preparation:
Take the triblock copolymer pluronic P123 of 1.0g, be dissolved in 15ml absolute ethyl alcohol, stirred at ambient temperature 0.5h, then ultrasonic process 10min, for P123/EtOH mixed solution,, the concentrated hydrochloric acid of 3.2ml is dropwise added in the tetra-n-butyl titanate of 4.0g meanwhile, and adds the Cd (NO of 0.0225g
3)
24H
2o, makes the CdO/TiO obtained
2mass ratio be that 1%, P123/EtOH mixed solution stirs after 0.5h and mixes with above-mentioned solution, stirred at ambient temperature is 3h at least.Poured into by the sol solution of synthesis in a unlimited culture dish, maintenance ambient humidity, light and temperature is 50%-60%, in left at room temperature 2-4 week, become after wet powder until it, grind calcine 4h at 200 DEG C after, powder is refluxed 48h in the ethylenediamine solution of pH11-12, temperature remains on 125 DEG C, pH regulates at 11-12, and reflux complete, suction filtration also spends deionized water, by product at 60 DEG C of dry 10h, finally, gained powder is first ground, then N at 350 DEG C
2middle calcining 3h, calcines 2h in air subsequently and namely obtains CdO/TiO at 500 DEG C
2;
(2) CdS/TiO
2the preparation of middle composite granule:
With the Na of 0.0112g
2s9H
2o is made into the Na of 100ml0.2mol/L
2s solution, takes the CdO/TiO that 0.6g has been prepared
2, be dispersed in 100mlNa
2in S solution, under room temperature, stir 6h energetically.Last suction filtration, by gained powder at 80 DEG C of dry 10h, through grinding and obtaining CdS/TiO
2middle composite granule; Get 50mgCdS/TiO
2for the methyl orange solution of the 50ml10PPm that degrades under simulated solar irradiation, after 75min, degradation rate reaches 60%;
(3) preparation of silver/cadmium sulfide/titanic oxide composite photochemical catalyst material:
Take 0.3g made CdS/TiO
2, 0.0094gAgNO
3be added in there-necked flask, add 45mlH simultaneously
2o and 5mlCH
3oH, by above-mentioned solution high-purity Ar or N
2purify away O
2, after purification 30min, open UV, visible light light source and irradiate 1h, then centrifugal and 80 DEG C of dry 10h will be deposited in obtain silver-colored/cadmium sulfide/titanic oxide composite photochemical catalyst material.
Embodiment 2
CdO/TiO
2preparation with step (1) in embodiment 1, add the Cd (NO of 0.0451g
3)
24H
2o, makes the CdO/TiO obtained
2mass ratio be 2%; Take the CdO/TiO that 0.6g has been prepared
2, CdS/TiO
2middle composite granule preparation method with step (2) in embodiment 1, with the Na of 0.0224g
2s9H
2o is made into the Na of 100ml0.2mol/L
2s solution, prepares CdS/TiO
2middle composite granule, gets 50mgCdS/TiO
2for the methyl orange solution of the 50ml10PPm that degrades under simulated solar irradiation, after 75min, degradation rate reaches 98.6%.
All the other are with embodiment 1.
Embodiment 3
CdO/TiO
2preparation with step (1) in embodiment 1, add the Cd (NO of 0.0902g
3)
24H
2o, makes the CdO/TiO obtained
2mass ratio be 4%; Take the CdO/TiO that 0.6g has been prepared
2, CdS/TiO
2middle composite granule preparation method with step (2) in embodiment 1, with the Na of 0.0449g
2s9H
2o is made into the Na of 100ml0.2mol/L
2s solution, prepares CdS/TiO
2middle composite granule, gets 50mgCdS/TiO
2for the methyl orange solution of the 50ml10PPm that degrades under simulated solar irradiation, after 75min, degradation rate reaches 73.7%.
All the other are with embodiment 1.
Embodiment 4
CdO/TiO
2preparation with step (1) in embodiment 1, add the Cd (NO of 0.1803g
3)
24H
2o, makes the CdO/TiO obtained
2mass ratio be 8%; Take the CdO/TiO that 0.6g has been prepared
2, CdS/TiO
2middle composite granule preparation method with step (2) in embodiment 1, with the Na of 0.0898g
2s9H
2o is made into the Na of 100ml0.2mol/L
2s solution, prepares CdS/TiO
2middle composite granule, gets 50mgCdS/TiO
2for the methyl orange solution of the 50ml10PPm that degrades under simulated solar irradiation, after 75min, degradation rate reaches 89.2%.
All the other are with embodiment 1.
The preparation of object of reference cadmium sulfide
(1) 2.4018gNa is taken
2s9H
2o and 3.0848gCd (NO
3)
24H
2the beaker that O is placed in 50mL respectively adds appropriate amount of deionized water dissolving.
(2) by Cd (NO
3)
24H
2o solution is placed in oil bath pan, stirring reaction 30min at 100 DEG C.
(3) subsequently by Na
2s9H
2o dropwise is added to Cd (NO
3)
24H
2in O solution, and at 100 DEG C stirring reaction 30min, make
with
abundant reaction.
(4) be then cooled to room temperature, centrifugation, and wash 2 times respectively by ethanol and deionized water, the product obtained is 70
lower dry 10h, grinds and obtains CdS powder.
Object of reference TiO
2preparation
(1) take the triblock copolymer pluronic P123 of 1.0g, be dissolved in 15ml absolute ethyl alcohol, stirred at ambient temperature 0.5h, then ultrasonic process 10min.
(2) concentrated hydrochloric acid of 3.2ml is dropwise added in the tetra-n-butyl titanate TBOT solution of 4.0g.P123/EtOH mixed solution mixes with above-mentioned solution after stirring 0.5h, stirs at least 3h energetically under room temperature.
(3) sol solution of synthesis is poured in a unlimited culture dish, keeps ambient humidity, light and temperature to be 50%---60%, left at room temperature several weeks.Become after wet powder until it, at 200 DEG C, calcine 4h carry out rock-steady structure.
(4) grinding after, powder is refluxed 48h in ethylenediamine solution, and temperature remains on 125 DEG C, and PH regulates 11---and 12.Reflux complete, suction filtration also spends deionized water, by product at 60 DEG C of dry 10h.
(5) subsequently, gained powder is first ground, then N at 350 DEG C
2middle calcining 3h makes meso-hole structure stablize.
(6) last, at 500 DEG C, in air, calcine 2h remove organic formwork and improve degree of crystallinity.
The CdS/TiO of four different proportions that embodiment 1-4 is corresponding
2intermediate product and CdS and TiO
2photocatalysis effect, shown in Figure of description 2, the CdS/TiO of four prepared different proportions
2in intermediate product, 2%CdS/TiO
2photocatalysis effect best, be better than CdS and TiO
2.
Adopt the 2%CdS/TiO that photocatalysis effect is best
2prepare silver/cadmium sulfide/titanic oxide composite photochemical catalyst material:
Take the 2%CdS/TiO that 0.3g is made
2, by 0.0094gAgNO
3be added in there-necked flask, make Ag/(CdO/TiO
2) mass ratio be 2%, add 45mlH simultaneously
2o and 5mlCH
3oH, by above-mentioned solution high-purity Ar or N
2purify away O
2, after purification 30min, open UV, visible light light source and irradiate 1h.Then centrifugal and 80 DEG C of dry 10h will be deposited in obtain silver-colored/cadmium sulfide/titanic oxide composite photochemical catalyst material.Get 50mg cadmium sulfide/titanium dioxide CdS/TiO
2for the methyl orange solution of the 50ml10PPm that degrades under simulated solar irradiation, after 75min, degradation rate reaches 71.1%.