Easily-recovered nitrogen-doped nucleocapsid structure ZnO/TiO
2The preparation of visible-light photocatalyst
Technical field
The invention belongs to ZnO/TiO
2The preparation field of visible-light photocatalyst particularly relates to a kind of easily-recovered nitrogen-doped nucleocapsid structure ZnO/TiO
2The preparation of visible-light photocatalyst.
Background technology
Characteristics such as that titanium dioxide has is cheap, nontoxic, stable performance have become the research focus of present photocatalysis field.But also there are many defectives in actual applications in titanium dioxide, wherein mainly contains: the one, and TiO
2Have bigger band-gap energy (≈ 3.2eV), can only utilize the ultraviolet light of about 3-5% in the sunshine; The 2nd, the TiO of nano-scale
2Photochemical catalyst is difficult to separate and recycle, and causes the raising of processing cost; The 3rd, the photochemical catalytic oxidation process is discontinuous operation, causes the loss of treatment effeciency than low and photochemical catalyst.
Doping metals and nonmetalloid are the effective means that improves the TiO 2 visible light response.From Asahi at Science, 2001, the 293:269-271 reported first behind the titanium dioxide that mixes of nitrogen, the doped with non-metals element as: nitrogen, carbon, boron, sulphur and fluorine have become the focus of everybody research.Be to solve the recycling of photochemical catalyst, it is that photochemical catalyst is coated on the magnetic material that people study more.Chen etc. are at Chemosphere 2001, but 44:1159-1168 has reported the photochemical catalyst (TiO of Magnetic Isolation
2/ SiO
2/ γ-Fe
2O
3) preparation.TiO wherein
2As shell, γ-Fe
2O
3As nuclear, the SiO between the nucleocapsid
2Be screener, this catalyst is degradation of dye under ultraviolet light and radiation of visible light, but its photocatalytic activity is lower than P-25.Gao etc. are at Mater.Chem.Phys.2003, and 80:348-355 has reported TiO
2As shell, γ-Fe
2O
3As the photocatalysis system of nuclear, can separate effectively under this photochemical catalyst outside magnetic field effect.But find to work as TiO
2Be lower than at 31% o'clock, its photocatalytic activity is extremely low, is because TiO
2And Fe
2O
3Formed Fe
2TiO
4Chung etc. are at Mater.Chem.Phys.2004, and 86:375-381 has reported that having synthesized with the nickel ferrite based magnetic loaded with the sputter pyrohydrolytic method is nuclear, TiO
2-SiO
2As the photochemical catalyst of shell, this photochemical catalyst is water-fast to be washed and easily separated.Zhang etc. are at Appl.Catal.B 2007, and 76:168-173 has reported anatase TiO
2Coat the photochemical catalyst of four-footed ZnO, degradation of phenol under the ultraviolet light studies show that: photocatalytic activity obviously is better than pure anatase TiO
2With four-footed ZnO and easily from waste water, separate.More than recyclable photochemical catalyst can only just have higher photocatalytic activity at ultraviolet region, realize making full use of sunshine, photochemical catalyst also must have response at visible region.Xu etc. are at Appl.Catal.B 2007, and 71:177-184 has reported with simple method and synthesized easy recovery visible-light photocatalyst (TiO
2-xN
x/ SiO
2/ NiFe
2O
4).Think SiO
2Be wrapped in NiFe
2O
4The surface on can stop light induced electron from TiO
2Conduction band move to NiFe
2O
4Conduction band, thereby improve visible light photocatalysis active.Experimental result also shows to be easy under this catalyst outside magnetic field effect separate to be reused.
Summary of the invention
Technical problem to be solved by this invention provides a kind of easily-recovered nitrogen-doped nucleocapsid structure ZnO/TiO
2The preparation of visible-light photocatalyst, this preparation method is simple, and required production equipment is simple, and cost is low, is suitable for suitability for industrialized production.
A kind of easily-recovered nitrogen-doped nucleocapsid structure ZnO/TiO of the present invention
2The preparation method of visible-light photocatalyst comprises:
(1) ZnO/TiO of nucleocapsid structure
2Preparation
Get four-footed zinc oxide, add absolute ethyl alcohol, stirred 2-5 minute, dropwise adding tetrabutyl titanate stirred 2-5 minute again, put into steam raising plant afterwards, put into drying baker after airtight, be heated to 100~200 ℃, and be incubated 10~15 hours, after treating that temperature is reduced to room temperature, sediment is washed with distilled water, remove impurity, use absolute ethanol washing again, remove the moisture in the sediment, avoid the generation of hard aggregation, promptly get the ZnO/TiO of the nucleocapsid structure of favorable dispersibility
2, with this product oven dry, calcine, obtain the ZnO/TiO of further crystallization
2Described four-footed zinc oxide is (0.1g~0.3g): (3mL~6mL) with the ratio of absolute ethyl alcohol; Four-footed zinc oxide is (0.1g~0.3g): (20 μ L~40 μ L) with the ratio of butyl titanate;
(2) ZnO/TiO
2The preparation of visible-light photocatalyst
With the ZnO/TiO after the above-mentioned crystallization
2, the tubular type of packing into atmosphere furnace feeds ammonia, is warming up to 525~600 ℃, under this temperature, is incubated 2~5 hours, then, under the ammonia that flows, naturally cools to room temperature, promptly gets easily-recovered nitrogen-doped nucleocapsid structure ZnO/TiO
2Visible-light photocatalyst.
Four-footed zinc oxide in the described step (1) is purchased in Chengdu National Chiao Tung University Jingyu Technology Co.
Bake out temperature 100-150 in the described step (1) ℃, the time is 12-15 hour.
Calcining heat in the described step (1) is 420~500 ℃, 1~2 hour time.
Described step (1) is by regulating the addition control TiO of butyl titanate and four-footed zinc oxide
2The thickness of layer.
Ammonia flow in the described step (2) is 0.1~0.3 liter/minute.
Heating rate in the described step (2) is 1~3 ℃/minute.
Process conditions such as the addition by changing butyl titanate, nitriding temperature, nitridation time, ammonia flow can obtain the ZnO/TiO of different-thickness and different nitrogen dopings
2Visible-light photocatalyst.
Photochemical catalyst of the present invention is because of its higher visible light photocatalysis active and easily reclaim characteristic, gathers around in the environmental pollution improvement field to have broad application prospects.
The present invention is a template with four-footed zinc oxide, and absolute ethyl alcohol is a dispersant, and butyl titanate is an initiation material, and under uniform temperature and pressure, the steam hydrolysis of tetrabutyl titanate obtains the ZnO/TiO of nucleocapsid structure
2,, obtain the ZnO/TiO of further crystallization again through calcining through washing, oven dry
2With ZnO/TiO
2In tubular react furnace, under mobile ammonia condition, high-temperature ammonolysis makes easily-recovered nitrogen-doped nucleocapsid structure ZnO/TiO
2Visible-light photocatalyst.
TiO of the present invention
2The preparation of/ZnO is that four-footed zinc oxide is dispersed in the absolute ethyl alcohol, under agitation, butyl titanate is dropwise joined in the four-footed zinc oxide alcoholic dispersion system.The steam that the water of reactor bottom at high temperature produces with being dissolved in the tetrabutyl titanate hydrolysis in the ethanol and being deposited on the surface of four-footed zinc oxide, obtains four-footed ZnO/TiO through washing, oven dry, high-temperature calcination
2
Beneficial effect
(1) preparation method of the present invention is simple, and required production equipment is simple, and cost is low, is suitable for suitability for industrialized production;
(2) the easily-recovered nitrogen-doped nucleocapsid structure ZnO/TiO of gained of the present invention
2Visible-light photocatalyst has stronger visible light-responded and three-dimensional structure, is easy to reclaim.
Description of drawings
3 hours gained nitrogen of Fig. 1 .550 ℃ nitrogenize is mixed ZnO/TiO
2The X-ray diffractogram of visible-light photocatalyst;
3 hours gained nitrogen of Fig. 2 .550 ℃ nitrogenize is mixed ZnO/TiO
2The field emission scanning electron microscope photo of photochemical catalyst;
3 hours gained nitrogen of Fig. 3 .550 ℃ nitrogenize is mixed ZnO/TiO
2The transmission electron microscope photo of visible-light photocatalyst;
3 hours gained nitrogen of Fig. 4 .550 ℃ nitrogenize is mixed ZnO/TiO
2The uv-visible absorption spectroscopy of photochemical catalyst;
3 hours gained nitrogen of Fig. 5 .550 ℃ nitrogenize is mixed ZnO/TiO
2The visible light catalysis activity figure of photochemical catalyst.
The specific embodiment
Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiment only to be used to the present invention is described and be not used in and limit the scope of the invention.Should be understood that in addition those skilled in the art can make various changes or modifications the present invention after the content of having read the present invention's instruction, these equivalent form of values fall within the application's appended claims institute restricted portion equally.
Embodiment 1
(1) takes by weighing 0.1g four-footed zinc oxide in the 10mL crucible, the absolute ethyl alcohol that adds 5mL, stirred 2 minutes with glass bar, the butyl titanate of 30 μ L is dropwise joined in the dispersion, stirred 2 minutes with glass bar again, crucible is put into steam raising plant, put into baking oven after airtight, be heated to 150 ℃, and be incubated 10 hours, after treating that temperature is reduced to room temperature, sediment with distilled water washing three times, is removed impurity, use absolute ethanol washing again three times, remove the moisture in the sediment, avoid the generation of hard aggregation, can obtain the ZnO/TiO of the nucleocapsid structure of favorable dispersibility
2, with this product oven dry, calcined 2 hours down at 425 ℃, obtain the ZnO/TiO of further crystallization
2
(2) with the ZnO/TiO after the above-mentioned crystallization
2Put into quartz boat, the tubular type of packing into atmosphere furnace feeds ammonia, and ammonia flow is 0.15 liter/minute, is warming up to 550 ℃, and heating rate is 3 ℃/minute, under this temperature, is incubated 3 hours, then, under the ammonia that flows, naturally cools to room temperature.Obtain nitrogen and mix ZnO/TiO
2Visible-light photocatalyst.
Fig. 1 mixes ZnO/TiO for the nitrogen of present embodiment preparation
2The X-ray diffractogram of visible-light photocatalyst, peak 1 expression anatase titania (101) crystal face diffraction maximum among the figure, all the other peaks are hexagonal wurtzite zinc oxide crystal face diffraction maximum.Fig. 2 is its field emission scanning electron microscope photo, and surface and the maintenance four-feet shape of titanium dioxide deposition to four-footed zinc oxide is described.Fig. 3 is its transmission electron microscope photo, illustrates that anatase titania is wrapped in the surface formation nucleocapsid structure of four-footed zinc oxide.Fig. 4 is its uv-visible absorption spectroscopy, and its absorption spectrum is extended to visible region as can be seen.Fig. 5 is its visible light catalysis activity figure.
Embodiment 2
(1) takes by weighing 0.3g four-footed zinc oxide in the 10mL crucible, the absolute ethyl alcohol that adds 5mL, stirred 2 minutes with glass bar, the butyl titanate of 20 μ L is dropwise joined in the dispersion, stirred 2 minutes with glass bar again, crucible is put into steam raising plant, put into baking oven after airtight, be heated to 100 ℃, and be incubated 12 hours, after treating that temperature is reduced to room temperature, sediment with distilled water washing three times, is removed impurity, use absolute ethanol washing again three times, remove the moisture in the sediment, avoid the generation of hard aggregation, can obtain the ZnO/TiO of the nucleocapsid structure of favorable dispersibility
2, with this product oven dry, calcined 1 hour down at 450 ℃, obtain the ZnO/TiO of further crystallization
2
(2) with the ZnO/TiO after the above-mentioned crystallization
2Put into quartz boat, the tubular type of packing into atmosphere furnace feeds ammonia, and ammonia flow is 0.1 liter/minute, is warming up to 550 ℃, and heating rate is 2 ℃/minute, under this temperature, is incubated 4 hours, then, under the ammonia that flows, naturally cools to room temperature.Obtain nitrogen and mix ZnO/TiO
2Visible-light photocatalyst.
Embodiment 3
(1) takes by weighing 0.15g four-footed zinc oxide in the 10mL crucible, the absolute ethyl alcohol that adds 5mL, stirred 2 minutes with glass bar, the butyl titanate of 40 μ L is dropwise joined in the dispersion, stirred 2 minutes with glass bar again, crucible is put into steam raising plant, put into baking oven after airtight, be heated to 180 ℃, and be incubated 10 hours, after treating that temperature is reduced to room temperature, sediment with distilled water washing three times, is removed impurity, use absolute ethanol washing again three times, remove the moisture in the sediment, avoid the generation of hard aggregation, can obtain the ZnO/TiO of the nucleocapsid structure of favorable dispersibility
2, with this product oven dry, calcined 1 hour down at 500 ℃, obtain the ZnO/TiO of further crystallization
2
(2) with the ZnO/TiO after the above-mentioned crystallization
2Put into quartz boat, the tubular type of packing into atmosphere furnace feeds ammonia, and ammonia flow is 0.2 liter/minute, is warming up to 600 ℃, and heating rate is 1 ℃/minute, under this temperature, is incubated 5 hours, then, under the ammonia that flows, naturally cools to room temperature.Obtain nitrogen and mix ZnO/TiO
2Visible-light photocatalyst.