CN110586058B - Preparation method of nano titanium dioxide/zirconium oxide composite photocatalyst - Google Patents
Preparation method of nano titanium dioxide/zirconium oxide composite photocatalyst Download PDFInfo
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- 239000002131 composite material Substances 0.000 title claims abstract description 80
- 239000011941 photocatalyst Substances 0.000 title claims abstract description 61
- 238000002360 preparation method Methods 0.000 title claims abstract description 33
- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical compound [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 0.000 title claims abstract description 13
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 title claims description 30
- 229910001928 zirconium oxide Inorganic materials 0.000 title claims description 10
- 239000000843 powder Substances 0.000 claims abstract description 66
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims abstract description 46
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims abstract description 46
- 229910010413 TiO 2 Inorganic materials 0.000 claims abstract description 43
- 238000001027 hydrothermal synthesis Methods 0.000 claims abstract description 33
- 239000002994 raw material Substances 0.000 claims abstract description 20
- 238000003756 stirring Methods 0.000 claims description 65
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- 239000000243 solution Substances 0.000 claims description 34
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- 239000000047 product Substances 0.000 claims description 29
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- YHWCPXVTRSHPNY-UHFFFAOYSA-N butan-1-olate;titanium(4+) Chemical compound [Ti+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] YHWCPXVTRSHPNY-UHFFFAOYSA-N 0.000 claims description 17
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 claims description 16
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- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 12
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- 229920001030 Polyethylene Glycol 4000 Polymers 0.000 claims description 11
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 claims description 11
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- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 claims description 5
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- 238000005261 decarburization Methods 0.000 claims description 4
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- FGUUSXIOTUKUDN-IBGZPJMESA-N C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 Chemical compound C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 FGUUSXIOTUKUDN-IBGZPJMESA-N 0.000 claims description 2
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- YLZOPXRUQYQQID-UHFFFAOYSA-N 3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)-1-[4-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]piperazin-1-yl]propan-1-one Chemical compound N1N=NC=2CN(CCC=21)CCC(=O)N1CCN(CC1)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F YLZOPXRUQYQQID-UHFFFAOYSA-N 0.000 description 4
- 239000000706 filtrate Substances 0.000 description 4
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- CMOAHYOGLLEOGO-UHFFFAOYSA-N oxozirconium;dihydrochloride Chemical compound Cl.Cl.[Zr]=O CMOAHYOGLLEOGO-UHFFFAOYSA-N 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- LDXJRKWFNNFDSA-UHFFFAOYSA-N 2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)-1-[4-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]piperazin-1-yl]ethanone Chemical compound C1CN(CC2=NNN=C21)CC(=O)N3CCN(CC3)C4=CN=C(N=C4)NCC5=CC(=CC=C5)OC(F)(F)F LDXJRKWFNNFDSA-UHFFFAOYSA-N 0.000 description 3
- OBOSXEWFRARQPU-UHFFFAOYSA-N 2-n,2-n-dimethylpyridine-2,5-diamine Chemical compound CN(C)C1=CC=C(N)C=N1 OBOSXEWFRARQPU-UHFFFAOYSA-N 0.000 description 3
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- KEQXNNJHMWSZHK-UHFFFAOYSA-L 1,3,2,4$l^{2}-dioxathiaplumbetane 2,2-dioxide Chemical group [Pb+2].[O-]S([O-])(=O)=O KEQXNNJHMWSZHK-UHFFFAOYSA-L 0.000 description 1
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
- B01J21/066—Zirconium or hafnium; Oxides or hydroxides thereof
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
- B01J35/39—Photocatalytic properties
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- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/0009—Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
- B01J37/0018—Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat)
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- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
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Abstract
A preparation method of a nano titanium dioxide/zirconia composite photocatalyst comprises a hydrothermal method and coprecipitation method for nano ZrO 2 Step of preparing powder and nano TiO 2 /ZrO 2 And (3) preparing the composite photocatalyst. The process uses TiO 2 And ZrO 2 The TiO with uniform particle size, good combination degree of two component particles, large specific surface area, stable mesoporous structure, good high temperature resistance, strong activity, complementary advantages and excellent synergistic photocatalytic performance is prepared as the raw material 2 /ZrO 2 The composite photocatalyst has the advantages of simple method and good practical effect.
Description
Technical Field
The invention relates to the technical field of preparation of nano materials, in particular to nano TiO 2 / ZrO 2 A preparation method of a composite photocatalyst belongs to a technical application of preparing composite powder by a coprecipitation method and a hydrothermal method.
Background
The nanometer titanium dioxide is the most commonly used semiconductor photocatalytic material and is widely applied to the fields of sewage treatment, air purification, antibiosis and sterilization, hydrogen production by photodecomposition of water and the like. However, the titanium dioxide has a narrow photoresponse range, can only absorb ultraviolet light in sunlight, and has low quantum efficiency, so that the practical application and the commercial development of the titanium dioxide are hindered.
The nanometer zirconia has the characteristics of high hydrothermal stability, good ion exchange performance, acid center and alkaline center, and the like, so that the nanometer zirconia becomes a research hotspot of catalytic mesoporous materials 2 The mesoporous material of (2). But pure ZrO 2 The effect of the mesoporous material directly applied in the field of catalysis is not very ideal, mainly because: pure ZrO 2 When the template agent is removed, the mesoporous material is easy to collapse at high temperature due to excessive shrinkage of the inorganic wall, and can not bear high-temperature and hydrothermal conditions in a catalytic environment for a long time, so that the mesoporous structure disappears, and the service life is shortened.
Therefore, how to prepare a composite material to make up for the use defects of the two catalytic materials of nano titanium dioxide and nano zirconium oxide when used alone is necessary, so that the composite material has excellent photocatalytic performance.
Disclosure of Invention
The technical purpose of the invention is as follows: with TiO 2 And ZrO 2 The TiO with uniform particle size, good combination degree of two component particles, large specific surface area, stable mesoporous structure, good high temperature resistance, strong activity, complementary advantages and excellent synergistic photocatalytic performance is prepared by taking the TiO as a raw material 2 / ZrO 2 A composite photocatalyst is provided.
The technical scheme adopted by the invention for solving the technical problems is as follows: a preparation method of a nano titanium dioxide/zirconia composite photocatalyst comprises the following steps:
(1) nano ZrO 2 Preparation of powder
a. Taking ZrOCl 2 ·8H 2 O and water to prepare ZrOCl with the molar concentration of 0.1-0.3 mol/L 2 Solution, then adding to said ZrOCl 2 ZrOCl is added into the solution 2 ·8H 2 YCl with 3-5% of O mass 3 ·6H 2 O, then ZrOCl is added thereto 2 ·8H 2 O and YCl 3 ·6H 2 PEG4000 with the total mass of O being 1.5-3%, and fully and uniformly mixing to prepare a mixed solution for later use;
b. b, adding an ammonia water solution with the volume concentration of 10% into the mixed solution prepared in the step a in a stirring and adding mode until the PH of the obtained reaction system is 9-10, then adding a surfactant CTAB into the mixed solution, continuously stirring until white flocculent precipitates appear in the obtained reaction system, and then continuously stirring for 15-30min to prepare a reaction product for later use;
c. taking the lower-layer precipitate in the reaction product obtained in the step b, and repeatedly washing the lower-layer precipitate by adopting absolute ethyl alcohol until the eluate does not contain Cl - To prepare a hydrothermal reaction precursor Zr (OH) 4 For standby;
d. zr (OH) obtained in the step c 4 Adding the mixture into deionized water, adding absolute ethyl alcohol with the same volume as the deionized water in a stirring and adding mode, fully and uniformly mixing to prepare a hydrothermal reaction system, then transferring the hydrothermal reaction system into a stainless steel hydrothermal kettle with a polytetrafluoroethylene lining, putting the hydrothermal kettle into a drying oven, controlling the heating rate of the drying oven to be 150-220 ℃ at a heating rate of 3-5 ℃/min, and carrying out hydrothermal reaction for 1-3 hours to prepare a hydrothermal product for later use;
e. d, stirring and filtering the reaction product obtained in the step d, taking filter residues, repeatedly adding absolute ethyl alcohol into the obtained filter residues for multiple times, stirring and filtering, and drying the finally obtained filter residues in vacuum to obtain zirconium dioxide powder for later use;
f. putting the zirconium dioxide powder prepared in the step e into a muffle furnaceControlling the temperature in the furnace to rise to 450-500 ℃, and carrying out decarbonization annealing treatment for 2-5 h to obtain the spherical mesoporous nano ZrO 2 Powder for later use;
(2) nano TiO 2 2 / ZrO 2 Preparation of composite photocatalyst
Firstly, according to finished TiO product 2 / ZrO 2 ZrO in composite photocatalyst 2 Is TiO 2 2 The mass ratio of the titanium tetrachloride to the nano ZrO prepared in the step (1) is 3-30 percent, and the tetrabutyl titanate and the nano ZrO prepared in the step (1) are respectively weighed 2 Powder, then adding the weighed tetrabutyl titanate into absolute ethyl alcohol, and firstly adding the weighed nano ZrO into the obtained mixed solution in a mode of adding the nano ZrO into the mixed solution while stirring 2 Adding distilled water dropwise into the powder to obtain a reaction solution raw material for later use;
secondly, transferring the reaction liquid raw material prepared in the first step into a stainless steel hydrothermal kettle with a polytetrafluoroethylene lining, then putting the hydrothermal kettle into a drying box, controlling the heating rate of the drying box to be 3-5 ℃/min to be 150-200 ℃, and carrying out hydrothermal reaction for 2-5 h to obtain a mixed reactant for later use;
thirdly, stirring and filtering the mixed reactant prepared in the second step, taking filter residue, repeatedly adding a detergent into the obtained filter residue for multiple times, stirring and filtering, drying the finally obtained filter residue in vacuum, grinding and sieving to obtain the finished product of nano TiO 2 / ZrO 2 A composite photocatalyst.
Preferably, in step a, said YCl 3 ·6H 2 The addition amount of O is ZrOCl 2 ·8H 2 3 percent of the mass of O, and the addition amount of the PEG4000 is ZrOCl 2 ·8H 2 O and YCl 3 ·6H 2 1.5 percent of the total mass of O.
Preferably, in step b, the amount of CTAB added in step b is equal to that of ZrOCl arranged in step a 2 The proportion relationship between the solutions is 0.003-0.005 mol/L.
Preferably, in step c, the eluate contains Cl - The content of (a) is 0.1mol/L of AgNO 3 Detecting the solution without white precipitate.
Preferably, in step d, the filling degree of the hydrothermal reaction system in the stainless steel hydrothermal kettle is 80%.
Preferably, in the step e, the temperature during vacuum drying is 60-120 ℃, and the drying time is 4-12 h.
Preferably, in the step f, the temperature rise rate in the muffle furnace is 3-5 ℃/min.
Preferably, in step (I), the TiO is adjusted to the final product 2 / ZrO 2 ZrO in composite photocatalyst 2 Is TiO 2 2 Respectively weighing tetrabutyl titanate and the nano ZrO prepared in the step (1) according to the mass ratio of 10% 2 The powder is in the optimal doping proportion.
Preferably, in the third step, the temperature during vacuum drying is 60-120 ℃, and the drying time is 4-12 h.
Has the beneficial effects that:
1. the preparation process adopts a mode of combined action of a coprecipitation method and a hydrothermal method in steps to carry out nano TiO 2 /ZrO 2 The preparation method of the composite photocatalyst has the advantages of simple operation and mild process conditions. The prepared finished product of nano TiO 2 /ZrO 2 The composite photocatalyst powder has good particle dispersibility, uniform particle size and TiO 2 And ZrO 2 Has fine particle diameter and high purity, and is TiO 2 Particles and ZrO 2 The uniformity of the mixed texture of the particles is high, and the problem of particle agglomeration of the same material is avoided. At the same time, TiO 2 At ZrO 2 In (b) is ZrO 2 The woven mesoporous material provides rational framework support and effectively prevents the mesoporous ZrO 2 The structure of the device collapses, so that the stability of the device is guaranteed, and the service life of the device is greatly prolonged; ZrO (ZrO) 2 Also improves TiO at the same time 2 The quantum efficiency of (2) and the photoresponse range of the quantum efficiency of (3) are widened. Nano TiO compounded by two components 2 /ZrO 2 The composite photocatalyst has the advantages of good particle combination degree of two components, strong activity, large specific surface area and excellent photocatalytic degradation performance.
2. In the preparation process of the invention, nano ZrO 2 Powder titanic acidThe TiO can be added into the tetrabutyl ester solution in a manner of stirring and dripping 2 Can rapidly infiltrate into ZrO after being added 2 In the mesoporous structure, the gel generated by the reaction of tetrabutyl titanate and water is prevented from being greatly agglomerated to cause TiO 2 Difficulty in formation of nanopowder, and TiO 2 /ZrO 2 The morphology of the composite structure is difficult to form. During the hydrothermal reaction, the temperature rise rate in the drying oven is 3-5 ℃/min, so that the intermediate product Ti (OH) can be well ensured 4 And Zr (OH) 4 To avoid too fast or too slow heating rate, (C) 4 H 9 O) 4 The incomplete reaction of Ti causes the newly generated powder to wrap the surface of the raw material, and inhibits the continuous and orderly progress of the reaction. Preparation of Zr (OH) 4 The process of (1) is washed by absolute ethyl alcohol, and can effectively control Zr (OH) 4 The appearance of the microsphere is formed, and the particle agglomeration can be effectively reduced.
3. The preparation method of the invention prepares nano-scale TiO by unique fine control of the process 2 /ZrO 2 Mixing the interwoven composite photocatalyst material. In the composite photocatalyst material, TiO 2 And ZrO 2 The nano particles of the two materials are evenly interwoven together, TiO 2 In a mesoporous structure of ZrO 2 The filling in (B) may be porous ZrO 2 The structure provides framework support, so that deformation or collapse of the mesoporous structure is avoided; and mesoporous ZrO 2 The unique void structure provides a certain limiting stress after the nucleation of the titanium dioxide, effectively preventing the TiO from being coated with the titanium dioxide 2 The crystal grains grow and the grains are agglomerated, thereby preparing the TiO with good dispersity and uniform doping 2 / ZrO 2 And (3) composite photocatalyst powder. In the specific process steps, the contents of a dispersing agent and a stabilizing agent, the PH value of the precursor solution, the content of a surfactant and the like are controlled to cooperatively control ZrO 2 Generating a mesoporous structure; then controlling the temperature rise rate of the hydrothermal reaction to control the mesoporous ZrO 2 By controlling the particle size of ZrO 2 The addition content and the addition mode of the two substances are used for adjusting the growth, combination, mutual assembly and texture of the two product particles, and the mutual matching of the energy level and the crystal lattice between the two substances. To form a topographyIdeally, the two substances are combined more tightly, and the synergistic photocatalytic performance is more excellent.
4. The preparation process of the invention is to carry out spherical porous nano ZrO 2 During the preparation of the powder, the mass ratio of the yttrium chloride to the zirconium oxychloride is limited to be 3%, and the mass ratio of the dispersing agent PEG4000 to the zirconium oxychloride and the yttrium chloride is limited to be 1.5%. Under the condition of the addition proportion, the yttrium oxide can be used as a stabilizer to lead the phase transition temperature range of the zirconium dioxide to be close to the normal temperature; PEG4000 can effectively slow down the self-agglomeration of zirconium dioxide particles as a dispersing agent. Thereby ensuring that the yttrium chloride and the zirconium oxychloride can be successfully coprecipitated to generate the yttrium oxide and the zirconium dioxide.
The CTAB content in the mixture is limited to be used as a template, the space between the aggregated micelles is filled with a solution (zirconium oxychloride) (taking columnar micelles as an example), when ammonia is added, inorganic salt is hydrolyzed and condensed, and the periphery of the micelles is coated with Zr (OH) 4 The colloid is wrapped to obtain an organic-inorganic mixture, and the organic-inorganic mixture is aged, washed, dried to remove the solvent (water), calcined to burn out the organic matter, and finally formed into pores with the size similar to that of the micelle. Therefore, CTAB is a guarantee for forming a mesoporous structure with uniform size and regular directional arrangement.
Defining the pH of the precursor to be 9-10, which may be Zr (OH) 4 Providing saturation conditions; stirring for Zr (OH) after white flocculent structure appears 4 The colloid-coated micelle provides sufficient reaction conditions and time, and is beneficial to volatilization of redundant ammonia water.
Drawings
FIG. 1 shows the nano TiO prepared in example 1 2 / ZrO 2 XRD pattern of the composite photocatalyst;
FIG. 2 shows the nano TiO compound prepared in example 1 2 / ZrO 2 SEM electron micrograph of the compound photocatalyst;
FIG. 3 shows the nano TiO prepared in example 2 2 / ZrO 2 SEM electron micrograph of the compound photocatalyst;
FIG. 4 shows the nano TiO prepared in example 2 2 / ZrO 2 Composite photocatalystN of (2) 2 Adsorption-desorption isotherm curves.
FIG. 5 shows the nano TiO compound prepared in example 2 2 / ZrO 2 The aperture distribution curve of the composite photocatalyst.
FIG. 6 shows the nano TiO compound prepared in example 2 2 / ZrO 2 BET profile of the composite photocatalyst.
FIG. 7 shows the nano TiO prepared in example 3 2 / ZrO 2 SEM electron microscope picture of the composite photocatalyst;
FIG. 8 shows the nano TiO prepared in example 3 2 / ZrO 2 The performance diagram of the composite photocatalyst for photocatalytic degradation of organic matters.
FIG. 9 shows the nano TiO prepared in example 3 2 / ZrO 2 XPS spectrum of the composite photocatalyst.
Detailed Description
The technical solution of the present invention will be further explained and explained in detail with reference to the drawings and the specific embodiments.
Nano TiO (titanium dioxide) 2 / ZrO 2 The preparation method of the composite photocatalyst comprises the following steps:
step one, taking ZrOCl2.8H2O and water to prepare 100ml of 0.1-0.3 mol/L ZrOCl 2 Adding 3-5% YCl in the solution 3 ·6H 2 O (with ZrOCl 2 ·8H 2 Calculated by the mass of O), adding 1.5-3 percent of PEG4000 (calculated as ZrOCl) 2 ·8H 2 O and YCl 3 ·6H 2 O mass) to prepare a mixed solution;
YCl in this step 3 ·6H 2 The addition amount of O is ZrOCl 2 ·8H 2 3-5% of O, the yttrium oxide formed by coprecipitation in the proportion can be used as a stabilizing agent to lead the phase transition temperature range of the zirconium dioxide to be close to room temperature, and the amount of PEG4000 is ZrOCl 2 ·8H 2 O and YCl 3 ·6H 2 1.5-3% of the mass of O, in which the self-agglomeration of the zirconium dioxide powder is effectively reduced.
Step two, dropwise adding an ammonia water solution with the volume concentration of 10% into the mixed solution prepared in the step one in a stirring and adding mode to carry out reaction, adding 0.03-0.05mol of CTAB serving as a surfactant in the process, regularly using a pH test paper to detect until the pH of the obtained reaction system is 9-10, then continuously stirring until white flocculent precipitate appears in the obtained reaction system, and then continuously stirring for 15-30min to ensure that the reaction is more complete to prepare a reaction product for later use;
the content of CTAB is important in the step, the CTAB in the proportion is taken as a surfactant and consists of hydrophilic groups and lipophilic groups, and Cetyl Trimethyl Ammonium Bromide (CTAB) saturated in the solution can form micelles to be used as a template for supplying Zr (OH) 4 And (3) colloid wrapping, which is a construction condition for forming the mesoporous structure. The pH is controlled to be about 9-10 and can be Zr (OH) 4 Providing saturation conditions; stirring thoroughly after white flocculent structure appears and may be Zr (OH) 4 The colloid-coated micelle provides sufficient reaction conditions and time, and is beneficial to volatilization of redundant ammonia water.
Step three, repeatedly washing the precipitate by using absolute ethyl alcohol until the filtrate does not contain Cl - Ion (by 0.1mol/L AgNO) 3 Solution detection) to obtain a hydrothermal reaction precursor Zr (OH) 4 ；
In the step, absolute ethyl alcohol is used for washing, because excessive acting force cannot be remained in the absolute ethyl alcohol washing, the precursor is not easy to agglomerate. At the same time, chloride ions have an adverse effect on the formation of pure zirconium dioxide, and must therefore be completely removed.
Step four, adding the precursor obtained in the step three into deionized water, adding equal amount of absolute ethyl alcohol while stirring, continuing stirring after the addition is finished, uniformly mixing, transferring the prepared slurry raw material into a stainless steel hydrothermal kettle with a polytetrafluoroethylene lining, wherein the filling degree is 80%, then placing the hydrothermal kettle into a drying oven, controlling the heating rate of the drying oven to be 150-220 ℃ at a heating rate of 3-5 ℃/min, and carrying out hydrothermal reaction for 1-3 hours to obtain a hydrothermal product for later use;
the ratio of water to absolute ethyl alcohol in the step is 1:1, and the pressure intensity in the reaction kettle at the same temperature can be effectively improved under the ratio, so that the mesoporous zirconium dioxide can be formed more favorably. Meanwhile, the control of the heating rate, the hydrothermal temperature and the hydrothermal time is important, the nucleation and growth of the crystal can be effectively controlled by controlling the heating rate, and the nucleation time and growth time of the crystal can be effectively controlled by controlling different hydrothermal temperatures and hydrothermal times.
And step five, stirring and filtering the hydrothermal product obtained in the step four, taking filter residue, repeatedly adding absolute ethyl alcohol into the obtained filter residue for multiple times, stirring and filtering, and drying the finally obtained filter residue in vacuum to obtain the zirconium dioxide powder.
In the step, repeated washing has great influence on the generation of powder nanocrystals, and unclean washing easily causes agglomeration and distortion of nanoparticles.
Sixthly, putting the powder prepared in the fifth step into a muffle furnace, controlling the temperature in the furnace to rise to 450-500 ℃, and performing decarburization annealing for 2-5 hours to prepare the spherical mesoporous nano ZrO 2 Powder for later use;
the decarbonization temperature in the step is important, and too high annealing or too long annealing time can cause collapse of the mesoporous structure, and the shorter annealing time can cause incomplete decarbonization.
Step seven, according to finished TiO 2 /ZrO 2 ZrO in composite materials 2 Is TiO 2 2 The mass ratio of the titanium dioxide to the nano ZrO prepared in the step four is 3-30 percent, and the tetrabutyl titanate and the nano ZrO prepared in the step four are respectively weighed 2 Powder, then adding the weighed tetrabutyl titanate into absolute ethyl alcohol, and firstly adding the weighed nano ZrO into the obtained mixed solution in a mode of adding the nano ZrO into the mixed solution while stirring 2 Adding distilled water dropwise into the powder to obtain a reaction solution raw material for later use;
in the step, nano ZrO is added while stirring 2 Powder is prepared by adding distilled water dropwise into the powder to ensure that colloid generated during stirring can infiltrate into nanometer gamma-Al 2 O 3 The aperture of the powder is in or can be matched with nano ZrO 2 The powder is fully contacted, and simultaneously self-agglomeration caused by the instant reaction of tetrabutyl titanate and water can be prevented, so that the final powder cannot reach the nanometer level. Adding nano ZrO in the step 2 The amount of the powder accounts for the amount of TiO finally generated 2 3-30% of the mass. When the doping amount is 3 percentThe optimum performance begins to appear, and the TiO can not be fully prevented by too little doping amount 2 Agglomerated by itself, but ZrO 2 After the doping amount is excessive, the surface potentials of the two particles attract each other, so that the composite powder begins to generate hard agglomeration, and the catalytic activity is linearly reduced. When the doping amount is 3-30%, the composite powder is soft agglomerated, the doping ratio of 5-10% is the optimal doping ratio, and ZrO is added 2 The catalytic degradation effect of the composite powder formed when the particle size of the powder is 500nm is optimal.
Step eight, transferring the reaction liquid raw material prepared in the step seven into a stainless steel hydrothermal kettle with a polytetrafluoroethylene lining, then placing the hydrothermal kettle into a drying oven, controlling the heating rate of the drying oven to be 3-5 ℃/min to be 150-200 ℃, and carrying out hydrothermal reaction for 2-5 h to obtain a mixed reactant for later use;
step nine, stirring and filtering the mixed reactant prepared in the step eight, taking filter residue, repeatedly adding a detergent into the obtained filter residue for multiple times, stirring and filtering, drying the finally obtained filter residue in vacuum, grinding and sieving to obtain a finished product of the nano TiO 2 /ZrO 2 Composite photocatalyst powder.
The invention adopts a step-by-step hydrothermal method to carry out TiO 2 /ZrO 2 The preparation of the composite photocatalyst powder is a brand new technology. The existing technical bottlenecks are mainly the following two: can react to produce TiO 2 And ZrO 2 The raw materials are many, but TiO is directly obtained by one-step hydrothermal method 2 /ZrO 2 The method of compounding powders has not been reported; secondly, the smaller the particles in the preparation process of the nano material, the more easily the particles cause mass agglomeration of products, and the TiO prepared by the low-temperature solution method 2 The nano powder is mostly mixed phase of an amorphous structure and an anatase structure, and is controlled by unique step parameters and ZrO through a 500nm mesoporous 2 Addition of particles to produce TiO 2 The growth and agglomeration of the particles are effectively limited, the two powders can be fully mixed and can interact with each other to promote the dispersion of the particles and the reduction of the particle size, and meanwhile, the TiO is improved 2 Crystallinity of (2), reduction of TiO 2 Crystal transformation temperature of the compound, thereby obtainingTo obtain the nano powder with smaller grain diameter and good dispersibility. This is because: mesoporous ZrO 2 Has a unique mesoporous structure, the aperture is about 4.58nm, and the mesoporous structure is in TiO 2 After nucleation, a certain stress is provided to limit TiO 2 The crystal grains grow and agglomerate to obtain the finished product of nano TiO 2 /ZrO 2 The two composite photocatalysts have better dispersibility.
The application is in mesoporous ZrO 2 The particle size of the particles is controlled by adopting a certain means, so that the finished product of the nano TiO is 2 /ZrO 2 The composite photocatalyst has more excellent performance.
Experiments prove that the precursor Zr (OH) is generated in the hydrothermal reaction 4 In the preparation process of (1), firstly, the stirring duration is in direct relation to the particle size of the finally produced zirconia particles. Stirring for about 20min under the same condition to obtain zirconia particles with fine particles and good dispersibility of about 100 nm; the zirconia particles are fine when not stirred or the stirring time is short, and the zirconia particles grow rapidly after the stirring time exceeds a certain time, and grow rapidly from the nanometer level to the micron level and the submicron level, because the continuous stirring can disturb a colloid system, so that particle agglomeration or indefinite particles are formed. After the reactant is milk white colloid, the dispersion degree of the particles is poor due to continuous stirring, the initial shape of the particles is dozens of nanometers, the surface viscosity and the activity of the particles are high at the stage, and the mechanical stirring force is far greater than the van der Waals force among the particles, so that the particles are easy to agglomerate to form large and stable particles.
Secondly, the concentration of the reactant also has a large influence on the particle size, and when the concentration of the reactant is large, ZrOCl 2 Zr (OH) formed by hydrolysis 4 The amount of crystalline monomer increases. The nucleation number of the crystal particles is increased, when the heating rate is increased quickly due to good heat transfer effect of a hydrothermal method, the temperature of the crystal monomer can be increased quickly, the activity among crystals is increased quickly, the Van der Waals force and other acting forces among the crystal particles are increased, the initial crystal particles are agglomerated, and the growth is enlarged.
Further, the annealing temperature during the decarburization annealing also affects the particle size of the zirconia grains to be formed. When the decarbonization annealing treatment is carried out for heat preservation, the higher the temperature is, the longer the heat preservation time is, and the more obvious the crystal grows in the range of the crystal growth area. When the temperature is increased, the longer the time of the nucleation zone, the more the crystal nucleation number is increased, so that the smaller the temperature increase rate is controlled within a certain range, the more the crystal nucleation number is increased, and more fine nano-particles can be prepared easily. On the contrary, the faster the temperature rise rate is, the less crystal nucleation occurs, the crystal nucleation is reduced after crossing the nucleation area, the growth is increased, and the zirconia particles with larger particles are easily prepared.
Through comprehensive cooperative control of a plurality of parameters in the steps, the particle size of the intermediate product zirconium oxide powder is regulated and controlled to be about 500 nanometers, so that the intermediate product zirconium oxide powder can play the best catalytic action.
The invention adopts the autonomously synthesized 500 nanometer mesoporous ZrO 2 As carrier material, nanometer TiO 2 Supported thereon, resulting in TiO 2 /ZrO 2 The composite powder has large specific surface area and strong catalytic degradation capability. In the experimental process, 38nm and 108nm zirconium dioxide is also used as a carrier, and because the particle size of the 38nm and 108nm zirconium dioxide is similar to that of nano titanium oxide, and surface potentials are mutually attracted, a dense agglomeration phenomenon is easily formed, so that catalytic active sites are covered, and the catalytic degradation performance is reduced.
Example 1:
nano TiO (titanium dioxide) 2 /ZrO 2 The preparation method of the composite photocatalyst comprises the following steps:
step one, taking ZrOCl 2 ·8H 2 O and water to prepare 100ml of 0.1mol/L ZrOCl 2 Adding 3% YCl by mass into the solution 3 ·6H 2 O (with ZrOCl 2 ·8H 2 Calculated by the mass of O), PEG4000 (calculated as ZrOCl) with the mass fraction of 1.5 percent is added 2 ·8H 2 O and YCl 3 ·6H 2 O mass), preparing a mixed solution for later use;
and step two, dropwise adding an ammonia water solution with the volume concentration of 10% into the mixed solution prepared in the step one in a stirring and adding mode to react, then adding 0.03mol of CTAB (cetyl trimethyl ammonium bromide) serving as a surfactant, controlling the pH value of the solution to be kept at 10, and detecting by using a pH test paper at regular time until white flocculent precipitates begin to appear. Then stirring is continued for 15min, so that the reaction is more complete;
step three, repeatedly washing the precipitate by using distilled water and absolute ethyl alcohol until the filtrate does not contain Cl - Ion (by 0.1mol/L AgNO) 3 Solution detection) to obtain a hydrothermal reaction precursor Zr (OH) 4 ；
Step four, adding the precursor obtained in the step three into deionized water, adding equal amount of absolute ethyl alcohol while stirring, continuing stirring after the addition is finished, uniformly mixing, transferring the prepared slurry raw material into a stainless steel hydrothermal kettle with a polytetrafluoroethylene lining, then placing the hydrothermal kettle into a drying oven, controlling the heating rate of the drying oven to be increased to 220 ℃ at a heating rate of 5 ℃/min, and carrying out hydrothermal reaction for 1 hour to obtain a hydrothermal product for later use;
and step five, stirring and filtering the hydrothermal product obtained in the step four, taking filter residue, repeatedly adding absolute ethyl alcohol into the obtained filter residue for multiple times, stirring and filtering, and drying the finally obtained filter residue in vacuum to obtain the zirconium dioxide powder.
Sixthly, putting the powder prepared in the fifth step into a muffle furnace, controlling the temperature in the furnace to rise to 450 ℃ at a temperature rise rate of 5 ℃/min, and performing decarburization annealing for 3 hours to prepare spherical mesoporous nano ZrO with the particle size of 38nm 2 Powder for later use;
step seven, according to finished TiO 2 /ZrO 2 ZrO in composite materials 2 Is made of TiO 2 The weight ratio of the titanium tetrachloride to the nano ZrO prepared in the step four is 10 percent, and the tetrabutyl titanate and the nano ZrO prepared in the step four are respectively weighed 2 Powder, then adding the weighed tetrabutyl titanate into absolute ethyl alcohol, and firstly adding the weighed nano ZrO into the obtained mixed solution in a mode of adding the tetrabutyl titanate into the absolute ethyl alcohol while stirring 2 And (3) dripping distilled water into the powder to prepare a reaction liquid raw material for later use.
Step eight, transferring the reaction liquid raw material prepared in the step six into a stainless steel hydrothermal kettle with a polytetrafluoroethylene lining, then putting the hydrothermal kettle into a drying oven, controlling the heating rate of the drying oven to be 3 ℃/min to be 170 ℃, and carrying out hydrothermal reaction for 5 hours to obtain a mixed reactant for later use;
step nine, stirring and filtering the mixed reactant prepared in the step seven, taking filter residue, repeatedly adding a detergent into the obtained filter residue for multiple times, stirring and filtering, drying the finally obtained filter residue in vacuum, grinding and sieving to obtain a finished product of the nano TiO 2 / ZrO 2 A composite photocatalyst.
For the nano TiO prepared in this example 2 / ZrO 2 The XRD pattern of the composite photocatalyst is shown in figure 1. As can be seen from FIG. 1: the composite material is formed by compounding titanium dioxide and zirconium dioxide.
For the nano TiO prepared in this example 2 / ZrO 2 The composite photocatalyst is observed by a scanning electron microscope, and an SEM electron microscope image of the composite photocatalyst is shown as an attached figure 2. As can be clearly seen from fig. 2: the surface of the large particle is attached with the small nano-ball, the nano-ball obtains a very high specific surface area due to the size effect and the surface area effect, the free path of electronic transition is reduced, and the nano-ball has a positive effect on improving the photocatalysis.
Example 2:
nano TiO (titanium dioxide) 2 /ZrO 2 The preparation method of the composite photocatalyst comprises the following steps:
step one, taking ZrOCl2.8H2O and water to prepare 100ml of 0.3mol/L ZrOCl 2 Adding 4% YCl by mass into the solution 3 ·6H 2 O (with ZrOCl 2 ·8H 2 Calculated by mass of O), PEG4000 (calculated as ZrOCl) with the mass fraction of 2 percent is added 2 ·8H 2 O and YCl 3 ·6H 2 O mass), preparing a mixed solution for later use;
and step two, dropwise adding an ammonia water solution with the volume concentration of 10% into the mixed solution prepared in the step one in a stirring and adding mode to react, then adding 0.04mol of CTAB (cetyl trimethyl ammonium bromide) serving as a surfactant, controlling the pH value of the solution to be kept at 10, and detecting by using a pH test paper at regular time until white flocculent precipitates begin to appear. Then stirring is continued for 30min, so that the reaction is more complete;
step three, repeatedly washing the precipitate by using distilled water and absolute ethyl alcohol until filtrate does not contain Cl - Ion (with 0.1mol/L AgNO) 3 Solution detection) to obtain a hydrothermal reaction precursor Zr (OH) 4 ；
Step four, adding the precursor obtained in the step three into deionized water, adding equal amount of absolute ethyl alcohol while stirring, continuing stirring after the addition is finished, uniformly mixing, transferring the prepared slurry raw material into a stainless steel hydrothermal kettle with a polytetrafluoroethylene lining, then placing the hydrothermal kettle into a drying oven, controlling the heating rate of the drying oven to be heated to 180 ℃ at a heating rate of 3 ℃/min, and carrying out hydrothermal reaction for 2 hours to obtain a hydrothermal product for later use;
and step five, stirring and filtering the hydrothermal product obtained in the step four, taking filter residue, repeatedly adding absolute ethyl alcohol into the obtained filter residue for multiple times, stirring and filtering, and drying the finally obtained filter residue in vacuum to obtain the zirconium dioxide powder.
Step six, putting the powder prepared in the step five into a muffle furnace, controlling the temperature in the furnace to rise at a rate of 3 ℃/min to 550 ℃, and annealing for 3 hours to prepare spherical mesoporous nano ZrO with the particle size of 500nm 2 Powder for later use;
step seven, according to finished TiO 2 /ZrO 2 ZrO in composite materials 2 Is made of TiO 2 The mass ratio of the titanium dioxide is 5 percent, and the tetrabutyl titanate and the nano ZrO prepared in the step four are respectively weighed 2 Powder, then adding the weighed tetrabutyl titanate into absolute ethyl alcohol, and firstly adding the weighed nano ZrO into the obtained mixed solution in a mode of adding the nano ZrO into the mixed solution while stirring 2 And (3) dripping distilled water into the powder to prepare a reaction liquid raw material for later use.
Step eight, transferring the reaction liquid raw material prepared in the step six into a stainless steel hydrothermal kettle with a polytetrafluoroethylene lining, then putting the hydrothermal kettle into a drying oven, controlling the heating rate of the drying oven to be 3 ℃/min to be 180 ℃, and carrying out hydrothermal reaction for 2 hours to obtain a mixed reactant for later use;
step nine, mixing and reaction of the mixture prepared in the step sevenStirring and filtering the reaction product, taking filter residue, repeatedly adding a detergent into the filter residue for many times, stirring and filtering, vacuum drying the finally obtained filter residue, and grinding and sieving to obtain the finished product of the nano TiO 2 / ZrO 2 A composite photocatalyst.
For the nano TiO prepared in this example 2 / ZrO 2 The composite photocatalyst is observed by a scanning electron microscope, and an SEM electron microscope image of the composite photocatalyst is shown in figure 3. Fine titanium oxide particles are attached to the surfaces of the larger zirconium dioxide particles.
For the nano TiO prepared in this example 2 / ZrO 2 The composite photocatalyst is subjected to BET detection, and the result is shown in figure 4. As can be seen from FIG. 4: the composite powder is typical IV class H2 type, and the curve of the mesoporous structure shows that the prepared composite powder is a mesoporous material with an ink bottle structure, and the BET specific surface area is 257.25m 2 /g。
For the nano TiO prepared in this example 2 / ZrO 2 The composite photocatalyst is subjected to BET detection and BJH analysis on the data, and the result is shown in figure 5. As can be seen from FIG. 5: the composite material has relatively uniform pore diameter, and the size of the nanometer pore is 4.54 nm. The mesoporous structure with fine aperture and narrow aperture formed by uniform accumulation has positive effect on improving the photocatalysis.
Example 3:
nano TiO (titanium dioxide) 2 /ZrO 2 The preparation method of the composite photocatalyst comprises the following steps:
step one, taking ZrOCl2.8H2O and water to prepare 100ml of 0.2mol/L ZrOCl 2 Adding 5% YCl by mass into the solution 3 ·6H 2 O (in ZrOCl 2 ·8H 2 Calculated by the mass of O), 3 percent of PEG4000 (calculated by ZrOCl) is added in mass fraction 2 ·8H 2 O and YCl 3 ·6H 2 O mass), preparing a mixed solution for later use;
and step two, dropwise adding 10% ammonia water solution into the mixed solution prepared in the step one in a stirring and adding mode to react, then adding 0.05mol of CTAB as a surfactant, controlling the pH value of the solution to be 9, and detecting by using a pH test paper at regular time until white flocculent precipitates begin to appear. Then, stirring is continuously carried out for 20min, so that the reaction is more complete;
step three, repeatedly washing the precipitate by using distilled water and absolute ethyl alcohol until the filtrate does not contain Cl - Ion (with 0.1mol/L AgNO) 3 Solution detection) to obtain a hydrothermal reaction precursor Zr (OH) 4 ；
Step four, adding the precursor obtained in the step three into deionized water, adding equal amount of absolute ethyl alcohol while stirring, continuing stirring after the addition is finished, uniformly mixing, transferring the prepared slurry raw material into a stainless steel hydrothermal kettle with a polytetrafluoroethylene lining, then placing the hydrothermal kettle into a drying oven, controlling the heating rate of the drying oven to be increased to 160 ℃ at a heating rate of 5 ℃/min, and carrying out hydrothermal reaction for 3 hours to obtain a hydrothermal product for later use;
and step five, stirring and filtering the hydrothermal product prepared in the step four, taking filter residue, repeatedly adding absolute ethyl alcohol into the obtained filter residue for multiple times, stirring and filtering, and drying the finally obtained filter residue in vacuum to obtain the zirconium dioxide powder.
Sixthly, putting the powder prepared in the fifth step into a muffle furnace, controlling the temperature in the furnace to rise to 500 ℃ at a heating rate of 3 ℃/min, and annealing for 3 hours to prepare the spherical mesoporous nano ZrO with the particle size of 108nm 2 Powder for later use;
step seven, according to finished TiO 2 /ZrO 2 ZrO in composite materials 2 Is TiO 2 2 The weight ratio of the titanium tetrachloride to the nano ZrO prepared in the step four is 10 percent, and the tetrabutyl titanate and the nano ZrO prepared in the step four are respectively weighed 2 Powder, then adding the weighed tetrabutyl titanate into absolute ethyl alcohol, and firstly adding the weighed nano ZrO into the obtained mixed solution in a mode of adding the nano ZrO into the mixed solution while stirring 2 And (3) dripping distilled water into the powder to prepare a reaction liquid raw material for later use.
Step eight, transferring the reaction liquid raw material prepared in the step six into a stainless steel hydrothermal kettle with a polytetrafluoroethylene lining, then putting the hydrothermal kettle into a drying oven, controlling the heating rate of the drying oven to be 3 ℃/min, heating to 160 ℃, and carrying out hydrothermal reaction for 3h to obtain a mixed reactant for later use;
step nine, stirring and filtering the mixed reactant prepared in the step seven, taking filter residue, repeatedly adding a detergent into the obtained filter residue for multiple times, stirring and filtering, drying the finally obtained filter residue in vacuum, grinding and sieving to obtain a finished product of nano TiO 2 / ZrO 2 A composite photocatalyst is provided.
For the nano TiO prepared in this example 2 / ZrO 2 The composite photocatalyst is observed by a scanning electron microscope, and an SEM electron microscope image of the composite photocatalyst is shown in figure 7. As can be seen in FIG. 7: the finished product of nano TiO prepared in this example 2 / ZrO 2 The particle size of the composite photocatalyst is 200 nm. The large particle surface in the composite material is attached with uniform secondary structure size of the nano-spheres, and a plurality of nano-particles are uniformly stacked to form a regular mesoporous channel, which has positive effect on improving the photocatalysis.
For the nano TiO prepared in this example 2 / ZrO 2 The composite photocatalyst was analyzed by XPS test as shown in FIG. 9. As shown in FIG. 9, the finished product of nano TiO prepared by the present example is obtained 2 / ZrO 2 The composite photocatalyst contains TiO as effective component 2 And ZrO 2 Meanwhile, the surface of the material contains C residues because the material is not subjected to decarbonization treatment.
For the finished nano TiO prepared in this example 2 / ZrO 2 The composite powder is subjected to organic matter degradation test experiments for multiple times, and the average value is taken. The test results are shown in fig. 8, and it can be seen from fig. 8 that: after half an hour of illumination, the ratio of the undegraded concentrations of all the experimental samples of the experimental product is 0 (when the ratio of the undegraded concentrations is less than 0.1, the experimental product is completely degraded when the degradation is finished), and the ratio of the undegraded concentrations of P25 is 0.41. The above results show that the product powder has much higher catalytic activity than the commercial catalyst P25, TiO 2 / ZrO 2 The composite powder has more excellent photocatalytic performance, very stable performance, better application prospect and lower cost. TiO formed by using 500nm mesoporous zirconium dioxide as carrier 2 / ZrO 2 The catalytic performance of the composite powder is better.
Claims (8)
1. A preparation method of a nano titanium dioxide/zirconia composite photocatalyst is characterized by comprising the following steps:
(1) nano ZrO 2 Preparation of powder
a. Taking ZrOCl 2 ·8H 2 O and water are prepared into ZrOCl with the molar concentration of 0.1-0.3 mol/L 2 Solution, then, adding to the ZrOCl 2 ZrOCl is added into the solution 2 ·8H 2 YCl with 3-5% of O mass 3 ·6H 2 O, then ZrOCl is added thereto 2 ·8H 2 O and YCl 3 ·6H 2 PEG4000 with the total mass of O being 1.5-3% is fully and uniformly mixed to prepare a mixed solution for later use;
b. adding an ammonia water solution with the volume concentration of 10% into the mixed solution prepared in the step a in a stirring and adding mode until the pH of the obtained reaction system is 9-10, and then adding a surfactant CTAB into the mixed solution, wherein the adding amount of the CTAB and the ZrOCl prepared in the step a are the same 2 The proportion relationship between the solutions is 0.003-0.005mol/L, the stirring is continued until white flocculent precipitate appears in the obtained reaction system, then the stirring is continued for 15-30min to prepare a reaction product for standby;
c. taking the lower-layer precipitate in the reaction product obtained in the step b, and repeatedly washing the lower-layer precipitate by adopting absolute ethyl alcohol until the eluate does not contain Cl - To prepare a hydrothermal reaction precursor Zr (OH) 4 And is ready for use;
d. zr (OH) obtained in the step c 4 Adding the mixture into deionized water, adding absolute ethyl alcohol with the same volume as the deionized water in a stirring and adding mode, fully and uniformly mixing to prepare a hydrothermal reaction system, then transferring the hydrothermal reaction system into a stainless steel hydrothermal kettle with a polytetrafluoroethylene lining, putting the hydrothermal kettle into a drying oven, controlling the heating rate of the drying oven to be 150-220 ℃ at a heating rate of 3-5 ℃/min, and carrying out hydrothermal reaction for 1-3 hours to prepare a hydrothermal product for later use;
e. d, stirring and filtering the reaction product obtained in the step d, taking filter residue, repeatedly adding absolute ethyl alcohol into the obtained filter residue for multiple times, stirring and filtering, and drying the finally obtained filter residue in vacuum to obtain zirconium dioxide powder for later use;
f. putting the zirconium dioxide powder prepared in the step e into a muffle furnace, controlling the temperature in the furnace to rise to 450-500 ℃, and performing decarburization annealing for 2-5 hours to obtain the spherical mesoporous nano ZrO 2 Powder for later use;
(2) nano TiO 2 2 / ZrO 2 Preparation of composite photocatalyst
Firstly, according to finished TiO product 2 / ZrO 2 ZrO in composite photocatalyst 2 Is TiO 2 2 The mass ratio of the titanium tetrachloride to the nano ZrO prepared in the step (1) is 3-30 percent, and the tetrabutyl titanate and the nano ZrO prepared in the step (1) are respectively weighed 2 Powder, then adding the weighed tetrabutyl titanate into absolute ethyl alcohol, and firstly adding the weighed nano ZrO into the obtained mixed solution in a mode of adding the nano ZrO into the mixed solution while stirring 2 Adding distilled water dropwise into the powder to obtain a reaction solution raw material for later use;
secondly, transferring the reaction liquid raw material prepared in the first step into a stainless steel hydrothermal kettle with a polytetrafluoroethylene lining, then putting the hydrothermal kettle into a drying box, controlling the heating rate of the drying box to be 3-5 ℃/min to be 150-200 ℃, and carrying out hydrothermal reaction for 2-5 h to obtain a mixed reactant for later use;
thirdly, stirring and filtering the mixed reactant prepared in the second step, taking filter residue, repeatedly adding a detergent into the obtained filter residue for a plurality of times, stirring and filtering, drying the finally obtained filter residue in vacuum, grinding and sieving to obtain a finished product of nano TiO 2 / ZrO 2 A composite photocatalyst is provided.
2. The preparation method of the nano titanium dioxide/zirconium oxide composite photocatalyst as claimed in claim 1, wherein: in step a, the YCl 3 ·6H 2 The addition amount of O is ZrOCl 2 ·8H 2 3 percent of the mass of O, and the addition amount of the PEG4000 is ZrOCl 2 ·8H 2 O and YCl 3 ·6H 2 1.5 percent of the total mass of O.
3. The preparation method of the nano titanium dioxide/zirconium oxide composite photocatalyst as claimed in claim 1, wherein: in step c, Cl is present in the eluate - By using AgNO with a molar concentration of 0.1mol/L 3 Detecting the solution without white precipitate.
4. The preparation method of the nano titanium dioxide/zirconium oxide composite photocatalyst as claimed in claim 1, wherein: in the step d, the filling degree of the hydrothermal reaction system in the stainless steel hydrothermal kettle is 80%.
5. The preparation method of the nano titanium dioxide/zirconium oxide composite photocatalyst as claimed in claim 1, wherein: in the step e, the temperature during vacuum drying is 60-120 ℃, and the drying time is 4-12 h.
6. The preparation method of the nano titanium dioxide/zirconium oxide composite photocatalyst as claimed in claim 1, wherein: in the step f, the temperature rise rate in the muffle furnace is 3-5 ℃/min.
7. The preparation method of the nano titanium dioxide/zirconia composite photocatalyst as claimed in claim 1, wherein the preparation method comprises the following steps: in the step I, TiO is prepared according to a finished product 2 / ZrO 2 ZrO in composite photocatalyst 2 Is TiO 2 2 The weight ratio of the titanium tetrachloride to the nano ZrO prepared in the step (1) is 10 percent, and the tetrabutyl titanate and the nano ZrO are respectively weighed 2 And (3) powder.
8. The preparation method of the nano titanium dioxide/zirconium oxide composite photocatalyst as claimed in claim 1, wherein: in the third step, the temperature during vacuum drying is 60-120 ℃, and the drying time is 4-12 h.
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