A bismuthene / Bi4Ti3O 12 Composite photocatalytic materials and their application in degradation of 2,4-dichlorophenol

Abstract

The present invention discloses a bismuthene / Bi4Ti3O 12 Composite photocatalytic material and its preparation method and application belong to the technical field of photocatalytic materials. 12 The composite photocatalyst is a structure with many small fragments growing around the flake block. Bismuthene carrier migration speed is fast, and it is similar to Bi4Ti3O 12 The composite can increase the material's electron separation efficiency, enhance the catalyst's probability of generating active species, and achieve a special catalytic or conversion effect when the catalyst contacts the organic molecule interface, thereby achieving the purpose of degrading 2,4-dichlorophenol in the environment. The method of the present invention does not cause waste of resources or the formation of additional pollution, is simple to operate, and is a green and environmentally friendly and efficient treatment technology.

Description

Technical Field

[0001] The present invention belongs to the technical field of photocatalytic materials, and specifically relates to a bismuthene / Bi4Ti3O 12 Composite photocatalytic material, preparation method and application thereof. Background Art

[0002] Water pollution poses a significant threat to the ecological environment, and effective treatment methods are urgently needed. Compared with traditional wastewater treatment methods, solar energy as a driving force for pollutant degradation is an effective and environmentally friendly technology. Effective degradation requires excellent photocatalysts. Perovskite materials have attracted much attention due to their structure that facilitates carrier migration. Bi4Ti3O 12 It is one of the layered perovskite materials, consisting of fluorite layer (Bi2O2) 2+ and perovskite layer (Bi4Ti3O 12 ) 2- This structure is beneficial to improve the efficiency of photogenerated carrier separation. However, due to the relatively fast carrier recombination, Bi4Ti3O 12 The photocatalytic activity of α-D-type α-D-piperidinium (D-PI) is still not ideal. Researchers have used various methods to improve its photocatalytic activity, such as doping, heterojunction construction, and co-catalyst deposition. Generally, a combination of different modification methods can achieve better photocatalytic activity.

[0003] Two-dimensional nanosheets represented by graphene have attracted widespread attention in the fields of energy, physics, biomedicine, etc. due to their unique and excellent physical and chemical properties. Emerging single-element 2D materials (Xenes), such as borene, phosphorene and antimonene, have excellent biocompatibility and show various biomedical properties such as tumor treatment, diagnosis and drug delivery. As a member of the VA family, bismuth is a non-toxic and low-cost heavy metal element. Bismuthene is an excellent material with a narrow band gap energy, excellent solar response ability and tunable band gap. In addition, the preparation of bismuthene is simple, which is conducive to the sustainable development of the environment and economy. The carrier mobility of bismuthene is as high as 5.7×10 6 cm 2 V -1 ·s -1 , which can promote ultrafast charge transfer.

[0004] Currently, the degradation efficiency of photocatalytic materials for 2,4-dichlorophenol is relatively low, requiring a long processing time and high-energy light sources to achieve a high degradation effect. Some commonly used photocatalytic materials, such as titanium dioxide (TiO2), are easily affected by factors such as redox reactions, light exposure and particle breakage during long-term use, resulting in decreased stability and weakened degradation effect. In addition, during the photocatalytic degradation of 2,4-dichlorophenol, some harmful or difficult-to-degrade by-products may be produced, such as aromatic aldehydes and acidic substances, causing secondary pollution to the environment.

[0005] Therefore, there is an urgent need for an efficient and environmentally friendly catalytic material to degrade phenol in the environment. The present invention couples Bi4Ti3O 12 , enhance the lattice matching between materials, expand the light response range of materials, promote the separation efficiency of electron-hole pairs of materials, and through interface interaction, 12 Combining with bismuthene to form an interfacial electric field can promote the separation of photogenerated charges in the composite material. This method does not cause waste of resources or the formation of additional pollution, and is easy to operate. It is a green, environmentally friendly and efficient treatment technology. Summary of the Invention

[0006] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0007] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0008] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a bismuthene / Bi4Ti3O 12 Composite photocatalytic materials.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions: comprising:

[0010] The photocatalytic material is Bi4Ti3O 12 As a bismuth source, Bi4Ti3O 12 Bismuthene is grown in situ on the surface, that is, bismuthene / Bi4Ti3O 12 Composite photocatalytic materials.

[0011] As the bismuthene / Bi4Ti3O 12 A preferred embodiment of the composite photocatalytic material, wherein: the Bi4Ti3O 12 The preparation method comprises:

[0012] Bi2O3, TiO2, NaCl, and KCl were fully ground and calcined in a muffle furnace to obtain Bi4Ti3O 12 , wherein the molar ratio of Bi2O3, TiO2, NaCl and KCl is 2:3:60:60.

[0013] As the bismuthene / Bi4Ti3O 12 A preferred solution of the composite photocatalytic material, wherein: the calcination temperature is 750° C., and the calcination time is 2 hours.

[0014] As the bismuthene / Bi4Ti3O 12 A preferred embodiment of the composite photocatalytic material, wherein: the in-situ growth method includes:

[0015] PVP was ultrasonically dispersed in ethylene glycol solution, and then Bi4Ti3O 12 , ammonia water and hydrazine hydrate, after fully mixing, heated to react and achieve in situ growth.

[0016] As the bismuthene / Bi4Ti3O 12 A preferred solution of composite photocatalytic material, wherein: the PVP and Bi4Ti3O 12 The mass ratio is 2:1~3.

[0017] As the bismuthene / Bi4Ti3O 12 A preferred embodiment of the composite photocatalytic material, wherein the mass volume ratio of the PVP to ethylene glycol is 1:30 g / ml.

[0018] As the bismuthene / Bi4Ti3O 12 A preferred embodiment of the composite photocatalytic material, wherein the volume ratio of ethylene glycol, ammonia water and hydrazine hydrate is 3:6:1.

[0019] As the bismuthene / Bi4Ti3O 12 A preferred embodiment of the composite photocatalytic material, wherein: the heating reaction, wherein the heating temperature is 100 ° C, and the heating time is 10 to 14 hours.

[0020] Another object of the present invention is to provide a bismuthene / Bi4Ti3O 12 Composite photocatalytic materials and their application in degrading 2,4-dichlorophenol in an environment.

[0021] As the bismuthene / Bi4Ti3O 12 A preferred embodiment of the composite photocatalytic material, wherein: the degradation rate of the photocatalytic material for degrading 2,4-dichlorophenol is greater than 85%.

[0022] Beneficial effects of the present invention:

[0023] The present invention prepares a bismuthene / Bi4Ti3O 12 The composite photocatalyst has a fast carrier migration speed of bismuthene and is comparable to Bi4Ti3O 12 The composite can increase the electron separation efficiency of the material and enhance the probability of the catalyst producing active species (superoxide radicals, hydroxyl radicals, etc.). When the catalyst contacts the interface with the organic molecules, it realizes a special catalytic or conversion effect, thereby achieving the purpose of degrading 2,4-dichlorophenol in the environment.

[0024] Compared with some other modification methods, bismuthene has strong electron migration ability and is similar to Bi4Ti3O 12 Belonging to the bismuth-based material, it can reduce the potential barrier between materials and significantly improve the removal rate of 2,4-dichlorophenol. This method will not cause waste of resources and the formation of additional pollution, and is easy to operate. It is a green, environmentally friendly and efficient treatment technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0026] Figure 1 TEM image of the product obtained in Example 1 of the present invention;

[0027] Figure 2 The UV-visible diffuse reflectance images of the products obtained in Example 1 and Comparative Example 1 of the present invention are shown;

[0028] Figure 3 Steady-state fluorescence images of the products obtained in Example 1 and Comparative Example 1 of the present invention; DETAILED DESCRIPTION

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0032] Unless otherwise specified, the raw materials of the present invention are commonly available in the market.

[0033] Particularly, the TiO2 used in the present invention is P25 TiO2, that is, commercially available TiO2 with an average particle size of 25 nm.

[0034] The present invention uses a photochemical reactor to conduct a photocatalytic simulation reaction experiment, specifically as follows:

[0035] Under visible light irradiation, 100 ml of 2,4-dichlorophenol simulated wastewater was added to the reactor and its initial value was measured. Then 20 mg of the prepared photocatalyst was added, magnetic stirring was performed, and air was introduced into the aeration device to keep the catalyst in a suspended or floating state. During the illumination process, samples were taken every 20 minutes for analysis. After centrifugation, the supernatant was taken and measured in a spectrophotometer. max =Measure the absorbance at 286nm and calculate the degradation rate according to the following formula:

[0036] η=[(1-C t / C0)]x100%

[0037] Where C0 is the absorbance of 2,4-dichlorophenol solution when adsorption equilibrium is reached, C t The absorbance of 2,4-dichlorophenol solution was measured by regular sampling, and multiple groups of parallel experiments were carried out. The average value was taken to obtain the degradation rate.

[0038] Example 1

[0039] This embodiment provides a bismuthene / Bi4Ti3O 12 The preparation method of the composite photocatalytic material is specifically as follows:

[0040] 1) 0.47gBi2O3, 0.12g P25 TiO2, 1.75gNaCl, and 2.24gKCl were fully ground and calcined in a muffle furnace. The temperature was raised from room temperature to 750℃, calcined for 2h, and naturally cooled to room temperature to obtain Bi4Ti3O 12 photocatalysts;

[0041] 2) 0.2g PVP was ultrasonically dispersed in 6ml ethylene glycol solution, and then 0.20g Bi4Ti3O 12 , 12 ml of ammonia water, 2 ml of hydrazine hydrate, mix thoroughly and transfer the mixed solution into a reactor for heating reaction at 100 ° C for 12 hours;

[0042] 3) After the reaction is cooled to room temperature, centrifugation is performed, ethanol washing is performed, and drying is performed to obtain bismuthene / Bi4Ti3O 12 Composite photocatalytic materials.

[0043] Figure 1 This is the TEM of the product obtained in this example. It can be seen from the figure that the composite material is a block with many small fragments around it, among which the block material is Bi4Ti3O 12 , the small fragments are bismuthene, and the close combination of the two materials is conducive to the rapid transfer of electrons and the generation of active species, thereby promoting the photocatalytic degradation rate.

[0044] A photocatalytic degradation test was carried out in a photochemical reactor, and it was determined that the degradation rate of 2,4-dichlorophenol by the photocatalyst reached 88% within 120 minutes.

[0045] Comparative Example 1

[0046] This comparative example provides a Bi4Ti3O 12 The preparation method of the photocatalytic material is specifically as follows:

[0047] 0.47gBi2O3, 0.12gP25 TiO2, 1.75gNaCl, and 2.24gKCl were fully ground and calcined in a muffle furnace. The temperature was raised from room temperature to 750℃, calcined for 2h, and naturally cooled to room temperature to obtain Bi4Ti3O 12 photocatalyst.

[0048] A photocatalytic degradation test was carried out in a photochemical reactor, and it was determined that the degradation rate of 2,4-dichlorophenol by the photocatalyst reached 45% within 120 minutes.

[0049] Figure 2 The UV-visible diffuse reflectance images of the catalysts prepared in Example 1 and Comparative Example 1 show that bismuthene / Bi4Ti3O 12 The photoresponse range of the composite material is much better than that of Bi4Ti3O 12 The wider and stronger visible light absorption ability indicates that the properly formed bismuthene / Bi4Ti3O 12 Composite materials are more conducive to the utilization of light energy and can provide more chances of producing active species in the photocatalytic process, thereby improving the efficiency of degradation.

[0050] Figure 3 The steady-state fluorescence diagram of the catalysts prepared in Example 1 and Comparative Example 1 shows that bismuthene / Bi4Ti3O 12 The fluorescence intensity of the composite material Bi4Ti3O 12 Lower, indicating that the formed bismuthene / Bi4Ti3O 12The composite material has a longer recombination time of electron and hole pairs under light, thus providing more chances to generate active species, thereby improving the photocatalytic degradation rate.

[0051] Example 2

[0052] The difference between this embodiment and embodiment 1 is that the heating reaction time in step 2) is adjusted to 10 hours, and the process parameters of the remaining steps are the same as those in embodiment 1, to obtain bismuthene / Bi4Ti3O 12 Composite photocatalytic materials.

[0053] A photocatalytic degradation test was carried out in a photochemical reactor, and it was determined that the degradation rate of 2,4-dichlorophenol by the photocatalyst reached 85% within 120 minutes.

[0054] Example 3

[0055] The difference between this embodiment and embodiment 1 is that the heating reaction time in step 2) is adjusted to 14 hours, and the process parameters of the remaining steps are the same as those in embodiment 1, to obtain bismuthene / Bi4Ti3O 12 Composite photocatalytic materials.

[0056] A photocatalytic degradation test was carried out in a photochemical reactor, and it was determined that the degradation rate of 2,4-dichlorophenol by the photocatalyst reached 86% within 120 minutes.

[0057] Comparative Example 2

[0058] The difference between this embodiment and embodiment 1 is that the Bi4Ti3O 12 The addition amount of bismuthene / Bi4Ti3O 12 Composite photocatalytic materials.

[0059] A photocatalytic degradation test was carried out in a photochemical reactor, and it was determined that the degradation rate of 2,4-dichlorophenol by the photocatalyst reached 64% within 120 minutes.

[0060] Comparative Example 3

[0061] The difference between this embodiment and embodiment 1 is that the Bi4Ti3O 12 The addition amount of bismuthene / Bi4Ti3O 12 Composite photocatalytic materials.

[0062] A photocatalytic degradation test was carried out in a photochemical reactor, and it was determined that the degradation rate of 2,4-dichlorophenol by the photocatalyst reached 61% within 120 minutes.

[0063] Table 1 shows the comparison results of the degradation rates of the composite photocatalysts prepared in Inventive Examples 1 to 3 and Comparative Examples 1 to 3.

[0064] Table 1

[0065]

[0066] It can be seen from the table that pure phase Bi4Ti3O 12 The degradation rate of the material is compared with Bi4Ti3O 12 The effects of the composite materials vary greatly, and different Bi4Ti3O 12 The addition amount of Bi4Ti3O also has a significant effect on the degradation effect. 12 Combining with bismuthene to form an interfacial electric field can promote the separation of photogenerated charges in the composite material, enhance the lattice matching between the materials, expand the light response range of the material, and promote the catalytic effect. However, excessive Bi4Ti3O 12 This will cause the grain size in the composite material to increase, the distance between particles to decrease, and the ion accumulation phenomenon to increase, resulting in the obstruction of charge transfer, thereby reducing the separation efficiency of photogenerated charges.

[0067] Comparative Example 4

[0068] This comparative example provides an existing CuInS2 quantum dot / NiAl-LDH composite photocatalyst and its application in the degradation of 2,4-dichlorophenol, specifically:

[0069] 1) Place 0.17 g of copper chloride dihydrate and 20 mL of ethylenediamine in a small beaker. After all of them are dissolved, add 0.22 g of indium chloride and 0.24 g of L-cysteine. Add 20 ml of deionized water and stir magnetically to assist the reaction for 30 minutes. Pour the mixture into an autoclave and heat it in a blast drying oven at 150°C for 7 hours. Remove the mixture and cool it naturally before centrifugation. Wash it with deionized water and ethanol three times each, and dry it in a blast drying oven to obtain a CuInS2 quantum dot photocatalyst.

[0070] 2) Weigh 1.875 g of nickel nitrate hexahydrate and 2.181 g of aluminum nitrate into a small beaker, add deionized water until completely dissolved, then add 2.453 g of hexamethylenetetramine, and react with magnetic stirring for 1 hour. Pour the mixture into an autoclave and heat it in a forced-air drying oven at 150° C. for 7 hours. Remove the mixture and cool it naturally before centrifugation. Wash it with deionized water and ethanol three times each, and dry it in a forced-air drying oven to obtain the NiAl-LDH photocatalyst.

[0071] 3) 0.008 g of CuInS2 quantum dots and 0.08 g of NiAl-LDH were placed in a small beaker, 20 ml of N,N-dimethylformamide was added and stirred thoroughly for 1 h, then poured into an autoclave and heated in a forced air drying oven at 150°C for 7 h. After cooling naturally, the mixture was centrifuged, washed, and dried in an oven to obtain a CuInS2 quantum dot / NiAl-LDH composite photocatalyst.

[0072] The CuInS2 quantum dots / NiAl-LDH composite photocatalyst prepared in this comparative example was placed in a photochemical reactor for a photocatalytic degradation test. The results showed that the degradation rate of 2,4-dichlorophenol by the prepared CuInS2 quantum dots / NiAl-LDH composite photocatalyst reached 75.6% within 120 minutes.

[0073] Comparative Example 5

[0074] This comparative example provides an existing CdS / TOC composite photocatalyst and its application in the degradation of 2,4-dichlorophenol, specifically:

[0075] 1) To 1.0724 g of pivalic acid, 20 mL of ethylene glycol and 1.7 mL of tetrabutyl titanate were added, and the mixture was stirred at 100° C. for 24 h. After centrifugation, the mixture was washed three times with tetrahydrofuran and dried for 12 h to obtain TOC.

[0076] 2) 0.05 g of TOC prepared above was added to 10-15 mL of water, CdS was added to the TOC solution, and ultrasonic treatment was performed for 5 h, followed by centrifugal washing and drying to finally obtain a multidimensional CdS / TOC photocatalyst; wherein the mass of the added CdS was 0.5% of the mass of the TOC.

[0077] 3) 0.02 g of the photocatalyst prepared in this comparative example was added to 30 mL of a 15 mg / L 2,4-dichlorophenol solution and stirred in the dark for 30 minutes to reach adsorption equilibrium; the sample was placed in a light-protection box, a filter was used to obtain the visible light portion of the xenon lamp, air was introduced into the sample, and a photocatalytic experiment was performed; every 20 minutes, 3 ml of the sample was extracted and the product was analyzed by liquid chromatography. The above test showed that the degradation rate of the photocatalyst for 2,4-dichlorophenol reached 73% within 120 minutes.

[0078] Comparative Example 6

[0079] This comparative example provides an existing three-dimensional porous rGO / AgBr / g-C3N4 composite photocatalyst and its application in the degradation of 2,4-dichlorophenol, specifically:

[0080] 1) Weigh 10 g of urea, grind it thoroughly, place it in a large crucible, and place it in a muffle furnace for calcination at 500 ° C for 4 h (heating rate of 2 ° C / min) to obtain the initial g-C3N4;

[0081] 2) Weigh 1.6 g of NaHCO3 and 0.4 g of initial g-C3N4, grind them thoroughly, and calcine them at 350°C for 1 h (heating rate of 5°C / min). The resulting sample is ground thoroughly in an agate mortar to obtain a three-dimensional porous g-C3N4 precursor.

[0082] 3) Weigh 0.2 g of the two-dimensional porous g-C3N4 precursor into a glass beaker, add ethanol, ultrasonically disperse for 1 hour, and magnetically stir; then add 50 mL of 0.12 mol / L CTAB to the mixed solution, fully magnetically stir for 6 hours, and then slowly add 50 mL of silver nitrate solution of the same concentration to the mixed solution. After fully magnetically stirring for 18 hours in the dark, the obtained solid precipitate is filtered, washed, and placed in a vacuum drying oven for vacuum drying at 60°C. After it is completely dry, it is taken out and ground to obtain a solid powder, which is the three-dimensional porous AgBr / g-C3N4 intermediate;

[0083] 4) 0.05 g of the sample obtained in step 3) was subjected to a photocatalytic degradation test of 2,4-dichlorophenol in a photochemical reactor. The degradation rate of 2,4-dichlorophenol by the photocatalyst was measured to be 25.31% within 2 hours and 55.68% within 6 hours.

[0084] In summary, it can be seen that compared with other photocatalysts for degrading 2,4-dichlorophenol in the prior art, the bismuthene / Bi4Ti3O 12 The composite material has significant advantages, mainly due to the combined effect of factors such as its enhanced light absorption capacity, improved photogenerated electron-hole separation efficiency, more active sites and better catalyst stability. It has better degradation effect and stability, mainly due to the combined effect of factors such as its enhanced light absorption capacity, improved photogenerated electron-hole separation efficiency, more active sites and better catalyst stability. 12 The composite material has a wide light absorption range, absorbing light in the visible and near-ultraviolet spectral ranges, which improves the efficiency of the photocatalytic reaction. In contrast, the light absorption range of CdS / TOC composite photocatalysts and rGO / AgBr / g-C3N4 composite photocatalysts may be narrow, limiting the efficiency of the photocatalytic reaction.

[0085] In addition, bismuthene, as a conductive agent, can effectively improve the separation efficiency of photogenerated electrons and holes, reduce the recombination of electrons and holes, and thus improve the photocatalytic activity. And bismuthene has good chemical stability and corrosion resistance, which can protect Bi4Ti3O 12The photocatalyst is protected from the influence of the external environment, thereby improving the cyclic stability of the catalyst.

[0086] Comparative Example 7

[0087] This comparative example verifies the effects of the composite photocatalytic material prepared by the present invention and the comparative example in degrading other environmental pollutants, including ethylene, ciprofloxacin, tetracycline and methylene blue. The results show that the material of the present invention has a significant advantage in degrading 2,4-dichlorophenol compared with other existing catalysts, but the effect of degrading other environmental pollutants is not outstanding, indicating that the bismuthene / Bi4Ti3O prepared by the present invention has a good degradation effect on 2,4-dichlorophenol. 12 The structural characteristics of the composite photocatalyst are more compatible with the molecular structure of 2,4-dichlorophenol, achieving efficient degradation.

[0088] In summary, the present invention prepares a bismuthene / Bi4Ti3O 12 The composite photocatalyst has a fast carrier migration speed of bismuthene and is comparable to Bi4Ti3O 12 Composite can increase the electron separation efficiency of the material and enhance the probability of the catalyst to produce active species (superoxide radicals, hydroxyl radicals, etc.). When the catalyst contacts the interface with organic molecules, it can achieve a special catalytic or conversion effect, thereby achieving the purpose of degrading 2,4-dichlorophenol in the environment. Compared with some other modification methods in the existing technology, bismuthene has strong electron migration ability and is more compatible with Bi4Ti3O 12 Belonging to the bismuth-based material, it can reduce the potential barrier between materials and significantly improve the removal rate of 2,4-dichlorophenol. This method will not cause waste of resources and the formation of additional pollution, and is easy to operate. It is a green, environmentally friendly and efficient treatment technology.

[0089] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A bismuthene / Bi4Ti3O 12 Composite photocatalytic material, characterized by: The photocatalytic material is Bi4Ti3O 12 As a bismuth source, Bi4Ti3O 12 Bismuthene is grown in situ on the surface, that is, bismuthene / Bi4Ti3O 12 Composite photocatalytic material, the in-situ growth method is: PVP was ultrasonically dispersed in ethylene glycol solution, and then Bi4Ti3O 12 , ammonia water and hydrazine hydrate, after fully mixing, heated to react and achieve in situ growth.

2. Bismuthene / Bi4Ti3O as described in claim 1 12 Composite photocatalytic material, characterized by: described Bi4Ti3O 12 The preparation method comprises: Bi2O3, TiO2, NaCl, and KCl were fully ground and calcined in a muffle furnace to obtain Bi4Ti3O 12 , wherein the molar ratio of Bi2O3, TiO2, NaCl and KCl is 2:3:60:

60.

3. Bismuthene / Bi4Ti3O as described in claim 2 12 Composite photocatalytic material, characterized by: The calcination temperature is 750° C. and the calcination time is 2 h.

4. Bismuthene / Bi4Ti3O as claimed in claim 1 12 Composite photocatalytic material, characterized by: The PVP and Bi4Ti3O 12 The mass ratio is 2:1~3.

5. Bismuthene / Bi4Ti3O as claimed in claim 4 12 Composite photocatalytic material, characterized by: The mass volume ratio of the PVP to ethylene glycol is 1:30 g / ml.

6. Bismuthene / Bi4Ti3O as claimed in claim 4 12 Composite photocatalytic material, characterized by: The volume ratio of the ethylene glycol, ammonia water and hydrazine hydrate is 3:6:

1.

7. Bismuthene / Bi4Ti3O as claimed in claim 4 12 Composite photocatalytic material, characterized by: The heating reaction is carried out at a temperature of 100° C. and a heating time of 10 to 14 hours.

8. Bismuthene / Bi4Ti3O according to any one of claims 1 to 7 12 Application of composite photocatalytic materials in the degradation of 2,4-dichlorophenol.

9. Bismuthene Bi4Ti3O according to claim 8 12 The application of composite photocatalytic materials in the degradation of 2,4-dichlorophenol is characterized by: The degradation rate of the photocatalytic material for degrading 2,4-dichlorophenol is greater than 85%.

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