阅读说明：本技术 锐钛矿型纳米二氧化钛/膨润土复合材料的制备方法 (Preparation method of anatase type nano titanium dioxide/bentonite composite material ) 是由 闫友军 于 2020-07-06 设计创作，主要内容包括：本发明适用于光催化材料制备技术领域,提供了一种锐钛矿型纳米二氧化钛/膨润土复合材料的制备方法,包括如下步骤：膨润土粉碎,然后将硫酸氧钛溶解,将膨润土粉末加入到溶解后的硫酸氧钛中,以一步水热法制备锐钛矿型纳米二氧化钛/膨润土复合材料。借此,本发明的原料便宜易得,制备过程简单易行,制备过程不需要引入酸、碱及有机溶剂,产物无需煅烧,适合工业化生产。(The invention is suitable for the technical field of photocatalytic material preparation, and provides a preparation method of an anatase type nano titanium dioxide/bentonite composite material, which comprises the following steps: and (2) crushing bentonite, dissolving titanyl sulfate, adding bentonite powder into the dissolved titanyl sulfate, and preparing the anatase type nano titanium dioxide/bentonite composite material by a one-step hydrothermal method. Therefore, the raw materials are cheap and easy to obtain, the preparation process is simple and easy to implement, acid, alkali and organic solvent are not required to be introduced in the preparation process, and the product is not required to be calcined, so that the method is suitable for industrial production.)

1. A preparation method of an anatase type nano titanium dioxide/bentonite composite material is characterized by comprising the following steps:

step one bentonite pulverization

Crushing raw bentonite ore, and sieving with a sieve of 80-120 meshes to obtain bentonite powder;

step titanyl sulfate dissolution

2-6 g of titanyl sulfate is placed in 120-180 mL of deionized water, and the mixture is fully stirred to obtain a transparent solution A; step three, preparing anatase type nano titanium dioxide/bentonite composite material

Adding 25-60 g of bentonite powder into the transparent solution A, and uniformly stirring to obtain a suspension B;

transferring the suspension B into a high-pressure reaction kettle for hydrothermal treatment, cooling after the hydrothermal treatment is finished, and performing suction filtration to obtain a precipitate C;

washing the precipitate C until the pH value is 6-8, and then carrying out suction filtration to obtain a filter cake;

and drying and grinding the filter cake to obtain the anatase type nano titanium dioxide/bentonite composite material.

2. The method for preparing the anatase type nano titanium dioxide/bentonite composite material according to claim 1, wherein the bentonite powder is uniformly added into the transparent solution A in 3-5 times during the adding process.

3. The method for preparing the anatase type nano titanium dioxide/bentonite composite material according to claim 1, wherein the hydrothermal treatment conditions in the autoclave are as follows: the temperature is 180-240 ℃, and the time is 8-12 h.

4. The method for preparing anatase type nano titanium dioxide/bentonite composite material according to claim 1 wherein the high pressure reaction kettle is provided with a stirring device.

5. The method for preparing the anatase type nano titanium dioxide/bentonite composite material according to any one of claims 1 to 4, wherein the particle size of the composite material is 8.5 to 12 nm.

6. The preparation method of the anatase type nano titanium dioxide/bentonite composite material according to any one of claims 1 to 4, wherein the BET specific surface area of the composite material is 125 to 165m²/g。

7. The method for preparing the anatase type nano titanium dioxide/bentonite composite material according to any one of claims 1 to 4, wherein the average pore diameter of the composite material is 5.8 to 8.5 nm.

8. The method for preparing the anatase type nano titanium dioxide/bentonite composite material according to any one of claims 1 to 4, wherein the pore volume of the composite material is 0.24 to 0.35cm³/g。

Technical Field

The invention relates to the technical field of preparation of photocatalytic materials, in particular to a preparation method of an anatase type nano titanium dioxide/bentonite composite material.

Background

Titanium dioxide is an important inorganic functional material and is widely applied to photocatalytic wastewater treatment. As a common heterogeneous photocatalyst, titanium dioxide nanoparticles are easy to agglomerate and difficult to separate in a solution, so that the practical application of the titanium dioxide nanoparticles is limited. Bentonite is a layered non-metal clay mineral widely present in nature. Because of its strong adsorption capacity and ion exchange capacity, it is widely used in the treatment of pollutants in waste water. The titanium dioxide and the bentonite are compounded, so that the problems of agglomeration and separation of the nano titanium dioxide can be effectively solved, and the photodegradation rate of the photocatalyst can be improved by effectively utilizing the adsorptive property of the bentonite.

At present, three methods are commonly used for preparing the nano titanium dioxide/bentonite composite material.

(1) Hydrolysis-hydrothermal method: with TiCl₄Hydrolyzing in alcohol solution to obtain polymeric hydroxy titanium ion, mixing with calcium-based or sodium-based bentonite dispersed in surfactant, aging, stirring, transferring to reaction kettle, and performing hydrothermal treatment to obtain titanium dioxide/bentonite composite material (Mao tree red, TiO, etc.)₂The bentonite pillared composite material has the adsorption performance and application, and is applied to chemical engineering in 2010). Hydrolysis-hydrothermal process with very hydrolyzable TiCl₄The titanium source is adopted, a large amount of volatile hydrochloric acid is generated in the experimental process, equipment is easy to corrode, a large amount of organic solvent is introduced in the preparation process, and the reaction cost is increased.

(2) Sol-gel method: titanium alkoxide (butyl titanate, etc.) is used as titanium source, titanium alkoxide is hydrolyzed and polymerized in acid medium absolute ethyl alcohol to obtain titanium sol particles, and then the titanium sol particles are mixed with bentonite suspension and calcined to obtain the titanium dioxide/bentonite composite material (Caoshi, etc. 1% La doped bentonite/nano TiO)₂Performance study of material treatment cyanide barren solution, hydrometallurgy, 2017,36(01):61-64+ 68.). The sol-gel method needs a large amount of organic solvent, the raw materials are expensive, the reaction process is difficult to control, and the high-temperature calcination affects the phase structure of the product, so that the realization of the industrialization degree is limited.

(3) Solid phase method: mixing titanium dioxide with the treated bentonite by taking the titanium dioxide as a titanium source, adding a fluxing agent, and calcining at high temperature to obtain TiO₂Bentonite composite material (Wangdingyong et al, a TiO)₂Preparation of bentonite composite material and a method for removing mercury ions in wastewater by using the bentonite composite material; high-efficiency titanium dioxide/bentonite composite material with quality of good and photocatalytic performance research, chemistryBulletin, 2003, 61(8): 1311-. The solid phase method directly mixes and calcines the solid phase titanium dioxide and the bentonite under the condition of the existence of a fluxing agent, so that the TiO is difficult to be mixed and calcined₂The bentonite is fully mixed, the purity of the prepared product is not high, and the high-temperature calcination process can also influence the phase of the product.

In view of the above, the prior art is obviously inconvenient and disadvantageous in practical use, and needs to be improved.

Disclosure of Invention

Aiming at the defects, the invention aims to provide a preparation method of an anatase type nano titanium dioxide/bentonite composite material, which has the advantages of cheap and easily-obtained raw materials, simple and feasible preparation process, no need of introducing acid, alkali and organic solvent in the preparation process, no need of calcining the product and suitability for industrial production.

In order to achieve the above object, the present invention provides a method for preparing an anatase type nano titanium dioxide/bentonite composite material, comprising the following steps:

step one bentonite pulverization

Crushing raw bentonite ore, and sieving with a sieve of 80-120 meshes to obtain bentonite powder;

step titanyl sulfate dissolution

2-6 g of titanyl sulfate is placed in 120-180 mL of deionized water, and the mixture is fully stirred to obtain a transparent solution A;

step three, preparing anatase type nano titanium dioxide/bentonite composite material

Adding 25-60 g of bentonite powder into the transparent solution A, and uniformly stirring to obtain a suspension B;

transferring the suspension B into a high-pressure reaction kettle for hydrothermal treatment, cooling after the hydrothermal treatment is finished, and performing suction filtration to obtain a precipitate C;

washing the precipitate C until the pH value is 6-8, and then carrying out suction filtration to obtain a filter cake;

and drying and grinding the filter cake to obtain the anatase type nano titanium dioxide/bentonite composite material.

According to the preparation method of the anatase type nano titanium dioxide/bentonite composite material, the bentonite powder is uniformly added into the transparent solution A for 3-5 times in the adding process.

According to the preparation method of the anatase type nano titanium dioxide/bentonite composite material, the hydrothermal treatment conditions in the high-pressure reaction kettle are as follows: the temperature is 180-240 ℃, and the time is 8-12 h.

According to the preparation method of the anatase type nano titanium dioxide/bentonite composite material, the high-pressure reaction kettle is provided with a stirring device.

According to the preparation method of the anatase type nano titanium dioxide/bentonite composite material, the particle size of the composite material is 8.5-12 nm.

According to the preparation method of the anatase type nano titanium dioxide/bentonite composite material, the BET specific surface area of the composite material is 125-165 m²/g。

According to the preparation method of the anatase type nano titanium dioxide/bentonite composite material, the average pore diameter of the composite material is 5.8-8.5 nm.

According to the preparation method of the anatase type nano titanium dioxide/bentonite composite material, the pore volume of the composite material is 0.24-0.35 cm³/g。

The invention aims to provide a preparation method of an anatase type nano titanium dioxide/bentonite composite material, which takes titanyl sulfate as a titanium source, has low price and easy obtainment, does not generate volatile acid in the using process, and obtains TiO by dissociating the titanyl sulfate in an aqueous solution²⁺Ions can enter the interlayer and pore canal of the bentonite more easily; natural bentonite is used and is directly activated by acidic titanyl sulfate solution in the reaction process, and acid activation treatment is not needed; the anatase type nano titanium dioxide/bentonite composite material is prepared by a one-step hydrothermal method, the operation is simple, the product does not need to be calcined for the second time, the product phase is excellent, no organic solvent is introduced, and the reaction cost can be effectively controlled; the reaction kettle is provided with a stirring device, so that the reactants can be uniformly mixed and distributed in the reaction process. In conclusion, the beneficial effects of the invention are as follows: the preparation raw materials are cheap and easy to obtainThe preparation process is simple and easy to implement, acid, alkali and organic solvent are not required to be introduced in the preparation process, and the product is not required to be calcined, so that the method is suitable for industrial production.

Drawings

FIG. 1 is a flow chart of the preparation process of anatase type nano titanium dioxide/bentonite composite material;

FIG. 2 is an XRD pattern of an anatase-type nano-titania/bentonite composite;

FIG. 3 is a BET adsorption curve of anatase type nano-titania/bentonite composite.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention provides a preparation method of an anatase type nano titanium dioxide/bentonite composite material, which comprises the following steps:

step one bentonite pulverization

Crushing raw bentonite ore, and sieving with a sieve of 80-120 meshes to obtain bentonite powder for later use; the bentonite is natural bentonite, and the natural bentonite can be directly activated by acidic titanyl sulfate solution in the reaction process without being subjected to acid activation treatment independently.

Step titanyl sulfate dissolution

2-6 g of titanyl sulfate is placed in 120-180 mL of deionized water, and fully stirred for 6-10 hours to obtain a transparent solution A; titanyl sulfate is used as a titanium source, so that the cost is low, the titanyl sulfate is easy to obtain, volatile acid is not generated in the using process, and the preparation process is safer; meanwhile, TiO obtained by dissociating titanyl sulfate in aqueous solution²⁺Ions can enter into the interlayer and pore canal of bentonite more easily, so that bentonite and TiO are added²⁺The mixing uniformity of the ions is better, and the obtained composite material has better catalytic performance.

Step three, preparing anatase type nano titanium dioxide/bentonite composite material

Under the condition of continuous stirring, adding 25-60 g of bentonite powder into the transparent solution A, and continuously stirring uniformly to obtain a suspension B; and in the addition process, the bentonite powder is uniformly added for 3-5 times, so that the uniform mixing degree of the bentonite powder and the transparent solution A is improved.

Transferring the suspension B into a high-pressure reaction kettle with a stirring function, carrying out hydrothermal treatment at 180-240 ℃ for 8-12 h, cooling after the hydrothermal treatment is finished, and carrying out suction filtration to obtain a precipitate C; the reaction kettle is provided with a stirring device, so that the reactants can be uniformly mixed and distributed in the reaction process, and the bentonite and TiO are further improved²⁺Uniformity of mixing of ions.

Washing the precipitate C with deionized water until the pH value of a washing liquid is 6-8, and then carrying out suction filtration to obtain a filter cake; and transferring the filter cake to a drying oven at 50-70 ℃ for drying, and then grinding to obtain a finished product of the anatase type nano titanium dioxide/bentonite composite material.

The anatase type nano titanium dioxide/bentonite composite material prepared by the invention is mainly applied to photocatalytic treatment of industrial wastewater.

The method directly adopts a one-step hydrothermal method to produce the composite material, is simple to operate, has fluffy particles, does not need secondary calcination, does not generate aggregation or hardening of the particles, and ensures that the composite material has better catalytic performance and excellent product quality. In addition, no organic solvent is introduced in the preparation method, so that the reaction cost can be effectively controlled.

The flow chart of the preparation process of the anatase type nano titanium dioxide/bentonite composite material is shown in figure 1.

In order to verify the performance of the composite material of the invention, the composite material obtained by the invention was subjected to X-ray diffraction analysis, XRD analysis and BET analysis, respectively.

The X-ray diffraction pattern is obtained after the X-ray diffraction analysis, and the X-ray diffraction pattern can be obtained by comparing with the standard pattern analysis of anatase type nano titanium dioxide, the composite material prepared by the invention is anatase type nano titanium dioxide, and the particle size of the composite material prepared by the invention is 8.5-12 nm, which shows that the composite material has high activity and better catalytic performance when the photocatalysis treatment is carried out on waste water.

XRD spectrum is obtained after XRD analysis, which shows that the composite material prepared by the invention is anatase type nano titanium dioxide/bentonite composite material.

Obtaining a BET adsorption curve after BET analysis, and simultaneously obtaining the BET specific surface area of the composite material of 125-165 m²The specific surface area of the composite material is large, and the catalytic performance is good; the pore volume of the composite material can be obtained after BET analysis and is 0.24-0.35 cm³/g。

In order to further verify the performance of the anatase type nano titanium dioxide/bentonite composite material prepared by the invention, the invention is provided with a plurality of examples. And XRD analysis and BET analysis were performed on the composite materials prepared in the respective examples, and the XRD analysis pattern is shown in fig. 2, and the BET analysis pattern is shown in fig. 3.