阅读说明：本技术 一种负载二氧化钛的复合光催化剂及其制备方法 (Titanium dioxide-loaded composite photocatalyst and preparation method thereof ) 是由 张云 史俊朋 柳林 于 2021-11-02 设计创作，主要内容包括：本发明公开了一种负载二氧化钛的复合光催化剂及其制备方法,该复合光催化剂的其成分为均匀包覆TiO-(2)的LiLuGeO-(4)-x％Bi,x取值范围为0.1～4。本发明在丙酮浴条件下使钛酸四钉酯在乙醇发生水解反应制备TiO-(2)包覆的LiLuGeO-(4)-x％Bi,采用原位生长技术将TiO-(2)包覆在Bi掺杂的LiLuGeO-(4)表面,使材料同时具备了长余辉材料在紫外光激发下可实现能量存储和TiO-(2)分散性好、比表面积大的优点,制得的TiO-(2)与Bi掺杂LiLuGeO-(4)结合紧密,不易发生脱落。该复合光催化可在无法外源光源时实现光催化、光电转换和生物材料方面的催化,应用前景十分广泛。(The invention discloses a titanium dioxide-loaded composite photocatalyst and a preparation method thereof, wherein the composite photocatalyst comprises the components of evenly coated TiO 2 LiLuGeO (R) in 4 -x% Bi, wherein x is in a value range of 0.1-4. The invention makes the titanic acid tetranychium ester generate hydrolysis reaction in ethanol under the condition of acetone bath to prepare TiO 2 Coated LiLuGeO 4 -x% Bi, in situ growth technique of TiO 2 Cladding Bi-doped LiLuGeO 4 The surface of the material is provided with the long afterglow material which can realize energy storage and TiO under the excitation of ultraviolet light 2 Good dispersivity and large specific surface area, and the prepared TiO 2 With Bi doped LiLuGeO 4 The combination is tight, and the falling is not easy to occur. The composite photocatalysis can realize photocatalysis, photoelectric conversion and generation when an external light source cannot be usedThe catalyst has wide application prospect in the aspect of material catalysis.)

1. A composite photocatalyst of load titanium dioxide, which is characterized in that:

the component is evenly coated TiO₂LiLuGeO (R) in₄-x％Bi。

2. The titanium dioxide-loaded composite photocatalyst as claimed in claim 1, wherein: the value range of x is 0.1-4.

3. The preparation method of the composite photocatalyst loaded with titanium dioxide, according to claim 1 or 2, is characterized by comprising the following preparation steps:

s1: synthesis of Bi-doped ultraviolet long-afterglow luminescent material

According to the chemical formula LiLuGeO₄Weighing lithium carbonate, lutetium oxide, germanium oxide and bismuth oxide according to the stoichiometric ratio in-x% of Bi, and uniformly grinding the compounds;

calcining, cooling and grinding the ground mixture for the first time;

the material obtained by the grinding in the last step is calcined, cooled and ground for the second time to obtain the Bi-doped ultraviolet long afterglow luminescent material LiLuGeO₄-x％Bi。

S2: composite photocatalyst LiLuGeO₄-x％Bi-TiO₂Synthesis of (2)

While stirring, adding dropwise tetranyctate titanate into ethanol;

continuously adding LiLuGeO prepared in S1₄-x% Bi and stirring to form a solution a;

adding deionized water into acetone to form a solution B;

slowly dripping the solution A into the solution B to react under the stirring condition;

centrifuging and drying the mixed solution after reaction;

and calcining the dried powder at high temperature.

4. The method for preparing the composite photocatalyst loaded with titanium dioxide, which is described in claim 3, is characterized in that:

in the step S1, the first calcination temperature is 800 ℃, and the calcination time is 2 hours; the second calcination temperature is 1000-1250 ℃, and the calcination time is 1-12 hours.

5. The method for preparing the composite photocatalyst loaded with titanium dioxide, which is described in claim 3, is characterized in that:

in step S2

Tetrakistitanate: ethanol: LiLuGeO₄-x% Bi ratio 1: 50: (1-20);

the reaction time of the solution A and the solution B is 6-24 hours; the drying temperature is 80 ℃;

the high-temperature calcination temperature is 400-600 ℃, and the calcination time is 2-6 hours.

Technical Field

The invention belongs to the field of photocatalysis, and particularly relates to a titanium dioxide loaded composite photocatalyst and a preparation method thereof.

Background

Environmental and energy issues have been two major challenges facing humans. Semiconductor photocatalysis technologyProvides an effective environmental pollution treatment and an efficient solar energy utilization way. Nano TiO 2₂Is the most common semiconductor photocatalytic material and is widely applied to the fields of sewage treatment, air purification, antibiosis and sterilization, photolysis hydrogen production and the like. TiO 2₂In the process of using as a catalyst, the powder particles are too small, so that the recovery is difficult, the catalytic cost is greatly improved, and the cost control of enterprises is not facilitated. In practice, TiO is often used₂The coating is on the surface of the particles, and the particle size of the particles is increased so as to facilitate recovery. However, TiO is used₂When the photocatalyst is used as a catalyst, certain requirements are placed on a light source in the catalysis process, the ultraviolet light can be used for excitation, and once the external light source is lost, the catalysis cannot be carried out. In practical application, the situation that the wavelength of a light source is filtered and light cannot penetrate through a medium often exists, and the dependence on an external light source limits TiO₂Application scenario of (1).

TiO is currently studied in part₂Doped with luminescent materials, e.g. CN103540318B, discloses a rare earth complex grafted luminescent TiO₂Preparation method of mesoporous microsphere and obtained rare earth complex functionalized mesoporous TiO₂The composite material emits visible light and near infrared light under the excitation of visible light, and has potential application prospects in the aspects of bioluminescence imaging, dye-sensitized solar cells, photocatalysis and the like. However, the TiO prepared in the above patent₂TiO on supported particles₂The crystals are not uniformly distributed, and the interface bonding between the catalyst and the substrate is difficult to control, and rare earth complex grafted to TiO is used₂The scheme of mesoporous microsphere surface is not beneficial to fully exciting TiO₂Catalytic activity, its practical effect is limited.

Disclosure of Invention

The invention aims to provide a composite photocatalyst loaded with titanium dioxide and a preparation method thereof, and aims to solve the technical problem that the dependence degree on an external light source is too large in the titanium dioxide catalysis process in the background technology.

The technical scheme for realizing the purpose of the invention is as follows:

composite photocatalyst of load titanium dioxide, its componentFor coating TiO uniformly₂LiLuGeO (R) in₄-x％Bi。

Furthermore, the value range of x is 0.1-4.

The invention also provides a preparation method of the composite photocatalyst loaded with titanium dioxide, which comprises the following preparation steps:

s1: synthesis of Bi-doped ultraviolet long-afterglow luminescent material

According to the chemical formula LiLuGeO₄Weighing lithium carbonate, lutetium oxide, germanium oxide and bismuth oxide according to the stoichiometric ratio in-x% of Bi, and uniformly grinding the compounds;

calcining, cooling and grinding the ground mixture for the first time;

carrying out secondary calcination, cooling and grinding on the material obtained by the last grinding step; and obtaining the Bi-doped ultraviolet long-afterglow luminescent material.

S2: composite photocatalyst LiLuGeO₄-x％Bi-TiO₂Synthesis of (2)

While stirring, adding dropwise tetranyctate titanate into ethanol;

continuously adding LiLuGeO prepared in S1₄-x% Bi and stirring to form a solution a;

adding deionized water into acetone to form a solution B;

slowly dripping the solution A into the solution B to react under the stirring condition;

centrifuging and drying the mixed solution after reaction;

and calcining the dried powder at high temperature.

Further, in step S1, the first calcination temperature is 800 ℃, and the calcination time is 2 hours; the second calcination temperature is 1000-1250 ℃, and the calcination time is 1-12 hours.

Further, in step S2:

tetrakistitanate: ethanol: LiLuGeO₄-x% Bi ratio 1: 50: (1-20);

the reaction time of the solution A and the solution B is 6-24 hours;

the drying temperature is 80 ℃;

further, in step S2:

the high-temperature calcination temperature is 400-600 ℃, and the calcination time is 2-6 hours.

In this scheme, the spodumene LiLuGeO₄Energy can be stored in the trap of the light source under the excitation of ultraviolet light, and after the light source is turned off, the energy stored in the trap is slowly released, so that afterglow luminescence is realized under the condition of no excitation of the light source.

In the scheme, an acetone bath in-situ growth method is adopted, the reaction preparation method is mild in condition and simple and feasible in process, and the conditions of particle growth and sintering caused by the traditional impregnation method and high energy consumption and waste gas generation in the calcining process are avoided to a certain extent; the growth of high-dispersity active components can be regulated and controlled, crystals grow uniformly, the components are combined more tightly, and the interface combination energy between the catalyst and the substrate is improved.

By adopting the technical scheme, the invention has the following beneficial effects:

the invention adopts the in-situ growth technology to grow TiO₂Cladding Bi-doped LiLuGeO₄The surface of the material is provided with the characteristic that the energy storage of the jopside can be realized under the excitation of ultraviolet light, and meanwhile, the TiO can be used for simultaneously storing the energy₂The catalyst is dispersed on the surface of the particles in a nano form, and has good dispersibility, large specific surface area and high catalytic efficiency. The resulting TiO₂With Bi doped LiLuGeO₄The combination is tight, and the falling is not easy to occur. The composite photocatalysis can realize photocatalysis, photoelectric conversion and catalysis in the aspects of biological materials when an external light source cannot be provided, breaks through the limitation of light sources, and has very wide application prospect.

Drawings

In order that the present disclosure may be more readily and clearly understood, reference is now made to the following detailed description of the present disclosure taken in conjunction with the accompanying drawings, in which

FIG. 1 is a scanning electron microscope picture of the ultraviolet long afterglow material and the composite photocatalyst loaded with titanium dioxide prepared by the present invention.

FIG. 2 is the afterglow emission spectrum of the ultraviolet long afterglow material prepared by the invention and the absorption spectrum of the composite photocatalyst loaded with titanium dioxide.

FIG. 3 is the afterglow emission spectra of the ultraviolet long afterglow material and the composite photocatalytic material prepared by the present invention.

FIG. 4 is a methylene blue degradation rate curve of the composite photocatalyst loaded with titanium dioxide prepared by the invention.

Detailed Description

In order to better understand the technical solution, the technical solution will be described in detail with reference to the drawings and the specific embodiments.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

(example 1)

In this example, the composite photocatalyst LiLuGeO supporting titanium dioxide₄-x％Bi-TiO₂Wherein x is 0.75.

The composite photocatalyst is prepared by adopting the following preparation steps:

s1: synthesis of Bi-doped ultraviolet long-afterglow luminescent material

According to the chemical formula LiLuGeO₄Lithium carbonate was weighed in stoichiometric ratio in-0.75% BiLutetium oxide, germanium oxide, and bismuth oxide;

putting the raw materials into an agate mortar, adding ethanol, and grinding for 10 minutes;

pre-sintering the obtained powder at 800 ℃ for 2 hours;

grinding the pre-sintered material again, and calcining for 5 hours at 1200 ℃;

calcining, cooling and grinding the ground mixture for the first time;

the LiLuGeO is prepared by the steps₄-0.75％Bi。

S2: composite photocatalyst LiLuGeO₄-0.75％Bi-TiO₂Synthesis of (2)

While stirring in an ice bath, 0.5mL of tetrakistitanate was added dropwise to 25mL of ethanol;

adding LiLuGeO with 5 times of titanium dioxide equivalent₄-0.75% Bi and stirring to form a solution a;

adding 1mL of deionized water into 100mL of acetone to form a solution B;

slowly dripping the solution A into the solution B to react under the stirring condition;

after reacting for 2 hours, centrifuging the mixed solution, collecting the lower-layer reactant and drying at the drying temperature of 80 ℃;

calcining the dried powder at high temperature, wherein the calcining temperature is 600 ℃, and the calcining time is 4 hours;

at the moment, the composite photocatalyst LiLuGeO loaded with titanium dioxide is prepared₄-0.75％Bi-TiO₂。

In order to characterize and prepare the composite photocatalyst LiLuGeO loaded with titanium dioxide₄-0.75％Bi-TiO₂The sample of example 1 was tested for:

figure 1 is a scanning electron microscope photograph of the long persistent material and the composite photocatalyst loaded with titanium dioxide prepared in example 1. Compared with the long afterglow material, the surface of the composite photocatalyst loaded with titanium dioxide is attached with tiny titanium dioxide nano particles, which indicates the successful preparation of the composite material.

FIG. 2 shows the afterglow emission spectrum of the long afterglow material prepared in example 1 and the absorption spectrum of titanium dioxide. As can be seen from the absorption spectrum of the composite photocatalyst loaded with titanium dioxide, the ultraviolet long afterglow emitted by the long afterglow material can be perfectly absorbed by the titanium dioxide.

FIG. 3 is the afterglow emission spectra of the long afterglow material and the composite photocatalyst loaded with titanium dioxide prepared in example 1. Compared with the afterglow emission spectrum of the long afterglow material, the afterglow emission spectrum of the composite photocatalyst loaded with titanium dioxide is obviously reduced, which indicates that the afterglow emitted by the long afterglow material can be absorbed by the titanium dioxide.

Figure 4 is a methylene blue degradation experiment of the titanium dioxide loaded composite photocatalyst prepared as in example 1. Under the irradiation of ultraviolet light, the concentration of methylene blue can be obviously reduced. More importantly, after the ultraviolet lamp is turned off, the concentration of methylene blue can still be continuously reduced, which shows that the ultraviolet afterglow emitted by the long afterglow material can support the titanium dioxide to generate active oxygen to degrade the methylene blue, and the continuous catalytic capability of the composite photocatalyst loaded with the titanium dioxide is proved.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.