阅读说明：本技术 铌酸钾钠-氮化碳光催化复合材料的合成方法及其产品 (Synthesis method of potassium-sodium niobate-carbon nitride photocatalytic composite material and product thereof ) 是由 江琳沁 邱羽 李平 林灵燕 范宝殿 熊浩 康臻菁 严琼 于 2020-12-11 设计创作，主要内容包括：本发明提供一种铌酸钾钠-氮化碳光催化复合材料的合成方法及其产品,所述合成方法包括如下步骤：将尿素于马弗炉中煅烧,生成氮化碳粉体；氮化碳超声分散于阳离子型分散剂CTAB溶液中,获得均匀的氮化碳悬浮液；然后与五氧化二铌、氢氧化钠、氢氧化钾在水溶剂中搅拌；再将混合溶液置于高压釜中进行水热反应,获得的固体产物经无水乙醇抽滤洗涤,得到铌酸钾钠-氮化碳光催化复合材料。本发明使用阳离子型表面活性剂修饰氮化碳,所获得的铌酸钾钠-氮化碳复合材料具有很好的界面结合作用,显示出优异的可见光催化效果,是一种新型的具有潜在应用前景的可见光催化材料。(The invention provides a method for synthesizing a potassium-sodium niobate-carbon nitride photocatalytic composite material and a product thereof, wherein the method comprises the following steps: calcining urea in a muffle furnace to generate carbon nitride powder; ultrasonically dispersing carbon nitride in a cationic dispersant CTAB solution to obtain a uniform carbon nitride suspension; then stirring with niobium pentoxide, sodium hydroxide and potassium hydroxide in a water solvent; and then placing the mixed solution into a high-pressure kettle for hydrothermal reaction, and carrying out suction filtration and washing on the obtained solid product by using absolute ethyl alcohol to obtain the potassium-sodium niobate-carbon nitride photocatalytic composite material. According to the invention, the cationic surfactant is used for modifying carbon nitride, the obtained potassium-sodium niobate-carbon nitride composite material has a good interface binding effect, shows an excellent visible light catalysis effect, and is a novel visible light catalysis material with a potential application prospect.)

1. A method for synthesizing a potassium-sodium niobate-carbon nitride photocatalytic composite material is characterized by comprising the following steps: the method comprises the following steps:

(1) placing urea in a crucible, and calcining in a muffle furnace to obtain carbon nitride powder;

(2) ultrasonically dispersing the carbon nitride powder obtained in the step (1) and a cationic dispersant cetyl trimethyl ammonium bromide to obtain a uniform carbon nitride suspension;

(3) mixing and stirring the carbon nitride suspension obtained in the step (2) with niobium pentoxide, sodium hydroxide and potassium hydroxide in deionized water;

(4) placing the mixed solution obtained in the step (3) into a high-pressure kettle for reaction, and repeatedly washing and precipitating with absolute ethyl alcohol after the reaction is finished;

(5) and (5) drying the solid product obtained in the step (4) in a drying oven overnight to obtain the potassium-sodium niobate-carbon nitride composite material.

2. The method for synthesizing the potassium sodium niobate-carbon nitride photocatalytic composite material according to claim 1, characterized in that: the calcination temperature in the step (1) is 500-550 ℃.

3. The method for synthesizing the potassium sodium niobate-carbon nitride photocatalytic composite material according to claim 1, characterized in that: in the step (2), the weight part ratio of the cationic dispersant cetyl trimethyl ammonium bromide to the carbon nitride is 1:1-2:1, and the ultrasonic time is 30-60 min.

4. The method for synthesizing the potassium sodium niobate-carbon nitride photocatalytic composite material according to claim 1, characterized in that: in the step (3), the weight part ratio of niobium pentoxide to sodium hydroxide is 1:1-1:10, the weight part ratio of niobium pentoxide to potassium hydroxide is 2:1-1:10, and the stirring time is 6-24 h.

5. The method for synthesizing the potassium sodium niobate-carbon nitride photocatalytic composite material according to claim 1, characterized in that: the weight part ratio of the carbon nitride to the niobium pentoxide in the step (3) is 1:10-1: 20.

6. The method for synthesizing the potassium sodium niobate-carbon nitride photocatalytic composite material according to claim 1, characterized in that: the reaction temperature in the step (4) is 220-240 ℃, and the reaction time is 24-48 h.

7. The method for synthesizing the potassium sodium niobate-carbon nitride photocatalytic composite material according to claim 1, characterized in that: in the potassium-sodium niobate-carbon nitride photocatalytic composite material obtained in the step (5), the drying temperature is 60-80 ℃, and the mass percentage of carbon nitride in the composite material is 3-10%.

8. A potassium sodium niobate-carbon nitride photocatalytic composite material prepared by the method for synthesizing a potassium sodium niobate-carbon nitride photocatalytic composite material according to any one of claims 1 to 7.

[ technical field ] A method for producing a semiconductor device

The invention relates to the field of photocatalytic materials, in particular to a method for synthesizing a potassium-sodium niobate-carbon nitride photocatalytic composite material and a product thereof.

[ background of the invention ]

Potassium sodium niobate is a conventional perovskite material with many interesting properties such as ferroelectric, piezoelectric, ionic conductivity and photocatalytic properties. The photocatalytic performance exhibited by ferroelectric perovskite materials is of particular interest due to their built-in electric field. However, the light absorption performance of pure potassium-sodium niobate materials needs to be improved, and the preparation of potassium-sodium niobate composite materials is imperative to improve the photocatalytic performance of the materials. The carbon nitride has low synthesis cost, high specific surface area, high thermal stability and chemical stability and unique superiority in the visible light catalysis field. But the photocatalytic performance of pure carbon nitride is limited by its low conductivity and high efficiency of recombination of photo-generated electron-holes. The preparation of the potassium-sodium niobate-carbon nitride composite material is an effective means for improving the photocatalytic efficiency, and the formed p-n type structure can promote the separation of photo-generated electron-hole pairs. In the process of preparing the potassium sodium niobate-carbon nitride composite material, how to realize effective interface combination between the potassium sodium niobate and the carbon nitride and enhance the separation of photoproduction electrons and holes is the key problem for obtaining excellent photocatalysis effect.

[ summary of the invention ]

The invention aims to solve the technical problem of providing a synthetic method for preparing a potassium-sodium niobate-carbon nitride photocatalytic composite material with high-efficiency photocatalytic performance by using a novel cationic dispersant Cetyl Trimethyl Ammonium Bromide (CTAB) and a product thereof.

The invention is realized by the following steps:

a method for synthesizing a potassium-sodium niobate-carbon nitride photocatalytic composite material comprises the following steps:

(1) placing urea in a crucible, and calcining in a muffle furnace to obtain carbon nitride powder;

(2) ultrasonically dispersing the carbon nitride powder obtained in the step (1) and a cationic dispersant cetyl trimethyl ammonium bromide to obtain a uniform carbon nitride suspension;

(3) mixing and stirring the carbon nitride suspension obtained in the step (2) with niobium pentoxide, sodium hydroxide and potassium hydroxide in deionized water;

(4) placing the mixed solution obtained in the step (3) into a high-pressure kettle for reaction, and repeatedly washing and precipitating with absolute ethyl alcohol after the reaction is finished;

(5) and (5) drying the solid product obtained in the step (4) in a drying oven overnight to obtain the potassium-sodium niobate-carbon nitride composite material.

Further, the calcination temperature in the step (1) is 500-550 ℃.

Further, in the step (2), the weight part ratio of the cationic dispersant cetyl trimethyl ammonium bromide to the carbon nitride is 1:1-2:1, and the ultrasonic time is 30-60 min.

Further, the weight ratio of niobium pentoxide to sodium hydroxide in the step (3) is 1:1-1:10, the weight ratio of niobium pentoxide to potassium hydroxide is 2:1-1:10, and the stirring time is 6-24 h.

Further, the weight part ratio of the carbon nitride to the niobium pentoxide in the step (3) is 1:10-1: 20.

Further, the reaction temperature in the step (4) is 220-240 ℃, and the reaction time is 24-48 h.

Further, in the potassium-sodium niobate-carbon nitride photocatalytic composite material obtained in the step (5), the drying temperature is 60-80 ℃, and the mass percentage of carbon nitride in the composite material is 3-10%.

Further, a potassium sodium niobate-carbon nitride photocatalytic composite material prepared by the synthesis method of the potassium sodium niobate-carbon nitride photocatalytic composite material.

The invention has the following advantages:

the method selects the cationic surfactant cetyl trimethyl ammonium bromide CTAB as the dispersant to obtain the potassium-sodium niobate-carbon nitride composite material, the synthesis method has the characteristic of environmental protection, the used cationic dispersant is an environment-friendly material, the synthesized potassium-sodium niobate-carbon nitride composite material has good interface combination effect, shows good visible light catalysis effect, is a photocatalytic composite material with potential application prospect, and can be applied to the fields of photocatalysis and photoelectricity.

[ description of the drawings ]

The invention will be further described with reference to the following examples with reference to the accompanying drawings.

FIG. 1 is an XRD spectrum of a potassium-sodium niobate-carbon nitride photocatalytic composite material prepared in example 1;

FIG. 2 is an SEM image of the sodium potassium niobate-carbon nitride photocatalytic composite material prepared in example 1;

FIG. 3 is the UV-VIS absorption spectrum of the PONA-CNN photocatalytic composite material prepared in example 1;

FIG. 4 is a comparative diagram of the photocatalytic degradation effect of the potassium sodium niobate-carbon nitride photocatalytic composite material synthesized without CTAB and under the action of CTAB.

[ detailed description ] embodiments

The invention relates to a method for synthesizing a potassium-sodium niobate-carbon nitride photocatalytic composite material, which comprises the following steps:

(1) placing urea in a crucible, and calcining in a muffle furnace to obtain carbon nitride powder;

(2) ultrasonically dispersing the carbon nitride powder obtained in the step (1) and a cationic dispersant cetyl trimethyl ammonium bromide to obtain a uniform carbon nitride suspension;

(3) mixing and stirring the carbon nitride suspension obtained in the step (2) with niobium pentoxide, sodium hydroxide and potassium hydroxide in deionized water;

(4) placing the mixed solution obtained in the step (3) into a high-pressure kettle for reaction, and repeatedly washing and precipitating with absolute ethyl alcohol after the reaction is finished;

(5) and (5) drying the solid product obtained in the step (4) in a drying oven overnight to obtain the potassium-sodium niobate-carbon nitride composite material.

Preferably, the calcination temperature in step (1) is 500-550 ℃.

Preferably, the weight part ratio of the cationic dispersant cetyl trimethyl ammonium bromide to the carbon nitride in the step (2) is 1:1-2:1, and the ultrasonic time is 30-60 min.

Preferably, the weight ratio of niobium pentoxide to sodium hydroxide in step (3) is 1:1-1:10, the weight ratio of niobium pentoxide to potassium hydroxide is 2:1-1:10, and the stirring time is 6-24 h.

Preferably, the weight ratio of the carbon nitride to the niobium pentoxide in the step (3) is 1:10-1: 20.

Preferably, the reaction temperature in the step (4) is 220-240 ℃, and the reaction time is 24-48 h.

Preferably, in the potassium sodium niobate-carbon nitride photocatalytic composite material obtained in the step (5), the drying temperature is 60-80 ℃, and the mass percentage of carbon nitride in the composite material is 3-10%.

The invention also relates to a potassium sodium niobate-carbon nitride photocatalytic composite material prepared by the synthesis method of the potassium sodium niobate-carbon nitride photocatalytic composite material.

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings and the detailed description. 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. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1

5 g of urea is taken and placed in a crucible, and then is placed in a muffle furnace to be calcined for 2 hours at 550 ℃, so as to synthesize carbon nitride powder.

0.1 g of carbon nitride and 0.173 g of cationic surfactant cetyl trimethyl ammonium bromide CTAB are dissolved in 35ml of deionized water, and the mixture is ultrasonically stirred for 30 minutes to obtain a uniformly dispersed carbon nitride suspension.

2.6581 g of niobium pentoxide, 2.8 g of sodium hydroxide, 1.4 g of potassium hydroxide and a suspension containing 0.1 g of carbon nitride are dissolved in 20ml of deionized water, ultrasonic stirring is carried out for 30 minutes, then the deionized water is added till 60ml, and stirring is carried out for 24 hours. The solution was then transferred to a 100ml Teflon reaction kettle and reacted at 200 ℃ for 24 hours. And after the reaction kettle is naturally cooled to room temperature, centrifugally washing and separating to obtain a light yellow solid product, respectively cleaning with deionized water and absolute ethyl alcohol for 3 times, and drying in a vacuum drying oven at 70 ℃ for 24 hours to obtain the potassium sodium niobate-carbon nitride photocatalytic composite material, wherein the mass percentage of carbon nitride in the composite material is 3%.

Fig. 1 shows an XRD spectrum of the potassium sodium niobate-carbon nitride photocatalytic composite material prepared in example 1 under the action of CTAB, indicating that the material is a pure-phase potassium sodium niobate-carbon nitride composite powder. FIG. 2 is an SEM image of a potassium sodium niobate-carbon nitride photocatalytic composite material under the action of CTAB, and the original morphology of the potassium sodium niobate is well maintained. FIG. 3 is the UV-VIS absorption spectrum of the potassium sodium niobate-carbon nitride photocatalytic composite material under the action of CTAB, showing an absorption edge of about 380 nm.

Example 2

5 g of urea is taken and placed in a crucible, and then is placed in a muffle furnace to be calcined for 2 hours at 500 ℃, so as to synthesize carbon nitride powder.

0.2 g of carbon nitride and 0.3g of cationic surfactant cetyl trimethyl ammonium bromide CTAB are dissolved in 35ml of deionized water, and the mixture is ultrasonically stirred for 30 minutes to obtain a uniformly dispersed carbon nitride suspension.

2.6581 g of niobium pentoxide, 7 g of sodium hydroxide, 3.5 g of potassium hydroxide and a suspension containing 0.2 g of carbon nitride are dissolved in 20ml of deionized water, ultrasonic stirring is carried out for 30 minutes, then the deionized water is added till 60ml, and stirring is carried out for 24 hours. The solution was then transferred to a 100ml Teflon reaction kettle and reacted at 200 ℃ for 24 hours. And after the reaction kettle is naturally cooled to room temperature, centrifugally washing and separating to obtain a light yellow solid product, respectively cleaning 3 times by using deionized water and absolute ethyl alcohol, and drying for 24 hours at 70 ℃ in a vacuum drying oven to obtain the potassium sodium niobate-carbon nitride photocatalytic composite material, wherein the mass percentage of carbon nitride in the composite material is 6%.

Example 3

5 g of urea is taken and placed in a crucible, and then is placed in a muffle furnace to be calcined for 2 hours at 550 ℃, so as to synthesize carbon nitride powder.

0.3g of carbon nitride and 0.3g of CTAB were dissolved in 35ml of deionized water, and ultrasonically stirred for 30 minutes to obtain a uniformly dispersed carbon nitride suspension.

2.6581 g of niobium pentoxide, 22.4 g of sodium hydroxide, 1.4 g of potassium hydroxide and a suspension containing 0.1 g of carbon nitride are dissolved in 20ml of deionized water, ultrasonic stirring is carried out for 30 minutes, then deionized water is added till 60ml, and stirring is carried out for 24 hours. The solution was then transferred to a 100ml Teflon reaction kettle and reacted at 220 ℃ for 24 hours. And after the reaction kettle is naturally cooled to room temperature, centrifugally washing and separating to obtain a light yellow solid product, respectively cleaning 3 times by using deionized water and absolute ethyl alcohol, and drying for 24 hours at 70 ℃ in a vacuum drying oven to obtain the potassium sodium niobate-carbon nitride photocatalytic composite material, wherein the mass percentage of carbon nitride in the composite material is 9%.

Example 4

In order to verify the visible light catalysis effect of the potassium sodium niobate-carbon nitride photocatalytic composite material, the embodiment uses the potassium sodium niobate-carbon nitride photocatalytic composite material as a catalyst, and the visible light catalysis effect of the composite material is tested by degrading rhodamine B through photocatalysis.

The experiment was carried out under visible light at room temperature. 0.3g of the potassium sodium niobate-carbon nitride photocatalytic composite material powder prepared in the example 1 is dispersed in deionized water containing a certain amount of rhodamine B, and the reaction is carried out for 10 minutes in a dark room before illumination, so as to achieve the adsorption-desorption balance. Then, a visible light source is used for irradiation to carry out photocatalytic reaction, 8ml of mixed solution is taken at proper time intervals, supernatant is obtained through centrifugal separation, and the degradation condition of the catalyst on rhodamine B is calculated through measurement of an ultraviolet visible spectrophotometer. As can be seen from FIG. 4, generated under CTAB actionThe potassium sodium niobate-carbon nitride photocatalytic composite material has good photocatalytic effect, and 40mg L of the potassium sodium niobate-carbon nitride composite material with 0.3g can be prepared within 180 minutes^-1The rhodamine B is completely degraded. For the potassium sodium niobate-carbon nitride composite material generated without adding CTAB, the sample with the same quality can not be degraded basically after 180 minutes. Therefore, the potassium-sodium niobate-carbon nitride photocatalytic composite material prepared by the method has a good visible light catalysis effect.

Although specific embodiments of the invention have been described above, it will be understood by those skilled in the art that the specific embodiments described are illustrative only and are not limiting upon the scope of the invention, and that equivalent modifications and variations can be made by those skilled in the art without departing from the spirit of the invention, which is to be limited only by the appended claims.