阅读说明：本技术 复合压电催化剂的制备方法及制备双氧水的方法 (Preparation method of composite piezoelectric catalyst and method for preparing hydrogen peroxide ) 是由 王梦晔 于 2020-12-09 设计创作，主要内容包括：本发明实施例提供一种复合压电催化剂的制备方法及制备双氧水的方法,包括：加热反应步骤：将原料Bi-2O-3、TiO-2、NaCl、KCl进行混合得到固体混合物,并放入马弗炉中加热到500-900℃并降温冷却,生成Bi-3Ti-4O-(12)；前驱体制作步骤：对Bi-4Ti-3O-(12)进行超声分散处理,并加入将六水硝酸钴和乌洛托品,搅拌直至得到均匀的混合溶液；置于油浴中保温,保温之后冷却并清洗,清洗干净之后放入烘箱中60℃干燥制得Bi-4Ti-3O-(12)/CoP前驱体；热处理步骤：对Bi-4Ti-3O-(12)/CoP前驱体与次磷酸二氢钠进行热处理,将Bi-4Ti-3O-(12)/CoP前驱体转化成Bi-4Ti-3O-(12)/CoP,其中,CoP均匀负载在Bi-4Ti-3O-(12)表面；将Bi-4Ti-3O-(12)/CoP作为复合压电催化剂用于制备双氧水。CoP负载Bi-4Ti-3O-(12)的压电催化氧还原制备H-2O-2产率提升明显。(The embodiment of the invention provides a preparation method of a composite piezoelectric catalyst and a method for preparing hydrogen peroxide, wherein the preparation method comprises the following steps: a heating reaction step: the raw material Bi 2 O 3 、TiO 2 NaCl and KCl are mixed to obtain a solid mixture, and the solid mixture is put into a muffle furnace to be heated to 500-900 ℃ and cooled to generate Bi 3 Ti 4 O 12 (ii) a A precursor preparation step: for Bi 4 Ti 3 O 12 Carrying out ultrasonic dispersion treatment, adding cobalt nitrate hexahydrate and urotropine, and stirring until a uniform mixed solution is obtained; placing the mixture in an oil bath for heat preservation, cooling and cleaning the mixture after heat preservation, and placing the cleaned mixture into an oven for drying at 60 ℃ to obtain Bi 4 Ti 3 O 12 A CoP precursor; a heat treatment step: for Bi 4 Ti 3 O 12 Heat treating CoP precursor with sodium dihydrogen hypophosphite to obtain Bi 4 Ti 3 O 12 /CoConversion of P precursor to Bi 4 Ti 3 O 12 /CoP, wherein CoP is uniformly loaded in Bi 4 Ti 3 O 12 A surface; adding Bi 4 Ti 3 O 12 the/CoP is used as a composite piezoelectric catalyst for preparing hydrogen peroxide. CoP loaded Bi 4 Ti 3 O 12 Preparation of H by piezoelectric catalytic oxidation reduction 2 O 2 The yield is obviously improved.)

1. The preparation method of the composite piezoelectric catalyst is characterized by comprising the following steps of:

a heating reaction step: the raw material Bi₂O₃、TiO₂NaCl and KCl are mixed to obtain a solid mixture, and the solid mixture is put into a muffle furnace to be heated to 500-900 ℃ and cooled to generate Bi₃Ti₄O₁₂；

A precursor preparation step: for Bi₄Ti₃O₁₂Performing ultrasonic dispersion treatment, adding cobalt nitrate hexahydrate and urotropine into the Bi subjected to dispersion treatment₄Ti₃O₁₂And stirring until a uniform mixed solution is obtained; placing the uniform mixed solution in an oil bath for heat preservation, cooling and cleaning after heat preservation, and drying in an oven at 60 ℃ after cleaning to obtain Bi₄Ti₃O₁₂A CoP precursor;

a heat treatment step: for Bi₄Ti₃O₁₂Heat treating CoP precursor with sodium dihydrogen hypophosphite to obtain Bi₄Ti₃O₁₂Conversion of CoP precursor to Bi₄Ti₃O₁₂/CoP, wherein CoP is uniformly loaded in Bi₄Ti₃O₁₂A surface; adding Bi₄Ti₃O₁₂the/CoP is used as a composite piezoelectric catalyst for preparing hydrogen peroxide.

2. The method for preparing a composite piezoelectric catalyst according to claim 1, wherein the heating step specifically comprises:

the raw material Bi₂O₃、TiO₂Mixing NaCl and KCl, and grinding the mixed raw materials by using a mortar to uniformly mix the raw materials to form a solid mixture; pressing the solid mixture into a columnar shape through a tablet machine for placing into a muffle furnace for heating, wherein the grinding time is 10-30 min; and/or the presence of a gas in the gas,

heating the solid mixture in a muffle furnace to produce a mixture containing Bi₃Ti₄O₁₂The mixture of NaCl and KCl is kept warm, and then the mixture is cooled down; washing the cooled mixture to remove NaCl and KCl to obtain pure Bi₃Ti₄O₁₂(ii) a Wherein the pair contains Bi₃Ti₄O₁₂And the mixture of NaCl and KCl is kept warm for 1-5h, and is washed by deionized water for multiple times to remove NaCl and KCl.

3. The method for preparing a composite piezoelectric catalyst according to claim 1, wherein the precursor preparation step further comprises:

adding Bi₄Ti₃O₁₂Performing ultrasonic dispersion in deionized water for 10-30min, wherein the deionized water and Bi₄Ti₃O₁₂The mixture ratio of: 20-100 g: 0.1-0.5 g; and/or the presence of a gas in the gas,

placing the uniform mixed solution in an oil bath at the temperature of 50-100 ℃ for heat preservation, wherein the heat preservation time of the oil bath at the temperature of 50-100 ℃ is 2-8 h; and/or the presence of a gas in the gas,

adding cobalt nitrate hexahydrate and urotropin into the dispersed Bi₄Ti₃O₁₂Stirring for 10-30min, wherein, Bi₄Ti₃O₁₂The proportion of the cobalt nitrate hexahydrate and the urotropine is 0.1-0.5 g:0.01-0.09g, 0.01-0.09 g; and/or the presence of a gas in the gas,

and cleaning the mixed solution for multiple times by using deionized water or alcohol during cleaning so as to remove residual cobalt nitrate and urotropine.

4. The method for preparing a composite piezoelectric catalyst according to claim 1, wherein the heat treatment step is specifically performed by:

adding Bi₄Ti₃O₁₂Respectively placing the CoP precursor and sodium dihydrogen hypophosphite in a tube furnace, heating to 200-500 ℃ in inert gas flow, and keeping the temperature for 2-5h to obtain Bi₄Ti₃O₁₂Conversion of CoP precursor to Bi₄Ti₃O₁₂/CoP, cooling to obtain Bi₄Ti₃O₁₂The CoP is uniformly loaded in Bi₄Ti₃O₁₂A surface.

5. The method for preparing a composite piezoelectric catalyst according to claim 4, comprising, in the heat treatment step:

the flow rate of the inert gas flow is 10-200 SCCM; and/or the presence of a gas in the gas,

when the heating is carried out in the inert gas flow, the heating rate is 1-5 ℃/min.

6. The method for preparing a composite piezoelectric catalyst according to claim 4, comprising, in the heat treatment step:

Bi₄Ti₃O₁₂the mixture ratio of the CoP precursor to the sodium dihydrogen hypophosphite is 0.1-0.5 g: 0.01-0.1 g.

7. The method for preparing a composite piezoelectric catalyst according to claim 1, wherein in the step of heating reaction, Bi is used₂O₃、TiO₂The proportion of NaCl to KCl is 0.1-0.5 g: 0.2-0.6 g: 2-10 g: 2-10 g.

8. The method for producing a composite piezoelectric catalyst according to claim 1, wherein in the precursor producing step, Bi is used₄Ti₃O₁₂The mixture ratio of the cobalt nitrate hexahydrate to the urotropine is 0.1-0.5 g:0.01-0.09 g:0.01-0.09 g.

9. A method for preparing hydrogen peroxide by adopting a composite piezoelectric catalyst is characterized by comprising the following steps:

bi to be produced by the method of any one of claims 1 to 8₄Ti₃O₁₂the/CoP is dispersed in deionized water, wherein Bi₄Ti₃O₁₂The proportion of CoP to deionized water is 1 g: 1000-10000 g;

composite piezoelectric catalyst Bi driven by mechanical force₄Ti₃O₁₂the/CoP is subjected to oxygen reduction reaction to generate hydrogen peroxide.

10. The method for preparing hydrogen peroxide by using the composite piezoelectric catalyst according to claim 9, comprising the following steps:

the mechanical force is provided by an ultrasonic generator which generates ultrasonic waves at a frequency of 20-100 KHz.

Technical Field

The invention relates to the technical field of preparation and application of novel functional materials, in particular to a preparation method of a composite piezoelectric catalyst and a method for preparing hydrogen peroxide.

Background

Hydrogen peroxide (H)₂O₂) Is a mild oxidant with high efficiency and environmental protection, and is widely applied to sewage treatment, environmental disinfection, organic synthesis and paper making and textile industries. In the process of implementing the invention, the applicant finds that at least the following problems exist in the prior art: large scale industrial production of H₂O₂The anthraquinone oxidation process (AO) is the predominant process of (ii), which suffers from several disadvantages: 1) the energy consumption is high, anthraquinone is required to be consumed, and the cost is high; 2) the product impurity removal process is complex and the like; 3) produced high concentration of H₂O₂Making transport and storage risky. In addition, researchers have attempted to use H₂And O₂Direct synthesis of H as starting material₂O₂However, this method also has several problems: 1) in the reaction process, noble metals such as Pt, Au and the like are required to be used as catalysts, so that the cost is high and the large-scale application is difficult; 2) h₂And O₂The mixing presents an explosion risk. Therefore, the low-cost, high-efficiency and environment-friendly H is developed₂O₂The preparation method is of great importance.

Disclosure of Invention

The embodiment of the invention provides a preparation method of a composite piezoelectric catalyst and a method for preparing hydrogen peroxide, and the prepared Bi4Ti3O12/CoP composite piezoelectric catalytic material enables CoP to be uniformly loaded on the surface of Bi4Ti3O12 to form a heterojunction composite material with two-phase interfaces in close contact, so that the H4 Ti3O12 production is greatly improved₂O₂Efficiency.

In order to achieve the above object, in one aspect, an embodiment of the present invention provides a method for preparing a composite piezoelectric catalyst, including the following steps:

a heating reaction step: the raw material Bi₂O₃、TiO₂NaCl and KCl are mixed to obtain a solid mixture, and the solid mixture is put into a muffle furnace to be heated to 500-900 ℃ and cooled to generate Bi₃Ti₄O₁₂；

A precursor preparation step: for Bi₄Ti₃O₁₂Performing ultrasonic dispersion treatment, adding cobalt nitrate hexahydrate and urotropine into the Bi subjected to dispersion treatment₄Ti₃O₁₂And stirring until a uniform mixed solution is obtained; placing the uniform mixed solution in an oil bath for heat preservation, cooling and cleaning after heat preservation, and drying in an oven at 60 ℃ after cleaning to obtain Bi₄Ti₃O₁₂A CoP precursor;

a heat treatment step: for Bi₄Ti₃O₁₂Heat treating CoP precursor with sodium dihydrogen hypophosphite to obtain Bi₄Ti₃O₁₂Conversion of CoP precursors to Bi₄Ti₃O₁₂/CoP, wherein CoP is uniformly loaded in Bi₄Ti₃O₁₂A surface; adding Bi₄Ti₃O₁₂the/CoP is used as a composite piezoelectric catalyst for preparing hydrogen peroxide.

On the other hand, the embodiment of the invention provides a method for preparing hydrogen peroxide by adopting a composite piezoelectric catalyst, which comprises the following steps:

bi to be produced by the aforementioned method₄Ti₃O₁₂the/CoP is dispersed in deionized water, wherein Bi₄Ti₃O₁₂The ratio of the/CoP to the deionized water is 1 g: 1000-10000 g;

composite piezoelectric catalyst Bi driven by mechanical force₄Ti₃O₁₂the/CoP is subjected to oxygen reduction reaction to generate hydrogen peroxide.

The technical scheme has the following beneficial effects: the Bi4Ti3O12/CoP composite piezoelectric catalytic material prepared by the invention enables CoP to be uniformly loaded on the surface of Bi4Ti3O12 to form a heterojunction composite material with two-phase interfaces in close contact, thereby greatly improving the H production₂O₂Efficiency.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a flow chart of a method of making a composite piezoelectric catalyst according to an embodiment of the present invention;

FIG. 2 shows Bi obtained by the complete technical scheme and all application examples of the invention₄Ti₃O₁₂(a) And Bi₄Ti₃O₁₂SEM image of/CoP (b) composite material;

FIG. 3 shows Bi obtained by the complete technical scheme and all application examples of the invention₄Ti₃O₁₂And Bi₄Ti₃O₁₂XRD contrast pattern of/CoP composite material.

FIG. 4 shows Bi obtained by the complete technical scheme and all application examples of the invention₄Ti₃O₁₂And Bi₄Ti₃O₁₂Piezoelectric catalytic production of H from/CoP composite material₂O₂The effect is compared with the figure.

Detailed Description

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 only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

As shown in fig. 1, the present invention provides a method for preparing a composite piezoelectric catalyst, comprising the steps of:

a heating reaction step 101: the raw material Bi₂O₃、TiO₂NaCl and KCl are mixed to obtain a solid mixture, and the solid mixture is put into a muffle furnace to be heated to 500-900 ℃ and cooled to generate Bi₃Ti₄O₁₂；

Precursor preparation step 102: for Bi₄Ti₃O₁₂Performing ultrasonic dispersion treatment, adding cobalt nitrate hexahydrate and urotropine into the Bi subjected to dispersion treatment₄Ti₃O₁₂And stirring until a uniform mixed solution is obtained; placing the uniform mixed solution in an oil bath for heat preservation, cooling and cleaning after heat preservationWashing, cleaning, drying at 60 deg.C in oven to obtain Bi₄Ti₃O₁₂A CoP precursor;

a heat treatment step 103: for Bi₄Ti₃O₁₂Heat treating CoP precursor with sodium dihydrogen hypophosphite to obtain Bi₄Ti₃O₁₂Conversion of CoP precursor to Bi₄Ti₃O₁₂/CoP, wherein CoP is uniformly loaded in Bi₄Ti₃O₁₂A surface; adding Bi₄Ti₃O₁₂the/CoP is used as a composite piezoelectric catalyst for preparing hydrogen peroxide.

Preferably, the heating step 101 specifically includes:

s101-1: the raw material Bi₂O₃、TiO₂Mixing NaCl and KCl, and grinding the mixed raw materials by using a mortar to uniformly mix the raw materials to form a solid mixture; pressing the solid mixture into a columnar shape through a tablet machine for placing into a muffle furnace for heating, wherein the grinding time is 10-30 min; and/or the presence of a gas in the gas,

s101-2: heating the solid mixture in a muffle furnace to produce a mixture containing Bi₃Ti₄O₁₂The mixture of NaCl and KCl is kept warm, and then the mixture is cooled down; washing the cooled mixture to remove NaCl and KCl to obtain pure Bi₃Ti₄O₁₂(ii) a Wherein the pair contains Bi₃Ti₄O₁₂And the mixture of NaCl and KCl is kept warm for 1-5h, and is washed by deionized water for multiple times to remove NaCl and KCl.

Preferably, the precursor preparing step 102 further includes:

s102-1: adding Bi₄Ti₃O₁₂Dispersing in deionized water for 10-30min by ultrasonic wave, wherein the deionized water and Bi₄Ti₃O₁₂The mixture ratio of: 20-100 g: 0.1-0.5 g; and/or the presence of a gas in the gas,

placing the uniform mixed solution in an oil bath at the temperature of 50-100 ℃ for heat preservation, wherein the heat preservation time of the oil bath at the temperature of 50-100 ℃ is 2-8 h; and/or the presence of a gas in the gas,

s102-2: adding cobalt nitrate hexahydrate and urotropin into the dispersed Bi₄Ti₃O₁₂Stirring for 10-30min, wherein, Bi₄Ti₃O₁₂The proportion of the cobalt nitrate hexahydrate and the urotropine is 0.1-0.5 g:0.01-0.09g, 0.01-0.09 g; and/or the presence of a gas in the gas,

s102-3: and cleaning the mixed solution for multiple times by using deionized water or alcohol during cleaning so as to remove residual cobalt nitrate and urotropine.

Preferably, the specific operations of the heat treatment step 103 are:

adding Bi₄Ti₃O₁₂Respectively placing the CoP precursor and sodium dihydrogen hypophosphite in a tube furnace, heating to 200-500 ℃ in inert gas flow, and keeping the temperature for 2-5h to obtain Bi₄Ti₃O₁₂Conversion of CoP precursor to Bi₄Ti₃O₁₂CoP, cooling to obtain Bi₄Ti₃O₁₂The CoP is uniformly loaded in Bi₄Ti₃O₁₂A surface.

Preferably, in the heat treatment step 103, it includes:

the flow rate of the inert gas flow is 10-200 SCCM; and/or the presence of a gas in the gas,

when the heating is carried out in the inert gas flow, the heating rate is 1-5 ℃/min.

Preferably, in the heat treatment step 103, it includes:

Bi₄Ti₃O₁₂the mixture ratio of the CoP precursor to the sodium dihydrogen hypophosphite is 0.1-0.5 g: 0.01-0.1 g.

Preferably, in the heating reaction step 101, Bi₂O₃、TiO₂The proportion of NaCl to KCl is 0.1-0.5 g: 0.2-0.6 g: 2-10 g: 2-10 g.

Preferably, in the precursor making step 102, Bi₄Ti₃O₁₂The mixture ratio of the cobalt nitrate hexahydrate to the urotropine is 0.1-0.5 g:0.01-0.09 g:0.01-0.09 g.

The embodiment of the invention also provides a method for preparing hydrogen peroxide by adopting the composite piezoelectric catalyst, which comprises the following steps:

s201: bi to be produced by the method of any one of claims 1 to 8₄Ti₃O₁₂the/CoP is dispersed in deionized water to form a solution, wherein Bi₄Ti₃O₁₂The proportion of CoP to deionized water is 1 g: 1000-10000 g;

s202: composite piezoelectric catalyst Bi driven by mechanical force₄Ti₃O₁₂the/CoP is subjected to oxygen reduction reaction to generate hydrogen peroxide.

Preferably, the method comprises the following steps:

the mechanical force is provided by an ultrasonic generator which generates ultrasonic waves at a frequency of 20-100 KHz.

With reference to fig. 2-4, the complete technical solution of the present invention comprises the following steps:

1) bi is added₂O₃、TiO₂Mixing the four raw materials of NaCl and KCl, and grinding for 10-30min by using a mortar to ensure uniform mixing to obtain an estimated mixture. Bi in step 1)₂O₃、TiO₂The proportion (ratio) of the four raw materials of NaCl and KCl is 0.1-0.5 g: 0.2-0.6 g: 2-10 g: 2-10 g.

2) Tabletting the solid mixture (for example, a tablet press is adopted, and the tablet press can be adopted in the test), placing the solid mixture into an alumina crucible, and placing the alumina crucible into a muffle furnace for heat preservation at 900 ℃ for 1-5 hours to fully react the raw materials, wherein NaCl and KCl are fluxing agents; and cooling after the reaction ratio is finished. After cooling, the solution is washed by deionized water for many times to completely remove NaCl and KCl, and then the solution is placed in an oven to be dried at 60 ℃ to obtain Bi₃Ti₄O₁₂。

3) Bi prepared in the step 2)₄Ti₃O₁₂Adding into deionized water, performing ultrasonic dispersion for 10-30min, adding cobalt nitrate hexahydrate and urotropine, and stirring for 10-30min to disperse uniformly to obtain uniform mixed solution. Preferably, the deionized water and Bi in the step 3)₄Ti₃O₁₂The ratio of cobalt nitrate hexahydrate to urotropine is 20-100 g: 0.1-0.5 g:0.01-0.09g, 0.01-0.09 g.

4) Placing the uniformly stirred mixed solution in the step 3) at 50-100 DEG CKeeping the temperature in the oil bath for 2 to 8 hours, wherein the temperature range during the heat preservation is 50 to 100 ℃, so that Bi is ensured₄Ti₃O₁Fully reacting with cobalt nitrate hexahydrate and urotropine, cooling after the reaction is finished, washing for many times (washing impurities) by deionized water or alcohol after the reaction is cooled to room temperature, and then drying in an oven at 60 ℃ to obtain Bi₄Ti₃O₁₂a/CoP precursor.

5) Bi prepared in the step 4)₄Ti₃O₁₂the/CoP precursor and the sodium dihydrogen hypophosphite are respectively placed in a tube furnace, wherein Bi₄Ti₃O₁₂The proportion of the CoP precursor to the sodium dihydrogen hypophosphite is 0.1-0.5 g: 0.01-0.1g, placing in an inert gas flow, heating to 200 ℃ and 500 ℃, wherein the flow rate of the inert gas flow is 10-200SCCM, keeping the temperature for 2-5h, and the heating rate is 1-5 ℃/min. Naturally cooling to obtain Bi₄Ti₃O₁₂/CoP, reaction of Bi₄Ti₃O₁₂the/CoP is used as a composite piezoelectric catalyst (composite piezoelectric catalytic material) for preparing hydrogen peroxide.

6) Weighing Bi obtained in the step 5)₄Ti₃O₁₂the/CoP composite piezoelectric catalytic material is prepared by taking 0.01g-0.05g of Bi₄Ti₃O₁₂the/CoP composite piezoelectric catalytic material is dispersed in 50-100g of deionized water.

7) And an ultrasonic generator with the ultrasonic frequency of 20-100KHz is used for providing a mechanical force source to drive the piezoelectric catalytic oxidation-reduction reaction to prepare H₂O₂After reacting for 1-5H, filtering out the catalyst to obtain H₂O₂And (3) solution. . The reaction can be driven by clean mechanical energy such as wind energy, tidal energy, water flow and the like to realize H₂O₂Can be prepared continuously.

The embodiment of the invention has the following beneficial effects:

compared with the method of utilizing electric energy and solar energy to drive catalytic reaction, H is prepared by piezoelectric catalysis₂O₂Has the following advantages: 1) complex reaction equipment is not needed, and the cost is low; 2) the method can be carried out in a darkroom without considering the time interval property of solar energy, and is convenient for continuous production; 3) can be directly utilizedMechanical energy widely exists in nature such as sound waves, water flow, vibration, tides, wind energy and the like.

The invention adopts a molten salt method (steps 1 and 2) and a chemical deposition method (steps 3, 4 and 5) to prepare Bi₄Ti₃O₁₂The CoP can be uniformly loaded on Bi by the method₄Ti₃O₁₂Surface (see figure 2) to form a heterojunction composite material with two-phase interfaces in close contact;

the mechanical energy conversion efficiency of the single-phase piezoelectric catalytic material is low, and H is difficult to meet₂O₂Actual production requirements; compared with single-phase Bi₄Ti₃O₁₂CoP loaded with Bi₄Ti₃O₁₂Preparation of H by piezoelectric catalytic oxidation reduction₂O₂The yield is obviously improved, and H is performed under the ultrasonic action of 68KHz₂O₂The yield is as high as 750umol/g/h (see figure 4), and the performance is much higher than that of single-phase Bi₄Ti₃O₁₂. Thereby overcoming the defect of adopting single-phase piezoelectric catalyst material in H₂O₂The preparation process has the disadvantage of low efficiency.

The above technical solutions of the embodiments of the present invention are described in detail below with reference to specific application examples, and reference may be made to the foregoing related descriptions for technical details that are not described in the implementation process.

The invention relates to a method for preparing hydrogen peroxide Bi by using (composite) piezoelectric catalyst₄Ti₃O₁₂A preparation method of a/CoP material, relating to a Bi with the function of preparing hydrogen peroxide by high-efficiency piezoelectric catalysis₄Ti₃O₁₂A preparation method of a/CoP composite material belongs to the technical field of preparation and application of novel functional materials.

Application example 1:

(1) 0.1g of Bi was weighed out separately₂O₃、0.2g TiO₂4.5g of KCl and 5g of NaCl, and ground in a mortar for 10min to mix them uniformly. The mixed powder was pressed into a columnar block having a diameter of 12mm by a hand press. Putting the mixture into a muffle furnace, heating to 900 ℃, preserving heat for 3 hours, and increasing the temperature at a rate of 5 ℃/min. Cooling, washing with deionized water for three timesThe samples were all freed of NaCl and KCl. Putting the cleaned sample into an oven at 60 ℃ for drying for 12h to obtain Bi₄Ti₃O₁₂Nanosheets (see figures 2 and 3). (this step corresponds to steps 1, 2 of the complete solution).

(2) Taking Bi prepared in the step 1₃Ti₄O₁₂0.2g of nanosheets were ultrasonically dispersed in 100g of deionized water. 0.05g of cobalt nitrate hexahydrate and 0.05g of urotropin were added. And putting the mixed solution into an oil bath at the temperature of 100 ℃ for heat preservation for 4 hours. Cooling, washing with alcohol for three times, and drying in a 60 ℃ oven for 12h to obtain Bi₄Ti₃O₁₂a/CoP precursor. (this step corresponds to steps 3, 4 of the complete solution).

(3) 0.05g of Bi prepared in step 2 is taken₄Ti₃O₁₂0.1g of CoP precursor and 0.05g of sodium dihydrogen hypophosphite are placed in a tube furnace open at 100SCCM N₂Heating the airflow to 200 ℃, heating up at a rate of 5 ℃/min, and keeping the temperature for 2 h. Cooling to obtain Bi₄Ti₃O₁₂the/CoP composite piezoelectric catalytic material. (see FIGS. 2 and 3) (this step corresponds to step 5 of the complete solution).

(4) Weighing Bi obtained in the step 3)₄Ti₃O₁₂0.02g of/CoP composite piezoelectric catalytic material is dispersed in 100ml of deionized water. The ultrasonic generator with the ultrasonic frequency of 68KHz is used for providing a mechanical force source to drive the piezoelectric catalytic oxygen reduction to prepare H₂O₂After reacting for 1H, the catalyst is filtered off to obtain H₂O₂Solutions of₂. (Steps 6, 7 of this quite complete solution).

Application example 2:

(1) 0.2g of Bi were weighed respectively₂O₃、0.6g TiO₂7.5g of KCl and 9g of NaCl, and ground in a mortar for 10min to mix them uniformly. The mixed powder was pressed into a columnar block having a diameter of 12mm by a hand press. Putting the mixture into a muffle furnace, heating to 700 ℃, preserving heat for 4 hours, and increasing the temperature at a rate of 10 ℃/min. After cooling, the sample was washed three times with deionized water to completely remove NaCl and KCl from the sample. Putting the cleaned sample into an oven at 60 ℃ for drying for 12h,to obtain Bi₄Ti₃O₁₂Nanosheets (see figures 2 and 3). (corresponding to steps 1 and 2 in the complete technical scheme).

(2) Taking Bi prepared in the step 1₄Ti₃O₁₂0.1g of nanosheets were ultrasonically dispersed in 100g of deionized water. 0.03g of cobalt nitrate hexahydrate and 0.03g of urotropin were added. And (3) putting the mixed solution into an oil bath at the temperature of 70 ℃ for heat preservation for 4 h. Cooling, washing with alcohol for three times, and drying in a 60 ℃ oven for 12h to obtain Bi₄Ti₃O₁₂a/CoP precursor. (corresponding to steps 3 and 4 in the complete technical scheme).

(3) 0.2g of Bi prepared in step 2 is taken₄Ti₃O₁₂a/CoP precursor. And 0.1g of sodium dihydrogen hypophosphite were separately placed in a tube furnace at 100SCCM N₂The airflow is heated to 400 ℃, the heating rate is 5 ℃/min, and the temperature is kept for 3 h. Cooling to obtain Bi₄Ti₃O₁₂the/CoP composite (piezo-catalytic) material (see figures 2, 3) (corresponds to step 5 of the complete solution).

(4) Weighing Bi obtained in the step 3)₄Ti₃O₁₂0.01g of/CoP composite piezoelectric catalytic material is dispersed in 100ml of deionized water. The ultrasonic generator with the ultrasonic frequency of 100KHz is used for providing a mechanical force source to drive the piezoelectric catalytic oxidation reduction for preparing H₂O₂After reacting for 1H, the catalyst is filtered off to obtain H₂O₂And (3) solution. (corresponding to steps 6, 7 of the complete solution).

Application example 3:

(1) 0.3g of Bi were weighed respectively₂O₃、0.2g TiO₂4.5g of KCl and 5g of NaCl, and ground in a mortar for 10min to mix them uniformly. The mixed powder was pressed into a columnar block having a diameter of 12mm by a hand press. Putting the mixture into a muffle furnace to be heated to 900 ℃, and keeping the temperature for 1h at the heating rate of 10 ℃/min. After cooling, the sample was washed three times with deionized water to completely remove NaCl and KCl from the sample. Putting the cleaned sample into an oven at 60 ℃ for drying for 12h to obtain Bi₄Ti₃O₁₂Nanosheets (see figures 2 and 3). (corresponding to steps 1 and 2 in the complete technical scheme).

(2) Taking Bi prepared in the step 1₄Ti₃O₁₂0.1g of nanosheets were ultrasonically dispersed in 100g of deionized water. 0.03g of cobalt nitrate hexahydrate and 0.03g of urotropin were added. And (3) putting the mixed solution into an oil bath at the temperature of 70 ℃ for heat preservation for 4 h. After cooling, the mixture is washed by deionized water for three times and then is put into a 60 ℃ oven to be dried for 12 hours to obtain Bi₄Ti₃O₁₂a/CoP precursor. (corresponding to steps 3 and 4 in the complete technical scheme).

(3) 0.1g of Bi prepared in step 2 is taken₄Ti₃O₁₂a/CoP precursor. And 0.05g of sodium dihydrogen hypophosphite are separately placed in a tubular furnace, heated to 400 ℃ in 20SCCM Ar gas flow, heated at the rate of 5 ℃/min, and kept warm for 4 h. Cooling to obtain Bi₄Ti₃O₁₂the/CoP composite (piezo-catalytic) material (see figures 2, 3) (corresponds to step 5 of the complete solution).

(4) Weighing Bi obtained in the step 3)₄Ti₃O₁₂0.03g of/CoP composite piezoelectric catalytic material is dispersed in 50ml of deionized water. The ultrasonic generator with the ultrasonic frequency of 40KHz is used for providing a mechanical force source to drive the piezoelectric catalytic oxidation reduction for preparing H₂O₂After reacting for 1H, the catalyst is filtered off, and H in the solution₂O₂The content of (A) is as follows. Corresponding to steps 6, 7 of the complete solution).

Application example 4:

(1) 0.4g of Bi were weighed out separately₂O₃、0.6g TiO₂9.5g of KCl and 10g of NaCl, and ground in a mortar for 10min to mix them uniformly. The mixed powder was pressed into a columnar block having a diameter of 12mm by a hand press. Putting the mixture into a muffle furnace, heating to 700 ℃, preserving heat for 4 hours, and increasing the temperature at a rate of 5 ℃/min. After cooling, the sample was washed three times with deionized water to completely remove NaCl and KCl from the sample. Putting the cleaned sample into an oven at 60 ℃ for drying for 12h to obtain Bi₄Ti₃O₁₂Nanosheets (see figures 2 and 3). (corresponding to steps 1 and 2 in the complete technical scheme).

(2) Taking Bi prepared in the step 1₄Ti₃O₁₂0.5g of nanosheet is ultrasonically dispersed in 100g of deionized water. 0.08g of cobalt nitrate hexahydrate and 0.08g of urotropin were added. And (3) putting the mixed solution into an oil bath at the temperature of 80 ℃ for heat preservation for 6 hours. After cooling, the mixture is washed by deionized water for three times and then is put into a 60 ℃ oven to be dried for 12 hours to obtain Bi₄Ti₃O₁₂a/CoP precursor. (corresponding to steps 3 and 4 in the complete technical scheme).

(3) 0.1g of Bi prepared in step 2 is taken₄Ti₃O₁₂the/CoP precursor and 0.1g of sodium dihydrogen hypophosphite are separately placed in a tube furnace, heated to 400 ℃ in 40SCCM Ar gas flow, heated at the rate of 2 ℃/min, and kept for 5 h. Cooling to obtain Bi₄Ti₃O₁₂the/CoP composite (piezo-catalytic) material (see figures 2, 3) (corresponds to step 5 of the complete solution).

(4) Weighing Bi obtained in the step 3)₄Ti₃O₁₂0.1g of/CoP composite piezoelectric catalytic material is dispersed in 100ml of deionized water. The ultrasonic generator with the ultrasonic frequency of 40KHz is used for providing a mechanical force source to drive the piezoelectric catalytic oxidation reduction for preparing H₂O₂After reacting for 1H, the catalyst is filtered off, and H in the solution is tested₂O₂The content of (a). (corresponding to steps 6, 7 of the complete solution).

It should be understood that the specific order or hierarchy of steps in the processes disclosed is an example of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged without departing from the scope of the present disclosure. The accompanying method claims present elements of the various steps in a sample order, and are not intended to be limited to the specific order or hierarchy presented.

In the foregoing detailed description, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the subject matter require more features than are expressly recited in each claim. Rather, as the following claims reflect, invention lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. To those skilled in the art; various modifications to these embodiments will be readily apparent, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the embodiments described herein are intended to embrace all such alterations, modifications and variations that fall within the scope of the appended claims. Furthermore, to the extent that the term "includes" is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term "comprising" as "comprising" is interpreted when employed as a transitional word in a claim. Furthermore, any use of the term "or" in the specification of the claims is intended to mean a "non-exclusive or".

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 merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.