A bismuth oxide nanocomposite, a preparation method and application thereof

Abstract

The application discloses a bismuth oxide nanocomposite and a preparation method and application thereof. Compared with other bismuth-based materials, the bismuth oxide nanocomposite prepared by the application has a nanotubular structure, an average diameter of 10-20 nm, a larger electrochemical active specific surface area and stronger CO2 adsorption capacity, thereby showing excellent electrocatalytic CO2 reduction activity and ideal formate selectivity. The preparation method is green and simple, and can realize rapid production of the catalyst in a short time, thereby promoting the development of a process of electrocatalytically reducing CO2 into formate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inorganic nanomaterial synthesis, in particular to a bismuth oxide nanocomposite material and a preparation method and application thereof. BACKGROUND

[0002] Formic acid (formate) is not only a basic chemical raw material for synthesizing downstream products such as formate and formamide, but also an ideal hydrogen storage material, which has important application value in the energy system. At present, formic acid is mainly prepared by methanol carbonylation reaction, which has a complex process and high energy consumption, thereby seriously reducing the economic benefit of formic acid. Therefore, it is extremely promising to directly convert CO2 into formic acid or formate through a mild and energy-saving electrochemical technology.

[0003] So far, metal-based catalysts such as Pb, Cd, Hg, In, Sn and Bi can effectively reduce CO2 to formic acid or formate. Among them, bismuth-based electrocatalysts are widely studied due to their low price and abundant reserves. However, in practical applications, bismuth-based catalysts are limited by complex synthesis steps and unsatisfactory catalytic current, which cannot meet the requirements of industrial applications. In order to solve this problem, the present study provides a simple method for mass production of bismuth oxide nanocomposites in a short time and realizes efficient electrocatalytic reduction of CO2 to prepare formate. SUMMARY

[0004] The present application aims to solve at least one of the above technical problems in the prior art. To this end, the purpose of the present application is to provide a bismuth oxide nanocomposite material and a preparation method and application thereof.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0006] The first aspect of the present application provides a preparation method of a bismuth oxide nanocomposite material.

[0007] The second aspect of the present application provides a bismuth oxide nanocomposite material.

[0008] The third aspect of the present application provides an application of a bismuth oxide nanocomposite material.

[0009] According to the first aspect of the present application, a preparation method of a bismuth oxide nanocomposite material is provided, which comprises the following steps:

[0010] S1: Dissolve bismuth salt in a strong acid solution to obtain solution A, and disperse it into water to obtain mixed solution B;

[0011] S2: Add ammonia water to mixed solution B, stir and react to obtain suspension C, centrifugally collect the solid product, wash and dry to obtain the bismuth oxide nanocomposite material.

[0012] In some embodiments of the present application, the bismuth salt of S1 is selected from bismuth nitrate pentahydrate or bismuth chloride.

[0013] In some embodiments of the present application, the bismuth salt is preferably bismuth nitrate pentahydrate.

[0014] In some embodiments of the present application, the strong acid of S1 is selected from one of concentrated nitric acid, concentrated hydrochloric acid.

[0015] In some embodiments of the present application, the molar ratio of the bismuth salt and the strong acid of S1 is 1:20-100.

[0016] In some embodiments of the present application, the molar concentration of the strong acid of S1 is 10-20 mol / L.

[0017] In some embodiments of the present application, the volume ratio of the solution A and water of S1 is 1:20-100, preferably 1:20-50, more preferably 1:20-30.

[0018] In some embodiments of the present application, the mass concentration of the ammonia water of S2 is 25%-30%.

[0019] In some embodiments of the present application, the volume ratio of the ammonia water and the mixed solution B of S2 is 1:2-4, preferably 1:2-3.

[0020] In some embodiments of the present application, the stirring reaction of S2 is at a temperature of 0-60℃ for 1 min-30 min.

[0021] In some embodiments of the present application, the stirring speed of the stirring reaction of S2 is 800-1000 rpm.

[0022] In some embodiments of the present application, the centrifugal speed of S2 is 8000-10000 rpm for 3-5 min.

[0023] In some embodiments of the present application, the washing of S2 is washing with deionized water for 3-5 times.

[0024] In some embodiments of the present application, the drying of S2 is vacuum drying at a temperature of 40-60℃.

[0025] According to a second aspect of the present application, a bismuth oxide nanocomposite is provided, which is prepared by the preparation method of the first aspect.

[0026] In some embodiments of the present application, the bismuth oxide nanocomposite has a nanotubular structure with an average diameter of 10-20 nm.

[0027] In some preferred embodiments of the present application, the average diameter of the bismuth oxide nanocomposite is 10-15 nm, preferably 10 nm.

[0028] According to a third aspect of the present application, there is provided a use of the bismuth oxide nanocomposite of the second aspect in the preparation of a catalyst.

[0029] In some embodiments of the present application, the catalyst is an electrocatalyst.

[0030] In some preferred embodiments of the present application, the catalyst electrocatalytically reduces CO2 into formate.

[0031] The present application has the following advantages:

[0032] Compared with other bismuth-based materials, the bismuth oxide nanocomposite of the present application has a larger electrochemical active area and stronger CO2 adsorption capacity, thereby exhibiting excellent electrocatalytic CO2 reduction activity and ideal formate selectivity. More importantly, the preparation method is green, simple and mass production in a short time, and is expected to be directly applied to industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A transmission electron microscope image of the bismuth oxide nanocomposite prepared in Example 1 of the present application;

[0034] Figure 2 An X-ray diffraction pattern of the bismuth oxide nanocomposite prepared in Example 1 of the present application;

[0035] Figure 3 A liquid-phase product detection of the cathode chamber when the bismuth oxide nanocomposite prepared in Example 1 of the present application is used to prepare a working electrode; 1 H-NMR chart;

[0036] Figure 4 A polarization curve chart when the bismuth oxide nanocomposite prepared in Example 1 of the present application and commercial bismuth are used to prepare a working electrode;

[0037] Figure 5 A formate faradic efficiency curve chart at different potentials when the bismuth oxide nanocomposite prepared in Example 1 of the present application and commercial bismuth are used to prepare a working electrode. DETAILED DESCRIPTION

[0038] The content of the present application is further described in detail through specific examples. The raw materials, reagents or devices used in the examples and comparative examples can be obtained from conventional commercial channels, or can be obtained by prior art methods, unless otherwise specified. Unless otherwise specified, the test or test method is a conventional method in the art.

[0039] The room temperature in each of the following examples is 20-30°C unless otherwise specified.

[0040] Example 1

[0041] In this example, a bismuth oxide nanocomposite is prepared, and the specific process is as follows:

[0042] (1) 400 mg of Bi(NO3)3·5H2O is dissolved in 5 mL of concentrated HNO3 (concentration 16 mol / L) at room temperature, and ultrasonic treatment is performed for 10 min until complete dissolution to obtain solution A;

[0043] (2) Solution A is dispersed into 100 mL of deionized water, and stirring is performed at a speed of 800 rpm for 30 min at room temperature to obtain solution B;

[0044] (3) 50 mL of ammonia water (mass concentration 30%) is quickly added to solution B, and stirring is performed at a speed of 800 rpm for 1 min at 0°C to obtain white suspension C;

[0045] (4) Solution C is centrifuged at 10,000 rpm for 3 min to collect the solid precipitate, which is washed with deionized water for 4 times, and then dried at 60°C in a vacuum drying box to obtain the bismuth oxide nanocomposite.

[0046] Example 2

[0047] In this example, a bismuth oxide nanocomposite is prepared, and the specific process is as follows:

[0048] (1) 156 mg of BiCl3 is dissolved in 5 mL of concentrated HCl (concentration 11.9 mol / L) at room temperature, and ultrasonic treatment is performed for 10 min until complete dissolution to obtain solution A;

[0049] (2) Solution A is dispersed into 100 mL of deionized water, and stirring is performed at a speed of 800 rpm for 30 min at room temperature to obtain solution B;

[0050] (3) 50 mL of ammonia water (mass concentration 30%) is quickly added to solution B, and stirring is performed at a speed of 900 rpm for 1 min at 0°C to obtain white suspension C;

[0051] (4) Solution C is centrifuged at 8,000 rpm for 5 min to collect the solid precipitate, which is washed with deionized water for 4 times, and then dried at 60°C in a vacuum drying box to obtain the bismuth oxide nanocomposite.

[0052] Example 4

[0053] In this example, a bismuth oxide nanocomposite is prepared, and the specific process is as follows:

[0054] (1) 400 mg of Bi(NO3)3·5H2O was dissolved in 2.5 mL of concentrated HNO3 (concentration 16 mol / L) at room temperature for 10 min to completely dissolve to obtain solution A;

[0055] (2) The A solution was dispersed into 100 mL of deionized water, and stirred at room temperature at a speed of 800 rpm for 30 min to obtain solution B;

[0056] (3) 50 mL of ammonia water (mass concentration 30%) was quickly added to the B solution, and stirred at 0°C for 1 min to obtain a white suspension C;

[0057] (4) The solution C was centrifuged at 9000 rpm for 4 min to collect the solid precipitate, and the product was washed with deionized water for 4 times. The separated solid was dried in a vacuum drying oven at 60°C to obtain a bismuth oxide nanocomposite.

[0058] Example 5

[0059] A bismuth oxide nanocomposite was prepared in this example, and the specific process was as follows:

[0060] (1) 400 mg of Bi(NO3)3·5H2O was dissolved in 5 mL of concentrated HNO3 (concentration 16 mol / L) at room temperature for 10 min to completely dissolve to obtain solution A;

[0061] (2) The A solution was dispersed into 100 mL of deionized water, and stirred at room temperature at a speed of 800 rpm for 30 min to obtain solution B;

[0062] (3) 50 mL of ammonia water (mass concentration 30%) was quickly added to the B solution, and stirred at 0°C for 1 min to obtain a white suspension C;

[0063] (4) The solution C was centrifuged at 10000 rpm for 3 min to collect the solid precipitate, and the product was washed with deionized water for 4 times. The separated solid was dried in a vacuum drying oven at 60°C to obtain a bismuth oxide nanocomposite.

[0064] Example 6

[0065] A bismuth oxide nanocomposite was prepared in this example, and the specific process was as follows:

[0066] (1) 400 mg of Bi(NO3)3·5H2O was dissolved in 5 mL of concentrated HNO3 (concentration 16 mol / L) at room temperature for 10 min to completely dissolve to obtain solution A;

[0067] (2) The A solution was dispersed into 100 mL of deionized water, and stirred at room temperature at a speed of 800 rpm for 30 min to obtain solution B;

[0068] (3) Take 50 mL of ammonia water (mass concentration 30%) and quickly add to the B solution, stir at 0°C for 1 min to obtain white suspension C;

[0069] (4) The solution C is centrifuged at 9000 rpm for 3 min to collect the solid precipitate, and the product is washed with deionized water for 4 times. After drying the separated solid in a vacuum drying oven at 60°C, a bismuth oxide nanocomposite is obtained.

[0070] Example 7

[0071] A bismuth oxide nanocomposite is prepared in this example, and the specific process is as follows:

[0072] (1) Dissolve 400 mg of Bi (NO3) 3·5H2O in 5 mL of concentrated HNO3 (concentration 16 mol / L) at room temperature, and ultrasonic for 10 min to completely dissolve to obtain solution A;

[0073] (2) Disperse the A solution into 100 mL of deionized water, and stir at 800 rpm for 30 min at room temperature to obtain solution B;

[0074] (3) Take 50 mL of ammonia water (mass concentration 30%) and quickly add to the B solution, stir at 0°C for 10 min to obtain white suspension C;

[0075] (4) The solution C is centrifuged at 8000 rpm for 3 min to collect the solid precipitate, and the product is washed with deionized water for 4 times. After drying the separated solid in a vacuum drying oven at 60°C, a bismuth oxide nanocomposite is obtained.

[0076] Example 8

[0077] A bismuth oxide nanocomposite is prepared in this example, and the specific process is as follows:

[0078] (1) Dissolve 400 mg of Bi (NO3) 3·5H2O in 5 mL of concentrated HNO3 (concentration 16 mol / L) at room temperature, and ultrasonic for 10 min to completely dissolve to obtain solution A;

[0079] (2) Disperse the A solution into 100 mL of deionized water, and stir at 800 rpm for 30 min at room temperature to obtain solution B;

[0080] (3) Take 50 mL of ammonia water (mass concentration 30%) and quickly add to the B solution, stir at 0°C for 30 min to obtain white suspension C;

[0081] (4) The solution C is centrifuged at 10000 rpm for 3 min to collect the solid precipitate, the product is washed with deionized water for 4 times, and the separated solid is dried in a vacuum drying box at 60°C to obtain the bismuth oxide nanocomposite.

[0082] Example 9

[0083] In this example, a bismuth oxide nanocomposite is prepared, and the specific process is as follows:

[0084] (1) 400 mg of Bi (NO3) 3·5H2O is dissolved in 5 mL of concentrated HNO3 (concentration 16 mol / L), ultrasonic for 10 min at room temperature until completely dissolved to obtain solution A;

[0085] (2) The A solution is dispersed into 100 mL of deionized water, stirred at 800 rpm for 30 min at room temperature to obtain solution B;

[0086] (3) 50 mL of ammonia water (mass concentration 30%) is quickly added to the B solution, stirred at 25°C for 1 min to obtain white suspension C;

[0087] (4) The solution C is centrifuged at 9000 rpm for 3 min to collect the solid precipitate, the product is washed with deionized water for 4 times, and the separated solid is dried in a vacuum drying box at 60°C to obtain the bismuth oxide nanocomposite.

[0088] Example 9

[0089] In this example, a bismuth oxide nanocomposite is prepared, and the specific process is as follows:

[0090] (1) 400 mg of Bi (NO3) 3·5H2O is dissolved in 5 mL of concentrated HNO3 (concentration 16 mol / L), ultrasonic for 10 min at room temperature until completely dissolved to obtain solution A;

[0091] (2) The A solution is dispersed into 100 mL of deionized water, stirred at 800 rpm for 30 min at room temperature to obtain solution B;

[0092] (3) 50 mL of ammonia water (mass concentration 25-30%) is quickly added to the B solution, stirred at 60°C for 1 min to obtain white suspension C;

[0093] (4) The solution C is centrifuged at 10000 rpm for 3 min to collect the solid precipitate, the product is washed with deionized water for 4 times, and the separated solid is dried in a vacuum drying box at 60°C to obtain the bismuth oxide nanocomposite.

[0094] Test Example

[0095] The bismuth oxide nanocomposite prepared in Example 1 was subjected to structural characterization and performance testing.

[0096] Structural characterization:

[0097] Figure 1 The transmission electron microscopy (TEM) image of the bismuth oxide nanocomposite prepared in Example 1 is shown in the figure. It can be seen from the figure that the sample exhibits a unique morphology of nanotubes, and the average diameter of the nanotubes is about 10-20 nm.

[0098] The bismuth oxide nanocomposite prepared in Example 1 was subjected to XRD testing under the following conditions: copper target Kα ray, 2θ scanning range of 10-80°, scanning speed of 15° / min, voltage of 40Kv, and the results are shown in Figure 2 Figure 2 It can be seen that the diffraction peaks of the bismuth oxide nanocomposite prepared in Example 1 correspond to standard cards PDF#47-1057 and PDF#51-1161, indicating that the bismuth oxide nanocomposite has been successfully prepared.

[0099] Performance testing:

[0100] (1) Electrode preparation

[0101] 10 mg of the bismuth oxide nanocomposite prepared in Example 1 and commercial Bi (brand: Angene Chemical, CAS:7440-89-9) were weighed as catalysts, 5 mg of commercial carbon powder (brand: Kaijin Chemical, model: Vulcan XC-72) was weighed, 950 μL of anhydrous ethanol and 50 μL of a 5% mass concentration Nafion solution were added, and a uniform dispersion was obtained by ultrasonic treatment. The dispersion was dropped onto a carbon cloth as a working electrode, and the catalyst loading was about 1 mg / cm 2 .

[0102] (2) Test conditions

[0103] Performance for electrochemical CO2 reduction to produce formate: the electrode prepared in step (1) was used as a working electrode, an Ag / AgCl electrode was used as a reference electrode, and a platinum sheet was used as a counter electrode to form a three-electrode system, and the electrolyte was a 0.5 mol / L KHCO3 solution.

[0104] The polarization curves (LSV) of the bismuth oxide nanocomposite of Example 1 and commercial bismuth were tested in a 0.5 mol / L KHCO3 solution saturated with Ar or CO2, and the results are shown in Figure 4 In the entire test voltage range, the current of the bismuth oxide nanocomposite prepared in Example 1 in saturated CO2 was greater than that in saturated Ar, indicating that it has the ability to reduce CO2. Combined with the detection of the liquid phase product in the cathode chamber, Figure 3 1 ​​The H-NMR chart shows that the reduction product is formate. As shown in Figure 5 Figure 2, at a potential of -1.1 V vs. RHE, the catalyst exhibits a formate faradaic efficiency of 98% and a total current density of greater than 75 mA / cm 2 The bismuth oxide nanocomposite prepared in Example 1 has a large electrochemical active area and strong CO2 adsorption capacity, thereby achieving efficient reduction of CO2 into formate.

[0105] The bismuth oxide nanocomposites prepared in other examples have similar structures and properties to the bismuth oxide nanocomposite prepared in Example 1, and are not described one by one.

[0106] The above examples are preferred embodiments of the present application, but the embodiments of the present application are not limited by the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application are equivalent replacement methods and are included in the protection scope of the present application.

Claims

1. Use of a bismuth oxide nanocomposite in the preparation of a catalyst, characterized in that, The bismuth oxide nanocomposite has a nanotubular structure with an average diameter of 10-20 nm; the bismuth oxide nanocomposite is Bi2O3 and BiO 2-x ; the catalyst electrocatalytically reduces CO2 into formate. The preparation method of the bismuth oxide nanocomposite comprises the following steps: S1: Dissolve a bismuth salt in a strong acid solution to obtain a solution A, and disperse the solution A into water to obtain a mixed solution B; the strong acid is selected from one of concentrated nitric acid and concentrated hydrochloric acid; the molar ratio of the bismuth salt to the strong acid is 1:50-100; the volume ratio of the solution A to water is 1:20-100; S2: Add ammonia water to the mixed solution B, stir and react to obtain a suspension C, centrifugally collect a solid product, wash, dry, and obtain the bismuth oxide nanocomposite; The volume ratio of the ammonia water to the mixed solution B is 1:2-4; The stirring and reaction in S2 are performed at a temperature of 0-60 ℃ for 1 min-30 min.

2. Use according to claim 1, characterized in that: The bismuth salt in S1 is selected from bismuth chloride or bismuth nitrate pentahydrate.

3. Use according to claim 1, characterized in that: The mass concentration of the ammonia water in S2 is 25%-35%.

4. Use according to claim 1, characterized in that: The drying in S2 is performed at a temperature of 40-60 ℃.

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