A dumbbell-shaped basic phosphate material, a preparation method and application thereof

Abstract

A dumbbell-shaped basic phosphate material and a preparation method and application thereof. A phosphate is dissolved in deionized water to obtain solution A; a transition metal acetate powder is dissolved in deionized water to obtain solution B; solution A is placed in an open container, and solution B is sprayed into solution A to generate a suspension of flocculent insoluble substances; the suspension of flocculent insoluble substances is aged under sealed conditions to convert the floating flocculent substances into precipitates; after the aging is completed and the temperature is lowered to room temperature, the obtained precipitates are separated, washed and dried to obtain the dumbbell-shaped basic phosphate material. The dumbbell-shaped basic phosphate material prepared by the method has a dumbbell-shaped morphology, and the dumbbell shape is assembled by rotating and twisting nanorods with gaps therebetween. The dumbbell-shaped basic phosphate material is applied as an electrocatalytic material, a secondary ion battery electrode material, a photocatalytic material and a photoanode material.

Description

Technical Field

[0001] This invention relates to the fields of nanomaterials and electrochemistry, specifically to a dumbbell-shaped basic phosphate material, its preparation method, and its application. Background Technology

[0002] Hydrogen is considered the most promising green energy source to replace fossil fuels. Electrocatalytic water splitting is an important method for large-scale hydrogen production. Currently, the main bottleneck in electrocatalytic water splitting is the development of highly efficient catalysts to reduce the overpotential required for water electrolysis. Transition metal materials, due to their low cost and good catalytic performance, have great development potential.

[0003] Transition metal basic phosphates, with their typical layered structure, not only facilitate mass transfer and ion migration between the electrode and electrolyte but also provide a large specific surface area, generating sufficient catalytic active sites. Furthermore, the diverse oxidation states of the metal ions result in rich redox behavior, while the protons of the phosphate groups can diffuse through the interlayer regions. These characteristics give them a unique advantage in highly active electrocatalysis.

[0004] Currently, methods for preparing transition metal basic phosphates include the copper site attraction method [Zhou Wei, Chen Xiaofang. Basic copper phosphate coated diatomite composite material and plastic composition and plastic product containing it and their preparation method [P]. Patent No.: CN201510627214.6]. Another method is the in-situ liquid phase growth method using copper sheets as a carrier [Che Wenchao, Jiao Wenling, Cheng Yifeng, et al. Flower-like and leaf-like basic copper phosphate composite materials based on copper sheets and their preparation method and application [P]. CN201611012615.1]. Hydrothermal method [Zeng Xiangbin, et al. Synthesis of basic copper phosphate and its LDS function study [J]. Plastics Industry, 2016, 44(2):34-38; BuX, et al. Two-dimensional cobalt phosphate hydroxide nanosheets: a new type of high-performance electrocatalysts with intrinsic CoO6 lattice distortion for water oxidation [J]. ACS applied materials & interfaces, 2019, 11(42):38633-38640.]. Precipitation method [Feng Xuefeng, et al. Preparation of basic iron phosphate and its electrocatalytic performance [J]. Journal of East China University of Technology (Natural Science Edition), 2018, 4, 426-429]. And solid-phase method [Tang Haijiang, et al. A method for preparing basic copper phosphate, a laser engraving material and its preparation method and application, CN202210758766.0].

[0005] As is well known, the performance of a catalyst is closely related to its specific surface area. Among the methods reported above, the copper site attraction method produces materials unsuitable for water electrolysis due to its complex procedures and long preparation time. The in-situ growth method of copper sheets is complex and influenced by numerous factors. Solid-state methods are energy-intensive and lack control over product morphology. Hydrothermal methods face many control variables, involving high-temperature and high-pressure reaction conditions, and the drawbacks of using a high-pressure reactor. Precipitation methods require surfactants to regulate morphology in order to prepare materials with a large specific surface area. Summary of the Invention

[0006] The purpose of this invention is to address the aforementioned technical problems by providing a dumbbell-shaped basic phosphate material, its preparation method, and its application.

[0007] To achieve the above objectives, the preparation method of the present invention is as follows:

[0008] 1) Dissolve phosphate in deionized water to obtain solution A with a phosphate concentration of 5-100 mmol / L;

[0009] 2) Dissolve transition metal acetate powder in deionized water to obtain solution B with a transition metal acetate concentration of 1-50 mmol / L;

[0010] 3) Take solution A and solution B in a volume ratio of 10:1. Place solution A in an open container and let it stand. Then spray solution B into solution A to generate a suspension of flocculent insoluble matter.

[0011] 4) The suspension of flocculent insoluble matter is transferred into a container and aged at 30-150°C under sealed conditions to turn the floating flocculent matter into precipitate;

[0012] 5) After the curing process is completed and the temperature is lowered to room temperature, the resulting precipitate is separated, washed, and dried to obtain dumbbell-shaped basic phosphate material.

[0013] In step 1), the phosphate is one of diammonium hydrogen phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, or a mixture thereof in any proportion.

[0014] In step 1), the phosphate concentration is 5–10 mmol / L.

[0015] The transition metal acetate in step 2) is cobalt acetate, iron acetate, nickel acetate, or copper acetate.

[0016] The concentration of the transition metal acetate solution in step 2) is 1–5 mmol / L.

[0017] Step 3) The spraying speed is ≥1mL / s.

[0018] The aging temperature in step 4) is 60–80°C.

[0019] Step 4) uses direct heating, water bath heating, or oil bath heating.

[0020] The dumbbell-shaped basic phosphate material prepared by the above method has a dumbbell-shaped morphology, and this dumbbell shape is assembled by rotating and twisting nanorods with gaps between them. The gaps between the nanorods can greatly increase the specific surface area of ​​the material, giving it more reactive sites.

[0021] The dumbbell-shaped basic phosphate materials prepared by the above method are used as electrocatalytic materials, secondary ion battery electrode materials, photocatalytic materials, and photoanode materials.

[0022] Compared with the prior art, the present invention has the following beneficial technical effects:

[0023] The method for preparing dumbbell-shaped basic phosphate materials in this invention has the following significant features: (1) This invention utilizes the difference in hydrolysis and ionization capabilities of phosphate and acetate ions to artificially create a reaction environment with a relative excess of phosphate ions but a very high reaction flux through a rapid spraying method, thereby obtaining basic phosphate materials in a short time. (2) During the synthesis process, acetate ions are adsorbed on specific crystal faces of the obtained crystal nuclei, inhibiting the growth of their crystal faces, thus producing a nano-column morphology. Furthermore, the nano-columns self-assemble through rotation and twisting to form a dumbbell morphology. (3) More importantly, because this invention is based on the difference in acid-base capabilities, there are very few factors that need to be controlled in the experiment, and the requirements for equipment and instruments are extremely simple, while the obtained material has a rich pore structure. (4) The preparation process is simple, easy to control and operate, has good safety and stability, is green and environmentally friendly, and is easy to achieve industrial-scale production. Attached Figure Description

[0024] Figure 1 This is the XRD pattern of the dumbbell-shaped basic copper phosphate nanomaterial prepared in Example 4 of this invention;

[0025] Figure 2 This is a SEM image of the dumbbell-shaped basic copper phosphate nanomaterial prepared in Example 4 of this invention;

[0026] Figure 3 This is a linear sweep voltammetric curve of the dumbbell-shaped basic copper phosphate nanomaterial prepared in Example 4 of the present invention for electrocatalytic hydrogen evolution.

[0027] Figure 4 This is a linear sweep voltammetric curve of the dumbbell-shaped basic copper phosphate nanomaterial prepared in Example 4 of the present invention for electrocatalytic oxygen evolution. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0029] Example 1

[0030] 1) Under magnetic stirring, diammonium hydrogen phosphate was dissolved in deionized water and stirred continuously for 0.5 h to obtain solution A with a phosphate concentration of 1 mmol / L;

[0031] 2) Under magnetic stirring, cobalt acetate powder of transition metal acetate was dissolved in deionized water and stirred continuously for 2 hours to obtain solution B with a transition metal acetate concentration of 5 mmol / L;

[0032] 3) Take solution A and solution B in a volume ratio of 10:1. Place solution A in an open container and, while it is in a static state, spray solution B into solution A at a spray rate of 5 mL / s to generate a suspension of flocculent insoluble matter.

[0033] 4) The suspension of flocculent insoluble matter is transferred into a container and heated to 60°C in a water bath under sealed conditions to mature the floating flocculent matter into precipitate;

[0034] 5) After the curing process is completed and the temperature is lowered to room temperature, the resulting precipitate is separated, washed, and dried to obtain dumbbell-shaped basic phosphate material.

[0035] Example 2

[0036] 1) Under magnetic stirring, a mixture of disodium hydrogen phosphate and dipotassium hydrogen phosphate was dissolved in deionized water and stirred continuously for 1 hour to obtain solution A with a phosphate concentration of 8 mmol / L.

[0037] 2) Under magnetic stirring, the transition metal acetate ferric acetate powder was dissolved in deionized water and stirred continuously for 4 hours to obtain solution B with a transition metal acetate concentration of 5 mmol / L.

[0038] 3) Take solution A and solution B in a volume ratio of 10:1. Place solution A in an open container and, while it is in a static state, spray solution B into solution A at a spray rate of 10 mL / s to generate a suspension of flocculent insoluble matter.

[0039] 4) The suspension of flocculent insoluble matter is transferred into a container and heated to 70°C in a water bath under sealed conditions to mature the floating flocculent matter into precipitate;

[0040] 5) After the curing process is completed and the temperature is lowered to room temperature, the resulting precipitate is separated, washed, and dried to obtain dumbbell-shaped basic phosphate material.

[0041] Example 3

[0042] 1) Under magnetic stirring, dissolve dipotassium hydrogen phosphate in deionized water and stir continuously for 2 hours to obtain solution A with a phosphate concentration of 10 mmol / L;

[0043] 2) Under magnetic stirring, the transition metal acetate nickel powder was dissolved in deionized water and stirred continuously for 1 hour to obtain solution B with a transition metal acetate concentration of 2.5 mmol / L;

[0044] 3) Take solution A and solution B in a volume ratio of 10:1. Place solution A in an open container and, while it is in a static state, spray solution B into solution A at a spray rate of 1 mL / s to generate a suspension of flocculent insoluble matter.

[0045] 4) The suspension of flocculent insoluble matter is transferred into a container and heated to 80°C under sealed conditions to mature the floating flocculent matter into precipitate;

[0046] 5) After the curing process is completed and the temperature is lowered to room temperature, the resulting precipitate is separated, washed, and dried to obtain dumbbell-shaped basic phosphate material.

[0047] Example 4

[0048] 1) Under magnetic stirring, diammonium hydrogen phosphate was dissolved in deionized water and stirred continuously for 2 hours to obtain solution A with a phosphate concentration of 1.5 mmol / L;

[0049] 2) Under magnetic stirring, copper acetate powder of transition metal acetate was dissolved in deionized water and stirred continuously for 2 hours to obtain solution B with a transition metal acetate concentration of 8 mmol / L.

[0050] 3) Take solution A and solution B in a volume ratio of 10:1. Place solution A in an open container and, while it is in a static state, spray solution B into solution A at a spray rate of 2 mL / s to generate a suspension of flocculent insoluble matter.

[0051] 4) The suspension of flocculent insoluble matter is transferred into a container and heated to 80°C in a water bath under sealed conditions to mature the floating flocculent matter into precipitate;

[0052] 5) After the curing process is completed and the temperature is lowered to room temperature, the resulting precipitate is separated, washed, and dried to obtain dumbbell-shaped basic phosphate material.

[0053] from Figure 1 As can be seen, the diffraction peaks of the prepared material conform well to standard card 36-0403, and the corresponding phase is Cu2(PO4)(OH). The diffraction peaks are sharp, the crystallinity is good, and there are no other impurity phases present, indicating that pure phase basic copper phosphate material can be obtained by using the technical route in this invention.

[0054] from Figure 2It can be seen that the prepared Cu2(PO4)(OH) material exhibits a dumbbell-shaped morphology, which is thinner in the middle and thicker at both ends. This dumbbell shape is formed by the self-assembly of nanopillars, and the abundant void structure between the nanopillars gives the material a high specific surface area. This is beneficial for electrolyte wetting and provides more reactive sites.

[0055] from Figure 3 and Figure 4 It can be seen that when the prepared Cu2(PO4)(OH) material is used for electrocatalytic water splitting, under alkaline conditions, the current density of the hydrogen evolution and oxygen evolution reactions reaches 10 mA / cm². 2 When the overpotentials are 215mV and 378mV respectively, the Cu2(PO4)(OH) material prepared in this invention can be used as a bifunctional catalyst for water electrolysis and has great application potential.

[0056] Example 5

[0057] 1) Disodium hydrogen phosphate was dissolved in deionized water under magnetic stirring for 3 hours to obtain solution A with a phosphate concentration of 30 mmol / L.

[0058] 2) Under magnetic stirring, the transition metal acetate cobalt acetate powder was dissolved in deionized water and stirred continuously for 0.5 h to obtain solution B with a transition metal acetate concentration of 1 mmol / L;

[0059] 3) Take solution A and solution B in a volume ratio of 10:1. Place solution A in an open container and, while it is in a static state, spray solution B into solution A at a spray rate of 3 mL / s to generate a suspension of flocculent insoluble matter.

[0060] 4) The suspension of flocculent insoluble matter is transferred into a container and heated to 100°C in an oil bath under sealed conditions to mature the floating flocculent matter into precipitate;

[0061] 5) After the curing process is completed and the temperature is lowered to room temperature, the resulting precipitate is separated, washed, and dried to obtain dumbbell-shaped basic phosphate material.

[0062] Example 6

[0063] 1) Under magnetic stirring, dissolve dipotassium hydrogen phosphate in deionized water and stir continuously for 4 hours to obtain solution A with a phosphate concentration of 50 mmol / L;

[0064] 2) Under magnetic stirring, copper acetate powder of transition metal acetate was dissolved in deionized water and stirred continuously for 3 hours to obtain solution B with a transition metal acetate concentration of 30 mmol / L.

[0065] 3) Take solution A and solution B in a volume ratio of 10:1. Place solution A in an open container and, while it is in a static state, spray solution B into solution A at a spray rate of 8 mL / s to generate a suspension of flocculent insoluble matter.

[0066] 4) The suspension of flocculent insoluble matter is transferred into a container and heated to 150°C under sealed conditions to mature the floating flocculent matter into precipitate;

[0067] 5) After the curing process is completed and the temperature is lowered to room temperature, the resulting precipitate is separated, washed, and dried to obtain dumbbell-shaped basic phosphate material.

[0068] Example 7

[0069] 1) Under magnetic stirring, a mixture of dipotassium hydrogen phosphate and diammonium hydrogen phosphate was dissolved in deionized water and stirred continuously for 3 hours to obtain solution A with a phosphate concentration of 100 mmol / L.

[0070] 2) Under magnetic stirring, the transition metal acetate ferric acetate powder was dissolved in deionized water and stirred continuously for 2 hours to obtain solution B with a transition metal acetate concentration of 50 mmol / L.

[0071] 3) Take solution A and solution B in a volume ratio of 10:1. Place solution A in an open container and, while it is in a static state, spray solution B into solution A at a spray rate of 6 mL / s to generate a suspension of flocculent insoluble matter.

[0072] 4) The suspension of flocculent insoluble matter is transferred into a container and heated to 30°C in a water bath under sealed conditions to mature the floating flocculent matter into precipitate;

[0073] 5) After the curing process is completed and the temperature is lowered to room temperature, the resulting precipitate is separated, washed, and dried to obtain dumbbell-shaped basic phosphate material.

Claims

1. A method for preparing a dumbbell-shaped basic phosphate material, characterized in that... Includes the following steps: 1) Dissolve phosphate in deionized water to obtain solution A with a phosphate concentration of 5~100 mmol / L; The phosphate is one of diammonium hydrogen phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, or a mixture thereof in any proportion; 2) Dissolve transition metal acetate powder in deionized water to obtain solution B with a transition metal acetate concentration of 1~50 mmol / L; 3) Take solution A and solution B in a volume ratio of 10:

1. Place solution A in an open container and let it stand. Then spray solution B into solution A to generate a suspension of flocculent insoluble matter. 4) The suspension of flocculent insoluble matter is transferred into a container and aged at 30~150℃ under sealed conditions to turn the floating flocculent matter into precipitate; 5) After the curing process is completed and the temperature is lowered to room temperature, the resulting precipitate is separated, washed, and dried to obtain dumbbell-shaped basic phosphate material.

2. The method for preparing dumbbell-shaped basic phosphate material according to claim 1, characterized in that: In step 1), the phosphate concentration is 5-10 mmol / L.

3. The method for preparing dumbbell-shaped basic phosphate material according to claim 1, characterized in that: The transition metal acetate in step 2) is cobalt acetate, iron acetate, nickel acetate, or copper acetate.

4. The method for preparing dumbbell-shaped basic phosphate material according to claim 1, characterized in that: The concentration of the transition metal acetate solution in step 2) is 1~5 mmol / L.

5. The method for preparing dumbbell-shaped basic phosphate material according to claim 1, characterized in that: Step 3) The spraying speed is ≥1 mL / s.

6. The method for preparing the dumbbell-shaped basic phosphate material according to claim 1, characterized in that: The aging temperature in step 4) is 60~80℃.

7. The method for preparing dumbbell-shaped basic phosphate material according to claim 1, characterized in that: Step 4) uses direct heating, water bath heating, or oil bath heating.

8. A dumbbell-shaped basic phosphate material prepared by any one of claims 1 to 7, characterized in that, The dumbbell-shaped basic phosphate material has a dumbbell-shaped morphology, and this dumbbell shape is assembled by rotating and twisting nanorods with gaps between them.

9. A dumbbell-shaped basic phosphate material prepared by any one of claims 1 to 7, characterized in that, This dumbbell-shaped basic phosphate material is used as an electrocatalytic material, a secondary ion battery electrode material, a photocatalytic material, and a photoanode material.

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