Preparation method of p-region element-containing lithium nitride and p-region element-containing lithium nitride

Abstract

The invention discloses a preparation method of a lithium nitride containing a p-region element and the lithium nitride containing the p-region element, and the preparation method comprises the following steps: in a nitrogen atmosphere, lithium hydride and a p-region element elementary substance are subjected to a reaction to obtain the lithium nitride containing the p-region element. The lithium nitride containing the p-region element is prepared by taking rich and cheap nitrogen molecules as a nitrogen source. And the prepared lithium nitride containing the p-region element is relatively high in purity. The preparation process is simple and easy to implement, easy to amplify and free of further separation and purification.

Description

Technical Field

[0001] The present application relates to a preparation method of lithium nitride containing p-zone elements and lithium nitride containing p-zone elements, belonging to the technical field of material synthesis. Background Art

[0002] Nitrogen molecules are the most important and abundant source of nitrogen in the material world and in living matter. Developing efficient conversion methods to convert nitrogen in nitrogen molecules into various functional nitrogen-containing compounds has long been the "holy grail" of academia and industry. The alkali metal element lithium (Li) can form ternary nitrides with many elements, including s-block, d-block, f-block, and p-block elements. Lithium nitrides containing p-block elements (such as Li3BN2, Li3AlN2, Li3GaN2, Li2SiN2) have rich physical and chemical properties and have potential application prospects in research fields such as optoelectronic devices and organic synthesis. Most of the synthetic methods reported in the literature use lithium nitride (Li3N) or lithium amide (LiNH2) as a nitrogen source to prepare lithium nitrides containing p-block elements. The reaction conditions are harsh (reaction temperature 750℃~900℃) and the yield is low.

[0003] The following are some typical synthesis methods of lithium nitrides containing p-block elements:

[0004] 1. Using lithium nitride as raw material, the reaction formula is as follows

[0005] Li3N+BN→Li3BN2

[0006] Li3N+AlN→Li3AlN2

[0007] 2Li3N+2Ga+N2→2Li3GaN2

[0008] 2Li3N+Si3N4→3Li2SiN2

[0009] 2. Using lithium amide as raw material, the reaction formula is as follows

[0010] 2LiNH2+LiBH4→Li3(BH4)(NH2)2; Li3(BH4)(NH2)2→Li3BN2+4H2

[0011] 2LiNH2+LiAlH4→Li3AlN2+4H2

[0012] 3LiNH2+GaN→Li3GaN2+2NH3

[0013] 3LiNH2+8Li3N+6SiCl4+12NH4Cl→6Li2SiN2+11NH3+15LiCl+21HCl

[0014] Nitrogen accounts for more than 78% of the volume of air and is the most abundant and cheapest nitrogen source. Synthesizing lithium nitrides containing p-block elements from nitrogen is more in line with the requirements of green and sustainable development of human society. However, the inherent inertness of nitrogen molecules determines that it is difficult to undergo chemical transformation. Exploring new ways to synthesize lithium nitrides containing p-block elements from nitrogen is very challenging. Summary of the invention

[0015] The present invention provides a method for directly synthesizing lithium nitrides containing p-zone elements (Li3BN2, Li3AlN2, Li3GaN2, Li2SiN2) from nitrogen. The present invention utilizes the reduction and nitrogen fixation properties of lithium hydride, directly uses nitrogen molecules and p-zone element single substances as raw materials to construct BN / Al-N / Ga-N / Si-N bonds, and develops a new synthesis route for lithium nitrides containing p-zone elements.

[0016] According to one aspect of the present application, a method for preparing a lithium nitride containing a p-block element is provided, the preparation method comprising:

[0017] In a nitrogen atmosphere, lithium hydride and a p-zone element are reacted to obtain the p-zone element-containing lithium nitride.

[0018] In the present application, a method for synthesizing lithium nitride containing p-block elements (Li3BN2, Li3AlN2, Li3GaN2, Li2SiN2) comprises the following steps:

[0019] Lithium hydride is reacted with a simple substance containing a p-region element (B, Al, Ga, Si) in a nitrogen atmosphere to prepare a lithium nitride containing a p-region element.

[0020] The reaction formula is as follows:

[0021] 2xLiH+2p+yN2→2Li x pN y +xH2(p=B,Al,Ga,Si)

[0022] Lithium hydride contains negatively charged hydrogen and has strong reducing properties. It can provide electrons to nitrogen to promote its activation and conversion.

[0023] Optionally, during the reaction, the nitrogen pressure is 1 to 50 bar.

[0024] Optionally, in the reaction, the nitrogen pressure is selected from any value of 1 bar, 2 bar, 5 bar, 10 bar, 20 bar, 30 bar, 40 bar, 50 bar, or a range between any two of the above values.

[0025] Optionally, the reaction temperature is 200-600°C.

[0026] Optionally, the reaction temperature is selected from any value of 200°C, 300°C, 400°C, 500°C, 600°C or a range between any two of the above values.

[0027] Optionally, the molar ratio of the lithium hydride to the p-block element is 1:0.1-100.

[0028] Optionally, the p-region element single substance is selected from at least one of inorganic boron single substance, aluminum single substance, gallium single substance, and inorganic silicon single substance.

[0029] Optionally, the inorganic boron element is selected from at least one of α-rhombic boron, β-rhombic boron, β-tetragonal boron, α-tetragonal boron, γ-orthorhombic boron and amorphous boron.

[0030] Optionally, the inorganic silicon element is selected from crystalline silicon and / or amorphous silicon.

[0031] Optionally, the reaction time is 1 to 24 hours.

[0032] Optionally, the reaction time is selected from any value of 1 h, 2 h, 5 h, 12 h, 16 h, 18 h, 24 h, or a range between any two of the above.

[0033] Optionally, the reaction conditions are: heating by electric furnace or microwave.

[0034] According to another aspect of the present application, a lithium nitride containing a p-region element prepared by the above-mentioned preparation method is provided.

[0035] Optionally, the p-region element-containing lithium nitride includes one of Li3BN2, Li3AlN2, Li3GaN2, and Li2SiN2.

[0036] The specific operation steps of the present invention are:

[0037] 1) Mixing lithium hydride and p-block element single substances (B, Al, Ga, Si);

[0038] 2) Explore the reaction temperature for synthesizing lithium nitrides containing p-block elements (Li3BN2, Li3AlN2, Li3GaN2, Li2SiN2) through temperature-programmed reduction-mass spectrometry (TPR-MS) characterization technology;

[0039] 3) preparing lithium nitrides containing p-block elements (Li3BN2, Li3AlN2, Li3GaN2, Li2SiN2) within a selected temperature range;

[0040] 4) Perform X-ray diffraction (XRD) test and analysis on the prepared lithium nitrides containing p-zone elements (Li3BN2, Li3AlN2, Li3GaN2, Li2SiN2).

[0041] The beneficial effects of this application include:

[0042] 1) The present application provides a method for preparing lithium nitrides containing p-region elements (Li3BN2, Li3AlN2, Li3GaN2, Li2SiN2) using abundant and cheap nitrogen molecules as a nitrogen source.

[0043] 2) The prepared lithium nitrides containing p-zone elements (Li3BN2, Li3AlN2, Li3GaN2, Li2SiN2) provided in this application have high purity.

[0044] 3) The preparation process of the present application is simple and easy to implement and scale up, and no further separation and purification is required. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is the XRD spectrum of Li3BN2 synthesized in Example 1 of the present application.

[0046] Figure 2 This is the XRD spectrum of Li3AlN2 synthesized in Example 2 of the present application.

[0047] Figure 3 This is the XRD spectrum of Li3GaN2 synthesized in Example 3 of the present application.

[0048] Figure 4 This is the XRD spectrum of Li2SiN2 synthesized in Example 4 of the present application.

[0049] Figure 5 This is the XRD spectrum of Li3GaN2 synthesized in Example 5 of the present application. DETAILED DESCRIPTION

[0050] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0051] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0052] The instruments used in this application are: the instrument used for ball milling experiment is PM400 planetary ball mill produced by Retsch Company of Germany; the instrument used for XRD characterization technology is Panalytical X'pert Pro rotating target X-ray powder diffractometer produced by Philips Company of the Netherlands; the mass spectrometer used for TPR-MS characterization technology is HPR20 gas phase mass spectrometer produced by Hidden Company of the United Kingdom.

[0053] Example 1: Li3BN2 was prepared by heating with lithium hydride, amorphous boron and nitrogen as raw materials using an electric furnace.

[0054] (1) In a glove box, under the protection of argon atmosphere, 0.4 g lithium hydride and 0.22 g amorphous boron (molar ratio 2.5:1) were accurately weighed, briefly mixed, and placed in a ball mill, and mechanically milled for 10 h at a speed of 200 rpm;

[0055] (2) taking 50 mg of the ball-milled product of step (1) for TPR-MS testing, heating from room temperature to 550°C at a heating rate of 5°C / min;

[0056] (3) Confirm the dehydrogenation temperature of the sample through step (2), select the appropriate electric furnace heating temperature of 450°C and nitrogen pressure of 10 bar to synthesize Li3BN2, react for 2 hours, and collect the product for XRD test. Figure 1 As shown, when an inorganic boron element (such as amorphous boron in Example 1) is used as a raw material, the characteristic diffraction peak of Li3BN2 can be observed in the XRD spectrum of the prepared product.

[0057] Example 2: Li3AlN2 was prepared by heating with lithium hydride, aluminum and nitrogen as raw materials using an electric furnace.

[0058] (1) In a glove box, under the protection of argon atmosphere, 0.48 g lithium hydride and 0.54 g aluminum (molar ratio 3:1) were accurately weighed, briefly mixed, and placed in a ball mill, and mechanically milled for 10 h at a speed of 200 rpm;

[0059] (2) taking 50 mg of the ball-milled product of step (1) for TPR-MS testing, heating from room temperature to 550°C at a heating rate of 5°C / min;

[0060] (3) Confirm the dehydrogenation temperature of the sample through step (2), select the appropriate electric furnace heating temperature of 550°C and nitrogen pressure of 10 bar to synthesize Li3AlN2, react for 3 hours, and collect the product for XRD test. Figure 2 As shown, using inorganic aluminum (such as aluminum in Example 2) as raw material, the characteristic diffraction peak of Li3AlN2 can be observed in the XRD spectrum of the prepared product.

[0061] Example 3: Li3GaN2 is prepared by heating with lithium hydride, gallium and nitrogen as raw materials using an electric furnace

[0062] (1) In a glove box, under the protection of argon atmosphere, 0.24 g lithium hydride and 0.70 g gallium (molar ratio 3:1) were accurately weighed, briefly mixed, and placed in a ball mill, and mechanically milled for 10 h at a speed of 200 rpm;

[0063] (2) taking 50 mg of the ball-milled product of step (1) for TPR-MS testing, heating from room temperature to 550°C at a heating rate of 5°C / min;

[0064] (3) Confirm the dehydrogenation temperature of the sample through step (2), select the appropriate electric furnace heating temperature of 550°C and nitrogen pressure of 10 bar to synthesize Li3GaN2, react for 2 hours, and collect the product for XRD test. Figure 3 As shown, using inorganic gallium (such as gallium in Example 3) as raw material, the characteristic diffraction peak of Li3GaN2 can be observed in the XRD spectrum of the prepared product.

[0065] Example 4: Li2SiN2 was prepared by heating with lithium hydride, amorphous silicon and nitrogen as raw materials using an electric furnace.

[0066] (1) In a glove box, under the protection of argon atmosphere, 0.32 g lithium hydride and 0.56 g amorphous silicon (molar ratio 2:1) were accurately weighed, briefly mixed, and placed in a ball mill, and mechanically milled for 10 h at a speed of 200 rpm;

[0067] (2) taking 50 mg of the ball-milled product of step (1) for TPR-MS testing, heating from room temperature to 550°C at a heating rate of 5°C / min;

[0068] (3) Confirm the dehydrogenation temperature of the sample through step (2), select the appropriate electric furnace heating temperature of 550°C and nitrogen pressure of 20 bar to synthesize Li2SiN2, react for 3 hours, and collect the product for XRD test. Figure 4 As shown, when inorganic silicon (such as amorphous silicon in Example 4) is used as raw material, the characteristic diffraction peak of Li2SiN2 can be observed in the XRD spectrum of the prepared product.

[0069] Example 5: Li3GaN2 was prepared by microwave heating using lithium hydride, gallium and nitrogen as raw materials.

[0070] (1) In a glove box, under the protection of argon atmosphere, 0.24 g lithium hydride and 0.70 g gallium (molar ratio 3:1) were accurately weighed, briefly mixed, and placed in a ball mill, and mechanically milled for 10 h at a speed of 200 rpm;

[0071] (2) taking 50 mg of the ball-milled product of step (1) for TPR-MS testing, heating from room temperature to 550°C at a heating rate of 5°C / min;

[0072] (3) Confirm the dehydrogenation temperature of the sample through step (2), select the appropriate microwave heating temperature of 400°C and nitrogen pressure of 1 bar to synthesize Li3GaN2, react for 3 hours, and collect the product for XRD test. Figure 3 and 5As shown, using inorganic gallium as raw material and heating by electric furnace (such as Example 3) or microwave (such as Example 5), the characteristic diffraction peak of Li3GaN2 can be observed in the XRD spectrum of the prepared product, indicating that Li3GaN2 can be successfully synthesized by these two heating methods.

[0073] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing a lithium nitride containing a p-block element, characterized in that: The preparation method comprises: In a nitrogen atmosphere, lithium hydride and a p-zone element are reacted to obtain the p-zone element-containing lithium nitride.

2. The preparation method according to claim 1, characterized in that: In the reaction, the nitrogen pressure is 1 to 50 bar.

3. The preparation method according to claim 1, characterized in that: The reaction temperature is 200-600°C.

4. The preparation method according to claim 1, characterized in that: The molar ratio of the lithium hydride to the p-zone element is 1:0.1-100.

5. The preparation method according to claim 1, characterized in that: The p-zone element single substance is selected from at least one of inorganic boron single substance, aluminum single substance, gallium single substance, and inorganic silicon single substance.

6. The preparation method according to claim 5, characterized in that: The inorganic boron element is selected from at least one of α-rhombic boron, β-rhombic boron, β-tetragonal boron, α-tetragonal boron, γ-orthorhombic boron and amorphous boron.

7. The preparation method according to claim 5, characterized in that: The inorganic silicon single substance is selected from crystalline silicon and / or amorphous silicon.

8. The preparation method according to claim 1, characterized in that The reaction time is 1 to 24 hours.

9. The preparation method according to claim 1, characterized in that: The reaction conditions are: heating by electric furnace or microwave.

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