A method of electrochemically synthesizing metal nitrides

Abstract

The application discloses a method for electrochemically synthesizing metal nitride, comprising: under anhydrous and anaerobic conditions, nitrogen is activated by a catalyst and reacts with metal ions in a solution containing the metal ions and an organic solvent under discharge to generate metal nitride. The method can produce metal nitride in a quick and simple manner, and has simple process and low cost; the method generates metal nitride through electrochemical nitrogen reduction, and is suitable for synthesis of various metal nitrides, and has strong universality and practicability.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of metal-air batteries, and particularly relates to a method for electrochemically synthesizing metal nitride. BACKGROUND

[0002] Metal nitride has great potential in the field of electrochemical catalysis. It has a special crystal structure, is an intermetallic compound, and has good electron conductivity, excellent chemical stability and high corrosion resistance. In particular, some metal nitrides have similar catalytic properties to noble metals due to the expansion of the metal lattice caused by the embedding of nitrogen atoms, which leads to a similar electronic structure to noble metals.

[0003] However, metal nitride is usually synthesized by high-temperature thermal reaction, which has harsh reaction conditions and complex subsequent processing. In addition, a large amount of energy needs to be applied to heat the reaction, and the energy utilization rate of the thermal reaction is low, and the excess heat is easily dispersed in the air, which can cause the greenhouse effect.

[0004] Metal-nitrogen battery systems store and convert energy by absorbing nitrogen feedstock. Notably, this battery system is promising in terms of nitrogen fixation capacity and Faraday efficiency (FE). Metal nitride can be relatively easily converted into NH3 product, which is essential in the manufacture of nitrogen fertilizer and is considered an ideal carbon-free energy carrier. However, there are currently few reports on the preparation of metal nitride by electrochemical methods based on metal-nitrogen battery systems. SUMMARY

[0005] In view of this, the present application aims to provide a method for electrochemically synthesizing metal nitride based on an organic system metal-nitrogen battery. The method dissolves the salt of the target metal in an organic solvent system, and in the organic solvent system containing the metal ion of the target metal, the inhaled nitrogen is catalytically reduced in the discharge process and combined with the metal ion, thereby generating metal nitride.

[0006] According to the present application, a method for electrochemically synthesizing metal nitride is provided, comprising:

[0007] Under anhydrous and anaerobic conditions, nitrogen is activated by a catalyst and reacts with metal ions in a solution containing metal ions and organic solvents under discharge to generate metal nitride.

[0008] According to the present application, N2 is activated to N* by a cathode catalyst material, and then N* is combined with metal ion M n + to generate metal nitride.

[0009] According to the present application, the overall reaction process for generating metal nitride is as follows:

[0010] M n+ +N2→ MN

[0011] where M is a metal ion, n is the valence, and MN is a metal nitride. n+

[0012] It is noted that the above reaction scheme is merely illustrative of the reaction process, for example, "MN" merely represents a metal nitride, but is not limited to the case where M and N are combined in equimolar amounts.

[0013] Optionally, the catalyst is used as a cathode, the metal is used as an anode, and the solution is used as an electrolyte.

[0014] Optionally, a separator is used between the cathode and the electrolyte.

[0015] Preferably, the separator comprises a polypropylene separator.

[0016] In one embodiment, the separator is a polypropylene separator, such as Celgard 2400.

[0017] Optionally, the discharging comprises applying a voltage, and reducing the voltage to 0.01 V at a constant current density.

[0018] Optionally, the constant current density is 0.01-0.25 mA.

[0019] Optionally, the constant current density is independently any value selected from 0.01 mA, 0.02 mA, 0.03 mA, 0.04 mA, 0.05 mA, 0.06 mA, 0.07 mA, 0.08 mA, 0.09 mA, 0.10 mA, 0.11 mA, 0.12 mA, 0.13 mA, 0.14 mA, 0.15 mA, 0.16 mA, 0.17 mA, 0.18 mA, 0.19 mA, 0.20 mA, 0.21 mA, 0.22 mA, 0.23 mA, 0.24 mA, 0.25 mA, or a range between any two of these values. Illustratively, the constant current density is 0.02 mA, 0.06 mA, 0.10 mA, 0.12 mA, 0.16 mA, or 0.20 mA.

[0020] Preferably, the constant current density is 0.02-0.20 mA.

[0021] Optionally, the catalyst comprises a metal catalyst.

[0022] Preferably, the catalyst is at least one selected from platinum (Pt), titanium (Ti), molybdenum (Mo), ruthenium (Ru), gold (Au), steel, nickel (Ni), and copper (Cu).

[0023] ​According to the present application, when steel is used as a catalyst, it means steel as generally known in the art.

[0024] Optionally, the metal comprises magnesium (Mg), zinc (Zn), iron (Fe) or nickel (Ni).

[0025] According to the present application, the catalyst used as cathode and the metal used as anode are independently in a form such as mesh or sheet.

[0026] Optionally, the organic solvent is at least one selected from ethylene glycol dimethyl ether (DME), tetrahydrofuran (THF), dimethyl carbonate (DMC), propylene carbonate (PC), tetraethylene glycol dimethyl ether (TEGDME), diethyl carbonate (DEC), 1-butyl-3-methylimidazolium chloride ionic liquid, 1-ethyl-3-methylimidazolium chloride ionic liquid, 1-methylimidazole ionic liquid, bistrifluoromethanesulfonylimide ionic liquid, N-alkyl-N-methylpyrrolidine ionic liquid, alkyltributylphosphonium ionic liquid.

[0027] According to the present application, the corresponding organic solvent can be selected depending on the kind of the metal-nitrogen battery, for example.

[0028] According to the present application, the method is performed in anhydrous and anaerobic environment.

[0029] According to the present application, the term “anhydrous (environment)” means that the content of water in the environment is ≤ 0.1 ppm; the term “anaerobic (environment)” means that the content of oxygen in the environment is ≤ 0.1 ppm.

[0030] Optionally, in the solution, the metal ion is in the form of at least one salt selected from chloride, trifluoromethylsulfonate.

[0031] Optionally, the flow rate of the nitrogen gas is 8-25 seem.

[0032] Optionally, the flow rate of the nitrogen gas is independently selected from any value or a range value between any two values selected from 8 seem, 9 seem, 10 seem, 11 seem, 12 seem, 13 seem, 14 seem, 15 seem, 16 seem, 17 seem, 18 seem, 19 seem, 20 seem, 21 seem, 22 seem, 23 seem, 24 seem, 25 seem.

[0033] Preferably, the flow rate of the nitrogen gas is 10-20 seem.

[0034] Optionally, the production rate of the metal nitride is 0.010-1.550 mg·h -1 ·cm -2 .

[0035] Optionally, the production rate of the metal nitride is independently selected from the group consisting of 0.010 mg-h -1 -cm -2 , 0.011 mg-h -1 -cm -2 , 0.012 mg-h -1 -cm -2 , 0.015 mg-h -1 -cm -2 , 0.018 mg-h -1 -cm -2 , 0.020 mg-h -1 -cm -2 , 0.025 mg-h -1 -cm -2 , 0.030 mg-h -1 -cm -2 , 0.040 mg-h -1 -cm -2 , 0.050 mg-h -1 -cm -2 , 0.060 mg-h -1 -cm -2 , 0.070 mg-h -1 -cm -2 , 0.080 mg-h -1 -cm -2 , 0.090 mg-h -1 -cm -2 , 0.100 mg-h -1 -cm -2 , 0.150 mg-h -1 -cm -2 , 0.200 mg-h -1 -cm -2 , 0.250 mg-h -1 -cm -2 , 0.300 mg-h -1 -cm -2 , 0.350 mg-h -1 -cm -2 , 0.400 mg-h -1 -cm -2 , 0.450 mg-h -1 -cm -2 , 0.500 mg-h -1 -cm -2 , 0.550 mg-h -1 -cm -2 , 0.600 mg-h -1 -cm-2 , 0.650 mg-h -1 ·cm -2 , 0.700 mg-h -1 ·cm -2 , 0.750 mg-h -1 ·cm -2 , 0.800 mg-h -1 ·cm -2 , 0.850 mg-h -1 ·cm -2 , 0.900 mg-h -1 ·cm -2 , 0.950 mg-h -1 ·cm -2 , 1.000 mg-h -1 ·cm -2 , 1.050 mg-h -1 ·cm -2 , 1.100 mg-h -1 ·cm -2 , 1.150 mg-h -1 ·cm -2 , 1.200 mg-h -1 ·cm -2 , 1.250 mg-h -1 ·cm -2 , 1.300 mg-h -1 ·cm -2 , 1.350 mg-h -1 ·cm -2 , 1.400 mg-h -1 ·cm -2 , 1.450 mg-h -1 ·cm -2 , 1.500 mg-h -1 ·cm -2 , 1.550 mg-h -1 ·cm -2 .

[0036] Optionally, the concentration of the metal ion in the solution is 0.5-2 mol·L -1 .

[0037] Optionally, the concentration of the metal ion in the solution is independently selected from the group consisting of 0.5 mol·L -1 , 0.6 mol·L -1 , 0.7 mol·L -1 , 0.8 mol·L -1 , 0.9 mol·L -11.0 mol·L-1 -1 1.1 mol·L-1 -1 1.2 mol·L-1 -1 1.3 mol·L-1 -1 1.4 mol·L-1 -1 1.5 mol·L-1 -1 1.6 mol·L-1 -1 1.7 mol·L-1 -1 1.8 mol·L-1 -1 1.9 mol·L-1 -1 2.0 mol·L-1 -1 any value or a range value between any two values.

[0038] In one embodiment, when the organic solvent is an ionic liquid, the mass ratio of the salt of metal ions to the ionic liquid is 1.5:1-1:1.5.

[0039] In one embodiment, the mass ratio of the salt of metal ions to the ionic liquid is independently selected from any value or a range value between any two values selected from 1.5:1, 1.4:1, 1.3:1, 1.2:1, 1.1:1, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5.

[0040] In one specific embodiment of the present application, the method comprises: in anhydrous and anaerobic environment, taking the catalyst as a cathode and the corresponding battery metal as an anode; passing nitrogen into a sealed reactor for 1 h to fill the reactor with nitrogen; setting a constant current density to generate a metal nitride.

[0041] The beneficial effects that can be produced by the present application include:

[0042] 1) The method of the present application can produce metal nitrides in a fast and simple manner, which is simple and low in cost compared with conventional processes which are complex, high in energy consumption and easy to cause environmental pollution.

[0043] 2) The method of the present application generates metal nitrides by electrochemical nitrogen reduction, which is suitable for the synthesis of various metal nitrides, and has strong universality and practicality. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 It is a schematic diagram of the assembly of Mg-N2 button cell in Example 1 and Zn-N2 button cell in Example 2.

[0045] Figure 2 It is a scanning electron microscope photo of Ti mesh used as a positive electrode in Example 1.

[0046] Figure 3The image shows the XRD pattern of the product Mg3N2 from Example 1.

[0047] Figure 4 This is a scanning electron microscope image of the Pt mesh used as the positive electrode in Example 2.

[0048] Figure 5 The image shows the XRD pattern of Zn3N2, the product from Example 2. Detailed Implementation

[0049] The technical solutions of this application will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to illustrate and explain this application, and should not be construed as limiting the scope of protection of this application. All technical solutions implemented based on the above content of this application are covered within the scope of protection claimed by this application.

[0050] Experimental methods not specified in the following examples are generally performed under standard conditions or as recommended by the manufacturer.

[0051] Unless otherwise stated, all raw materials and reagents used in the embodiments of this application were purchased commercially and used directly without treatment. Celgard 2400 polypropylene diaphragms were purchased from Celgard Corporation, USA.

[0052] The instruments used in the embodiments of this application are as follows:

[0053] The LAND battery testing system, model land-ct2001a, was purchased from Wuhan Shenglan Electronics Technology Co., Ltd. X-ray diffraction (XRD) was performed using an X-ray diffractometer, model DX-2700BH, purchased from Dandong Haoyuan Instrument Co., Ltd. X-ray photoelectron spectroscopy (XPS) was performed using a Kratos X-ray photoelectron spectrometer, model AXIS SUPRA+, purchased from Shimadzu Corporation. Scanning electron microscopy (SEM) was performed using a ZEISS Sigma scanning electron microscope, purchased from Carl Zeiss Corporation.

[0054] Example 1

[0055] (1) Preparation and characterization of magnesium nitride

[0056] 1.935 g of magnesium trifluoromethanesulfonate (Mg(CF3SO3)2) was dissolved in 10 ml of DME to prepare Mg(CF3SO3)2 with a concentration of 0.6 mol·L⁻¹. -1 The prepared solution was used as the electrolyte, a 1.6 cm diameter Ti sheet was used as the positive electrode, a 1.6 cm diameter Mg mesh was used as the negative electrode, and a Celgard 2400 polypropylene membrane was used as the separator to assemble a Mg-N2 coin cell.

[0057] Figure 1 The assembly schematic of the Mg-N2 button cell is shown. Figure 2 The scanning electron microscope photo of Ti sheet used as the positive electrode is shown (scale bar 300 pm).

[0058] In the anhydrous and anaerobic glove box, N2was passed to the positive electrode side at a certain flow rate, and the reaction was started after 30 min activation.

[0059] The voltage was applied using the LAND battery testing system, and the constant current discharge was set to 0.01 V. It was considered that the nitrogen molecules were reduced by the cathode at a potential of about 0.35 V, and the total reaction process was as shown below:

[0060] 3Mg 2+ +N2→Mg3N2

[0061] The product in Example 1 was characterized using XRD and XPS. Figure 3 The XRD spectrum of the product obtained on the surface of the cathode catalyst is shown, in which the typical characteristic peaks of Mg3N2are clearly shown, indicating that Mg3N2was successfully prepared in Example 1.

[0062] (2) Production rate of magnesium nitride

[0063] The inventors found through experiments that when the current density was set to be different, the amount of Mg3N2obtained was also different under the condition that the nitrogen flow rate and the reaction time were unchanged. Under the condition that the nitrogen flow rate was 10 sccm for 6 h, the production rate of Mg3N2obtained is shown in Table 1.

[0064] Table 1: Mg3N2production rate when the nitrogen flow rate is the same and the current density is different

[0065]

[0066] In addition, when the nitrogen flow rate was set to be different, the amount of Mg3N2obtained was also different under the condition that the current density and the reaction time were unchanged. Under the condition that the current density was 0.02 mA·cm -2 for 6 h, the production rate of Mg3N2obtained is shown in Table 2.

[0067] Table 2: Mg3N2production rate when the current density is the same and the nitrogen flow rate is different

[0068]

[0069] From the above experiments, it can be known that under the condition that the discharge current density is 0.02-0.20 mA·cm -2 , the nitrogen flow rate is 10-20 sccm, the optimal production rate of Mg3N2is 1.539 mg·h -1 ·cm-2 .

[0070] Comparative Example 1

[0071] Preparation and characterization were carried out in the same way as in Example 1, except that N2was replaced by Ar. That is, in an anhydrous and oxygen-free glove box, Ar was introduced into the positive electrode side at a flow rate of 10 sccm, and the electrolysis was started after standing for 30 min.

[0072] The product in Comparative Example 1 was characterized using XRD. From the XRD spectra of the electrode surface before and after electrolysis, it can be seen that Mg3N2cannot be prepared under Ar atmosphere, and can only be synthesized under N2atmosphere.

[0073] Example 2

[0074] (1) Preparation and characterization of zinc nitride

[0075] 5 g of zinc chloride (ZnCl2) was dissolved in 5 g of 1-butyl-3-methylimidazolium chloride ionic liquid to prepare a solution at a mass ratio of 1:1. Using the prepared solution as the electrolyte, a Pt mesh with a diameter of 1.6 cm was used as the positive electrode, a Zn sheet with a diameter of 1.6 cm was used as the negative electrode, and a Celgard 2400 polypropylene separator was used as the separator, thereby assembling a Zn-N2button cell.

[0076] Figure 1 The schematic diagram of the assembly of the Zn-N2button cell is shown. Figure 4 The scanning electron microscope photo of the Pt mesh used as the positive electrode is shown (scale bar 300 μm).

[0077] In an anhydrous and oxygen-free glove box, N2was introduced into the positive electrode side at a certain flow rate, and the reaction was started after activation for 30 min.

[0078] The voltage was applied using a LAND battery detection system, and a constant current discharge was set to 0.01 V. It is believed that nitrogen molecules are reduced by the cathode at a potential of about 0.24 V, and the overall reaction process is as follows:

[0079] 3Zn 2+ +N2→Zn3N2

[0080] The product in Example 2 was characterized using XRD and XPS. Figure 5 The XRD spectrum of the product on the surface of the cathode catalyst is shown, in which the typical characteristic peaks of Zn3N2are clearly shown, indicating that Zn3N2was successfully prepared in Example 2.

[0081] (2) Production rate of zinc nitride

[0082] The inventors found through experiments that when different current densities were set, the amount of Zn3N2obtained was also different, under the condition that the nitrogen flow rate and reaction time were unchanged. The production rate of Zn3N2obtained under the condition that the nitrogen flow rate was 10 sccm for 6 h is shown in Table 3.

[0083] Table 3: Zn3N2production rate when the nitrogen flow rate is the same and the current density is different

[0084]

[0085] In addition, when different nitrogen flow rates were set, the amount of Zn3N2obtained was also different, under the condition that the current density and reaction time were unchanged. The production rate of Zn3N2obtained under the condition that the current density was 0.02 mA·cm -2 for 6 h is shown in Table 4.

[0086] Table 4: Zn3N2production rate when the current density is the same and the nitrogen flow rate is different

[0087]

[0088] Through the above experiments, it can be known that when the discharge current density is 0.02-0.20 mA·cm -2 , the nitrogen flow rate is 10-20 sccm, the optimal production rate of Zn3N2is 0.951 mg·h -1 ·cm -2 .

[0089] Comparative Example 2

[0090] Preparation and characterization were performed according to the same process as Example 2, except that N2was replaced by Ar. That is, in an anhydrous and oxygen-free glove box, Ar was introduced into the positive electrode side at a flow rate of 10 sccm, and electrolysis was started after standing for 30 min.

[0091] The product in Comparative Example 2 was characterized using XRD. From the XRD spectra of the electrode surface before and after electrolysis, it can be known that Zn3N2cannot be prepared under Ar atmosphere, and can only be synthesized under N2atmosphere.

[0092] Example 3

[0093] (1) Preparation of magnesium nitride

[0094] Magnesium trifluoromethanesulfonate (Mg(CF3SO3)2) was dissolved in the organic solvent ethylene glycol dimethyl ether (DME) to prepare a solution with a Mg(CF3SO3)2concentration of 0.6 M. Using the prepared solution as the electrolyte, a Mo mesh with a diameter of 1.6 cm as the catalyst and positive current collector, a Mg mesh with a diameter of 1.6 cm as the negative electrode, and a Celgard 2400 polypropylene separator as the separator, a Mg-N2button cell was assembled.

[0095] In an anhydrous and anaerobic glove box, N2was introduced to the positive electrode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 ·2. -1 ·2. -2 .

[0096] (2) Preparation of zinc nitride

[0097] Zinc chloride (ZnCl2) was dissolved in 1-butyl-3-methylimidazolium chloride ionic liquid to prepare a solution with a mass ratio of 1:1. Using the prepared solution as the electrolyte, a Mo mesh with a diameter of 1.6 cm as the catalyst and positive current collector, a Zn sheet with a diameter of 1.6 cm as the negative electrode, and a Celgard 2400 polypropylene separator as the separator, a Zn-N2button cell was assembled.

[0098] In an anhydrous and anaerobic glove box, N2was introduced to the positive electrode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 ·2. -1 ·2. -2 .

[0099] Example 4

[0100] (1) Preparation of magnesium nitride

[0101] Magnesium trifluoromethanesulfonate (Mg(CF3SO3)2) was dissolved in the organic solvent ethylene glycol dimethyl ether (DME) to prepare a solution with a Mg(CF3SO3)2concentration of 0.6 M. Using the prepared solution as the electrolyte, a Mo mesh with a diameter of 1.6 cm as the catalyst and positive current collector, a Mg mesh with a diameter of 1.6 cm as the negative electrode, and a Celgard 2400 polypropylene separator as the separator, a Mg-N2button cell was assembled.

[0102] In an anhydrous and anaerobic glove box, N2was bubbled into the cathode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The production rate of Mg3N2was 0.126 mg-h -1 -cm -2 .

[0103] (2) Preparation of zinc nitride

[0104] Zinc chloride (ZnCl2) was dissolved in 1-butyl-3-methylimidazolium chloride ionic liquid to prepare a solution with a mass ratio of 1:1. A Zn-N2button cell was assembled using the prepared solution as the electrolyte, using a Au mesh with a diameter of 1.6 cm as the catalyst and the positive current collector, using a Zn sheet with a diameter of 1.6 cm as the negative electrode, and using a Celgard 2400 polypropylene separator as the separator.

[0105] In an anhydrous and anaerobic glove box, N2was bubbled into the cathode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The production rate of Zn3N2was 0.017 mg-h -1 -cm -2 .

[0106] Example 5

[0107] (1) Preparation of magnesium nitride

[0108] Magnesium trifluoromethylsulfonate (Mg(CF3SO3)2) was dissolved in an organic solvent dimethoxyethane (DME) to prepare a solution with a Mg(CF3SO3)2concentration of 0.6 M. A Mg-N2button cell was assembled using the prepared solution as the electrolyte, using a Ru sheet with a diameter of 1.6 cm as the catalyst and the positive current collector, using a Mg mesh with a diameter of 1.6 cm as the negative electrode, and using a Celgard 2400 polypropylene separator as the separator.

[0109] In an anhydrous and anaerobic glove box, N2was bubbled into the cathode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The production rate of Mg3N2was 0.612 mg-h -1 -cm -2 .

[0110] (2) Preparation of zinc nitride

[0111] Zinc chloride (ZnCl2) was dissolved in 1-butyl-3-methylimidazolium chloride ionic liquid to prepare a solution with a mass ratio of 1:1. A Zn-N2 button cell was assembled using the prepared solution as electrolyte, using a Ru mesh with a diameter of 1.6 cm as catalyst and positive current collector, using a Zn sheet with a diameter of 1.6 cm as negative electrode, and using a Celgard 2400 polypropylene separator as separator.

[0112] In an anhydrous and anaerobic glove box, N2was introduced to the positive side at a flow rate of 10 sccm, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 -1 -2

[0113] Example 6

[0114] (1) Preparation of magnesium nitride

[0115] Magnesium trifluoromethylsulfonate (Mg(CF3SO3)2) was dissolved in an organic solvent dimethoxyethane (DME) to prepare a solution with a Mg(CF3SO3)2concentration of 0.6 M. A Mg-N2 button cell was assembled using the prepared solution as electrolyte, using a Ni sheet with a diameter of 1.6 cm as catalyst and positive current collector, using a Mg mesh with a diameter of 1.6 cm as negative electrode, and using a Celgard 2400 polypropylene separator as separator.

[0116] In an anhydrous and anaerobic glove box, N2was introduced to the positive side at a flow rate of 10 sccm, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 -1 -2

[0117] (2) Preparation of zinc nitride

[0118] Zinc chloride (ZnCl2) was dissolved in 1-butyl-3-methylimidazolium chloride ionic liquid to prepare a solution with a mass ratio of 1:1. A Zn-N2 button cell was assembled using the prepared solution as electrolyte, using a Ni mesh with a diameter of 1.6 cm as catalyst and positive current collector, using a Zn sheet with a diameter of 1.6 cm as negative electrode, and using a Celgard 2400 polypropylene separator as separator.

[0119] ​​​​​​In an anhydrous and oxygen-free glove box, N2was introduced to the positive electrode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The production rate of Zn3N2was 0.131 mg-h -1 -cm -2 .

[0120] Example 7

[0121] (1) Preparation of magnesium nitride

[0122] Magnesium trifluoromethylsulfonate (Mg(CF3SO3)2) was dissolved in an organic solvent dimethoxyethane (DME) to prepare a solution with a Mg(CF3SO3)2concentration of 0.6 M. Using the prepared solution as an electrolyte, a steel mesh with a diameter of 1.6 cm as a catalyst and positive current collector, Mg mesh with a diameter of 1.6 cm as a negative electrode, and Celgard 2400 polypropylene separator as a separator, a Mg-N2button cell was assembled.

[0123] In an anhydrous and oxygen-free glove box, N2was introduced to the positive electrode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The production rate of Mg3N2was 0.155 mg-h -1 -cm -2 .

[0124] (2) Preparation of zinc nitride

[0125] Zinc chloride (ZnCl2) was dissolved in 1-butyl-3-methylimidazolium chloride ionic liquid to prepare a solution with a mass ratio of 1:1. Using the prepared solution as an electrolyte, a steel mesh with a diameter of 1.6 cm as a catalyst and positive current collector, Zn sheet with a diameter of 1.6 cm as a negative electrode, and Celgard 2400 polypropylene separator as a separator, a Zn-N2button cell was assembled.

[0126] In an anhydrous and oxygen-free glove box, N2was introduced to the positive electrode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The production rate of Zn3N2was 0.012 mg-h -1 -cm -2 .

[0127] Example 8

[0128] (1) Preparation of magnesium nitride

[0129] Magnesium trifluoromethylsulfonate (Mg(CF3SO3)2) was dissolved in the organic solvent ethylene glycol dimethyl ether (DME) to prepare a solution with a Mg(CF3SO3)2concentration of 0.6 M. Using the prepared solution as the electrolyte, a Cu sheet with a diameter of 1.6 cm as the catalyst and positive current collector, a Mg mesh with a diameter of 1.6 cm as the negative electrode, and a Celgard 2400 polypropylene separator as the separator, a Mg-N2button cell was assembled.

[0130] In an anhydrous and oxygen-free glove box, N2was introduced to the positive electrode side at a flow rate of 10 sccm, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA·cm -2 The product structure was characterized by XRD. The Mg3N2production rate was 0.218 mg·h -1 ·cm -2 .

[0131] (2) Preparation of zinc nitride

[0132] Zinc chloride (ZnCl2) was dissolved in 1-butyl-3-methylimidazolium chloride ionic liquid to prepare a solution with a mass ratio of 1:1. Using the prepared solution as the electrolyte, a Cu sheet with a diameter of 1.6 cm as the catalyst and positive current collector, a Zn sheet with a diameter of 1.6 cm as the negative electrode, and a Celgard 2400 polypropylene separator as the separator, a Zn-N2button cell was assembled.

[0133] In an anhydrous and oxygen-free glove box, N2was introduced to the positive electrode side at a flow rate of 10 sccm, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA·cm -2 The product structure was characterized by XRD. The Zn3N2production rate was 0.115 mg·h -1 ·cm -2 .

[0134] Example 9

[0135] (1) Preparation of magnesium nitride

[0136] Magnesium trifluoromethanesulfonate (Mg(CF3SO3)2) was dissolved in the organic solvent ethylene glycol dimethyl ether (DME) to prepare a solution with a Mg(CF3SO3)2concentration of 0.6 M. Using the prepared solution as the electrolyte, a Pt sheet with a diameter of 1.6 cm as the catalyst and positive current collector, a Mg mesh with a diameter of 1.6 cm as the negative electrode, and a Celgard 2400 polypropylene separator as the separator, a Mg-N2button cell was assembled.

[0137] In an anhydrous and anaerobic glove box, N2was introduced to the positive side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The Mg3N2production rate was 0.219 mg-h -1 -cm -2 .

[0138] (2) Preparation of zinc nitride

[0139] Zinc chloride (ZnCl2) was dissolved in 1-butyl-3-methylimidazolium chloride ionic liquid to prepare a solution with a mass ratio of 1:1. Using the prepared solution as the electrolyte, a Ti mesh with a diameter of 1.6 cm as the catalyst and positive current collector, a Zn sheet with a diameter of 1.6 cm as the negative electrode, and a Celgard 2400 polypropylene separator as the separator, a Zn-N2button cell was assembled.

[0140] In an anhydrous and anaerobic glove box, N2was introduced to the positive side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The Zn3N2production rate was 0.016 mg-h -1 -cm -2 .

[0141] Example 10

[0142] (1) Preparation of magnesium nitride

[0143] Magnesium trifluoromethanesulfonate (Mg(CF3SO3)2) was dissolved in the organic solvent tetrahydrofuran (THF) to prepare a solution with a Mg(CF3SO3)2concentration of 0.6 M. Using the prepared solution as the electrolyte, a Ti sheet with a diameter of 1.6 cm as the catalyst and positive current collector, a Mg mesh with a diameter of 1.6 cm as the negative electrode, and a Celgard 2400 polypropylene separator as the separator, a Mg-N2button cell was assembled.

[0144] In an anhydrous and anaerobic glove box, N2was bubbled into the cathode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The production rate of Mg3N2was 0.119 mg-h -1 -cm -2 .

[0145] (2) Preparation of zinc nitride

[0146] Zinc chloride (ZnCl2) was dissolved in 1-ethyl-3-methylimidazolium chloride ionic liquid to prepare a solution with a mass ratio of 1:1. A Zn-N2button cell was assembled using the prepared solution as the electrolyte, using a Pt mesh with a diameter of 1.6 cm as the catalyst and the positive current collector, using a Zn sheet with a diameter of 1.6 cm as the negative electrode, and using a Celgard 2400 polypropylene separator as the separator.

[0147] In an anhydrous and anaerobic glove box, N2was bubbled into the cathode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The production rate of Zn3N2was 0.016 mg-h -1 -cm -2 .

[0148] Example 11

[0149] (1) Preparation of magnesium nitride

[0150] Magnesium trifluoromethylsulfonate (Mg(CF3SO3)2) was dissolved in an organic solvent dimethyl carbonate (DMC) to prepare a solution with a Mg(CF3SO3)2concentration of 0.6 M. A Mg-N2button cell was assembled using the prepared solution as the electrolyte, using a Ti sheet with a diameter of 1.6 cm as the catalyst and the positive current collector, using a Mg mesh with a diameter of 1.6 cm as the negative electrode, and using a Celgard 2400 polypropylene separator as the separator.

[0151] In an anhydrous and anaerobic glove box, N2was bubbled into the cathode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The production rate of Mg3N2was 0.119 mg-h -1 -cm -2 .

[0152] (2) Preparation of zinc nitride

[0153] Zinc chloride (ZnCl2) was dissolved in 1-methylimidazole ionic liquid to prepare a solution with a mass ratio of 1:1. A Zn-N2 button cell was assembled using the prepared solution as electrolyte, Pt mesh with a diameter of 1.6 cm as catalyst and positive current collector, Zn sheet with a diameter of 1.6 cm as negative electrode, and Celgard 2400 polypropylene separator as separator.

[0154] In an anhydrous and anaerobic glove box, N2was introduced to the positive side at a flow rate of 10 sccm, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA·cm -2 -2. The product structure was characterized by XRD. The yield of Zn3N2was 0.086 mg·h -1 ·cm -2 -2.

[0155] Example 12

[0156] (1) Preparation of magnesium nitride

[0157] Magnesium trifluoromethylsulfonate (Mg(CF3SO3)2) was dissolved in an organic solvent propylene carbonate (PC) to prepare a solution with a Mg(CF3SO3)2concentration of 0.6 M. A Mg-N2 button cell was assembled using the prepared solution as electrolyte, Ti sheet with a diameter of 1.6 cm as catalyst and positive current collector, Mg mesh with a diameter of 1.6 cm as negative electrode, and Celgard 2400 polypropylene separator as separator.

[0158] In an anhydrous and anaerobic glove box, N2was introduced to the positive side at a flow rate of 10 sccm, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA·cm -2 -2. The product structure was characterized by XRD. The yield of Mg3N2was 0.219 mg·h -1 ·cm -2 -2.

[0159] (2) Preparation of zinc nitride

[0160] Zinc chloride (ZnCl2) was dissolved in bis-trifluoromethanesulfonylimide ionic liquid to prepare a solution with a mass ratio of 1:1. A Zn-N2 button cell was assembled using the prepared solution as electrolyte, Pt mesh with a diameter of 1.6 cm as catalyst and positive current collector, Zn sheet with a diameter of 1.6 cm as negative electrode, and Celgard 2400 polypropylene separator as separator.

[0161] In an anhydrous and oxygen-free glove box, N2was introduced to the cathode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The production rate of Zn3N2was 0.016 mg-h -1 -cm -2 .

[0162] Example 13

[0163] (1) Preparation of magnesium nitride

[0164] Magnesium trifluoromethylsulfonate (Mg(CF3SO3)2) was dissolved in an organic solvent tetraethylene glycol dimethyl ether (TEGDME) to prepare a solution of Mg(CF3SO3)2with a concentration of 0.6 M. Using the prepared solution as an electrolyte, a Ti sheet with a diameter of 1.6 cm as a catalyst and a cathode current collector, a Mg mesh with a diameter of 1.6 cm as an anode, and a Celgard 2400 polypropylene separator as a separator, a Mg-N2button cell was assembled.

[0165] In an anhydrous and oxygen-free glove box, N2was introduced to the cathode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The production rate of Mg3N2was 0.119 mg-h -1 -cm -2 .

[0166] (2) Preparation of zinc nitride

[0167] Zinc chloride (ZnCl2) was dissolved in N-alkyl-N-methyl pyrrolidinium ionic liquid to prepare a solution according to a mass ratio of 1:1. Using the prepared solution as an electrolyte, a Pt mesh with a diameter of 1.6 cm as a catalyst and a cathode current collector, a Zn sheet with a diameter of 1.6 cm as an anode, and a Celgard 2400 polypropylene separator as a separator, a Zn-N2button cell was assembled.

[0168] In an anhydrous and oxygen-free glove box, N2was introduced to the cathode side at a flow rate of 10 seem, and after standing for 30 min for activation, discharge was performed from the open-circuit voltage to 0.01 V at a current density of 0.02 mA-cm -2 The product structure was characterized by XRD. The production rate of Zn3N2was 0.016 mg-h -1 -cm -2 .

[0169] Example 14

[0170] (1) Preparation of magnesium nitride

[0171] Magnesium triflate (Mg(CF3SO3)2) was dissolved in the organic solvent diethyl carbonate (DEC) to prepare a solution with a Mg(CF3SO3)2concentration of 0.6 M. Using the prepared solution as the electrolyte, a Ti sheet with a diameter of 1.6 cm as the catalyst and positive current collector, a Mg mesh with a diameter of 1.6 cm as the negative electrode, and a Celgard 2400 polypropylene separator as the separator, a Mg-N2button cell was assembled.

[0172] In an anhydrous and anaerobic glove box, N2was introduced to the positive electrode side at a flow rate of 10 sccm, and after standing for 30 min for activation, discharge was performed from the open circuit voltage to 0.01 V at a current density of 0.02 mA·cm -2 -2. The product structure was characterized by XRD. The Mg3N2production rate was 0.139 mg·h -1 ·cm -2 -2.

[0173] (2) Preparation of zinc nitride

[0174] Zinc chloride (ZnCl2) was dissolved in an alkyltributylphosphonium ionic liquid to prepare a solution with a mass ratio of 1:1. Using the prepared solution as the electrolyte, a Pt mesh with a diameter of 1.6 cm as the catalyst and positive current collector, a Zn sheet with a diameter of 1.6 cm as the negative electrode, and a Celgard 2400 polypropylene separator as the separator, a Zn-N2button cell was assembled.

[0175] In an anhydrous and anaerobic glove box, N2was introduced to the positive electrode side at a flow rate of 10 sccm, and after standing for 30 min for activation, discharge was performed from the open circuit voltage to 0.01 V at a current density of 0.02 mA·cm -2 -2. The product structure was characterized by XRD. The Zn3N2production rate was 0.056 mg·h -1 ·cm -2 -2.

[0176] Example 15

[0177] (1) Preparation of iron nitride

[0178] Iron chloride (FeCl3) was dissolved in an organic solvent, dimethoxyethane (DME), to prepare a solution with a FeCl3 concentration of 1 M. Using the prepared solution as an electrolyte, an Au mesh with a diameter of 1.6 cm as a catalyst and positive current collector, a Fe sheet with a diameter of 1.6 cm as a negative electrode, and a Celgard 2400 polypropylene separator as a separator, a Fe-N2 button cell was assembled.

[0179] In an anhydrous and anaerobic glove box, N2was introduced to the positive electrode side at a flow rate of 10 sccm, and after standing for 30 min for activation, discharge was performed from the open circuit voltage to 0.01 V at a current density of 0.02 mA·cm -2 -2. The product structure was characterized by XRD. The Fe6N2production rate was 0.195 mg·h -1 ·cm -2 .

[0180] (2) Production rate of iron nitride

[0181] The production rate of the obtained Fe6N2at a nitrogen flow rate of 10 sccm for 6 h is shown in Table 5.

[0182] Table 5: Fe6N2production rate at the same nitrogen flow rate and different current densities

[0183]

[0184] Example 16

[0185] (1) Preparation of nickel nitride

[0186] Nickel chloride (NiCl2) was dissolved in 1-butyl-3-methylimidazolium chloride ionic liquid to prepare a solution at a mass ratio of 1:1. Using the prepared solution as an electrolyte, a Pd mesh with a diameter of 1.6 cm as a catalyst and positive current collector, a Ni sheet with a diameter of 1.6 cm as a negative electrode, and a Celgard 2400 polypropylene separator as a separator, a Ni-N2 button cell was assembled.

[0187] In an anhydrous and anaerobic glove box, N2was introduced to the positive electrode side at a flow rate of 10 sccm, and after standing for 30 min for activation, discharge was performed from the open circuit voltage to 0.01 V at a current density of 0.02 mA·cm -2 -2. The product structure was characterized by XRD. The Fe6N2production rate was 0.195 mg·h -1 ·cm -2 .

[0188] (2) Production rate of nickel nitride

[0189] The production rate of Ni3N2 under the condition of nitrogen flow rate of 10 seem for 6 h is shown in Table 6.

[0190] Table 6: Ni3N2 production rate under the condition of same nitrogen flow rate and different current density

[0191]

[0192] The above only describes several embodiments of the present application, and does not limit the present application in any form. Although the above describes the preferred embodiments of the present application, these embodiments are not intended to limit the present application. Any skilled person in the art can make some changes or modifications to the above disclosed technical contents without departing from the scope of the technical solutions of the present application, which are equivalent to equivalent embodiments, and are within the scope of the technical solutions of the present application.

Claims

1. A method for electrochemical synthesis of metal nitrides, characterized in that, Includes the following steps: (1) Use a catalyst as the cathode, use a metal as the anode, and use a solution containing metal ions and organic solvents as the electrolyte; (2) Under anhydrous and oxygen-free conditions, nitrogen is activated by a catalyst and reacted with the metal ions in a solution containing metal ions and organic solvent under discharge to generate metal nitrides; The catalyst is selected from at least one of platinum, titanium, molybdenum, ruthenium, gold, steel, nickel, and copper. The metal includes magnesium, zinc, iron, or nickel; The organic solvent is selected from at least one of ethylene glycol dimethyl ether, tetrahydrofuran, dimethyl carbonate, propylene carbonate, tetraethylene glycol dimethyl ether, diethyl carbonate, 1-butyl-3-methylimidazolium chloride ionic liquid, 1-ethyl-3-methylimidazolium chloride ionic liquid, 1-methylimidazolium ionic liquid, bis(trifluoromethanesulfonyl)imide ionic liquid, and N-alkyl-N-methylpyrrolidine ionic liquid; The metal ion exists in the form of at least one salt selected from chlorides and trifluoromethylsulfonates; The discharge includes applying a voltage, starting from the open-circuit voltage, at a rate of 0.02~0.20 mA·cm. -2 The constant current density causes the voltage to drop to 0.01V.

2. The method according to claim 1, characterized in that, A diaphragm is used between the cathode and the electrolyte; The diaphragm includes a polypropylene diaphragm.

3. The method according to claim 1, characterized in that, The flow rate of the nitrogen gas is 8-25 sccm.

4. The method according to claim 1, characterized in that, The production rate of the metal nitride is 0.010-1.550 mg·h. -1 ·cm -2 .

5. The method according to claim 1, characterized in that, The concentration of the metal ions in the solution is 0.5-2 mol·L⁻¹. -1 .

6. The method according to claim 1, wherein the mass ratio of the metal ion salt to the ionic liquid is 1:1.5 to 1.5:1.

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