Preparation method of black phosphorus doped magnesium-based novel hydrogen storage material
By using black phosphorus-doped magnesium-based hydrogen storage materials, and combining chemical absorption and physical adsorption, the thermodynamic and kinetic limitations of magnesium-based hydrogen storage materials have been overcome, achieving efficient and stable hydrogen storage.
Patent Information
- Application Number
- CN202311489023.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-09
- Publication Date
- 2026-03-03
- Estimated Expiration
- 2043-11-09
AI Technical Summary
The high thermodynamic stability and poor kinetic properties of magnesium-based hydrogen storage materials limit their practical application. Furthermore, the aggregation and growth of nano-MgH2/Mg particles lead to poor cycle stability, and traditional methods are difficult to operate under high temperature and high pressure conditions.
By doping black phosphorus into magnesium-based materials, utilizing the lone pair electrons of black phosphorus as anchors and electronic modulators, and combining chemical absorption and physical adsorption for hydrogen storage, a novel magnesium-based hydrogen storage material doped with black phosphorus is prepared. Nanoscale magnesium particles are embedded in the black phosphorus interlayer, regulating the Mg-H bond to reduce the dehydrogenation temperature.
It expands hydrogen storage capacity, improves magnesium particle agglomeration, lowers the dehydrogenation energy barrier, and enhances cycle stability and dehydrogenation temperature, achieving efficient hydrogen storage under mild conditions.
Smart Images
Figure CN117682478B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of nanomaterials for hydrogen storage and black phosphorus applications, specifically to a novel magnesium-based hydrogen storage material doped with black phosphorus and its preparation method. Background Technology
[0002] The rapid depletion of non-renewable energy and the increasing deterioration of the Earth's environment have prompted humanity to accelerate the development of sustainable, environmentally friendly, and green renewable energy sources. Hydrogen energy has attracted widespread attention due to its abundant reserves, high renewability, and environmental friendliness. However, the flammable, explosive, and easily diffused nature of hydrogen makes its storage and transportation a bottleneck restricting its large-scale application. Currently, there are three main methods for hydrogen storage: high-pressure gaseous hydrogen storage, cryogenic liquid hydrogen storage, and solid-material hydrogen storage. Among these, solid-material hydrogen storage effectively addresses the problems of low hydrogen storage density and poor safety factor in traditional hydrogen storage technologies. Based on the hydrogen storage mechanism, it is further divided into two categories: physical adsorption hydrogen storage and chemical absorption hydrogen storage.
[0003] Magnesium-based hydrogen storage materials belong to the category of chemical absorption hydrogen storage. Due to their high hydrogen storage capacity (MgH2, with a theoretical hydrogen storage capacity of 7.6 wt%), abundant resources, low cost, and good reversibility, they are considered one of the most promising solid-state hydrogen storage materials. However, their high thermodynamic stability and poor kinetic properties limit their practical application. Furthermore, the aggregation and growth of MgH2 / Mg particles during hydrogen absorption and desorption cycles also lead to poor cycle stability. Currently, methods such as nano-sizing, alloying, adding catalysts, and composite light metal coordination hydrides are used to improve the hydrogen storage performance of the MgH2 / Mg system. The improved hydrogen storage capacity is typically between 6.0 and 6.8 wt%. In addition, Saita synthesized a high-purity needle-like single-crystal nanofiber MgH2 via high-pressure chemical vapor deposition. The MgH2 prepared by this method has a short reaction path in the radial direction of the fiber, and the fiber can maintain its shape after hydrogenation and dehydrogenation, thus resulting in a high hydrogen adsorption rate and a reversible hydrogen storage capacity of 7.6 wt%, which is the same as the theoretical value. However, the harsh conditions of high temperature and high pressure (870 K, 4 MpaH2) make the operation extremely difficult and dangerous, and are not conducive to large-scale preparation.
[0004] In addition to possessing unique semiconductor material properties such as a band gap tunable with the number of layers and high electron mobility, two-dimensional black phosphorus also exhibits excellent layered structure and nano-effects. The atomic layers are bound together by van der Waals forces, making it easy to exfoliate into few-layer nanosheets. Due to the controllable layer dimensions of two-dimensional black phosphorus nanosheets, they have numerous interlayer adsorption vacancies and a strong ability to mildly bind and release hydrogen, thus making them a potential functional material for physical adsorption hydrogen storage. However, the hydrogen storage efficiency of pure black phosphorus is not high. Furthermore, the exposed lone pairs of electrons in black phosphorus have a significant modulating effect on the electronic properties of metals.
[0005] Therefore, this invention provides a black phosphorus-doped magnesium-based hydrogen storage material that combines chemical absorption and physical adsorption hydrogen storage to provide a larger hydrogen storage capacity. The lone pair electrons of black phosphorus are used as anchor points to accurately anchor magnesium atoms at specific positions, preventing magnesium particle aggregation. Finally, the attraction of the lone pair electrons of black phosphorus to the high-valence magnesium in magnesium hydride is utilized to adjust the electronic properties of magnesium hydride, weaken the Mg-H bond, lower the kinetic energy barrier, and thus reduce the dehydrogenation temperature. Summary of the Invention
[0006] The purpose of this invention is to combine chemical absorption hydrogen storage and physical adsorption hydrogen storage to provide a novel magnesium-based hydrogen storage material doped with black phosphorus and its preparation method. The method involves mixing black phosphorus micro powder and commercially available magnesium powder in a certain proportion, and then using ball milling and ultrasonic treatment to embed nano-magnesium particles between the black phosphorus layers. This increases the hydrogen storage capacity of the hydrogen storage material, improves the agglomeration of magnesium particles, and reduces the dehydrogenation energy barrier.
[0007] The technical solution adopted by this invention to solve its technical problem is: a method for preparing a novel magnesium-based hydrogen storage material doped with black phosphorus, comprising the following steps:
[0008] (1) Under inert gas protection, black phosphorus powder and magnesium powder were mixed in a certain proportion and subjected to high-energy ball milling to obtain Mg / BP composite material;
[0009] (2) Under the protection of inert gas, the obtained Mg / BP composite material was uniformly dispersed in an ultra-dry organic solvent and subjected to ultrasonic treatment for a certain period of time. Then, it was centrifuged, separated, washed and dried to obtain nano Mg / BP composite material.
[0010] (3) Under a hydrogen atmosphere, the obtained nano-Mg / BP composite material was heat-treated to obtain nano-MgH2 / BP hydrogen storage material.
[0011] Further, in step (1), the black phosphorus micro powder is obtained by electrochemically stripping blocky black phosphorus; the magnesium powder is commercially available magnesium powder; the ratio of black phosphorus micro powder to commercially available magnesium powder is 1:1 to 1:10.
[0012] Further, in step (1), the grinding jar and grinding balls used in the high-energy ball milling operation are made of any one or more of stainless steel, agate, corundum, tungsten carbide, nylon, zirconium oxide, polytetrafluoroethylene, and polyurethane; the diameter of the grinding balls is 3 to 10 mm; the ball milling speed is 100 to 400 r / min; the ball-to-material ratio is 20:1 to 100:1; and the ball milling time is 10 to 36 h.
[0013] Further, in step (2), the ultra-dry organic solvent is one or more of N-methylpyrrolidone, N-vinylpyrrolidone, N-cycloethylpyrrolidone, N-octylpyrrolidone, formamide, N-methylformamide, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, acetone and 2-pentanone that have been freeze-dried and molecularly sieved.
[0014] The freeze-drying and molecular sieve treatment process is as follows: ① Load the solvent into a Schlenk flask, connect it to a double-row tube, and evacuate for 2-3 minutes; ② Place the flask in a liquid nitrogen Dewar flask until the solvent is completely frozen; ③ Evacuate the flask for 2-3 minutes; ④ Remove the flask from the liquid nitrogen Dewar flask and place it in a warm water bath to thaw; ⑤ Repeat steps ②-④, performing a freeze-drying-evacuation cycle three times. ⑥ After the final thawing, purge the flask with nitrogen and transfer it to a glove box; ⑦ Add 3A molecular sieves for dehydration and drying overnight.
[0015] The freeze-drying and molecular sieve ultra-drying processes described in this application can effectively remove trace amounts of moisture and oxygen from the solvent. Furthermore, nano-black phosphorus is more easily decomposed under conditions containing moisture, air, or oxygen.
[0016] Further, in step (2), the ultrasonic treatment is a variable amplitude rod ultrasonic treatment, in which the variable amplitude rod is inserted into the dispersion liquid and carried out in an ice bath at 4 ~ 15℃ for 3 ~ 36 h.
[0017] Furthermore, in step (2), the centrifugal speed is 10000 ~ 14000 r / min;
[0018] Further, in step (2), the washing reagent is ultra-dry acetone or ultra-dry tetrahydrofuran, and the washing time is 1~2 h;
[0019] Furthermore, in step (2), the drying process is carried out in a vacuum drying oven or inert gas, and the drying temperature is 80°C.
[0020] Further, in step (3), the heat treatment process is as follows: the obtained nano Mg / BP composite material is loaded into a tube furnace and heated to 200 ~ 400℃, hydrogen is continuously passed through for 30 ~ 90 min, and then cooled to room temperature and hydrogen is continuously passed through for 60 min to obtain nano MgH2 / BP hydrogen storage material and realize hydrogen storage.
[0021] This invention provides a novel magnesium-based hydrogen storage material doped with black phosphorus, as described in the above technical solution.
[0022] The beneficial effects of this invention are:
[0023] (1) By using black phosphorus-doped magnesium nanoparticles, the physical adsorption hydrogen storage and chemical absorption hydrogen storage are combined. At the same time, the hydrogen storage capacity of the hydrogen storage material is expanded by utilizing the two major characteristics of black phosphorus' large specific surface area adsorption and magnesium hydride's excellent hydrogen storage density.
[0024] (2) Pure nano-magnesium particles are prone to agglomeration and sticking to the container during ball milling. After ball milling with black phosphorus doping, the nano-magnesium particles are embedded between the expanded black phosphorus layers, thus avoiding the problem of agglomeration and sticking to the container.
[0025] (3) In the hydrogen absorption and desorption cycle, the aggregation and growth of MgH2 / Mg particles in magnesium hydride leads to poor cycle stability. The nano-MgH2 / BP hydrogen storage material uses the lone pair electrons of black phosphorus as anchor points to anchor magnesium atoms near the lone pair electrons, preventing magnesium particles from getting close to each other, thereby preventing particle aggregation.
[0026] (4) Due to its high thermodynamic stability and poor kinetic properties, MgH2 / Mg can only slowly release hydrogen at temperatures above 300℃. Nano-MgH2 / BP hydrogen storage materials utilize the attraction of black phosphorus lone pair electrons to high-valence magnesium to adjust the electronic structure of MgH2, weaken the Mg-H bond, and significantly reduce the dehydrogenation temperature. Attached Figure Description
[0027] Figure 1 SEM image of expanded black phosphorus flakes obtained by electrochemical stripping.
[0028] Figure 2 The graph shows the hydrogen charge / discharge curves of the nano-MgH2 / BP-3 hydrogen storage material prepared in Example 3.
[0029] Figure 3 The above are temperature-progression dehydrogenation curves for the examples and comparative examples. Detailed Implementation
[0030] The present invention will be further described below with reference to specific embodiments. The following embodiments are for illustrative purposes only and should not be construed as limiting the present invention. Unless otherwise specified, the reagents used in the following embodiments are commercially available or commercially accessible reagents; unless otherwise specified, the equipment used in the following examples is equipment conventionally used in the art.
[0031] Example 1
[0032] (1) In a nitrogen-filled glove box, black phosphorus powder and magnesium powder obtained by electrochemical stripping were mixed in a molar ratio of 1:1 and loaded into a zirconia ball mill jar. Zirconia grinding balls with a diameter of 5 mm were then loaded, with a ball-to-material ratio of 20:1. The jar was sealed and transferred to a planetary ball mill, where it was ball-milled at 200 r / min for 24 h to obtain the Mg / BP composite material.
[0033] (2) In a nitrogen-filled glove box, the obtained Mg / BP composite material was uniformly dispersed in a wide-mouth bottle containing 100 mL of ultra-dry N-methylpyrrolidone, sealed with a rubber stopper, and transferred to a 10°C circulating ice bath in an ultrasonic cell disruptor. The amplitude transformer was inserted below the liquid surface of the wide-mouth bottle through the rubber stopper, and ultrasonic disruption was performed for 12 h (with a 4-s pause after every 2 s of ultrasonication). The sample was then removed, centrifuged at 12000 r / min for 30 min, and the precipitate was separated and washed twice with ultra-dry acetone for 1 h each time. The precipitate was then transferred to a vacuum drying oven and dried at 80°C to obtain the nano-Mg / BP composite material.
[0034] (3) The obtained nano-Mg / BP composite material was loaded into a tube furnace, and the air inside the tube was completely replaced with hydrogen. While continuously passing hydrogen, the tube furnace was heated to 200°C at a heating rate of 10°C / min and held at that temperature for 60 min. After naturally cooling to room temperature, hydrogen was passed through the tube for another 60 min to obtain nano-MgH2 / BP-1 hydrogen storage material.
[0035] Example 2
[0036] (1) In a nitrogen-filled glove box, black phosphorus powder and magnesium powder obtained by electrochemical stripping were mixed in a molar ratio of 1:2 and loaded into a zirconia ball mill jar. Zirconia grinding balls with a diameter of 5 mm were then loaded, with a ball-to-material ratio of 20:1. The jar was sealed and transferred to a planetary ball mill, where it was ball-milled at 200 r / min for 24 h to obtain the Mg / BP composite material.
[0037] (2) In a nitrogen-filled glove box, the obtained Mg / BP composite material was uniformly dispersed in a wide-mouth bottle containing 100 mL of ultra-dry N-methylpyrrolidone, sealed with a rubber stopper, and transferred to a 10°C circulating ice bath in an ultrasonic cell disruptor. The amplitude transformer was inserted below the liquid surface of the wide-mouth bottle through the rubber stopper, and ultrasonic disruption was performed for 12 h (with a 4-s pause after every 2 s of ultrasonication). The sample was then removed, centrifuged at 12000 r / min for 30 min, and the precipitate was separated and washed twice with ultra-dry acetone for 1 h each time. The precipitate was then transferred to a vacuum drying oven and dried at 80°C to obtain the nano-Mg / BP composite material.
[0038] (3) The obtained nano-Mg / BP composite material was loaded into a tube furnace, and the air inside the tube was completely replaced with hydrogen. While continuously passing hydrogen, the tube furnace was heated to 200°C at a heating rate of 10°C / min and held at that temperature for 60 min. After naturally cooling to room temperature, hydrogen was passed through the tube for another 60 min to obtain nano-MgH2 / BP-2 hydrogen storage material.
[0039] Example 3
[0040] (1) In a nitrogen-filled glove box, black phosphorus powder and magnesium powder obtained by electrochemical stripping were mixed in a molar ratio of 1:4 and loaded into a zirconia ball mill jar. Zirconia grinding balls with a diameter of 5 mm were then loaded, with a ball-to-material ratio of 40:1. The jar was sealed and transferred to a planetary ball mill, where it was ball-milled at 200 r / min for 24 h to obtain the Mg / BP composite material.
[0041] (2) In a nitrogen-filled glove box, the obtained Mg / BP composite material was uniformly dispersed in a wide-mouth bottle containing 100 mL of ultra-dry N,N-dimethylformamide, sealed with a rubber stopper, and transferred to a 10°C circulating ice bath in an ultrasonic cell disruptor. The amplitude transformer was inserted below the liquid surface of the wide-mouth bottle through the rubber stopper, and ultrasonic disruption was performed for 24 h (with a 4-s pause after every 2 s of ultrasonication). The sample was then removed, centrifuged at 12000 r / min for 30 min, and the precipitate was separated and washed twice with ultra-dry acetone for 1 h each time. The precipitate was then transferred to a vacuum drying oven and dried at 80°C to obtain the nano-Mg / BP composite material.
[0042] (3) The obtained nano-Mg / BP composite material was loaded into a tube furnace, and the air inside the tube was completely replaced with hydrogen. While continuously passing hydrogen, the tube furnace was heated to 200°C at a heating rate of 10°C / min and held at that temperature for 60 min. After naturally cooling to room temperature, hydrogen was passed through the tube for another 60 min to obtain nano-MgH2 / BP-3 hydrogen storage material.
[0043] Example 4
[0044] (1) In a nitrogen-filled glove box, black phosphorus powder and magnesium powder obtained by electrochemical stripping were mixed at a molar ratio of 1:8 and loaded into a zirconia ball mill jar. Zirconia grinding balls with a diameter of 5 mm were then loaded, with a ball-to-material ratio of 80:1. The jar was sealed and transferred to a planetary ball mill, where it was ball-milled at 300 r / min for 36 h to obtain the Mg / BP composite material.
[0045] (2) In a nitrogen-filled glove box, the obtained Mg / BP composite material was uniformly dispersed in a wide-mouth bottle containing 100 mL of ultra-dry dimethyl sulfoxide, sealed with a rubber stopper, and transferred to a 10°C circulating ice bath in an ultrasonic cell disruptor. The amplitude transformer was inserted below the liquid surface of the wide-mouth bottle through the rubber stopper, and ultrasonic disruption was performed for 36 h (with a 4-s pause after every 2 s of ultrasonication). The sample was then removed, centrifuged at 12000 r / min for 30 min, and the precipitate was separated and washed twice with ultra-dry acetone for 1 h each time. The precipitate was then transferred to a vacuum drying oven and dried at 80°C to obtain the nano-Mg / BP composite material.
[0046] (3) The obtained nano-Mg / BP composite material was loaded into a tube furnace, and the air inside the tube was completely replaced with hydrogen. While continuously passing hydrogen, the tube furnace was heated to 200°C at a heating rate of 10°C / min and held at that temperature for 60 min. After naturally cooling to room temperature, hydrogen was passed through the tube for another 60 min to obtain nano-MgH2 / BP-4 hydrogen storage material.
[0047] Example 5
[0048] (1) In a nitrogen-filled glove box, black phosphorus powder and magnesium powder obtained by electrochemical stripping were mixed at a molar ratio of 1:10 and loaded into a zirconia ball mill jar. Zirconia grinding balls with a diameter of 5 mm were then loaded, with a ball-to-material ratio of 80:1. The jar was sealed and transferred to a planetary ball mill, where it was ball-milled at 300 r / min for 36 h to obtain the Mg / BP composite material.
[0049] (2) In a nitrogen-filled glove box, the obtained Mg / BP composite material was uniformly dispersed in a wide-mouth bottle containing 100 mL of ultra-dry dimethyl sulfoxide, sealed with a rubber stopper, and transferred to a 10°C circulating ice bath in an ultrasonic cell disruptor. The amplitude transformer was inserted below the liquid surface of the wide-mouth bottle through the rubber stopper, and ultrasonic disruption was performed for 36 h (with a 4-s pause after every 2 s of ultrasonication). The sample was then removed, centrifuged at 12000 r / min for 30 min, and the precipitate was separated and washed twice with ultra-dry acetone for 1 h each time. The precipitate was then transferred to a vacuum drying oven and dried at 80°C to obtain the nano-Mg / BP composite material.
[0050] (3) The obtained nano-Mg / BP composite material was loaded into a tube furnace, and the air inside the tube was completely replaced with hydrogen. While continuously passing hydrogen, the tube furnace was heated to 200°C at a heating rate of 10°C / min and held at that temperature for 60 min. After naturally cooling to room temperature, hydrogen was passed through the tube for another 60 min to obtain nano-MgH2 / BP-5 hydrogen storage material.
[0051] Comparative Example 1
[0052] (1) In a nitrogen-filled glove box, magnesium powder was loaded into a zirconia ball mill jar, and then zirconia grinding balls with a diameter of 5 mm were added, with a ball-to-material ratio of 40:1. The jar was sealed and transferred to a planetary ball mill, where it was ball-milled at 300 r / min for 24 h to obtain ultrafine magnesium powder material. This magnesium powder material exhibited obvious sticking to the jar.
[0053] (2) In a nitrogen-filled glove box, the obtained ultrafine magnesium powder material was uniformly dispersed in a wide-mouth bottle containing 100 mL of ultra-dry N-methylpyrrolidone, sealed with a rubber stopper, and transferred to a 10°C circulating ice bath in an ultrasonic cell disruptor. The amplitude transformer was inserted below the liquid surface of the wide-mouth bottle through the rubber stopper, and ultrasonic disruption was performed for 24 h (with a 4-s pause after every 2 s of ultrasonication). The sample was then removed, centrifuged at 12000 r / min for 30 min, and the precipitate was separated and washed twice with ultra-dry acetone for 1 h each time. The precipitate was then transferred to a vacuum drying oven and dried at 80°C to obtain the nano-magnesium powder material.
[0054] (3) The obtained nano-magnesium powder material was loaded into a tube furnace, and the air inside the tube was completely replaced with hydrogen. While continuously passing hydrogen, the tube furnace was heated to 200°C at a heating rate of 10°C / min and held at that temperature for 60 min. After naturally cooling to room temperature, hydrogen was passed through the furnace for another 60 min to obtain nano-MgH2 hydrogen storage material.
[0055] Comparative Example 2
[0056] (1) In a nitrogen-filled glove box, black phosphorus powder and magnesium powder obtained by electrochemical stripping were mixed at a molar ratio of 1:20 and loaded into a zirconia ball mill jar. Zirconia grinding balls with a diameter of 3 mm were then loaded, with a ball-to-material ratio of 100:1. The jar was sealed and transferred to a planetary ball mill, where it was ball-milled at 400 r / min for 36 h to obtain the Mg / BP composite material.
[0057] (2) In a nitrogen-filled glove box, the obtained Mg / BP composite material was uniformly dispersed in a wide-mouth bottle containing 100 mL of ultra-dry dimethyl sulfoxide, sealed with a rubber stopper, and transferred to a 10°C circulating ice bath in an ultrasonic cell disruptor. The amplitude transformer was inserted below the liquid surface of the wide-mouth bottle through the rubber stopper, and ultrasonic disruption was performed for 36 h (with a 4-s pause after every 2 s of ultrasonication). The sample was then removed, centrifuged at 12000 r / min for 30 min, and the precipitate was separated and washed twice with ultra-dry acetone for 1 h each time. The precipitate was then transferred to a vacuum drying oven and dried at 80°C to obtain the nano-Mg / BP composite material.
[0058] (3) The obtained nano-Mg / BP composite material was loaded into a tube furnace, and the air inside the tube was completely replaced with hydrogen. While continuously passing hydrogen, the tube furnace was heated to 200°C at a heating rate of 10°C / min and held at that temperature for 60 min. After naturally cooling to room temperature, hydrogen was passed through the tube for another 60 min to obtain nano-MgH2 / BP-6 hydrogen storage material.
[0059] Comparative Example 3
[0060] (1) In a nitrogen-filled glove box, black phosphorus powder and magnesium powder obtained by electrochemical stripping were mixed at a molar ratio of 1:0.5 and loaded into a zirconia ball mill jar. Zirconia grinding balls with a diameter of 5 mm were then loaded, with a ball-to-material ratio of 20:1. The jar was sealed and transferred to a planetary ball mill, where it was ball-milled at 300 r / min for 24 h to obtain the Mg / BP composite material.
[0061] (2) In a nitrogen-filled glove box, the obtained Mg / BP composite material was uniformly dispersed in a wide-mouth bottle containing 100 mL of ultra-dry dimethyl sulfoxide, sealed with a rubber stopper, and transferred to a 10°C circulating ice bath in an ultrasonic cell disruptor. The amplitude transformer was inserted below the liquid surface of the wide-mouth bottle through the rubber stopper, and ultrasonic disruption was performed for 12 h (with a 4-s pause after every 2 s of ultrasonication). The sample was then removed, centrifuged at 12000 r / min for 30 min, and the precipitate was separated and washed twice with ultra-dry acetone for 1 h each time. The precipitate was then transferred to a vacuum drying oven and dried at 80°C to obtain the nano-Mg / BP composite material.
[0062] (3) The obtained nano-Mg / BP composite material was loaded into a tube furnace, and the air inside the tube was completely replaced with hydrogen. While continuously passing hydrogen, the tube furnace was heated to 200°C at a heating rate of 10°C / min and held at that temperature for 60 min. After naturally cooling to room temperature, hydrogen was passed through the tube for another 60 min to obtain nano-MgH2 / BP-7 hydrogen storage material.
[0063] Comparative Example 4
[0064] (1) In a nitrogen-filled glove box, the black phosphorus micro powder obtained by electrochemical stripping was loaded into a zirconia ball mill jar, and then zirconia grinding balls with a diameter of 3 mm were loaded in, with a ball-to-material ratio of 20:1. The jar was sealed and transferred to a planetary ball mill, where it was ball-milled at a speed of 300 r / min for 24 h to obtain ultrafine BP material.
[0065] (2) In a nitrogen-filled glove box, the obtained ultrafine BP material was uniformly dispersed in a wide-mouth bottle containing 100 mL of ultra-dry N-methylpyrrolidone, sealed with a rubber stopper, and transferred to a 10°C circulating ice bath in an ultrasonic cell disruptor. The amplitude transformer was inserted below the liquid surface of the wide-mouth bottle through the rubber stopper, and ultrasonic disruption was performed for 24 h (with a 4-s pause after every 2 s of ultrasonication). The sample was then removed, centrifuged at 12000 r / min for 30 min, and the precipitate was separated and washed twice with ultra-dry acetone for 1 h each time. The precipitate was then transferred to a vacuum drying oven and dried at 80°C to obtain nano-BP material.
[0066] (3) The obtained nano-BP material was loaded into a tube furnace, and the air inside the tube was completely replaced with hydrogen. While continuously passing hydrogen, the tube furnace was heated to 200°C at a heating rate of 10°C / min and held at that temperature for 60 min. After cooling naturally to room temperature, hydrogen was passed through the tube for another 60 min to obtain the nano-BP hydrogen storage material.
[0067] Comparative Example 5
[0068] (1) In a nitrogen-filled glove box, hydroxyapatite (HAP) and magnesium powder were mixed at a molar ratio of 1:4 and loaded into a zirconia ball mill jar. Zirconia grinding balls with a diameter of 3 mm were then added, with a ball-to-material ratio of 100:1. The jar was sealed and transferred to a planetary ball mill, where it was ball-milled at 400 r / min for 36 h to obtain the HAP / Mg composite material.
[0069] (2) In a nitrogen-filled glove box, the obtained HAP / Mg composite material was uniformly dispersed in a wide-mouth bottle containing 100 mL of ultra-dry acetone, sealed with a rubber stopper, and transferred to a 10°C circulating ice bath in an ultrasonic cell disruptor. The amplitude transformer was inserted below the liquid surface of the bottle through the rubber stopper, and ultrasonic disruption was performed for 36 h (with a 4-second pause after every 2 seconds of sonication). The sample was then removed, centrifuged at 12000 r / min for 30 min, and the precipitate was separated and washed twice with ultra-dry acetone for 1 h each time. The precipitate was then transferred to a vacuum drying oven and dried at 80°C to obtain the nano-HAP / Mg composite material.
[0070] (3) The obtained nano-HAP / Mg composite material was loaded into a tube furnace, and the air inside the tube was completely replaced with hydrogen. While continuously passing hydrogen, the tube furnace was heated to 200°C at a heating rate of 10°C / min and held at that temperature for 60 min. After naturally cooling to room temperature, hydrogen was passed through the furnace for another 60 min to obtain the nano-HAP / MgH2 hydrogen storage material.
[0071] The hydrogen storage performance of the materials prepared in Examples 1-5 and Comparative Examples 1-5 was tested using a PCT (Potentially Transformed Gas Turbine) tester. Approximately 0.2 g of sample was placed into the reactor in a glove box and connected to the tester for hydrogen absorption and desorption performance testing. The pressure and temperature inside the tester, as well as the temperature changes inside the reactor over time, were recorded using a data acquisition device. The data were analyzed according to the ideal gas law PV = nRT. The test results are shown in Table 1. Figure 1 As shown.
[0072] Hydrogen release was measured using a programmed temperature-release (TPD) test. The temperature was increased from room temperature to 450°C at a rate of 5°C / min, and the pressure changes were recorded throughout the heating process. A curve showing the hydrogen release rate as a function of temperature was plotted using the formula, yielding the initial hydrogen release temperature and the peak hydrogen release temperature of the sample. The test results are as follows: Figure 3 As shown.
[0073] Table 1. Test results of hydrogen storage performance of materials obtained in Examples 1-5 and Comparative Examples 1-5.
[0074] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Hydrogen storage rate (%) 5.7 6.4 7.4 6.8 6.1 5.2 5.3 3.7 2.1 5.0
Claims
1. A preparation method of black phosphorus doped magnesium-based novel hydrogen storage material, characterized in that, The method comprises the following steps: (1) mixing black phosphorus powder and magnesium powder in a certain proportion under inert gas protection and performing high-energy ball milling to obtain Mg / BP composite material; (2) dispersing the obtained Mg / BP composite material in ultra-dry organic solvent under inert gas protection, performing ultrasonic crushing treatment for a certain time, then centrifuging, separating, washing and drying to obtain nano Mg / BP composite material; The ultra-dry organic solvent is an organic solvent subjected to freeze extraction and molecular sieve drying treatment, and the organic solvent is selected from one or more of N-methyl pyrrolidone, N-vinyl pyrrolidone, N-cycloethyl pyrrolidone, N-octyl pyrrolidone, formamide, N-methyl formamide, N,N-dimethyl formamide, N,N-dimethyl acetamide, dimethyl sulfoxide, acetone and 2-pentanone The operation of freeze extraction and molecular sieve treatment is as follows: 1) the organic solvent is loaded into a Schlenk flask, the flask is connected to a double-tube pipe and vacuumized for 2-3 minutes; 2) the flask is placed into a liquid nitrogen Dewar flask until the solvent is completely frozen; 3) the flask is vacuumized for 2-3 minutes; 4) the flask is taken out of the liquid nitrogen Dewar flask and placed into a warm water bath for thawing; 5) steps 2-4 are repeated for three times of freeze-pumping-thaw cycles; 6) after the last thawing is completed, nitrogen is filled into the flask and the flask is transferred into a glove box; 7) 3A molecular sieve is added for water removal and drying overnight; (3) the obtained nano Mg / BP composite material is subjected to heat treatment under a hydrogen atmosphere to obtain nano MgH2 / BP hydrogen storage material, and the heat treatment process is as follows: the obtained nano Mg / BP composite material is loaded into a tube furnace and heated to 200-400℃, hydrogen is continuously supplied for 30-90 minutes, then the temperature is lowered to room temperature and hydrogen is continuously supplied for 60 minutes to realize hydrogen storage.
2. The method for preparing black phosphorus doped magnesium-based novel hydrogen storage material according to claim 1, characterized in that, In step (1), the black phosphorus powder is obtained by electrochemical exfoliation of bulk black phosphorus; and the magnesium powder is a commercially available magnesium powder.
3. The method for preparing black phosphorus doped magnesium-based novel hydrogen storage material according to claim 1, characterized in that, In step (1), the ratio of the black phosphorus powder to the commercially available magnesium powder is 1:1-1:
10.
4. The method for preparing black phosphorus doped magnesium-based novel hydrogen storage material according to claim 1, characterized in that, In step (1), the ball milling tank and the grinding ball used in the high-energy ball milling operation are made of any one or more of stainless steel, agate, corundum, tungsten carbide, nylon, zirconium oxide, polytetrafluoroethylene and polyurethane; the diameter of the grinding ball is 3-10 mm; and the ball-to-material ratio is 20:1-100:
1.
5. The method for preparing black phosphorus doped magnesium-based novel hydrogen storage material according to claim 1, characterized in that, In step (1), the ball milling speed is 100-400 r / min, and the ball milling time is 10-36 hours.
6. The method for preparing the novel magnesium-based hydrogen storage material doped with black phosphorus according to claim 1, characterized in that, In step (2), the ultrasonic treatment is performed in an ice bath at 4-15℃, and the ultrasonic treatment time is 3-36 hours.
7. The method for preparing the novel magnesium-based hydrogen storage material doped with black phosphorus according to claim 1, characterized in that, In step (2), the centrifugation speed is 10000-14000 r / min; the washing reagent is ultra-dry acetone or ultra-dry tetrahydrofuran; and the washing time is 1-2 hours.
8. The method for preparing the novel magnesium-based hydrogen storage material doped with black phosphorus according to claim 1, characterized in that, In step (2), the drying process is performed in a vacuum drying box or inert gas, and the drying temperature is 80℃.
9. A black phosphorus doped magnesium-based novel hydrogen storage material, characterized in that, The hydrogen storage material is prepared based on the method according to any one of claims 1-8.