Boron-doped fulleramine-loaded metal nanoparticle electrocatalyst and preparation method thereof

Abstract

The present invention discloses a boron-doped fulleramine-supported metal nanoparticle electrocatalyst and a preparation method thereof, comprising the steps of: 1. Mixing C 60 powder with ethylenediamine, and stirring in a nitrogen atmosphere until C 60 is completely dissolved in ethylenediamine to obtain solution A. Rotating and evaporating the excessive ethylenediamine to obtain a precipitate, dissolving the precipitate with an acid solution to obtain solution B, and adjusting it to neutral with an alkali solution to obtain solution C 60 -EDA-Z; 2. After rotating and evaporating solution C 60 -EDA-Z, dialyzing it in ultrapure water for several days, and freeze-drying to obtain C 60 -EDA; 3. Taking C 60 -EDA and dissolving it in deionized water, heating it from room temperature to 100-125 °C with stirring, adding a metal source and a boron source to the aqueous solution of C 60 -EDA in small portions and keeping warm, then freeze-drying. Under an argon atmosphere, heating it from room temperature to 700-900 °C at a heating rate of 5 °C / min and keeping warm, and then cooling it to 300 °C at a cooling rate of 10 °C / min. After cooling, a boron-doped fulleramine-supported metal nanoparticle electrocatalyst M / CNB is obtained, which increases the dispersion of metal nanoparticles and reduces the production cost.

Description

Technical Field

[0001] The invention belongs to the technical field of electrocatalysts, and in particular is a boron-doped fulleramine-loaded metal nanoparticle electrocatalyst and a preparation method thereof. Background Art

[0002] With the consumption of fossil energy, environmental pollution and energy depletion are becoming increasingly serious, and the development of clean and efficient hydrogen energy is urgent. Electrocatalytic water splitting is an environmentally friendly and efficient hydrogen production technology. It not only produces high-purity hydrogen, but also can be used for large-scale industrial production. During the electrolysis of water, the electrodes will polarize, generate overpotential, and consume more energy. Therefore, it is necessary to use efficient and stable catalysts to reduce the reaction barrier to meet the needs of industrialization.

[0003] Platinum and platinum-based catalysts are recognized as the most efficient catalysts, but their high prices and scarce resources limit their widespread application in production. In recent years, researchers have developed many new, efficient, stable and cheap catalysts, such as transition metals and their sulfides, carbides, phosphides, oxides, etc. However, there are still some problems, such as the poor stability and easy deactivation of transition metals under acidic conditions, the low activity of non-precious metal catalysts, the poor dispersibility of nanomaterials, and the low conductivity of semiconductor materials.

[0004] Nanocarbon materials have special structures and compositions, excellent electrical conductivity and negligible environmental impact, and are widely used as catalyst carrier materials. Among them, fullerene is a cage-like structure, a good electron acceptor, and has high reactivity. Therefore, other atoms or groups can be introduced inside and outside the cage. However, due to its relatively stable structure, weak catalytic ability, and poor water solubility, its application in the field of electrocatalysis is limited. However, studies have shown that fullerene has high reactivity and designability, and can exhibit excellent hydrogen evolution catalytic activity after functional modification. According to density functional theory calculations, the hydrogen adsorption Gibbs free energy of nanocarbon catalysts can be reduced by doping other heteroatoms. Therefore, the combination of highly active metal nanoparticles and highly stable nanocarbon materials has been widely used in catalytic reactions, showing excellent performance. The loading of metal nanoparticles can significantly improve the conductivity of composite electrocatalysts and accelerate the efficiency of electron transfer. The synergistic effect between metal nanoparticles and carbon bases can regulate the electronic structure, thereby improving the catalytic activity, but metal nanoparticles are easy to agglomerate, thereby covering the active sites. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a boron-doped fulleramine-loaded metal nanoparticle electrocatalyst and a preparation method thereof, which not only increases the dispersibility of the metal nanoparticles but also reduces the production cost.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for preparing a boron-doped fulleramine-supported metal nanoparticle electrocatalyst comprises the following steps:

[0008] Step 1: C 60 The powder was mixed with ethylenediamine and stirred under nitrogen atmosphere until the temperature reached C. 60 Completely dissolve in ethylenediamine to obtain solution A, and then evaporate the excess ethylenediamine to obtain a black precipitate, which is then dissolved in acid to obtain solution B, and then adjust solution B to a pH of 7 with alkaline solution to obtain solution C. 60 -EDA-Z;

[0009] Step 2: Solution C 60 -EDA-Z was rotary evaporated for 10-30 min, then placed in a dialysis bag and dialyzed in ultrapure water for several days. After freeze drying, a yellow fluffy solid C was obtained. 60 -EDA;

[0010] Step 3: Take 50-150 mg C 60 -EDA is dissolved in deionized water and heated from room temperature to 100-125°C while stirring. 60 -EDA aqueous solution was added with 0.1-0.8 mmol metal source and 0.1-0.6 mmol boron source in small amounts and repeatedly and kept warm. After freeze-drying, a solid powder was obtained. Under an argon atmosphere, the temperature was first increased from room temperature to 700-900°C at a heating rate of 5°C / min and kept warm, then decreased to 300°C at a cooling rate of 10°C / min. After naturally cooling to room temperature, a boron-doped fulleramine-loaded metal nanoparticle electrocatalyst M / CNB was obtained.

[0011] Furthermore, in step 1, C 60 The powder was dissolved in ethylenediamine.

[0012] Furthermore, the rotary evaporation in step 1 is carried out using a rotary evaporator at 50-60° C. for 20-40 min.

[0013] Furthermore, the acid solution in step 1 is hydrochloric acid solution, acetic acid solution, sulfuric acid solution or phosphoric acid solution.

[0014] Furthermore, the alkali solution in step 1 is sodium hydroxide solution, ammonia solution or calcium hydroxide solution.

[0015] Furthermore, the rotary evaporation in step 2 is carried out using a rotary evaporator at 65-80° C. for 10-30 min.

[0016] Furthermore, the dialysis in step 2 is performed using a cellulose dialysis bag with a MWCO of 3500 for two days, and ultrapure water is replaced every 12 hours.

[0017] Furthermore, the insulation time of step 3 is 6-10h and 2h respectively.

[0018] Further, the metal source of step 3 is one or more of nitrates, sulfates, acetates or chlorides containing cobalt, nickel, manganese, copper, zinc, platinum, gold, rhodium, silver, palladium or ruthenium;

[0019] The boron source is one or more of elemental boron, phenylboric acid, boron oxide, boric acid, boron nitride, triphenylborane or sodium tetraphenylborate.

[0020] A boron-doped fulleramine-supported metal nanoparticle electrocatalyst.

[0021] Compared with the prior art, the present invention has the following technical effects:

[0022] 1) The present invention adopts a simple solid-liquid mixing method to 60 By mixing with ethylenediamine solution, fullerene is modified into fulleramine, thereby increasing active sites, enhancing the activity of the substrate and the interaction between the substrate and metal particles, improving the shortcoming of poor hydrophilicity of fullerene, and loading metal nanoparticles on the modified carbon base and introducing boron through a solid-liquid reaction method, which significantly improves the conductivity and catalytic activity of the catalyst; moreover, the combination of highly active metal nanoparticles and a stable carbon substrate allows the metal nanoparticles to be evenly dispersed on the carbon substrate without agglomeration or covering the active sites of the electrocatalyst, thereby changing the electronic structure of the electrocatalyst, promoting electron transfer efficiency, and having excellent hydrogen evolution catalytic activity.

[0023] 2) The present invention only involves a simple solid-liquid mixing method and a solid-liquid reaction method, which is convenient to operate and easy to control, and provides an effective strategy for promoting large-scale industrial production of electrocatalytic water splitting.

[0024] 3) The boron-doped fulleramine-supported metal nanoparticle electrocatalyst prepared by the present invention has low cost and excellent hydrogen evolution catalytic activity, and is an ideal new catalyst product to replace traditional precious metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 C prepared in Example 2 of the present invention 60 - XRD pattern of EDA;

[0026] Figure 2 XRD pattern of Ru / CNB prepared in Example 2 of the present invention;

[0027] Figure 3This is the full XPS spectrum of Ru / CNB prepared in Example 2 of the present invention;

[0028] FIG. 4( a ) and FIG. 4( b ) are TEM characterization images of Ru / CNB prepared in Example 2 of the present invention;

[0029] FIG4( c ) is a particle size distribution diagram of Ru nanoparticles in Ru / CNB prepared in Example 2 of the present invention;

[0030] Figure 5 This is the polarization curve diagram of Ru / CNB prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0031] The specific contents of the present invention are further explained in detail below in conjunction with embodiments.

[0032] Example 1

[0033] Step 1: At room temperature, 200 mg C 60 The powder was mixed with 400 mL of ethylenediamine and stirred for 10 h under a nitrogen atmosphere to allow C 60 Completely dissolved in ethylenediamine to obtain solution A, evaporated at 55°C for 20 min using a rotary evaporator to obtain a black precipitate, then dissolved in 2 mM hydrochloric acid to obtain solution B, and adjusted the pH value of solution B to 7 with 2 mM sodium hydroxide solution to obtain solution C. 60 -EDA-Z;

[0034] Step 2: Using a rotary evaporator at 70°C, 60 -EDA-Z was rotary evaporated for 20 min, then placed in a cellulose dialysis bag with a MWCO of 3500, dialyzed in ultrapure water for two days, and the ultrapure water was replaced every 12 h. After freeze drying, a yellow fluffy solid C was obtained. 60 -EDA;

[0035] Step 3: Take 50 mg C 60 -EDA was dissolved in 150 mL of deionized water and heated from room temperature to 120°C while stirring. 0.1 mmol of benzene ruthenium trichloride and 0.1 mmol of phenylboric acid were added in small amounts and several times. 60 -EDA aqueous solution, kept warm for 6 hours, and freeze-dried to obtain a solid powder. Under an argon atmosphere, the temperature was first increased from room temperature to 800°C at a heating rate of 5°C / min and kept warm for 2 hours, and then cooled to 300°C at a cooling rate of 10°C / min. After naturally cooling to room temperature, the boron-doped fulleramine-loaded ruthenium nanoparticle electrocatalyst Ru / CNB was obtained.

[0036] Example 2

[0037] Step 1: At room temperature, 150 mg C 60 The powder was mixed with 300 mL of ethylenediamine and stirred for 10 h under a nitrogen atmosphere to allow C 60 Completely dissolved in ethylenediamine to obtain solution A, evaporated at 55°C for 20 min using a rotary evaporator to obtain a black precipitate, then dissolved in 2 mM hydrochloric acid to obtain solution B, and adjusted the pH value of solution B to 7 with 2 mM sodium hydroxide solution to obtain solution C. 60 -EDA-Z;

[0038] Step 2: Using a rotary evaporator at 70°C, 60 -EDA-Z was rotary evaporated for 25 min, then placed in a cellulose dialysis bag with a MWCO of 3500, dialyzed in ultrapure water for two days, and the ultrapure water was replaced every 12 h. After freeze drying, a yellow fluffy solid C was obtained. 60 -EDA;

[0039] Step 3: Take 100 mg C 60 -EDA was dissolved in 200 mL of deionized water and heated from room temperature to 120°C while stirring. 0.5 mmol of ruthenium trichloride and 0.3 mmol of phenylboric acid were added in small amounts several times to C 60 -EDA aqueous solution, kept warm for 7 hours, freeze-dried to obtain a solid powder, and under argon atmosphere, first heated from room temperature to 800°C at a heating rate of 5°C / min and kept warm for 2 hours, then cooled to 300°C at a cooling rate of 10°C / min, and after naturally cooling to room temperature, a boron-doped fulleramine-loaded ruthenium nanoparticle electrocatalyst Ru / CNB was obtained.

[0040] Figure 1 C prepared in Example 2 60 -EDA XRD pattern shows that Example 2 successfully modified fullerene into fulleramine with high purity and no residual fullerene; the large peak near 20° is amorphous carbon.

[0041] Figure 2 The XRD diagram of Ru / CNB prepared in Example 2 shows that ruthenium nanoparticles are successfully loaded on the carbon substrate. When the 2θ angle is 38.3°, 42.1° and 44.0°, three obvious absorption peaks appear in the spectrum, corresponding to the (100), (101), and (102) crystal planes of ruthenium nanocrystals, respectively. This corresponds to the standard card JCPDS-NO06-0663, proving that Ru is successfully loaded on fulleramine in the form of nanocrystals, and the structure of the ruthenium nanoparticles is hexagonal close-packed.

[0042] Figure 3This is the full XPS spectrum of Ru / CNB prepared in Example 2. It can be seen that fullerene is successfully modified into fulleramine, and the carbon base is doped with nitrogen and boron, with the contents of nitrogen and boron being 1.04% and 1.9% respectively. The loading amount of ruthenium Ru nanoparticles is 6.61%.

[0043] FIG4(a) and FIG4(b) are TEM characterization images of Ru / CNB prepared in Example 2. FIG4(a) shows that the Ru nanoparticles are uniformly dispersed and loaded on the nanocarbon substrate. FIG4(b) shows that the average lattice spacing of the small particles is d=0.195 nm, corresponding to the (101) crystal plane of ruthenium.

[0044] FIG4( c ) is a bar graph showing the particle size distribution of Ru nanoparticles in Ru / CNB prepared in Example 2, from which it can be seen that the average particle size is 3.15 nm.

[0045] Figure 5 This is the polarization curve of the Ru / CNB electrocatalyst prepared in Example 2 obtained by linear sweep voltammetry (LSV) under 1 M KOH. It can be seen that the boron-doped fulleramine-supported ruthenium nanoparticle electrocatalyst Ru / CNB reaches a current density of 10 mA / cm 2 When the overpotential is only 37 mV, it has excellent hydrogen evolution catalytic activity, which is mainly attributed to the strong interaction between the nanocarbon substrate and the metal nanoparticles, which changes the original surface electronic state of the carbon cage, increases the charge density, and thus increases the number of active sites.

[0046] Example 3

[0047] Step 1: At room temperature, 180 mg C 60 The powder was mixed with 350 mL of ethylenediamine and stirred for 6 h under a nitrogen atmosphere to allow C 60 Completely dissolved in ethylenediamine to obtain solution A, evaporated at 50°C for 40 min using a rotary evaporator to obtain a black precipitate, then dissolved in 2 mM sulfuric acid to obtain solution B, and adjusted the pH value of solution B to 7 with 2 mM ammonia solution to obtain solution C 60 -EDA-Z;

[0048] Step 2: Using a rotary evaporator at 65°C, 60 -EDA-Z was rotary evaporated for 30 min, then placed in a cellulose dialysis bag with a MWCO of 3500, dialyzed in ultrapure water for two days, and the ultrapure water was replaced every 12 h. After freeze drying, a yellow fluffy solid C was obtained. 60 -EDA;

[0049] Step 3: Take 150 mg C 60-EDA was dissolved in 250 mL of deionized water and heated from room temperature to 110°C while stirring. 0.8 mmol of cobalt nitrate and 0.2 mmol of boron oxide were added in small amounts and several times to C 60 -EDA aqueous solution, kept warm for 8 hours, and freeze-dried to obtain a solid powder. Under an argon atmosphere, the temperature was first increased from room temperature to 750°C at a heating rate of 5°C / min and kept warm for 2 hours, and then cooled to 300°C at a cooling rate of 10°C / min. After naturally cooling to room temperature, the boron-doped fulleramine-loaded cobalt nanoparticle electrocatalyst Co / CNB was obtained.

[0050] Example 4

[0051] Step 1: At room temperature, 220 mg C 60 The powder was mixed with 450 mL of ethylenediamine and stirred for 8 h under a nitrogen atmosphere to allow C 60 Completely dissolved in ethylenediamine to obtain solution A, evaporated at 60°C for 35 min using a rotary evaporator to obtain a black precipitate, then dissolved in a 2 mM phosphoric acid solution to obtain solution B, and adjusted the pH value of solution B to 7 with a 2 mM calcium hydroxide solution to obtain solution C. 60 -EDA-Z;

[0052] Step 2: Using a rotary evaporator at 70°C, 60 -EDA-Z was rotary evaporated for 15 min, then placed in a cellulose dialysis bag with a MWCO of 3500, dialyzed in ultrapure water for two days, and the ultrapure water was replaced every 12 h. After freeze drying, a yellow fluffy solid C was obtained. 60 -EDA;

[0053] Step 3: Take 75 mg C 60 -EDA was dissolved in 180 mL of deionized water and heated from room temperature to 125°C while stirring. 0.3 mmol of copper sulfate and 0.5 mmol of boric acid were added in small amounts and several times. 60 -EDA aqueous solution, kept warm for 9 hours, and freeze-dried to obtain a solid powder. Under an argon atmosphere, the temperature was first increased from room temperature to 850°C at a heating rate of 5°C / min and kept warm for 2 hours, and then cooled to 300°C at a cooling rate of 10°C / min. After naturally cooling to room temperature, the boron-doped fulleramine-loaded copper nanoparticle electrocatalyst Cu / CNB was obtained.

[0054] Example 5

[0055] Step 1: At room temperature, 250 mg C 60 The powder was mixed with 500 mL of ethylenediamine and stirred for 12 h under a nitrogen atmosphere to allow C 60Completely dissolved in ethylenediamine to obtain solution A, evaporated at 50°C for 30 min using a rotary evaporator to obtain a black precipitate, then dissolved in 2 mM acetic acid solution to obtain solution B, and adjusted the pH value of solution B to 7 with 2 mM calcium hydroxide solution to obtain solution C. 60 -EDA-Z;

[0056] Step 2: Using a rotary evaporator at 80°C, 60 -EDA-Z was rotary evaporated for 10 min, then placed in a cellulose dialysis bag with a MWCO of 3500, dialyzed in ultrapure water for two days, and the ultrapure water was replaced every 12 h. After freeze drying, a yellow fluffy solid C was obtained. 60 -EDA;

[0057] Step 3: Take 125 mg C 60 -EDA was dissolved in 225 mL of deionized water and heated from room temperature to 115°C while stirring. 0.6 mmol of zinc acetate and 0.6 mmol of boron nitride were added in small amounts and several times to C 60 -EDA aqueous solution, kept warm for 10 hours, and freeze-dried to obtain a solid powder. Under an argon atmosphere, the temperature was first increased from room temperature to 900°C at a heating rate of 5°C / min and kept warm for 2 hours, and then cooled to 300°C at a cooling rate of 10°C / min. After naturally cooling to room temperature, the boron-doped fulleramine-supported zinc nanoparticle electrocatalyst Zn / CNB was obtained.

[0058] The ruthenium trichloride, cobalt nitrate, copper sulfate or zinc acetate in Examples 1 to 5 of the present invention can also be replaced by nickel nitrate, manganese nitrate, copper nitrate, zinc nitrate, platinum nitrate, gold nitrate, rhodium nitrate, silver nitrate, palladium nitrate, ruthenium nitrate, nickel sulfate, manganese sulfate, cobalt sulfate, zinc sulfate, platinum sulfate, gold sulfate, rhodium sulfate, silver sulfate, palladium sulfate, ruthenium sulfate, cobalt chloride, nickel chloride, copper chloride, zinc chloride, platinum chloride, gold chloride, rhodium chloride, silver chloride or palladium chloride.

[0059] The phenylboric acid, boron oxide, boric acid or boron nitride in Examples 1 to 5 of the present invention may also be replaced by elemental boron, triphenylborane or sodium tetraphenylborate.

Claims

1. A method for preparing a boron-doped fulleramine-supported metal nanoparticle electrocatalyst, characterized in that: The steps include: Step 1: C 60 The powder was mixed with ethylenediamine and stirred under nitrogen atmosphere until the temperature reached C. 60 Completely dissolve in ethylenediamine to obtain solution A, and then rotary evaporate the excess ethylenediamine to obtain a black precipitate, which is then dissolved with acid to obtain solution B, and then titrate solution B to pH 7 with alkaline solution to obtain solution C. 60 -EDA-Z; Step 2: Solution C 60 -EDA-Z was rotary evaporated for 10-30 min, then placed in a dialysis bag and dialyzed in ultrapure water for several days. After freeze drying, a yellow fluffy solid C was obtained. 60 -EDA; Step 3: Take 50-150 mg C 60 -EDA is dissolved in deionized water and heated from room temperature to 100-125°C while stirring. 60 -EDA aqueous solution is added with 0.1-0.8mmol metal source and 0.1-0.6mmol boron source in small amounts and repeatedly and kept warm, freeze-dried to obtain solid powder, and in an argon atmosphere, first heated from room temperature to 700-900℃ at a heating rate of 5℃ / min and kept warm, then cooled to 300℃ at a cooling rate of 10℃ / min, and after naturally cooling to room temperature, a boron-doped fulleramine-supported metal nanoparticle electrocatalyst M / CNB is obtained; The metal source is a nitrate, sulfate, acetate or chloride containing ruthenium; The boron source is elemental boron, phenylboric acid, boron oxide, boric acid, boron nitride, triphenylborane or sodium tetraphenylborate.

2. The method for preparing the boron-doped fulleramine-supported metal nanoparticle electrocatalyst according to claim 1, characterized in that: In step 1, C 60 The powder was dissolved in ethylenediamine.

3. The method for preparing the boron-doped fulleramine-supported metal nanoparticle electrocatalyst according to claim 1, characterized in that: The rotary evaporation in step 1 is performed using a rotary evaporator at 50-60° C. for 20-40 min.

4. The method for preparing the boron-doped fulleramine-supported metal nanoparticle electrocatalyst according to claim 1, characterized in that: The acid solution in step 1 is hydrochloric acid solution, acetic acid solution, sulfuric acid solution or phosphoric acid solution.

5. The method for preparing the boron-doped fulleramine-supported metal nanoparticle electrocatalyst according to claim 1, characterized in that: The alkali solution in step 1 is sodium hydroxide solution, ammonia solution or calcium hydroxide solution.

6. The method for preparing the boron-doped fulleramine-supported metal nanoparticle electrocatalyst according to claim 1, characterized in that: The rotary evaporation in step 2 is performed using a rotary evaporator at 65-80° C. for 10-30 min.

7. The method for preparing the boron-doped fulleramine-supported metal nanoparticle electrocatalyst according to claim 1, characterized in that: The dialysis in step 2 was performed using a cellulose dialysis bag with a MWCO of 3500 for two days, and ultrapure water was replaced every 12 hours.

8. The method for preparing the boron-doped fulleramine-supported metal nanoparticle electrocatalyst according to claim 1, characterized in that: The insulation time of step 3 is 6-10h and 2h respectively.

9. A boron-doped fulleramine-supported metal nanoparticle electrocatalyst prepared by the method according to any one of claims 1 to 8.

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