阅读说明：本技术 一种高熵非晶型阳极析氧电极材料及其制备方法 (High-entropy amorphous anode oxygen evolution electrode material and preparation method thereof ) 是由 潘冶 钟旭 陆韬 朱银安 于金 于 2021-09-30 设计创作，主要内容包括：本发明公开了一种高熵非晶型阳极析氧电极材料及其制备方法,所述电极材料为非晶态(Fe-(0.2)Co-(0.2)Ni-(0.2)Cr-(0.2)V-(0.2))-(100-x)B-(x)合金材料,所述合金材料上构建有多孔结构,多孔结构均匀分布在合金材料上。所述制备方法为：先制备高熵非晶型(Fe-(0.2)Co-(0.2)Ni-(0.2)Cr-(0.2)V-(0.2))-(100-x)B-(x)自支撑析氧电极基材,再采用循环伏安法对制备出的电极基材进行电化学激活,进一步生成有利于析氧过程的带多孔结构活性物质的电极材料。本发明(Fe-(0.2)Co-(0.2)Ni-(0.2)Cr-(0.2)V-(0.2))-(100-x)B-(x)电极材料有良好的耐腐蚀性能,在碱性电解液KOH中稳定性良好；同时还具有优异的阳极析氧性能。(The invention discloses a high-entropy amorphous anode oxygen evolution electrode material and a preparation method thereof, wherein the electrode material is amorphous (Fe) 0.2 Co 0.2 Ni 0.2 Cr 0.2 V 0.2 ) 100‑x B x The alloy material is provided with a porous structure, and the porous structure is uniformly distributed on the alloy material. The preparation method comprises the following steps: firstly preparing high-entropy amorphous (Fe) 0.2 Co 0.2 Ni 0.2 Cr 0.2 V 0.2 ) 100‑x B x And carrying out electrochemical activation on the prepared electrode base material by adopting a self-supporting oxygen evolution electrode base material and adopting a cyclic voltammetry method to further generate an electrode material which is favorable for an oxygen evolution process and is provided with a porous structure active substance. Invention (Fe) 0.2 Co 0.2 Ni 0.2 Cr 0.2 V 0.2 ) 100‑x B x The electrode material has good corrosion resistance in alkaliThe stability in the KOH is good; meanwhile, the anode has excellent anode oxygen evolution performance.)

1. A high-entropy amorphous anode oxygen evolution electrode material is characterized in that: the electrode material is amorphous (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xThe alloy material is provided with a porous structure, and the porous structure is uniformly distributed on the alloy material.

2. A high entropy amorphous anodic oxygen evolution electrode material according to claim 1, characterized in that: the pore structure is a circular pore structure, and the diameter of the circular pore is 80-150 nm.

3. A high entropy amorphous anodic oxygen evolution electrode material according to claim 1, characterized in that: amorphous state (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xIn the alloy material, X is 15-20.

4. A method for preparing the high-entropy amorphous anode oxygen evolution electrode material as claimed in claim 1, wherein the method comprises: first, amorphous state (Fe) is prepared_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xAlloy material, in amorphous state (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xAnd performing electrochemical activation on the alloy material by adopting a cyclic voltammetry method to obtain an electrode material.

5. The method for preparing a high-entropy amorphous anodic oxygen evolution electrode material according to claim 4, characterized in that: amorphous state (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xThe alloy material is prepared by the following method: converting the set atomic percentages into element mass ratios, and weighing Fe, Co, Ni, Cr, V and B particles; uniformly mixing the weighed particles, and repeatedly smelting the particles in a high-vacuum smelting furnace to obtain an alloy ingot with determined components; crushing an alloy ingot into small metal blocks, placing the small metal blocks in a spray pipe, and carrying out induction heating to obtain a metal melt; and spraying the molten metal liquid onto a copper roller which is matched with the alloy components and rotates at a high speed to obtain the anode oxygen evolution electrode base material.

6. The method for preparing a high-entropy amorphous anodic oxygen evolution electrode material according to claim 4, characterized in that: the potential range of electrochemical activation is-0.5-1V, the scanning frequency range of cyclic voltammetry is 100-1000 times, and the scanning speed range of electrochemical activation is 0.005-0.5V/s.

Technical Field

The invention relates to a high-entropy amorphous anode oxygen evolution electrode material and a preparation method thereof.

Background

With the development of human society, haze and acid rain have caused problems due to the greenhouse effect caused by traditional fossil energy (coal, oil and natural gas). Fossil energy reserves on the earth are limited, and excessive exploitation is not beneficial to sustainable development of human society. Therefore, the search for new clean and sustainable energy has become a major issue for human beings. Hydrogen energy has received much attention as a clean energy source with a high energy density. Hydrogen production by water electrolysis is a widely adopted hydrogen production method at present, and in a water electrolysis device, a cathode and an anode of a three-electrode system respectively generate hydrogen and oxygen. However, the current water electrolysis still needs to overcome a large energy barrier, which results in low conversion efficiency. Therefore, the key to developing an anode catalytic material is to reduce the activation energy required for the reaction while having certain requirements on the stability of the electrode. Currently, the most common materials for anodic catalytic electrodes are noble metal oxides, including RuO₂、IrO₂And the like. However, the high price of noble metals limits their application and is difficult to meet practical requirements. And the noble metal oxide is less stable in the alkaline electrolyte KOH.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a high-entropy amorphous anode oxygen evolution electrode material which is low in price, good in corrosion resistance and excellent in electrocatalysis performance; the invention also aims to provide a preparation method of the anode oxygen evolution electrode material.

The technical scheme is as follows: the high-entropy amorphous anode oxygen evolution electrode material is amorphous (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xThe alloy material is provided with a porous structure, and the porous structure is uniformly distributed on the alloy material.

Invention (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xThe alloy material is in an amorphous state in structure and is in a thermodynamically metastable disordered state, the amorphous structure can ensure the high uniformity of the alloy components, more active sites are provided, the electron transfer in the oxygen evolution process is facilitated, and the reaction process is accelerated. Surface structure adjustment is carried out by cyclic voltammetry to realize (Fe) after cyclic voltammetry_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xAnd (3) uniformly distributing the porous structure on the high-entropy amorphous strip.

Wherein, the pore structure is a round hole structure, and the diameter of the round hole structure is 80-150 nm.

Wherein, amorphous state (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xIn the alloy material, X is 15-20.

The preparation method of the high-entropy amorphous anode oxygen evolution electrode material comprises the following steps: first, amorphous state (Fe) is prepared_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xAlloy material, in amorphous state (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xThe alloy material is electrochemically activated by adopting a cyclic voltammetry method to generate an electrode material which is favorable for an oxygen evolution process and is provided with a plurality of active substances with porous structures.

The electrode material of the invention is prepared by the amorphous state (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xThe alloy material is electrochemically activated, and porous multi-component-containing oxyhydroxide (the oxyhydroxide contains various metal ions) can be obtained on the surface of the alloy material, so that the catalytic activity of a single point on the surface of the strip is increased, and after the electrochemical activation, the specific surface area and the electrocatalytic activity of the alloy strip are effectively improved.

Wherein, amorphous state (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xThe high-entropy alloy is prepared by the following method: converting the set atomic percentages into element mass ratios to weigh Fe, Co,Ni, Cr, V, B particles; uniformly mixing the weighed particles, and repeatedly smelting the particles in a high-vacuum smelting furnace to obtain an alloy ingot with accurate components; crushing an alloy ingot into small metal blocks and placing the small metal blocks in a spray pipe; fixing the spray pipe in an induction coil of a vacuum belt throwing machine, and setting a specific copper rod rotation speed after the belt throwing machine is pumped to a vacuum state; after the small metal blocks are fully melted, the molten metal is sprayed onto the copper roller rotating at high speed from the small hole at the bottom of the spray pipe by using the pressure difference between the inside and the outside. The amorphous structure can ensure the high uniformity of the alloy components, and the long-range disordered state of the amorphous can provide more active sites, thereby being beneficial to the electron transfer in the oxygen evolution process, accelerating the reaction kinetic process, reducing the activation energy required by the reaction and being beneficial to the implementation of the oxygen evolution reaction process.

Wherein, the electrochemical activation adopts an electrochemical workstation three-electrode system, wherein Ag/AgCl is used as a reference electrode, a Pt electrode is used as a counter electrode, (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xThe high-entropy amorphous strip is a working electrode.

In the electrochemical activation process, the activated potential range is-0.5-1V, the cyclic voltammetry scanning frequency range is 100-1000 times, and the activated scanning speed range is 0.005-0.5V/s.

Fe, Co, Ni and Cr elements in the alloy system can be gradually converted into active substance oxyhydroxide in the oxygen evolution process in the cyclic voltammetry process, and V elements can be gradually precipitated from the alloy system, and finally, a porous structure is generated.

Has the advantages that: compared with the prior art, the invention has the remarkable advantages that: firstly, the raw materials in the high-entropy amorphous alloy material are non-noble metal elements Fe, Co, Ni, Cr and V, non-metal element B and noble metal oxide RuO₂、IrO₂Compared with the prior art, the cost is low, and the elements are stored in the earth crust abundantly, thus being beneficial to practical application; secondly, (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xThe electrode material has good corrosion resistance and can be used in alkaline electrolyteThe stability in KOH is good; finally, (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)_100-xB_xThe electrode material has excellent anodic oxygen evolution performance; wherein (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀After electrochemical activation, the surface porous strip is placed in KOH solution with the concentration of 1mol/L and the current density is 10 mA-cm^-2When the oxygen evolution overpotential is 259 mV.

Drawings

FIG. 1 is (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀An XRD diffraction pattern of the electrode material;

FIG. 2 shows (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀The alloy material is 1 mol.L before and after electrochemical activation treatment^{- 1}Polarization curves in KOH solution (LSV curves);

FIG. 3 is (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀SEM atlas of surface structure of alloy material before electrochemical activation treatment;

FIG. 4 shows (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀SEM atlas of surface structure of alloy material after electrochemical activation treatment.

Detailed Description

The technical scheme of the invention is further explained by combining the attached drawings.

Example 1

The preparation method of the high-entropy amorphous anode oxygen evolution electrode material specifically comprises the following steps:

step 1, according to the target composition (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀Repeatedly smelting for 5-6 times in a high vacuum smelting furnace to obtain a master alloy ingot with uniform components;

step 2, the master alloy ingot obtained in the step 1 is put intoCrushing and placing in a spray pipe; under the condition of protective gas, melting an alloy ingot into a molten liquid under the heating of an induction coil; the molten metal liquid is rapidly sprayed onto the copper roller from the small hole at the bottom of the spray pipe by using pressure difference, the amorphous forming capacity of the alloy is matched with the cooling speed of the melt, and the volume of the sprayed metal liquid is set to be 1200-1300 mm³(Fe) was obtained at a linear speed of the copper roll of 50 to 55m/s_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀An amorphous ribbon;

step 3, the (Fe) obtained in the step 2_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀The strip was electrochemically activated in 1mol/L KOH solution at a temperature of 25 ℃. The potential range of the cyclic voltammetry set in the electrochemical workstation is 0-1V, the scanning times of the cyclic voltammetry set are 100 times, and the scanning speed is 0.005V/s; after activation, (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀An electrode material.

The overpotential of the activated tape obtained in example 1 was 10mA cm^-2The lower value was 259 mV.

In example 1 (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀The XRD diffraction pattern of the alloy is shown in FIG. 1. As can be seen from FIG. 1, the alloy strip prepared in example 1 has an amorphous structure, (Fe)_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀Polarization curves before and after the alloy is activated by adopting the cyclic voltammetry are shown in fig. 2, and as can be known from fig. 2, the electrocatalytic performance of the electrode material can be effectively improved by adopting the electrochemical activation of the cyclic voltammetry. As can be seen from FIGS. 3 to 4, the surface of the strip before activation is flat, and a porous structure containing multiple elements (multiple metal ions) is generated on the surface of the strip after activation, which indicates that the surface of the strip is reconstructed during the cyclic voltammetry process, and the diameter of the porous structure is about 100 nm.

Example 2

To demonstrate the potential range versus performance of cyclic voltammetryOn (Fe) obtained by steps 1 and 2 of example 1_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀The potential range of the cyclic voltammetry set in the step 3 in the example 1 is-0.5-0V, the scanning frequency of the cyclic voltammetry set is 100 times, and the scanning speed is 0.005V/s.

Example 2 the resulting post-activation tape had an overpotential of 10mA cm^-2The lower value is 289 mV.

Example 3

To demonstrate the effect of the number of sweeps of cyclic voltammetry on performance, for (Fe) prepared using steps 1 and 2 in example 1_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀The electrode material was scanned with cyclic voltammetry at 1000 times, set at a potential range of 0-1V, and at a scanning speed of 0.005V/s, as set in step 3 of example 1.

The overpotential of the activated tape obtained in example 3 was 10mA cm^-2The lower value is 276 mV.

Example 4

To demonstrate the effect of the sweep rate of cyclic voltammetry on performance, for (Fe) prepared using steps 1 and 2 in example 1_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₀B₂₀The electrode material is prepared by setting the cyclic voltammetry scanning speed of 0.5V/s, the potential range of 0-1V and the cyclic voltammetry scanning frequency of 100 in step 3 in example 1.

The overpotential of the activated tape obtained in example 4 was 10mA cm^-2The lower value is 303 mV.

Example 5

Example 5 the procedure for preparing an electrode material was substantially the same as in example 1, except that the target composition of the alloy material was (Fe) in order to demonstrate the effect of the element content in different proportions and the adapted strip-spinning process parameters on the performance_0.2Co_0.2Ni_0.2Cr_0.2V_0.2)₈₅B₁₅(ii) a Molten metal liquid rapidly flows from small holes in the bottom of the lanceWhen the metal liquid is sprayed onto the copper roller, the volume of the sprayed metal liquid is 1100-1200 mm³The linear velocity of the copper roller is 55-60m/s, meanwhile, the potential range of the cyclic voltammetry set in the step 3 in the example 5 is 0-1V, the scanning times of the cyclic voltammetry set are 100 times, and the scanning speed is 0.005V/s.

The overpotential of the activated tape obtained in example 5 was 10mA cm^-2The lower is 264mV, and the diameter of the micropores of the porous structure on the surface of the strip after the activation of example 5 is about 150 nm.