阅读说明：本技术 一种琼脂凝胶法金属氧化物碳复合材料的制备与应用 (Preparation and application of metal oxide carbon composite material by agar gel method ) 是由 李梅 李霞 李泽坤 张云强 于 2020-12-24 设计创作，主要内容包括：本发明涉及一种琼脂凝胶法金属氧化物碳复合材料的制备与应用。其制备步骤如下：将一定量的琼脂溶解于50 mL去离子水中,放置于水浴锅中,在一定温度下搅拌0.5 h,记作溶液A；量取50 mL去离子水于烧杯中,按照一定摩尔比分别称量六水合硝酸镍、六水合硝酸钴和硫酸亚铁加入到烧杯中,在磁力搅拌器上搅拌溶解得到溶液B；将溶液A与溶液B混合后继续放于水浴锅中搅拌一定时间,使其混合均匀；反应完成后,在室温下静置反应,得到的溶液去除上清液后进行冷冻干燥；得到的材料在氩气气氛下碳化,最终得到一种金属氧化物碳复合材料。本发明制备得到的金属氧化物碳复合材料电化学性能优异、结构稳定,非常适合作为电极材料应用于电催化析氧领域。(The invention relates to a preparation method and application of a metal oxide carbon composite material by an agar gel method. The preparation method comprises the following steps: dissolving a certain amount of agar in 50 mL of deionized water, placing the solution in a water bath, and stirring the solution at a certain temperature for 0.5 h, wherein the solution is marked as solution A; weighing 50 mL of deionized water into a beaker, respectively weighing nickel nitrate hexahydrate, cobalt nitrate hexahydrate and ferrous sulfate according to a certain molar ratio, adding into the beaker, and stirring and dissolving on a magnetic stirrer to obtain a solution B; mixing the solution A and the solution B, and then continuously placing the mixture in a water bath kettle to stir for a certain time to uniformly mix the mixture; after the reaction is finished, standing at room temperature for reaction, removing supernatant from the obtained solution, and then freeze-drying; the obtained material is carbonized in argon atmosphere to finally obtain the metal oxide carbon composite material. The metal oxide carbon composite material prepared by the method has excellent electrochemical performance and stable structure, and is very suitable for being used as an electrode material in the field of electrocatalytic oxygen evolution.)

1. The preparation and application of the metal oxide carbon composite material by the agar gel method comprise the following steps:

(1) dissolving 0.1-5 g of agar in 50 mL of deionized water, placing the solution in a water bath kettle, and stirring the solution at 50-80 ℃ for 0.5 h to obtain a light yellow liquid which is recorded as a solution A;

(2) weighing 50 mL of deionized water into a beaker, respectively weighing 0-3 g of nickel nitrate hexahydrate, 0-3 g of cobalt nitrate hexahydrate and 0-3 g of ferrous sulfate according to a certain molar ratio, adding into the beaker, and stirring and dissolving on a magnetic stirrer to obtain a solution B;

(3) mixing the solution A and the solution B, then continuously placing the mixture in a water bath kettle for stirring to uniformly mix the mixture, and continuously stirring and reacting for 0.5-5 h at the same temperature as the step (1);

(4) after the reaction in the step (3) is finished, standing at room temperature for 12-72 hours, removing supernatant from the obtained solution, and freeze-drying;

(5) and (4) carbonizing the material obtained in the step (4) at 300-800 ℃ for 1-5 hours under the protection of argon gas to finally obtain the metal oxide carbon composite material.

2. The method for preparing a metal oxide carbon composite material according to claim 1, wherein the amount of agar used in the step (1) is 1 g.

3. The method for preparing a metal oxide carbon composite material according to claim 1, wherein the reaction temperature in the step (1) is 80 ℃.

4. The method for preparing a metal oxide carbon composite material by an agar gel method according to claim 1, wherein the mass of the nickel nitrate hexahydrate, the cobalt nitrate hexahydrate and the ferrous sulfate in the step (2) are 2.91 g, 2.91 g and 2.78 g, respectively.

5. The method for preparing a metal oxide carbon composite material according to claim 1, wherein the stirring time in the step (3) is 3 hours.

6. The method for preparing a metal oxide carbon composite material according to claim 1, wherein the reaction time in the step (4) is 72 hours.

7. The method for preparing a metal oxide carbon composite material according to claim 1, wherein the carbonization temperature in the step (5) is 700 ℃.

8. The method for preparing a metal oxide carbon composite material according to claim 1, wherein the optimal carbonization time in the step (5) is 2.5 hours.

9. A preparation method and application of a metal oxide carbon composite material by an agar gel method are applied to electrocatalytic oxygen evolution reaction.

Technical Field

The invention belongs to the technical field of new energy electronic materials, and relates to preparation and application of a metal oxide carbon composite material by an agar gel method.

Background

The method is especially important for realizing large-scale utilization and sustainable development of energy while protecting the environment as much as possible. The further development of renewable energy sources such as wind energy, solar energy and the like enables the energy sources to be changed from fossil fuels to diversification and has a huge excitation effect, but the renewable energy sources have untimely availability, and electrocatalysis has zero carbon emissionThe advantages of traditional renewable energy sources such as high product purity and the like promote the renewable energy sources to become research hotspots of scientific researchers. Platinum (Pt) and other noble metal oxides such as iridium oxide (IrO)₂) Ruthenium oxide (RuO)₂) And the like exhibit excellent electrocatalytic properties, but have limited large-scale use thereof in the field of electrocatalysis in view of cost problems. Fortunately, there have been great advances in transition metal oxide-based materials with wide application in catalysis, sensors, fuel cells, and particularly in electrocatalysis. Therefore, it is of great practical significance to design and develop various high-efficiency transition metal oxide electrocatalysis devices. Among them, Fominykh K et al report that a Fe-doped NiO nanocrystal is synthesized, which has excellent dispersibility in ethanol, and further allows uniform about 8 nm thin films to be prepared on various substrates, and has a smooth surface. And producing the resulting Fe_0.1Ni_0.9O exhibits excellent electrocatalytic properties in alkaline medium at a current density of 10 mA cm^-2The overpotential is 297 mV, which has a large lifting space (Fominykh K, Chernev P, Zaharieva I, et al, Iron-double Nickel Oxide as high efficiency electrochemical catalysts for Alkaline Water spraying [ J]ACS Nano 2015, 9(5): 5180-. Ni/NiFeMoO prepared from Li and the like_xThe electrode material prepared by the method has amorphous active substances and rapid electron/mass transfer performance, has higher inherent activity and abundant active sites, and the corresponding water electrolysis device has the characteristics of low battery voltage, strong alkali resistance and the like, but the preparation process is complicated, and the deposition of the electrode material on the foamed nickel also has certain limitation. There are therefore still many points to be improved (Yong-Ke Li, Zhang G, Wang-Ting Lu, et al, Amorphous Ni-Fe-Mo Suboxides Coupled with Ni networks as Porous Array on Nickel Foam: A high efficiency and double functional Electrode for improved Water spraying [ J]. Advanced ence, 2020, 7(7).)。

Chinese patent document CN110201697A discloses a three-dimensional nitrogen-doped transition metal oxide/nickel sulfide composite catalyst, which comprises nickel foam as a substrate, nitrogen-doped transition metal oxide grown in situ on the nickel foam, and nickel sulfide. Also discloses a method for preparing the three-dimensional nitrogen-doped molybdenum dioxide/nickel sulfide composite catalyst, which comprises the following steps: soaking the nickel foam substrate in an ammonium tetrathiomolybdate solution, and drying after the soaking is finished to obtain a nickel foam precursor containing ammonium tetrathiomolybdate; calcining the nickel foam precursor at high temperature in vacuum to obtain a molybdenum dioxide/nickel sulfide composite catalyst; and further performing thermal ammoniation treatment on the molybdenum dioxide/nickel sulfide composite material to obtain the three-dimensional nitrogen-doped molybdenum dioxide/nickel sulfide composite catalyst. The invention also provides application of the composite catalyst as a cathode catalytic material in the HER reaction of an electrolytic water cathode, but the research on the oxygen evolution performance is not carried out.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a preparation method and application of a metal oxide carbon composite material by an agar gel method.

According to the invention, the preparation method of the metal oxide carbon composite material by the agar gel method comprises the following steps:

(1) dissolving 0.1-5 g of agar in 50 mL of deionized water, placing the solution in a water bath kettle, and stirring the solution at 50-80 ℃ for 0.5 h to obtain a light yellow liquid which is recorded as a solution A;

(2) weighing 50 mL of deionized water into a beaker, respectively weighing 0-3 g of nickel nitrate hexahydrate, 0-3 g of cobalt nitrate hexahydrate and 0-3 g of ferrous sulfate according to a certain molar ratio, adding into the beaker, and stirring and dissolving on a magnetic stirrer to obtain a solution B;

(3) mixing the solution A and the solution B, then continuously placing the mixture in a water bath kettle for stirring to uniformly mix the mixture, and continuously stirring and reacting for 0.5-5 h at the same temperature as the step (1);

(4) after the reaction in the step (3) is finished, standing at room temperature for 12-72 hours, removing supernatant from the obtained solution, and freeze-drying;

(5) and (4) carbonizing the material obtained in the step (4) at 300-800 ℃ for 1-5 hours under the protection of argon gas to finally obtain the metal oxide carbon composite material.

According to the present invention, it is preferred that the agar in step (1) has a mass of 1 g.

According to the present invention, it is preferred that the reaction temperature in step (1) is 80 ℃.

According to the present invention, it is preferred that the nickel nitrate hexahydrate, the cobalt nitrate hexahydrate and the ferrous sulfate in step (2) have mass amounts of 2.91 g, 2.91 g and 2.78 g, respectively.

According to the present invention, it is preferable that the stirring time in the step (3) is 3 hours.

According to the present invention, it is preferred that the reaction time in step (4) is 72 hours.

According to the present invention, it is preferable that the carbonization temperature in the step (5) is 700 ℃.

According to the present invention, it is preferable that the carbonization time in the step (5) is 2.5 hours.

A metal oxide carbon composite material prepared by an agar gel method is applied to electrocatalytic oxygen evolution reaction.

The technical advantages of the invention are as follows:

(1) the preparation method is simple in preparation process, easy to operate and high in repeatability.

(2) The agar gel method metal oxide carbon composite material prepared by the invention has excellent electrochemical performance, stable structure and good cycling stability, and is very suitable for being used as an electrode material in the field of electrocatalytic oxygen evolution.

Drawings

Fig. 1 is a scanning electron microscope image of a metal oxide carbon composite material prepared in example 1 of the present invention.

Fig. 2 is a linear cyclic voltammogram of the metal oxide carbon composite prepared in example 1 of the present invention.

Detailed Description

The present invention will be further described with reference to the following embodiments and drawings, but is not limited thereto.

Meanwhile, the experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.

Example 1:

first, 1 g of agar was dissolved in 50 mL of deionized water, placed in a water bath, and stirred at 80 ℃ for 0.5 h to obtain a pale yellow liquid, which was designated as solution A. 50 mL of deionized water is weighed into a beaker, 2.91 g of nickel nitrate hexahydrate, 2.91 g of cobalt nitrate hexahydrate and 2.78 g of ferrous sulfate are respectively weighed into the beaker according to a certain molar ratio, and the solution B is obtained by stirring and dissolving on a magnetic stirrer. Mixing the solution A and the solution B, then continuously placing the mixture in a water bath kettle for stirring to ensure that the mixture is uniformly mixed, and continuously stirring for reaction for 3 hours at the temperature of 80 ℃; and after the reaction is finished, standing at room temperature for 72 h, removing supernate from the obtained solution, freeze-drying, and carbonizing the material obtained after freeze-drying at 700 ℃ for 2.5 h under the protection of argon to finally obtain the metal oxide carbon composite material.

Adopting a three-electrode system, in 1 mol/L KOH electrolyte, the sweep rate is 2 mV s^-1Linear cyclic voltammetry tests were performed under conditions.

As shown in fig. 1, a scanning electron microscope image of the metal oxide carbon composite material prepared in this example shows that the metal oxide carbon composite material has a bulk structure and extremely fine nanoparticles on the surface, as can be seen from fig. 1.

The linear cyclic voltammogram of the metal oxide carbon composite material prepared in this example is shown in FIG. 2, and it can be seen from FIG. 2 that the current density is 10 mA cm^-2The overpotential is only 266 mV, which shows that the catalyst in this example has excellent performance.

Example 2:

first, 3 g of agar was dissolved in 50 mL of deionized water, placed in a water bath, and stirred at 80 ℃ for 0.5 h to obtain a pale yellow liquid, which was designated as solution A. 50 mL of deionized water is weighed into a beaker, 0.582 g of nickel nitrate hexahydrate, 0.582 g of cobalt nitrate hexahydrate and 0.556 g of ferrous sulfate are respectively weighed into the beaker according to a certain molar ratio, and the solution B is obtained by stirring and dissolving on a magnetic stirrer. Mixing the solution A and the solution B, then continuously placing the mixture in a water bath kettle for stirring to ensure that the mixture is uniformly mixed, and continuously stirring for reaction for 3 hours at the temperature of 80 ℃; and after the reaction is finished, standing at room temperature for 72 h, removing supernate from the obtained solution, freeze-drying, and carbonizing the material obtained after freeze-drying at 700 ℃ for 2.5 h under the protection of argon to finally obtain the metal oxide carbon composite material.

Adopting a three-electrode system, in 1 mol/L KOH electrolyte, the sweep rate is 2 mV s^-1Linear cyclic voltammetry tests were performed under conditions.

Example 3:

first, 1 g of agar was dissolved in 50 mL of deionized water, placed in a water bath, and stirred at 50 ℃ for 0.5 h to obtain a pale yellow liquid, which was designated as solution A. 50 mL of deionized water is weighed into a beaker, 2.91 g of nickel nitrate hexahydrate, 2.91 g of cobalt nitrate hexahydrate and 2.78 g of ferrous sulfate are respectively weighed into the beaker according to a certain molar ratio, and the solution B is obtained by stirring and dissolving on a magnetic stirrer. Mixing the solution A and the solution B, then continuously placing the mixture in a water bath kettle for stirring to ensure that the mixture is uniformly mixed, and continuously stirring for reaction for 3 hours at the temperature of 80 ℃; and after the reaction is finished, standing at room temperature for 72 h, removing supernate from the obtained solution, freeze-drying, and carbonizing the material obtained after freeze-drying at 350 ℃ for 2.5 h under the protection of argon to finally obtain the metal oxide carbon composite material.

Adopting a three-electrode system, in 1 mol/L KOH electrolyte, the sweep rate is 2 mV s^-1Linear cyclic voltammetry tests were performed under conditions.

Example 4:

first, 1 g of agar was dissolved in 50 mL of deionized water, placed in a water bath, and stirred at 80 ℃ for 0.5 h to obtain a pale yellow liquid, which was designated as solution A. 50 mL of deionized water is weighed into a beaker, 2.91 g of nickel nitrate hexahydrate, 2.91 g of cobalt nitrate hexahydrate and 2.78 g of ferrous sulfate are respectively weighed into the beaker according to a certain molar ratio, and the solution B is obtained by stirring and dissolving on a magnetic stirrer. Mixing the solution A and the solution B, then continuously placing the mixture in a water bath kettle for stirring to ensure that the mixture is uniformly mixed, and continuously stirring for reaction for 1 hour at the temperature of 80 ℃; and after the reaction is finished, standing at room temperature for 24 hours, removing supernate from the obtained solution, freeze-drying, and carbonizing the material obtained after freeze-drying at 700 ℃ for 2.5 hours under the protection of argon to finally obtain the metal oxide carbon composite material.

Adopting a three-electrode system, in 1 mol/L KOH electrolyte, the sweep rate is 2 mV s^-1Linear cyclic voltammetry tests were performed under conditions.

Example 5:

first, 5 g of agar was dissolved in 50 mL of deionized water, placed in a water bath, and stirred at 80 ℃ for 0.5 h to obtain a pale yellow liquid, which was designated as solution A. 50 mL of deionized water is weighed into a beaker, 2.91 g of nickel nitrate hexahydrate, 2.91 g of cobalt nitrate hexahydrate and 2.78 g of ferrous sulfate are respectively weighed into the beaker according to a certain molar ratio, and the solution B is obtained by stirring and dissolving on a magnetic stirrer. Mixing the solution A and the solution B, then continuously placing the mixture in a water bath kettle for stirring to ensure that the mixture is uniformly mixed, and continuously stirring for reaction for 3 hours at the temperature of 80 ℃; and after the reaction is finished, standing at room temperature for 72 h, removing supernate from the obtained solution, freeze-drying, and carbonizing the material obtained after freeze-drying at 700 ℃ for 1 h under the protection of argon to finally obtain the metal oxide carbon composite material.

Adopting a three-electrode system, in 1 mol/L KOH electrolyte, the sweep rate is 2 mV s^-1Linear cyclic voltammetry tests were performed under conditions.