阅读说明：本技术 一种生物质硼掺杂碳球诱导氧化锰复合物催化剂电极的制备方法及性能 (Preparation method and performance of biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode ) 是由 董国华 孙贝贝 吴昊 张文治 于菲 于 2021-07-22 设计创作，主要内容包括：一种生物质硼掺杂碳球诱导氧化锰复合物催化剂电极(B-CS/MnO-(2))的制备方法及性能,它涉及一种催化剂电极的制备方法及性能。本发明的目的是要解决现有电催化剂价格高昂、材料来源匮乏、稳定性差、电化学性能低以及催化活性低的问题。方法：一、泡沫镍去除表面油脂；二、去除表面氧化膜；三、去除表面吸附离子；四、真空干燥；五、制备分散系A；六、水热处理；七、过滤和透析；八、旋蒸；九、烘干和研磨；十、制备催化剂前驱物混合溶液B；十一、水热处理；十二、洗涤泡沫镍；十三、烘干,得到由生物质硼掺杂碳球诱导氧化锰复合物催化剂电极。生物质硼掺杂碳球诱导氧化锰复合物催化剂电极用于电催化析氧反应。利用本发明制备的硼掺杂碳球/氧化锰复合物催化剂电极具有较高的电催化析氧性能,达到10mA·cm～(-2)的电流密度仅需要170mV的过电势,Tafel斜率仅为31.43mV dec～(-1)。本发明可获得一种生物质硼掺杂碳球诱导氧化锰复合物催化剂电极。(Biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode (B-CS/MnO) 2 ) Relates to a preparation method and performance of a catalyst electrode. The invention aims to solve the problems of high price, deficient material source, poor stability, low electrochemical performance and low catalytic activity of the conventional electrocatalyst. The method comprises the following steps: firstly, removing surface grease by using foamed nickel; secondly, removing the surface oxide film; thirdly, removing surface adsorbed ions; fourthly, vacuum drying; fifthly, preparing a dispersion system A; sixthly, carrying out hydrothermal treatment; seventhly, filtering and dialyzing; eighthly, rotary steaming; ninth, drying and grinding; preparing a catalyst precursor mixed solution B;eleventh, carrying out hydrothermal treatment; twelfth, washing the foam nickel; thirteen, drying to obtain the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode. The biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode is used for electrocatalytic oxygen evolution reaction. The boron-doped carbon sphere/manganese oxide composite catalyst electrode prepared by the method has higher electro-catalysis oxygen evolution performance which reaches 10 mA-cm ‑2 The current density of (1) only needs 170mV overpotential, and the Tafel slope is only 31.43mV dec ‑1 . The invention can obtain a biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode.)

1. A preparation method of a biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode is characterized in that the preparation method of the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode is completed according to the following steps:

(1) and immersing the sheared foam nickel into a proper amount of acetone for ultrasonic cleaning to remove surface grease. Obtaining the foam nickel after oil removal.

(2) And taking out the foam nickel after oil removal, immersing the foam nickel into a hydrochloric acid solution for ultrasonic cleaning, and removing the surface oxide film. And removing the surface oxide film to obtain the foamed nickel.

(3) And taking out the foamed nickel without the oxide film, and then respectively soaking the foamed nickel into deionized water and ethanol for ultrasonic cleaning to remove surface adsorbed ions.

(4) And drying the treated foamed nickel under vacuum condition for later use.

(5) Mixing boric acid, starch and absolute ethyl alcohol to obtain a dispersion system A;

the ratio of the mass of the boric acid to the volume of the absolute ethyl alcohol in the step five is (0.5 g-5.0 g): 5 mL-50 mL;

the volume ratio of the mass of the starch to the absolute ethyl alcohol in the step five is (0.5 g-5.0 g): 5 mL-50 mL;

(6) carrying out hydrothermal treatment on the obtained dispersion system A, and storing for 4-48 h in a sealed stainless steel high-pressure reaction kettle at the temperature of 80-200 ℃.

(7) And after the oven is naturally cooled to room temperature, filtering the liquid sample by using a water system microporous membrane (the aperture is 0.12-0.55 mu m), and dialyzing in ethanol for 2-24 h to obtain the carbon sphere liquid sample.

(8) And (4) carrying out rotary evaporation on the obtained carbon sphere liquid sample by using a rotary evaporator to obtain a carbon sphere solid.

(9) And drying the obtained carbon sphere solid at 30-150 ℃ for 2-48 h, and grinding the carbon sphere solid into solid powder to obtain a carbon sphere powder sample.

(10) Mixing carbon spheres, potassium permanganate and deionized water, and stirring to obtain a mixed solution B;

the mass of the carbon spheres in the step ten and the volume ratio of the deionized water are (0.01 g-5.00 g): 5 mL-50 mL;

the volume ratio of the mass of the potassium permanganate to the volume of the deionized water in the step ten is (0.1 g-10.0 g): 5 mL-80 mL;

(11) and (3) putting the processed nickel foam into the obtained mixed solution B for hydro-thermal treatment, and storing for 4-48 h in a sealed stainless steel high-pressure reaction kettle at the temperature of 80-200 ℃.

(12) After the oven is naturally cooled to room temperature, washing the catalyst-loaded foam nickel for a plurality of times by using deionized water;

(13) and (3) washing the catalyst-loaded foam nickel for several times, and finally drying at the temperature of between 20 and 140 ℃ for 4 to 48 hours to obtain the carbon sphere-induced manganese oxide composite catalyst electrode.

2. The preparation method of the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode according to claim 1, wherein the width of the nickel foam in the step one is 1 cm-6 cm, and the length of the nickel foam is 0.5 cm-10.5 cm. (ii) a The ultrasonic cleaning time for removing the surface grease in the step one is 5-60 min, and the power of the ultrasonic cleaning is 200-700W.

3. The preparation method of the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode according to claim 1, wherein the mass fraction of the hydrochloric acid solution in the second step is 0.1-6M; and in the second step, the ultrasonic cleaning time for removing the surface grease of the surface oxidation film is 5-60 min, and the ultrasonic cleaning power is 200-700W.

4. The preparation method of the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode according to claim 1, wherein the time for removing the surface adsorbed ions in the step three is 5-60 min, and the power for ultrasonic cleaning is 200-700W.

5. The preparation method of the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode according to claim 1, wherein the drying temperature in the fourth step is 30-140 ℃, and the drying time is 4-48 h.

6. The method for preparing the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode according to claim 1, wherein the starch in the fifth step is soluble starch.

7. The preparation method of the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode according to claim 1, wherein the hydrothermal treatment time in the sixth step is 6-48 h.

8. The method for preparing the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode according to claim 1, wherein the dialysis time in the seventh step is 3-18 h.

9. The preparation method of the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode according to claim 1, wherein the eight-step rotary evaporation temperature is 15-95 ℃.

10. The preparation method of the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode according to claim 1, wherein the drying temperature in the ninth step is 15-140 ℃.

11. The method for preparing the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode according to claim 1, wherein the stirring speed in the step ten is 2r/s to 9r/s, and the stirring time is 5min to 60 min.

12. The preparation method of the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode according to claim 1, wherein the hydrothermal treatment time in the eleventh step is 6-48 h.

13. The method for preparing the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode according to claim 1, wherein the number of times of cleaning in the step twelve is 5-50.

14. The method for preparing the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode according to claim 1, wherein the drying time in the thirteenth step is 4-48 h.

Technical Field

The invention relates to a preparation method and performance of an electrode.

Background

Increasing energy consumption and environmental issues have prompted the development of clean energy. As a clean carbon-neutral energy carrier, hydrogen is considered an attractive alternative to fossil fuels. Ideally, hydrogen is produced by water splitting driven by renewable clean energy sources. Generally, water splitting proceeds through two basic half-reactions: hydrogen Evolution Reaction (HER) at the cathode and evolution reaction (OER) at the anode for water oxidation (also known as oxygen). Compared with HER, the OER process involves relatively high reaction energy barrier and four-electron mechanism of electrocatalytic oxygen evolution, so that the reaction overpotential is large, the reaction rate is slow, the electric energy consumption is large, and the electrolytic hydrogen production efficiency is low. Therefore, the high-activity oxygen evolution electrocatalyst breaks through the bottleneck of high-efficiency energy-saving full water cracking. There is therefore an urgent need to develop an alternative electrocatalyst which is explored by using low cost non-noble metal based oxygen evolution catalysts.

Manganese oxide (MnOx) is used as the only oxygen evolution catalytic active center in natural photosynthesis, and Mn has inherent catalytic oxygen evolution performance incomparable with other metals. Although MnOx shows great promise in driving OER, its electrocatalytic activity is still not comparable to that of IrOx and RuOx catalysts due to its relatively low intrinsic activity, limited available active sites and poor electrical conductivity. Therefore, it is urgent to find a reasonable preparation route of manganese oxide and to improve its electrocatalytic activity, so that the electrocatalyst has important significance in improving the OER performance.

Researchers have combined guest cations with a range of metal cations (e.g., K)⁺、Na⁺、Mg²⁺、Zn²⁺、Ni²⁺And Co²⁺Ion) exchange to controlThe possibility of interlayer properties, which may improve the electrocatalytic activity by exploiting the conductivity and catalytic activity of the metal ions themselves, promotes OER performance. However, the catalyst prepared by the above method has a limited effect of improving the electrocatalytic performance.

At present, the biomass carbon material is an easily-obtained, low-cost, nontoxic and good-biocompatibility nano material, and has the advantages of large specific surface area, good conductivity, strong electron transfer capacity, strong electron storage capacity and the like.

According to the invention, biomass boron-doped carbon spheres (B-CS) are mainly added into the prepared manganese oxide, and the electrochemical active area and the stability are increased by utilizing the high dispersibility and the high conductivity of the biomass boron-doped carbon spheres, so that the electrocatalytic oxygen evolution performance of the manganese oxide is obviously improved.

Disclosure of Invention

The invention aims to solve the problems of high price, deficient material source, poor stability, low electrochemical performance and low catalytic activity of the conventional electrocatalyst. And provides a preparation method and performance of the biomass boron-doped carbon sphere induced manganese oxide composite electrocatalyst.

A preparation method of a biomass boron-doped carbon sphere induced manganese oxide composite electrocatalyst is completed by the following steps:

firstly, soaking the sheared foam nickel into a proper amount of acetone for ultrasonic cleaning, and removing surface grease. Obtaining the foam nickel after oil removal.

And secondly, taking out the foam nickel after oil removal, immersing the foam nickel into a hydrochloric acid solution for ultrasonic cleaning, and removing the surface oxide film. And removing the surface oxide film to obtain the foamed nickel.

And thirdly, taking out the foamed nickel without the oxide film, and then respectively soaking the foamed nickel into deionized water and ethanol for ultrasonic cleaning to remove surface adsorbed ions.

Fourthly, drying the treated foam nickel under vacuum condition for standby.

Mixing boric acid, starch and absolute ethyl alcohol to obtain a dispersion system A;

the ratio of the mass of the boric acid to the volume of the absolute ethyl alcohol in the step five is (0.5 g-5.0 g): 5 mL-50 mL;

the volume ratio of the mass of the starch to the absolute ethyl alcohol in the step five is (0.5 g-5.0 g): 5 mL-50 mL;

and sixthly, performing hydrothermal treatment on the obtained dispersion system A, and storing the dispersion system A for 4-48 h in a sealed stainless steel high-pressure reaction kettle at the temperature of 80-200 ℃.

Seventhly, after the oven is naturally cooled to the room temperature, filtering the liquid sample by using a water system microporous membrane (the aperture is 0.12-0.55 mu m), and dialyzing in ethanol for 2-24 hours to obtain the carbon sphere liquid sample.

And eighthly, carrying out rotary evaporation on the obtained carbon sphere liquid sample by using a rotary evaporator to obtain a carbon sphere solid.

And ninthly, drying the obtained carbon sphere solid at the temperature of 30-150 ℃ for 2-48 h, and grinding the carbon sphere solid into solid powder to obtain a carbon sphere powder sample.

Mixing carbon spheres, potassium permanganate and deionized water, and stirring to obtain a mixed solution B;

the mass of the carbon spheres in the step ten and the volume ratio of the deionized water are (0.01 g-5.00 g): 5 mL-50 mL;

the volume ratio of the mass of the potassium permanganate to the volume of the deionized water in the step ten is (0.1 g-10.0 g): 5 mL-80 mL;

and eleventh, putting the processed foamed nickel into the obtained mixed solution B for hydro-thermal treatment, and storing for 4-48 h in a sealed stainless steel high-pressure reaction kettle at the temperature of 80-200 ℃.

After the oven is naturally cooled to the room temperature, washing the catalyst-loaded foam nickel for a plurality of times by using deionized water;

thirteen, washing the catalyst-loaded foam nickel for several times, and drying at 20-140 ℃ for 4-48 h to obtain the carbon sphere induced manganese oxide composite catalyst electrode.

A biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode is used for electrocatalytic oxygen evolution.

The invention has the advantages that:

the invention provides a preparation method of a biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode, which has the advantages of simple preparation process, easy operation, low cost, low equipment investment and suitability for popularization and application;

the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode prepared by the method has the advantages of low oxygen evolution overpotential, low Tafel slope, high stability and good conductivity, and has important theoretical and practical significance;

the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode provided by the invention has the advantages of strong oxidation capacity, high controllability, mild reaction conditions, small occupied area, no pollution to the environment, and the like;

fourthly, the boron-doped carbon sphere induced manganese oxide composite catalyst electrode prepared by the method is used for electrocatalytic oxygen evolution, has less side reaction and reaches 10 mA-cm^-2In the case of the current density of (1), the overpotential for the oxygen evolution performance is 170mV, and the Tafel slope is 31.43mV dec^-1。

The invention can obtain a biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode.

Drawings

FIG. 1 is a scanning electron microscope image of a low power of a prepared biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode;

FIG. 2 is a scanning electron microscope image of a prepared pure manganese oxide catalyst electrode;

FIG. 3 is a scanning electron microscope image of the prepared biomass boron-doped carbon spheres;

FIG. 4 is an XPS spectrum of a prepared biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode;

fig. 5 is an XRD spectrogram of the prepared biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode, in fig. 4, 1 is a manganese dioxide standard card, 2 is a manganese dioxide catalyst electrode, and 3 is an XRD curve of the prepared biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode;

FIG. 6 is a linear voltammetric scan of a prepared biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode;

fig. 7 is a tafel diagram of the prepared biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode.

Detailed Description

The first embodiment is as follows: a preparation method of a biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode comprises the following steps:

firstly, soaking the sheared foam nickel into a proper amount of acetone for ultrasonic cleaning, and removing surface grease. Obtaining the foam nickel after oil removal.

And secondly, taking out the foam nickel after oil removal, immersing the foam nickel into a hydrochloric acid solution for ultrasonic cleaning, and removing the surface oxide film. And removing the surface oxide film to obtain the foamed nickel.

And thirdly, taking out the foamed nickel without the oxide film, and then respectively soaking the foamed nickel into deionized water and ethanol for ultrasonic cleaning to remove surface adsorbed ions.

Fourthly, drying the treated foam nickel under vacuum condition for standby.

Mixing boric acid, starch and absolute ethyl alcohol to obtain a dispersion system A;

the ratio of the mass of the boric acid to the volume of the absolute ethyl alcohol in the step five is (0.5 g-5.0 g): 5 mL-50 mL;

the volume ratio of the mass of the starch to the absolute ethyl alcohol in the step five is (0.5 g-5.0 g): 5 mL-50 mL;

and sixthly, performing hydrothermal treatment on the obtained dispersion system A, and storing the dispersion system A for 4-48 h in a sealed stainless steel high-pressure reaction kettle at the temperature of 80-200 ℃.

Seventhly, after the oven is naturally cooled to the room temperature, filtering the liquid sample by using a water system microporous membrane (the aperture is 0.12-0.55 mu m), and dialyzing in ethanol for 2-24 hours to obtain the carbon sphere liquid sample.

And eighthly, carrying out rotary evaporation on the obtained carbon sphere liquid sample by using a rotary evaporator to obtain a carbon sphere solid.

And ninthly, drying the obtained carbon sphere solid at the temperature of 30-150 ℃ for 2-48 h, and grinding the carbon sphere solid into solid powder to obtain a carbon sphere powder sample.

Mixing carbon spheres, potassium permanganate and deionized water, and stirring to obtain a mixed solution B;

the mass of the carbon spheres in the step ten and the volume ratio of the deionized water are (0.01 g-5.00 g): 5 mL-50 mL;

the volume ratio of the mass of the potassium permanganate to the volume of the deionized water in the step ten is (0.1 g-10.0 g): 5 mL-80 mL;

and eleventh, putting the processed foamed nickel into the obtained mixed solution B for hydro-thermal treatment, and storing for 4-48 h in a sealed stainless steel high-pressure reaction kettle at the temperature of 80-200 ℃.

After the oven is naturally cooled to the room temperature, washing the catalyst-loaded foam nickel for a plurality of times by using deionized water;

thirteen, washing the catalyst-loaded foam nickel for several times, and finally drying at 20-140 ℃ for 4-48 h to obtain the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode.

The second embodiment is as follows: the present embodiment differs from the present embodiment in that: the width of the foam nickel in the step one is 1 cm-6 cm, and the length of the foam nickel is 0.5 cm-10.5 cm. Other steps are the same as in the first embodiment. The ultrasonic cleaning time for removing the surface grease in the step one is 5-60 min, and the power of the ultrasonic cleaning is 200-700W. The other steps are the same as in the first or second embodiment.

The third concrete implementation mode: the present embodiment differs from the first or second embodiment in that: the mass fraction of the hydrochloric acid solution in the second step is 0.1-6M; and the ultrasonic cleaning time for removing the surface oxide film in the step two is 5-60 min, and the ultrasonic cleaning power is 200-700W. The other steps are the same as in the first or second embodiment.

The fourth concrete implementation mode: the difference between this embodiment and one of the first to third embodiments is as follows: the ultrasonic cleaning time for removing the surface adsorption ions in the third step is 5-60 min, and the power of the ultrasonic cleaning is 200-700W. The other steps are the same as those in the first to third embodiments.

The fifth concrete implementation mode: the difference between this embodiment and one of the first to fourth embodiments is: the drying temperature in the fourth step is 30-140 ℃, and the drying time is 4-48 h. The other steps are the same as those in the first to fourth embodiments.

The sixth specific implementation mode: the difference between this embodiment and one of the first to fifth embodiments is as follows: and the starch in the fifth step is soluble starch. The other steps are the same as those in the first to fifth embodiments.

The seventh embodiment: the difference between this embodiment and one of the first to sixth embodiments is: the time of the hydrothermal treatment in the sixth step is 6-48 h. The other steps are the same as those in the first to sixth embodiments.

The specific implementation mode is eight: the difference between this embodiment and one of the first to seventh embodiments is: the dialysis time in the seventh step is 3-18 h. The other steps are the same as those in the first to seventh embodiments.

The specific implementation method nine: the difference between this embodiment and the first to eighth embodiments is: and the rotary evaporation temperature in the step eight is 15-95 ℃. The other steps are the same as those in the first to eighth embodiments.

The detailed implementation mode is ten: the difference between this embodiment and one of the first to ninth embodiments is as follows: the drying temperature in the ninth step is 15-140 ℃. The other steps are the same as those in the first to ninth embodiments.

The concrete implementation mode eleven: the present embodiment differs from the first to tenth embodiments in that: the stirring speed in the step ten is 2 r/s-9 r/s, and the stirring time is 5 min-60 min. The other steps are the same as those in the first to tenth embodiments.

The specific implementation mode twelve: the present embodiment differs from the first to eleventh embodiments in that: the time of the hydrothermal treatment in the eleventh step is 6-48 h. The other steps are the same as those in the first to tenth embodiments.

The specific implementation mode is thirteen: the difference between this embodiment and the first to twelfth embodiments is: the number of washing times in the step twelve is 5 to 50. The other steps are the same as those in the first to twelfth embodiments.

The specific implementation mode is fourteen: the difference between this embodiment and the first to twelfth embodiments is: and the drying time in the step thirteen is 4-48 h. The other steps are the same as those in the first to third embodiments.

The following examples were used to demonstrate the beneficial effects of the present invention:

firstly, soaking the sheared foam nickel into a proper amount of acetone for ultrasonic cleaning, and removing surface grease. Obtaining foam nickel after oil removal;

the width of the foamed nickel in the first step is 2cm, and the length of the foamed nickel is 4 cm;

the ultrasonic cleaning time for removing the surface grease in the step one is 15 min;

the power of ultrasonic cleaning in the step one is 200W;

and secondly, taking out the deoiled foam nickel, immersing the foam nickel into a hydrochloric acid solution with the mass fraction of 2M, and ultrasonically cleaning to remove the surface oxide film. Obtaining the foam nickel with the surface oxide film removed;

the ultrasonic cleaning time for removing the surface oxide film in the step two is 15 min;

the power of ultrasonic cleaning in the step two is 200W;

thirdly, taking out the foamed nickel without the surface oxide film, and then respectively soaking the foamed nickel into deionized water and ethanol for ultrasonic cleaning to remove surface adsorbed ions;

the ultrasonic cleaning time for removing the surface adsorption ions in the third step is 15 min;

the power of ultrasonic cleaning in the third step is 200W;

fourthly, drying the treated foam nickel under a vacuum condition for later use;

the drying temperature in the fourth step is 50 ℃, and the drying time is 12 hours;

mixing boric acid, starch and absolute ethyl alcohol to obtain a dispersion system A;

the volume ratio of the mass of the boric acid to the absolute ethyl alcohol in the step five is 1.0g:15 mL;

the volume ratio of the mass of the starch to the absolute ethyl alcohol in the step five is 1.0g:15 mL;

sixthly, carrying out hydrothermal treatment on the obtained dispersion system A, and storing the dispersion system A in a sealed stainless steel high-pressure reaction kettle;

the temperature of the hydrothermal treatment in the sixth step is 180 ℃, and the storage time is 12 h;

seventhly, after the oven is naturally cooled to the room temperature, carrying out microporous membrane filtration on the liquid sample, and then dialyzing in ethanol to obtain a carbon sphere liquid sample;

the pore diameter of the microporous membrane filtration in the seventh step is 0.22 μm;

the dialysis time in the seventh step is 12 hours;

eighthly, carrying out rotary evaporation on the obtained carbon sphere liquid sample by using a rotary evaporator to obtain a carbon sphere solid;

the rotary evaporation temperature in the step eight is 50 ℃;

drying the obtained carbon sphere solid, and grinding the dried carbon sphere solid into solid powder to obtain a carbon sphere powder sample;

and the drying temperature in the ninth step is 80 ℃, and the drying time is 10 hours.

Mixing carbon spheres, potassium permanganate and deionized water, and stirring to obtain a mixed solution B;

the mass of the carbon spheres in the step ten and the volume ratio of the deionized water are 0.08g to 10 mL;

the volume ratio of the mass of the potassium permanganate to the volume of the deionized water in the step ten is 0.4g:20 mL;

the stirring speed in the step ten is 3 r/s-6 r/s, and the stirring time is 15 min.

And eleventh, putting the processed foamed nickel into the obtained mixed solution B for hydro-thermal treatment, and storing the treated foamed nickel in a sealed stainless steel high-pressure reaction kettle.

The temperature of the hydrothermal treatment in the eleventh step is 130 ℃, and the storage time is 10 hours;

after the oven is naturally cooled to the room temperature, washing the catalyst-loaded foam nickel for a plurality of times by using deionized water;

the washing times in the step twelve are 20 times;

thirteen, washing the blackened foam nickel for a plurality of times, and finally drying to obtain the carbon sphere induced manganese oxide compound catalyst electrode.

The drying temperature in the step thirteen is 60 ℃, and the drying time is 12 hours;

as can be seen from fig. 1, the biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode prepared under a 5 μm electron microscope uniformly forms nanospheres with small-particle high-density cellular structures on the surface of the foamed nickel, so that the specific surface area of the catalyst is increased, the charge transfer performance is enhanced, and the conductivity of the catalyst is improved.

As can be seen from fig. 2, the pure manganese oxide catalyst electrode prepared under a 5 μm electron microscope forms nanospheres that are agglomerated and have a larger particle cell structure on the surface of the foamed nickel.

As shown in FIG. 3, the particle size of the biomass boron-doped carbon spheres prepared under a 2 μm electron microscope is 50 to 200 nm.

Fig. 4 is an XPS spectrum of a biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode prepared in example one;

as can be seen from FIG. 4, it is B1s at 170eV, C1s at 286eV, O1s at 531eV, and Mn 2p at 641eV confirm that the catalyst is composed of Mn, C, O, and B, and that Mn is +4, C is +2, O is-2, and B is-2 or + 3.

Fig. 5 is an XRD spectrum of the biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode prepared in example one, in fig. 5, 1 is manganese dioxide, 2 is a manganese dioxide standard card, and 3 is an XRD curve of the biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode prepared in example one;

as can be seen from fig. 5, the composition of the catalyst is manganese dioxide, the biomass boron-doped carbon sphere induced manganese oxide compound is consistent with the comparison result of the standard card, and the characteristic peaks of manganese dioxide at 2 θ ═ 19.112 °, 37.120 °, 38.957 °, 45.067 °, 49.496 °, 59.597 °, 65.701 ° and 69.581 ° respectively correspond to the labeled crystal planes in the figure, and we can see that the crystallinity of the carbon spheres and manganese dioxide is better through the characteristic peaks.

Fig. 6 is a linear voltammogram of a biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode prepared in example one;

fig. 7 is a tafel plot of a biomass boron-doped carbon sphere-induced manganese oxide composite catalyst electrode prepared in example one;

as can be seen from FIGS. 6 and 7, the organism prepared in example oneThe boron-doped carbon sphere-induced manganese oxide composite catalyst electrode has low over-potential and Tafel slope. When the current reaches 10mA cm^-2In the case of the current density of (1), the overpotential for the oxygen evolution performance is 170mV, and the Tafel slope is 31.43mV dec^-1。

Example two: the application of the biomass boron-doped carbon sphere induced manganese oxide composite catalyst electrode prepared in the first embodiment to electrocatalytic oxygen evolution performance is completed according to the following steps:

electrochemical experimental configuration; in 1M KOH and using a standard three-electrode system, wherein a sample of foamed nickel (2 cm. times.4 cm) in size, a graphite rod and an Hg/HgO electrode were used as working, counter and reference electrodes, respectively. Linear Sweep Voltammetry (LSV) at 5mV s^-1The polarization curve is acquired at the scan rate of (a). Reversible Hydrogen Electrodes (RHE) at all Hg/HgO potentials were switched by calibration with nernst equation E (rvs. RHE) ═ E (vs. Hg/HgO) +0.05910 × PH + 0.098V).

B-CS/MnO prepared in example one₂The composite catalyst electrode is added as an anode, and the current density is 10mA/cm²The overpotential is 170mV, and the Tafel slope is as low as 31.43mV dec^-1。

FIG. 6 shows B-CS/MnO prepared using example one₂The composite catalyst electrode extracts the corresponding tafel slope plot from the LSV curve.

As can be seen from FIGS. 5 and 6, B-CS/MnO was dissolved in 1M KOH₂The oxygen evolution performance of the composite catalyst electrode reaches 10mA cm^-2In the case of the current density of (1), the overpotential for the oxygen evolution performance is 170mV, and the Tafel slope is 31.43mV dec^-1。

B-CS/MnO prepared in example one₂In the composite catalyst electrode, under the condition of keeping other conditions unchanged, the Cs content is changed from 0.08g to 0g, 0.04g, 0.06g and 0.1g respectively, other samples are obtained and marked as 1, 2, 3, 4 and 5 respectively.

B-CS/MnO with different carbon ball dosage added thereto in FIG. 5 and FIG. 6₂The oxygen evolution performance of the composite catalyst electrode, i.e. the overpotential and the Tafel slope, are shown in table 1.

TABLE 1

Sample (I)	1	2	3	4	5
						Carbon sphere dosage/g	0	0.04	0.06	0.08	0.1
overpotential/mV	390	280	320	170	410
						Tafel slope/mV dec-1	107.53	75.27	86.02	31.43	112.9

As is clear from FIGS. 5 and 6 and Table 1, B-CS/MnO at a carbon sphere content of 0.08g₂The electrocatalytic oxygen evolution performance of the composite catalyst electrode is optimal.