Self-doped porous carbon derived from chicken feather as well as preparation method and application of self-doped porous carbon

Abstract

The invention discloses self-doped porous carbon derived from chicken feather as well as a preparation method and application of the self-doped porous carbon. Materials required by the self-doped porous carbon derived from the chicken feather are a chicken feather raw material, potassium hydroxide and hydrochloric acid. The method comprises the following steps: firstly, carbonizing, pickling and drying chicken feathers at low temperature; then, mixing with potassium hydroxide in a wet ball milling manner to obtain a mixture precursor; and finally, carrying out high-temperature calcination, acid pickling and drying on the mixture precursor in an argon atmosphere to obtain the nitrogen-oxygen-sulfur heteroatom self-doped porous carbon material. The large specific surface area of the electrocatalyst can provide more active sites, and rich micropores and mesopores can provide higher mass transfer efficiency, so that the oxygen reduction reaction rate can be increased.

Description

Technical Field

[0001] The invention relates to the technical field of electrocatalytic production of hydrogen peroxide, and in particular to self-doped porous carbon derived from chicken feathers, and a preparation method and application thereof. Background Art

[0002] Hydrogen peroxide (H2O2), also known as hydrogen peroxide, is a chemical with significant oxidizing ability. Due to its green and pollution-free characteristics and wide application fields, it has become one of the indispensable important chemicals in modern society. From pulp bleaching to medical disinfection to the degradation of environmental pollutants, hydrogen peroxide plays a key role in industrial production and daily life with its unique chemical properties. At present, the industry mainly uses the anthraquinone method to produce hydrogen peroxide on a large scale. Although the production process is mature and the system is complete, its disadvantages are also obvious, such as complicated process, high energy consumption, high pollution and high cost. In addition, the direct catalytic synthesis of H2O2 using hydrogen and oxygen under the action of precious metal catalysts such as Pd has the advantages of simple process, low production cost and atom economy. However, the hydrogen-oxygen mixing reaction is an exothermic reaction in thermodynamics, so there is a risk of explosion in the mixed gas. Therefore, people have to seek alternative methods for hydrogen peroxide synthesis that are both low-cost, environmentally friendly, high in resource utilization and sustainable.

[0003] In recent years, electrochemical methods, especially through the two-electron oxygen reduction reaction (2e - The technology of producing hydrogen peroxide by two-electron oxygen reduction (ORR) has attracted wide attention due to its advantages such as high hydrogen peroxide synthesis efficiency, economic safety, and environmental friendliness. The key to two-electron oxygen reduction is to design high-performance catalysts with good activity, high selectivity, and long-term stability. Precious metals and their alloys (such as Pt-Hg, Pd-Hg, AuPd) are currently considered to be efficient 2e-ORR catalysts with small overpotential and high selectivity, but their large-scale application is greatly limited by their shortage of resources, high cost, and poor stability. Carbon materials have attracted wide attention from researchers due to their excellent conductivity, controllable structure, abundant resources, and low cost. Biomass resources are abundant and widely available, which can not only provide abundant carbon sources and heteroatoms, but also biomass is easy to form porous structures after pyrolysis and post-treatment due to the characteristics of its own structure. Therefore, seeking a suitable method to process biomass to prepare carbon-based nanomaterial electrocatalysts with high ORR activity and high H2O2 selectivity, so as to achieve the dual purpose of environmental protection and biomass value-added, has become one of the problems that need to be solved urgently. Summary of the invention

[0004] The purpose of the present invention is to provide a self-doped porous carbon derived from chicken feathers and a preparation method and application thereof, which can obtain a rich nanoporous structure and effective 2e -ORR active centers are obtained to obtain efficient nitrogen, oxygen and sulfur self-doped porous carbon electrocatalysts to improve the performance of carbon-based nanomaterial electrocatalysts in electrochemical production of H2O2.

[0005] In one aspect of the present invention, the present invention provides a self-doped porous carbon derived from chicken feathers. According to an embodiment of the present invention, the self-doped porous carbon is composed of chicken feathers and potassium hydroxide. The cystine in the keratin contained in the chicken feathers dopes a variety of elements into the carbon skeleton during high-temperature calcination, wherein the elements include nitrogen, oxygen and sulfur. At the same time, potassium hydroxide acts as an activator and chemically reacts with carbon at high temperature to form a porous structure.

[0006] In another aspect of the present invention, the present invention provides a method for preparing chicken feather-derived self-doped porous carbon. According to an embodiment of the present invention, the method comprises the following steps:

[0007] (1) carbonizing, pickling and drying chicken feathers at low temperature to obtain pre-carbonized carbon;

[0008] (2) mixing the pre-carbonized carbon with potassium hydroxide by wet ball milling to obtain a mixture precursor;

[0009] (3) The mixture precursor is subjected to high-temperature calcination, acid washing, and drying in an inert atmosphere to obtain a porous carbon material self-doped with nitrogen, oxygen, and sulfur atoms, namely, the self-doped porous carbon derived from chicken feathers.

[0010] In addition, the method for preparing a self-doped porous carbon derived from chicken feathers according to the above embodiment of the present invention may also have the following additional technical features:

[0011] In some embodiments of the present invention, step (1) specifically includes the following steps: placing the feather in a magnetic boat, and then placing it in a tube furnace, carbonizing it under an inert atmosphere, cooling it to room temperature, grinding it, pickling it, and drying it to obtain pre-carbonized carbon.

[0012] In some embodiments of the present invention, the inert atmosphere is argon, the carbonization temperature is 250-300°C, the carbonization heating rate is 3-5°C / min, the carbonization time is 1-2h, the pickling adopts 0.5-1mol / L hydrochloric acid, the pickling temperature is 60-80°C, the pickling time is 4-6h, the drying temperature is 60-70°C, and the drying time is 8-12h.

[0013] In some embodiments of the present invention, in step (2), the mass ratio of potassium hydroxide to pre-carbonized carbon is (1-5):1, the ball milling time is 2-4 hours, the rotation speed is 400-500 rpm, and the ball milling is reversed every 30-60 minutes.

[0014] In some embodiments of the present invention, in step (3), the inert atmosphere is argon, the calcination temperature is 750-800° C., the heating rate is 5-10° C. / min, and the calcination time is 1-2 h.

[0015] In some embodiments of the present invention, in step (3), the pickling is performed using 0.5-1 mol / L hydrochloric acid, the pickling temperature is 60-80°C, the pickling time is 4-6 hours, and the drying temperature is 60-70°C, and the drying time is 8-12 hours.

[0016] In another aspect of the present invention, the present invention provides an application of self-doped porous carbon derived from chicken feathers. According to an embodiment of the present invention, the self-doped porous carbon derived from chicken feathers is used as an electrocatalyst.

[0017] In addition, the application of the self-doped porous carbon derived from chicken feathers according to the above embodiment of the present invention may also have the following additional technical features:

[0018] In some embodiments of the present invention, the chicken feather-derived self-doped porous carbon is used as an electrocatalyst in an electrocatalytic oxygen reduction reaction in a flow electrolysis cell.

[0019] In some embodiments of the present invention, the electrocatalyst is used for electrosynthesis of hydrogen peroxide.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) Compared with precious metal-based catalysts with lower ORR activity and lower H2O2 selectivity, the self-doped porous carbon electrocatalyst derived from chicken feathers of the present invention has higher ORR activity, higher H2O2 selectivity and higher stability. The heteroatom-doped porous carbon is successfully prepared by a simple mixing and high-temperature alkaline activation method.

[0022] (2) The effective doping of N, O, and S atoms changes the electron spin state of carbon atoms, thereby obtaining rich 2e - ORR active center.

[0023] (3) The chicken feather-derived self-doped porous carbon electrocatalyst of the present invention has abundant micropores and mesopores, which can provide higher O2 mass transfer efficiency on the one hand, and increase its specific surface area on the other hand, thereby exposing more active sites, which is beneficial to improving the ORR reaction rate.

[0024] (4) The mesoporous structure enables 2e - The H2O2 generated by the ORR reaction quickly diffuses into the solution, preventing it from being further reduced to generate H2O, which is beneficial to improving the H2O2 selectivity of the material, thereby greatly improving the efficiency of electrocatalytic production of hydrogen peroxide.

[0025] (5) Compared with metal-based catalysts, the chicken feather-derived self-doped porous carbon electrocatalyst of the present invention is low-cost and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a morphology of the self-doped porous carbon derived from chicken feathers in Example 1 of the present invention;

[0027] Figure 2 This is a pore size distribution diagram of the self-doped porous carbon derived from chicken feathers in Example 1 of the present invention;

[0028] Figure 3 In the figure, Figure a is the LSV (Linear Sweep Voltammetry) diagram of the self-doped porous carbon derived from chicken feathers in Examples 1 to 3 of the present invention and Comparative Example 1; Figure b is the self-doped porous carbon derived from chicken feathers in Examples 1 to 3 and Comparative Example 1; wherein CFDC-0, CFDC-1, CFDC-3, and CFDC-5 refer to catalysts prepared with a mass ratio of KOH to pre-carbonized carbon of (0 to 5): 1, respectively;

[0029] Figure 4 Graph showing H2O2 yield and Faraday efficiency of the self-doped porous carbon electrocatalyst derived from chicken feathers at different voltages in Application Examples 1-5 of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Example 1

[0032] A method for preparing chicken feather-derived self-doped porous carbon comprises the following steps:

[0033] (1) A certain amount of chicken feathers were placed in a magnetic boat, and then placed in a tube furnace. In an argon atmosphere, the temperature was raised to 300°C at 5°C / min and kept at this temperature for 2 hours. After cooling to room temperature, the feathers were taken out and ground, and then 80 ml of 1 mol / L hydrochloric acid was added for acid washing for 4 hours. Then, the feathers were filtered and dried at 70°C overnight to obtain pre-carbonized carbon.

[0034] (2) The pre-carbonized carbon (0.4 g) and potassium hydroxide (1.2 g) were placed in a ball mill, ball milled at a speed of 400 rpm, reversed once every 30 minutes, and ball milled for 2 hours. After drying and grinding, a mixture precursor was obtained.

[0035] (3) The mixture precursor was heated to 800°C at 10°C / min under an argon atmosphere and kept at this temperature for 2 hours. After cooling to room temperature, it was taken out and ground, and then 80 ml of 1 mol / L hydrochloric acid was added and acid-washed at 80°C for 4 hours. It was then filtered and dried at 70°C overnight to obtain nitrogen, oxygen and sulfur self-doped porous carbon, i.e., the self-doped porous carbon derived from chicken feathers, which was recorded as CFDC-3.

[0036] like Figure 1 Thermal field scanning electron microscopy images and Figure 2 As shown in the pore size distribution diagram, the prepared chicken feather-derived self-doped porous carbon has abundant micropores and mesoporous structures. The porous structure enables it to have a higher O2 mass transfer efficiency and can expose more active sites, which is beneficial to improve the ORR reaction rate. In addition, the mesoporous structure can make 2e - The H2O2 generated by the ORR reaction quickly diffuses into the bulk of the solution, preventing it from being further reduced to generate H2O, which is beneficial to improving the H2O2 selectivity of the material.

[0037] like Figure 3 As shown in the figure, the self-doped porous carbon electrocatalyst derived from chicken feathers prepared according to the above steps has an initial potential of 0.54V and a H2O2 selectivity of 94% under the electrochemical performance test (scanning speed 10mV / s, electrolyte is perchloric acid solution with pH=1). In terms of kinetics, the above-obtained catalyst is more favorable for 2e - ORR produces H2O2.

[0038] Example 2

[0039] A method for preparing self-doped porous carbon derived from chicken feathers is different from Example 1 only in that the mass of potassium hydroxide in step (2) is 0.4 g, and other parameters are the same as those in the steps. The self-doped porous carbon derived from chicken feathers is denoted as CFDC-1.

[0040] like Figure 3 As shown, after testing, the chicken feather-derived self-doped porous carbon electrocatalyst prepared according to the above steps has a starting potential of 0.521V and a H2O2 selectivity of 88.2% under the electrochemical performance test (scanning rate 10mV / s, electrolyte is a perchloric acid solution with pH=1).

[0041] Example 3

[0042] A method for preparing self-doped porous carbon derived from chicken feathers is different from that of Example 1 only in that the mass of potassium hydroxide in step (2) is 2.0 g, and other parameters are the same as those of the steps. The self-doped porous carbon derived from chicken feathers is denoted as CFDC-5.

[0043] like Figure 3As shown, after testing, the chicken feather-derived self-doped porous carbon electrocatalyst prepared according to the above steps has a starting potential of 0.447V and a H2O2 selectivity of 97% under the electrochemical performance test (scanning rate 10mV / s, electrolyte is a perchloric acid solution with pH=1).

[0044] Comparative Example 1

[0045] A method for preparing self-doped porous carbon derived from chicken feathers is different from that of Example 1 only in that the mass of potassium hydroxide in step (2) is 0 g, and other parameters are the same as those in the steps. The self-doped porous carbon derived from chicken feathers is denoted as CFDC-0.

[0046] like Figure 3 As shown, after testing, the chicken feather-derived self-doped porous carbon electrocatalyst prepared according to the above steps has a starting potential of 0.588V and a H2O2 selectivity of 48.6% under the electrochemical performance test (scanning rate 10mV / s, electrolyte is a perchloric acid solution with pH=1).

[0047] Application Example 1

[0048] The method for electrocatalytic oxygen reduction in a mobile electrolytic cell comprises the following steps:

[0049] (1) Weigh 10 mg of the CFDC-3 catalyst sample prepared in Example 1, prepare it into ink and spray it on carbon paper (1×1 cm) as the working electrode, and use Ag / AgCl and RuOx / Ti plates (1×1 cm) as the reference electrode and counter electrode, respectively;

[0050] (2) Add 20 ml of 1 mol / L perchloric acid as the electrolyte to the cathode and anode chambers respectively, and use a peristaltic pump to flow at 30% power, while oxygen is introduced into the cathode chamber at a rate of 100 mL / min; set the voltage to -0.2 V and perform electrolysis for 15 min;

[0051] (3) Take 10 μL of the electrolyzed solution and add it to 4 ml of 0.5 mM cerium sulfate solution. Compare the absorbance of the test solution with the standard curve to obtain the concentration of hydrogen peroxide.

[0052] like Figure 4 As shown in the flow electrolysis cell test, the prepared CFDC-3 catalyst has a Faraday efficiency of 72.79% at a voltage of -0.2 V and a hydrogen peroxide yield of 1063.08 mg·L -1 ·h -1 .

[0053] Application Example 2

[0054] A method for producing hydrogen peroxide by oxygen reduction in a flowable electrolytic cell, which differs from Application Example 1 only in that the voltage in step (2) is set to -0.4V, and the other parameters and steps are the same.

[0055] like Figure 4 As shown in the flow electrolysis cell test, the catalyst has a Faradaic efficiency of 75.47% at a voltage of -0.4 V and a hydrogen peroxide yield of 1936.32 mg·L -1 ·h -1 .

[0056] Application Example 3

[0057] A method for producing hydrogen peroxide by oxygen reduction in a flowable electrolytic cell, which differs from Application Example 1 only in that the voltage in step (2) is set to -0.6V, and the other parameters and steps are the same.

[0058] like Figure 4 As shown in the flow electrolysis cell test, the prepared CFDC-3 catalyst has a Faraday efficiency of 74.24% at a voltage of -0.6 V and a hydrogen peroxide yield of 2767.98 mg·L -1 ·h -1 .

[0059] Application Example 4

[0060] A method for producing hydrogen peroxide by oxygen reduction in a flowable electrolytic cell, which differs from Application Example 1 only in that the voltage in step (2) is set to -0.8V, and the other parameters and steps are the same.

[0061] like Figure 4 As shown in the flow electrolysis cell test, the prepared CFDC-3 catalyst has a Faraday efficiency of 74.55% at a voltage of -0.8 V and a hydrogen peroxide yield of 3292.97 mg·L -1 ·h -1 .

[0062] Application Example 5

[0063] A method for producing hydrogen peroxide by oxygen reduction in a flowable electrolytic cell, which differs from Example 1 only in that the voltage in step (2) is set to -1V, and the other parameters and steps are the same.

[0064] like Figure 4 As shown in the flow electrolysis cell test, the prepared CFDC-3 catalyst has a Faraday efficiency of 78.98% at a voltage of -1 V and a hydrogen peroxide yield of 4187 mg·L -1 ·h -1 .

[0065] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A self-doped porous carbon derived from chicken feathers, characterized in that: It is composed of chicken feathers and potassium hydroxide. The cystine in the keratin contained in the chicken feathers itself dopes a variety of elements into the carbon skeleton during high-temperature calcination, including nitrogen, oxygen and sulfur. At the same time, potassium hydroxide acts as an activator and chemically reacts with carbon at high temperature to form a porous structure.

2. A method for preparing chicken feather-derived self-doped porous carbon according to claim 1, characterized in that: The following steps are involved: (1) carbonizing, pickling and drying chicken feathers at low temperature to obtain pre-carbonized carbon; (2) mixing the pre-carbonized carbon with potassium hydroxide by wet ball milling to obtain a mixture precursor; (3) The mixture precursor is subjected to high-temperature calcination, acid washing, and drying in an inert atmosphere to obtain a porous carbon material self-doped with nitrogen, oxygen, and sulfur atoms, namely, the self-doped porous carbon derived from chicken feathers.

3. The method for preparing chicken feather-derived self-doped porous carbon according to claim 2, characterized in that: Step (1) specifically includes the following steps: placing the feather in a magnetic boat, and then placing it in a tube furnace, carbonizing it under an inert atmosphere, cooling it to room temperature, grinding it, pickling it, and drying it to obtain pre-carbonized carbon.

4. The method for preparing chicken feather-derived self-doped porous carbon according to claim 3, characterized in that: The inert atmosphere is argon, the carbonization temperature is 250-300°C, the carbonization heating rate is 3-5°C / min, the carbonization time is 1-2h, the pickling adopts 0.5-1mol / L hydrochloric acid, the pickling temperature is 60-80°C, the pickling time is 4-6h, the drying temperature is 60-70°C, and the drying time is 8-12h.

5. The method for preparing chicken feather-derived self-doped porous carbon according to claim 2, characterized in that: In step (2), the mass ratio of potassium hydroxide to pre-carbonized carbon is (1-5):1, the ball milling time is 2-4 hours, the rotation speed is 400-500 rpm, and the ball milling is reversed every 30-60 minutes.

6. The method for preparing chicken feather-derived self-doped porous carbon according to claim 2, characterized in that: In step (3), the inert atmosphere is argon, the calcination temperature is 750-800° C., the heating rate is 5-10° C. / min, and the calcination time is 1-2 h.

7. The method for preparing chicken feather-derived self-doped porous carbon according to claim 2, characterized in that: In step (3), the acid pickling adopts 0.5-1 mol / L hydrochloric acid, the acid pickling temperature is 60-80°C, the acid pickling time is 4-6h, and the drying temperature is 60-70°C, and the drying time is 8-12h.

8. An application of the chicken feather-derived self-doped porous carbon according to claim 1, characterized in that: The chicken feather-derived self-doped porous carbon was used as an electrocatalyst.

9. The use of chicken feather-derived self-doped porous carbon according to claim 8, characterized in that: The chicken feather-derived self-doped porous carbon is used as an electrocatalyst in the electrocatalytic oxygen reduction reaction in a flow electrolysis cell.

10. The use of chicken feather-derived self-doped porous carbon according to claim 8, characterized in that: The electrocatalyst is used for electrosynthesis of hydrogen peroxide.

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