Preparation method of porous hollow carbon microsphere co-doped with oxygen and nitrogen

Abstract

The invention discloses a preparation method of a porous hollow carbon microsphere co-doped with oxygen and nitrogen. A spherical precursor (namely composite microsphere) is obtained by spray drying on a mixed solution of lignin and a metal compound, the crosslinking degree of the spherical precursor is improved by oxidizing the spherical precursor in air in advance, so that the spherical morphology during the subsequent carbonization process protected by inert atmosphere is maintained, and the porous hollow carbon microsphere co-doped with oxygen and nitrogen is finally obtained by oxidization of concentrated nitric acid. The preparation method is simple in process, production on a large scale is easily achieved, moreover, the main raw material lignin is industrial waste such as papermaking and is low in cost, and high utilization of the microsphere can be achieved; and the porous hollow carbon microsphere prepared by the method is uniform in grain size, high in size controllability and has relatively large specific area and developed hierarchical hole structure, and the electrochemical performance is excellent when the porous hollow carbon microsphere is used as a supercapacitorelectrode material.

Description

technical field

[0001] The invention relates to the technical field of porous carbon materials, in particular to a preparation method of oxygen and nitrogen co-doped porous hollow carbon microspheres. Background technique

[0002] Today, with the rapid development of social economy and the increasing shortage of resources, new energy storage components have been developed rapidly. Porous carbon is widely used in mobile communications, aerospace, Information technology and national defense technology are widely used. At present, supercapacitors have become energy storage devices that are widely concerned by researchers due to their fast charge and discharge, high power density, excellent cycle stability, and high stability. Electrode materials are one of the key factors determining the performance of supercapacitors. Carbon materials such as carbon fibers, activated carbon, carbon nanotubes, graphene, and porous carbon spheres are widely studied electrode materials for super...

Examples

Embodiment 1

[0037] Dissolve alkali lignin and sodium hydroxide with a mass ratio of 5:1 in deionized water to form a solution, control the mass fraction of alkali lignin and sodium hydroxide in the solution to be 10%, and stir at room temperature for 2h; The final solution was transferred to the spray drying equipment, and the composite microspheres were obtained by the spray drying method; the composite microspheres were placed in the air for pre-oxidation treatment, and the temperature was raised to 200°C at a heating rate of 0.1°C / min, and kept at a constant temperature for 20h. Then cool naturally to room temperature; place the pre-oxidized composite microspheres in a nitrogen atmosphere, raise the temperature to 700 °C at a rate of 10 °C / min, and carbonize at a constant temperature for 2 hours, then cool naturally to room temperature; use a concentration of 2.0 mol / Soak the carbonized composite microspheres in 1 L of hydrochloric acid solution to remove the inorganic matter, then was...

Embodiment 2

[0040] Dissolve kraft lignin and potassium carbonate with a mass ratio of 3:1 in deionized water to form a solution, control the mass fraction of kraft lignin and potassium carbonate in the solution to 20%, and stir at room temperature for 1 h; The final solution was transferred to the spray drying equipment, and the composite microspheres were obtained by the spray drying method; the composite microspheres were placed in the air for pre-oxidation treatment, and the temperature was raised to 270 °C at a heating rate of 1 °C / min, and kept at a constant temperature for 12 hours. Then cool naturally to room temperature; place the pre-oxidized composite microspheres in an argon atmosphere, raise the temperature to 800 °C at a rate of 2 °C / min, and carbonize at a constant temperature for 0.5 h, then cool naturally to room temperature; use a concentration of 1.0 Soak the carbonized composite microspheres in mol / L sulfuric acid solution to remove the inorganic matter, then wash them w...

Embodiment 3

[0043] Dissolve lignosulfonate and calcium chloride with a mass ratio of 2:1 in deionized water to form a solution, control the mass fraction of lignosulfonate and calcium chloride in the solution to 40%, and stir at room temperature 10h; transfer the stirred solution to a spray drying device, and obtain composite microspheres by spray drying; place the composite microspheres in the air for pre-oxidation treatment, and raise the temperature to 300°C at a heating rate of 5°C / min, and Keep the temperature at a constant temperature for 2 h, and then cool down to room temperature naturally; place the pre-oxidized composite microspheres in an argon atmosphere, raise the temperature to 900 °C at a rate of 30 °C / min, and carbonize at a constant temperature for 1 h, and then cool down to room temperature naturally; Soak the carbonized composite microspheres in a nitric acid solution with a concentration of 0.5mol / L to remove the inorganic matter, then wash with water until the pH value...

technical field

[0001] The invention relates to the technical field of porous carbon materials, in particular to a preparation method of oxygen and nitrogen co-doped porous hollow carbon microspheres. Background technique

[0002] Today, with the rapid development of social economy and the increasing shortage of resources, new energy storage components have been developed rapidly. Porous carbon is widely used in mobile communications, aerospace, Information technology and national defense technology are widely used. At present, supercapacitors have become energy storage devices that are widely concerned by researchers due to their fast charge and discharge, high power density, excellent cycle stability, and high stability. Electrode materials are one of the key factors determining the performance of supercapacitors. Carbon materials such as carbon fibers, activated carbon, carbon nanotubes, graphene, and porous carbon spheres are widely studied electrode materials for super...

Examples

Embodiment 1

[0037] Dissolve alkali lignin and sodium hydroxide with a mass ratio of 5:1 in deionized water to form a solution, control the mass fraction of alkali lignin and sodium hydroxide in the solution to be 10%, and stir at room temperature for 2h; The final solution was transferred to the spray drying equipment, and the composite microspheres were obtained by the spray drying method; the composite microspheres were placed in the air for pre-oxidation treatment, and the temperature was raised to 200°C at a heating rate of 0.1°C / min, and kept at a constant temperature for 20h. Then cool naturally to room temperature; place the pre-oxidized composite microspheres in a nitrogen atmosphere, raise the temperature to 700 °C at a rate of 10 °C / min, and carbonize at a constant temperature for 2 hours, then cool naturally to room temperature; use a concentration of 2.0 mol / Soak the carbonized composite microspheres in 1 L of hydrochloric acid solution to remove the inorganic matter, then was...

Embodiment 2

[0040] Dissolve kraft lignin and potassium carbonate with a mass ratio of 3:1 in deionized water to form a solution, control the mass fraction of kraft lignin and potassium carbonate in the solution to 20%, and stir at room temperature for 1 h; The final solution was transferred to the spray drying equipment, and the composite microspheres were obtained by the spray drying method; the composite microspheres were placed in the air for pre-oxidation treatment, and the temperature was raised to 270 °C at a heating rate of 1 °C / min, and kept at a constant temperature for 12 hours. Then cool naturally to room temperature; place the pre-oxidized composite microspheres in an argon atmosphere, raise the temperature to 800 °C at a rate of 2 °C / min, and carbonize at a constant temperature for 0.5 h, then cool naturally to room temperature; use a concentration of 1.0 Soak the carbonized composite microspheres in mol / L sulfuric acid solution to remove the inorganic matter, then wash them w...

Embodiment 3

[0043] Dissolve lignosulfonate and calcium chloride with a mass ratio of 2:1 in deionized water to form a solution, control the mass fraction of lignosulfonate and calcium chloride in the solution to 40%, and stir at room temperature 10h; transfer the stirred solution to a spray drying device, and obtain composite microspheres by spray drying; place the composite microspheres in the air for pre-oxidation treatment, and raise the temperature to 300°C at a heating rate of 5°C / min, and Keep the temperature at a constant temperature for 2 h, and then cool down to room temperature naturally; place the pre-oxidized composite microspheres in an argon atmosphere, raise the temperature to 900 °C at a rate of 30 °C / min, and carbonize at a constant temperature for 1 h, and then cool down to room temperature naturally; Soak the carbonized composite microspheres in a nitric acid solution with a concentration of 0.5mol / L to remove the inorganic matter, then wash with water until the pH value...

Images