PREPREARATION AND APPLICATION OF 2,6-DIAMINOANTHRAQUINONE BIFUNCTIONAL GROUP COVALENTLY GRAFTED GRAPHENE AS NEGATIVE MATERIAL OF SUPERCAPACITOR

Abstract

An electrode material of a supercapacitor includes a negative material prepared by the following steps: first dispersing graphite oxide in deionized water; after stirring and ultrasonic treatment, reducing the graphite oxide into reduced graphene oxide by using a hydrazine hydrate, and vacuum drying at 40-80° C.; dispersing the reduced graphene oxide in a DMF solution with 2,6-diaminoanthraquinone, and stirring and performing the ultrasonic treatment again; at 60-90° C., adding isoamyl nitrite, and reacting for 18-24 h; and washing reaction products with ethanol and deionized water for multiple times, and finally freeze drying to obtain a product.

Claims

1. An electrode material of a supercapacitor, the electrode material comprising a negative material prepared by the following steps: (1) dispersing graphite oxide in deionized water, stirring for 1-2 h in advance, and then performing ultrasonic treatment for 2-6 h; and adding 10-15 ml of hydrazine hydrate at 80-110° C., and vacuum drying at 40-80° C. to obtain a reduced graphite oxide substrate; and (2) dissolving 2,6-diaminoanthraquinone in a DMF solution, stirring for 1-2 h, adding the reduced graphite oxide into the above solution, continuously stirring for 2-4 h, and then performing the ultrasonic treatment for 4-8 h; when the mixed solution is heated to 60-90° C., adding isoamyl nitrite, and reacting for 18-24 h; washing reaction products with ethanol and deionized water for multiple times, and finally freeze drying to obtain the 2,6-diaminoanthraquinone bifunctional group covalently grafted graphene.

2. The electrode material of a supercapacitor according to claim 1, wherein a mass ratio of 2,6-diaminoanthraquinone to the graphite oxide is 0.1:1-0.4:2.

3. The electrode material of a supercapacitor according to claim 1, wherein a mass ratio of 2,6-diaminoanthraquinone to the graphite oxide is 0.2:1-0.6:1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1 is a scanning electron microscope image of reduced graphite oxide (RGO);

[0036] FIG. 2 is a scanning electron microscope image of a DAAQ-RGO composite material prepared by the present invention;

[0037] FIG. 3 is a transmission electron microscope image of the DAAQ-RGO composite material prepared by the present invention;

[0038] FIG. 4 is an FI-IR analysis of RGO, DAAQ and DAAQ-RGO composite electrode material;

[0039] FIG. 5 illustrates N.sub.2 adsorption and desorption analysis of the DAAQ-RGO composite electrode material;

[0040] FIG. 6 illustrates cyclic voltammetry curves of RGO and DAAQ-RGO composite electrode material in 1 mol L.sup.−1 of H.sub.2SO.sub.4 electrolyte solution at a scanning rate of 5 mV s.sup.−1;

[0041] FIG. 7 is a constant-current charge and discharge diagram of RGO and the DAAQ-RGO composite electrode material in 1 mol L.sup.−1 of H.sub.2SO.sub.4 electrolyte solution at a current density of 1 A g.sup.−1;

[0042] FIG. 8 illustrates cyclic voltammetry curves of a DAAQ-RGO composite material electrode in 1 mol L.sup.−1 of H.sub.2SO.sub.4 electrolyte solution at different scanning rates;

[0043] FIG. 9 illustrates constant-current charge and discharge curves of the DAAQ-RGO composite material electrode in 1 mol L.sup.−1 of H.sub.2SO.sub.4 electrolyte solution at different current densities; and

[0044] FIG. 10 is an AC impedance diagram of the DAAQ-RGO composite material electrode.

DETAILED DESCRIPTION OF THE INVENTION

[0045] Preparation and electrochemical performance of 2,6-diaminoanthraquinone bifunctional group covalently grafted graphene (DAAQ-RGO) as a negative material of a supercapacitor of the present invention is further described in detail below through specific embodiments.

[0046] Applied instruments and reagents: CHI760E electrochemical workstation (Shanghai Chenhua Instrument Co., Ltd.) for electrochemical performance test; electronic balance (Beijing Sartorius Instrument Co., Ltd.) for weighing chemicals; transmission electron microscope (TEM JEOL, JEM-2010, Japan); constant-temperature magnetic stirrer (90-1 Shanghai Huxi Analytical Instrument Factory); LGJ-10C freeze drier (Xiangyi Centrifuge Instrument Co., Ltd.); scanning electron microscope (Ultra Plus, Carl Zeiss, Germany) for material morphology characterization; FTS3000 Fourier infrared spectrometer (DIGILAB, America); specific surface area and pore size distribution are tested by a nitrogen adsorption instrument (BET, micromeritics ASAP 2020, America); and 2,6-diaminoanthraquinone (TCI (Shanghai) Chemical Industry Development Co., Ltd.), isoamyl nitrite (Alfa Aesar China Chemical Co., Ltd.), and conductive carbon black (Tansha Graphite Factory in Guiyang, Hunan Province). Water used in the experimental process is deionized water. Reagents used in the experiment are all analytically pure.

Embodiment 1

[0047] 1. Preparation of a DAAQ-RGO-1 Composite Material:

[0048] (1) 0.1 g of graphite oxide is dispersed in deionized water, stirred for 1 h in advance, and then subjected to ultrasonic treatment for 2 h; and 10 ml of hydrazine hydrate is added at 80° C., and solid substances are vacuum dried at 40° C. to obtain a reduced graphite oxide substrate.

[0049] (2) 0.1 g of 2,6-diaminoanthraquinone is dissolved in a DMF solution and stirred for 1 h, then reduced graphite oxide is added into the above solution and stirred continuously for 2 h, and then the ultrasonic treatment is performed for 4 h; when the mixed solution is heated to 60° C., isoamyl nitrite is added, and reaction is performed for 18 h; and reaction products are washed with ethanol and deionized water for multiple times and finally freeze dried to obtain a target product.

[0050] 2. Preparation of a DAAQ-RGO-1 composite material electrode: a solid mixture of DAAQ-RGO composite material and conductive carbon black is weighed in total of 4.7 mg, and the mass percentages of the DAAQ-RGO and the conductive carbon black are 65% and 35% respectively. After the uniform mixing, 0.4 mL of 0.25 wt % Nafion solution is dropwise added and ultrasonically dispersed for 3 h to form a suspension. 6 μL of the above suspension is dropwise added to the surface of a glassy carbon electrode and dried at a room temperature for test.

[0051] 3. Test of Electrochemical Performance:

[0052] A tri-electrode system is formed by taking a DAAQ-RGO-1 composite material electrode as a working electrode, a conductive carbon rod as a counter electrode and a saturated calomel electrode as a reference electrode. 1 mol L.sup.−1 of H.sub.2SO.sub.4 solution is used as an electrolyte solution, and a potential window is set in a range of −0.4 V to 0.6 V. It can be calculated from the constant-current charge and discharge curve that when the current density is 1 A g.sup.−1, the specific capacitance of the electrode material can reach up to 327.4 F g.sup.−1.

Embodiment 2

[0053] 1. Preparation of IT-RGO-2 Composite Material:

[0054] 1. Preparation of DAAQ-RGO-2 Composite Material:

[0055] (1) 0.1 g of graphite oxide is dispersed in deionized water, stirred for 1 h in advance, and then subjected to ultrasonic treatment for 2 h; and 10 ml of hydrazine hydrate is added at 80° C., and solid substances are vacuum dried at 40° C. to obtain a reduced graphite oxide substrate.

[0056] (2) 0.4 g of 2,6-diaminoanthraquinone is dissolved in a DMF solution and stirred for 1 h, then reduced graphite oxide is added into the above solution and stirred continuously for 2 h, and then the ultrasonic treatment is performed for 4 h; when the mixed solution is heated to 60° C., isoamyl nitrite is added, and reaction is performed for 18 h; and reaction products are washed with ethanol and deionized water for multiple times and finally freeze dried to obtain a target product.

[0057] 2. Preparation of the DAAQ-RGO-2 composite material electrode is the same as that in embodiment 1;

[0058] 3. Test of electrochemical performance: the test method is the same as that in embodiment 1; and the test result is: when the current density is 1 A g.sup.−1, the specific capacitance of the electrode material can reach up to 412.7 F

Embodiment 3

[0059] 1. Preparation of DAAQ-RGO-3 Composite Material:

[0060] 1. Preparation of DAAQ-RGO-3 Composite Material:

[0061] (1) 0.1 g of graphite oxide is dispersed in deionized water, stirred for 1 h in advance, and then subjected to ultrasonic treatment for 2 h; and 10 ml of hydrazine hydrate is added at 80° C., and solid substances are vacuum dried at 40° C. to obtain a reduced graphite oxide substrate.

[0062] (2) 0.6 g of 2,6-diaminoanthraquinone is dissolved in a DMF solution and stirred for 1 h, then reduced graphite oxide is added into the above solution and stirred continuously for 2 h, and then the ultrasonic treatment is performed for 4 h; when the mixed solution is heated to 60° C., isoamyl nitrite is added, and reaction is performed for 18 h; and reaction products are washed with ethanol and deionized water for multiple times and finally freeze dried to obtain a target product.

[0063] 2. Preparation of the IT-RGO-3 composite material electrode is the same as that in embodiment 1;

[0064] 3. Test of electrochemical performance: the test method is the same as that in embodiment 1; and the test result is: when the current density is 1 A g.sup.−1, the specific capacitance of the electrode material can reach up to 356.7 F g.sup.−1.