Preparation method and application of ternary CoS / NiCoAl-LDH / NGQDs heterostructure electrode material
By constructing ternary CoS/NiCoAl-LDH/NGQDs heterostructure electrode materials, the problems of low energy density and structural instability of supercapacitor electrode materials were solved, achieving electrochemical performance with high specific capacitance, excellent cycle stability and high power density.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TONGHUA NORMAL UNIV
- Filing Date
- 2026-04-24
- Publication Date
- 2026-05-29
AI Technical Summary
Existing supercapacitor electrode materials have low energy density and suffer from poor conductivity and structural instability during cycling, which limits their widespread application.
A method for preparing ternary CoS/NiCoAl-LDH/NGQDs heterostructure electrode materials was adopted. Co-MOF was grown in situ on carbon cloth, CoS nanotubes were formed by hydrothermal sulfidation, NiCoAl-LDH nanosheets were deposited, and NGQDs were anchored on the surface to construct a hierarchical core-shell structure.
It significantly improves the conductivity, multi-electron redox reactivity and interfacial stability of the material, enhances the specific capacitance, energy density and power density of the supercapacitor, and exhibits excellent cycle stability.
Smart Images
Figure CN122117663A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of composite electrode materials technology, and relates to a method for preparing a ternary CoS / NiCoAl-LDH / NGQDs heterostructure electrode material and its application. Background Technology
[0002] Supercapacitors are a type of modern energy storage system with high power density, rapid charge and discharge capabilities, and excellent cycle stability, suitable for a wide range of applications from electric vehicles to smart grids. However, compared to batteries, their lower energy density limits their wider application. This limitation stems from the inherent defects of traditional electrode materials: electric double-layer capacitors achieve energy storage through surface adsorption, resulting in high power output but limited energy density; in contrast, pseudocapacitive materials rely on redox reactions to achieve higher energy density, but often suffer from poor conductivity and structural instability.
[0003] A widely adopted strategy for improving electrochemical performance is to coat a high-capacity active material onto a highly conductive substrate, constructing a core-shell heterostructure that synergistically combines excellent conductivity with enhanced Faraday reactivity. Layered bimetallic hydroxides (LDHs) have become highly promising candidate materials due to their tunable composition and unique layered structure. Ternary layered bimetallic hydroxides (such as NiCoM-LDH, where M = Cu, Mn, Al, Fe, etc.) exhibit significant advantages over binary systems. The synergistic effect between multiple metal cations enables multi-electron redox reactions within a wider potential window, while the open layered structure facilitates efficient intercalation and diffusion of electrolyte ions.
[0004] To further optimize structural stability and alleviate the inherent stacking problem of LDHs, metal-organic frameworks (MOFs) have recently been used as an efficient synthesis strategy. Using MOFs as precursor templates, LDHs materials with regular morphology, high specific surface area, and stronger structural stability can be prepared. Recent research shows that constructing a tight heterojunction between metal sulfides and LDHs can create a built-in electric field at the interface. This built-in electric field can act as a highly efficient "charge pump," significantly accelerating interfacial charge transfer kinetics and improving specific capacitance and rate performance. Despite these advances, binary hybrid materials are still limited by insufficient interfacial charge regulation and the continuous stacking of LDHs during cycling, thus affecting long-term cycling stability.
[0005] To address the aforementioned shortcomings, introducing a third nanocomponent for finely designed heterostructures has become an advanced materials design strategy. Nitrogen-doped graphene quantum dots (NGQDs), due to their extremely small size and abundant surface functional groups, can be firmly anchored to the surface of the host material, attracting widespread attention as efficient interface modifiers. More importantly, NGQDs can serve as multifunctional electron libraries and transport media, effectively controlling the local charge distribution at heterostructure interfaces. These multifunctional synergistic effects can significantly improve the cycling stability and rate performance of materials. Therefore, designing ternary heterostructures can achieve a synergistic improvement in energy storage performance and has promising application prospects. Summary of the Invention
[0006] The purpose of this invention is to provide a method for preparing ternary CoS / NiCoAl-LDH / NGQDs heterostructure electrode materials and their applications, so as to solve the problems mentioned in the background art.
[0007] The technical solution of this invention is: a method for preparing a ternary CoS / NiCoAl-LDH / NGQDs heterostructure electrode material, comprising the following steps:
[0008] First, carbon cloth (CC) is immersed in a solution containing cobalt ions and 2-methylimidazole to allow cobalt-based metal-organic framework (Co-MOF) arrays to grow in situ on the carbon cloth substrate. Subsequently, the Co-MOF precursor is converted into hollow cobalt sulfide (CoS) nanotubes through hydrothermal sulfidation.
[0009] Next, nickel-cobalt-aluminum layered double hydroxide (NiCoAl-LDH) nanosheets were uniformly deposited on the surface of CoS nanotubes using an electrodeposition method to form a hierarchical core-shell structure.
[0010] Finally, nitrogen-doped graphene quantum dots (NGQDs) were anchored onto the surface of the composite material by electrostatic adsorption, thus completing the construction of the ternary heterostructure.
[0011] Specifically, a method for preparing a ternary CoS / NiCoAl-LDH / NGQDs heterostructure electrode material includes the following steps:
[0012] A. A piece of carbon cloth (CC) was ultrasonically pretreated in deionized (DI) water and then dried to serve as a substrate. 0.582g of Co(NO3) was weighed. 2· Dissolve 6H₂O in 40 mL of deionized water to prepare a cobalt ion solution. Separately, add 1.32 g of 2-methylimidazole (2-MIM) to 40 mL of deionized water and sonicate to obtain a homogeneous solution.
[0013] A carbon cloth measuring 1×2 cm² was first immersed in a cobalt nitrate solution and allowed to stand at room temperature for 1 h. Then, a 2-MIM solution was poured into the same container and soaked at 60 °C for 2–6 h. After soaking, the mixture was allowed to cool naturally to room temperature. The product was then rinsed with deionized water to remove residual solution and impurities and dried at 60 °C to obtain rod-shaped CC@Co-MOFs grown on CC.
[0014] B. Dissolve 0.0376 g of thioacetamide (TAA) in 10 mL of ethanol by ultrasonication. Transfer the resulting homogeneous solution and the prepared 1×2 cm² CC@Co-MOF into a 25 mL polytetrafluoroethylene-lined high-pressure reactor. React at 120~200℃ for 4~8 h. After the reactor cools naturally to room temperature, rinse several times with anhydrous ethanol and deionized water, and dry at 60℃ overnight to obtain hollow tubular cobalt sulfide CC@CoS.
[0015] C. Dissolve 0.436 g Ni(NO3)2·6H2O, 0.146 g Co(NO3)2·6H2O, 0.094 g Al(NO3)3·9H2O, and 0.506 g KNO3 in 50 mL of deionized water and sonicate until dissolved. A standard three-electrode system was used, with Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and a 1×2 cm² carbon cloth-supported cobalt sulfide (CC@CoS) as the working electrode. NiCoAl-LDH was deposited on the CC@CoS surface using chronoamperometry (it) at a constant potential of -1.1 V for 250–350 s. After deposition, the sample was repeatedly rinsed with deionized water and dried at 60 °C to obtain the CC@CoS / NiCoAl-LDH composite electrode. Finally, the composite electrode was immersed in a nitrogen-doped graphene quantum dot (NGQD) dispersion to obtain CC@CoS / NiCoAl-LDH / NGQDs.
[0016] In step A, the sample is soaked at 60 °C for 4 hours.
[0017] In step A, the cobalt source is Co(NO3)2 or CoCl2, preferably Co(NO3)2.
[0018] In step A, the pretreated CC is ultrasonically cleaned with acetone, ethanol, and deionized water in sequence, and then dried for later use.
[0019] In step B, the reaction is carried out at 160°C for 6 hours.
[0020] In step B, the sulfur source is thioacetamide (C2H5NS, TAA) or thiourea (CH4N2S, TU), preferably thioacetamide.
[0021] In step C, deposition is performed for 300 s using the chronoamperometry (it) method at a constant potential of -1.1 V.
[0022] CoS hollow nanotubes serve as a conductive scaffold, supporting the uniformly grown NiCoAl-LDH nanosheets, while nitrogen-doped graphene quantum dots (NGQDs) are tightly anchored to their surface through electrostatic interactions.
[0023] The CC@CoS / NiCoAl-LDH / NGQDs composite material prepared by the method described in this invention shows that, under microscopic conditions, CoS has a hollow tubular morphology, while NiCoAl-LDH nanosheets are uniformly coated on its outer surface, and the core and shell components are tightly bonded together.
[0024] Another object of the present invention is to provide the application of the prepared CC@CoS / NiCoAl-LDH / NGQDs composite material as a positive electrode material for supercapacitors.
[0025] The prepared CC@CoS / NiCoAl-LDH / NGQDs composite material was used as the positive electrode of a supercapacitor. 6 M KOH was used as the electrolyte. Activated carbon, acetylene black, and polyvinylidene fluoride were uniformly mixed in a mass ratio of 8:1:1, and then an appropriate amount of N-methylpyrrolidone was added dropwise. The mixture was then ground into a uniform slurry, coated onto nickel foam, and dried to serve as the negative electrode material for the supercapacitor. Cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) were performed on the two-electrode system to evaluate the electrochemical performance of the prepared CC@CoS / NiCoAl-LDH / NGQDs electrode material. The voltage range for CV testing was 0–0.5 V, and the scan rates were 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 mV s. -1 The voltage range for GCD testing is 0–0.5 V, and the current density is 1, 2, 3, 5, 8, and 10 A g. -1 .
[0026] The CC@CoS / NiCoAl-LDH / NGQDs composite electrode material prepared in this invention was characterized structurally and analyzed using instruments such as field emission scanning electron microscopy (FE-SEM) and a CHI760E electrochemical workstation to evaluate its electrochemical performance.
[0027] All reactants and reagents used in this invention are commercially available and of analytical grade.
[0028] The beneficial effects of this invention are as follows: This invention synthesizes a ternary hierarchical heterostructure CC@CoS / NiCoAl-LDH / NGQDs composite electrode material through three steps using hydrothermal and electrochemical deposition methods. Its core advantage lies in the directional construction of a synergistic interface, with each component specifically addressing different key issues: CoS provides a stable conductive network, NiCoAl-LDH imparts multi-electron redox reactivity, and NGQDs enhance interface stability and charge injection efficiency. Attached Figure Description
[0029] Figure 1 This is a field emission scanning electron microscope image of the CC@CoS / NiCoAl-LDH / NGQDs electrode material prepared in Example 1.
[0030] Figure 2 The image shows the GCD curve of the CC@CoS / NiCoAl-LDH / NGQDs electrode material prepared in Example 1.
[0031] Figure 3 This is the energy density-power density diagram of the supercapacitor assembled from the CC@CoS / NiCoAl-LDH / NGQDs electrode material prepared in Example 1.
[0032] Figure 4 This is a cycle stability diagram of the supercapacitor assembled with the CC@CoS / NiCoAl-LDH / NGQDs electrode material prepared in Example 1. Detailed Implementation
[0033] Example 1
[0034] A method for preparing a CC@CoS / NiCoAl-LDH / NGQDs heterostructure electrode material includes the following steps:
[0035] Step 1: A piece of carbon cloth (CC) is ultrasonically pretreated and dried in deionized (DI) water to serve as the substrate. 0.582 g of Co(NO3)2·6H2O is weighed and dissolved in 40 mL of deionized water to prepare a cobalt ion solution. Separately, 1.32 g of 2-methylimidazole (2-MIM) is added to 40 mL of deionized water and ultrasonicated to obtain a homogeneous solution.
[0036] A carbon cloth measuring 1×2 cm² was first immersed in a cobalt nitrate solution and allowed to stand at room temperature for 1 h. Then, a 2-MIM solution was poured into the same container and soaked at 60 °C for 4 h. After soaking, the cloth was allowed to cool naturally to room temperature. The product was then rinsed with deionized water to remove residual solution and impurities and dried at 60 °C to obtain rod-shaped CC@Co-MOFs grown on CC.
[0037] Step 2: Dissolve 0.0376 g of thioacetamide (TAA) in 10 mL of ethanol by ultrasonication. Transfer the resulting homogeneous solution and the prepared 1×2 cm² CC@Co-MOF into a 25 mL polytetrafluoroethylene-lined high-pressure reactor. React at 160℃ for 6 h. After the reactor cools naturally to room temperature, rinse several times with anhydrous ethanol and deionized water, and dry at 60℃ overnight to obtain hollow tubular cobalt sulfide CC@CoS.
[0038] Step 3: Dissolve 0.436 g Ni(NO3)2·6H2O, 0.146 g Co(NO3)2·6H2O, 0.094 g Al(NO3)3·9H2O, and 0.506 g KNO3 in 50 mL of deionized water and sonicate until dissolved. A standard three-electrode system was used, with Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and a 1×2 cm² carbon cloth-supported cobalt sulfide (CC@CoS) as the working electrode. NiCoAl-LDH was deposited on the CC@CoS surface using chronoamperometry (it) at a constant potential of -1.1 V for 300 s. After deposition, the sample was repeatedly rinsed with deionized water and dried at 60 °C to obtain the CC@CoS / NiCoAl-LDH composite electrode. Finally, the composite electrode was immersed in a nitrogen-doped graphene quantum dot (NGQD) dispersion to obtain CC@CoS / NiCoAl-LDH / NGQDs.
[0039] Experimental Example 1
[0040] Characterization and analysis of the CC@CoS / NiCoAl-LDH / NGQDs hybrid electrode material obtained in Example 1
[0041] like Figure 1 As shown, under microscopic conditions, CC@CoS / NiCoAl-LDH / NGQDs form a unique composite structure of neatly arranged nanotube arrays with grown nanoparticles, which significantly increases the number of active sites.
[0042] like Figure 2 As shown in the figure, the GCD curve of the CC@CoS / NiCoAl-LDH / NGQDs composite material can be seen. The calculated values of this material at 1 A g are...-1 It has 1585.6 F g at that time. -1 High specific capacity.
[0043] like Figure 3 As shown, the CC@CoS / NiCoAl-LDH / NGQDs composite material prepared in Example 1 is used as the positive electrode of a supercapacitor in a two-electrode system. The energy density-power density diagram shows that the assembled supercapacitor exhibits excellent power density and energy density, with a power density of 800 W / kg. -1 The maximum energy density is 90.6 Wh / kg. -1 .
[0044] like Figure 4 As shown, the CC@CoS / NiCoAl-LDH / NGQDs composite material prepared in Example 1 was used as the positive electrode of a supercapacitor. After 7000 cycles, its specific capacitance remained at 83.1% of the initial capacitance, demonstrating excellent cycle stability.
[0045] Example 2
[0046] A method for preparing a CC@CoS / NiCoAl-LDH / NGQDs heterostructure electrode material includes the following steps:
[0047] Step 1: A piece of carbon cloth (CC) is ultrasonically pretreated and dried in deionized (DI) water to serve as the substrate. 0.582 g of Co(NO3)2·6H2O is weighed and dissolved in 40 mL of deionized water to prepare a cobalt ion solution. Separately, 1.32 g of 2-methylimidazole (2-MIM) is added to 40 mL of deionized water and ultrasonicated to obtain a homogeneous solution.
[0048] A carbon cloth with a size of 1×2 cm² was first immersed in a cobalt nitrate solution and allowed to stand at room temperature for 1 h. Then, a 2-MIM solution was poured into the same container and soaked at 60 °C for 2 h. After soaking, the cloth was allowed to cool naturally to room temperature. The product was rinsed with deionized water to remove residual solution and impurities and dried at 60 °C to obtain rod-shaped CC@Co-MOFs grown on CC.
[0049] Step 2: Dissolve 0.0376 g of thioacetamide (TAA) in 10 mL of ethanol by ultrasonication. Transfer the resulting homogeneous solution and the prepared 1×2 cm² CC@Co-MOF into a 25 mL polytetrafluoroethylene-lined high-pressure reactor. React at 160℃ for 6 h. After the reactor cools naturally to room temperature, rinse several times with anhydrous ethanol and deionized water, and dry at 60℃ overnight to obtain hollow tubular cobalt sulfide CC@CoS.
[0050] Step 3: Dissolve 0.436 g Ni(NO3)2·6H2O, 0.146 g Co(NO3)2·6H2O, 0.094 g Al(NO3)3·9H2O, and 0.506 g KNO3 in 50 mL of deionized water and sonicate until dissolved. A standard three-electrode system was used, with Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and a 1×2 cm² carbon cloth-supported cobalt sulfide (CC@CoS) as the working electrode. NiCoAl-LDH was deposited on the CC@CoS surface using chronoamperometry (it) at a constant potential of -1.1 V for 300 s. After deposition, the sample was repeatedly rinsed with deionized water and dried at 60 °C to obtain the CC@CoS / NiCoAl-LDH composite electrode. Finally, the composite electrode was immersed in a nitrogen-doped graphene quantum dot (NGQD) dispersion to obtain CC@CoS / NiCoAl-LDH / NGQDs.
[0051] The results of the cycle stability test of the CC@CoS / NiCoAl-LDH / NGQDs composite material prepared in this embodiment as the positive electrode of the supercapacitor show that its specific capacitance remains at 75.5% of the initial capacitance after 7000 cycles.
[0052] Example 3
[0053] A method for preparing a CC@CoS / NiCoAl-LDH / NGQDs heterostructure electrode material includes the following steps:
[0054] Step 1: A piece of carbon cloth (CC) is ultrasonically pretreated and dried in deionized (DI) water to serve as the substrate. 0.582 g of Co(NO3)2·6H2O is weighed and dissolved in 40 mL of deionized water to prepare a cobalt ion solution. Separately, 1.32 g of 2-methylimidazole (2-MIM) is added to 40 mL of deionized water and ultrasonicated to obtain a homogeneous solution.
[0055] A carbon cloth with a size of 1×2 cm² was first immersed in a cobalt nitrate solution and allowed to stand at room temperature for 1 h. Then, a 2-MIM solution was poured into the same container and soaked at 60 °C for 6 h. After soaking, the mixture was allowed to cool naturally to room temperature. The product was then rinsed with deionized water to remove residual solution and impurities and dried at 60 °C to obtain rod-shaped CC@Co-MOFs grown on CC.
[0056] Step 2: Dissolve 0.0376 g of thioacetamide (TAA) in 10 mL of ethanol by ultrasonication. Transfer the resulting homogeneous solution and the prepared 1×2 cm² CC@Co-MOF into a 25 mL polytetrafluoroethylene-lined high-pressure reactor. React at 160℃ for 6 h. After the reactor cools naturally to room temperature, rinse several times with anhydrous ethanol and deionized water, and dry at 60℃ overnight to obtain hollow tubular cobalt sulfide CC@CoS.
[0057] Step 3: Dissolve 0.436 g Ni(NO3)2·6H2O, 0.146 g Co(NO3)2·6H2O, 0.094 g Al(NO3)3·9H2O, and 0.506 g KNO3 in 50 mL of deionized water and sonicate until dissolved. A standard three-electrode system was used, with Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and a 1×2 cm² carbon cloth-supported cobalt sulfide (CC@CoS) as the working electrode. NiCoAl-LDH was deposited on the CC@CoS surface using chronoamperometry (it) at a constant potential of -1.1 V for 300 s. After deposition, the sample was repeatedly rinsed with deionized water and dried at 60 °C to obtain the CC@CoS / NiCoAl-LDH composite electrode. Finally, the composite electrode was immersed in a nitrogen-doped graphene quantum dot (NGQD) dispersion to obtain CC@CoS / NiCoAl-LDH / NGQDs.
[0058] The results of the cycle stability test of the CC@CoS / NiCoAl-LDH / NGQDs composite material prepared in this embodiment as the positive electrode of the supercapacitor show that its specific capacitance remains at 79.4% of the initial capacitance after 7000 cycles.
[0059] Example 4
[0060] A method for preparing a CC@CoS / NiCoAl-LDH / NGQDs heterostructure electrode material includes the following steps:
[0061] Step 1: A piece of carbon cloth (CC) is ultrasonically pretreated and dried in deionized (DI) water to serve as the substrate. 0.476 g of CoCl2·6H2O is weighed and dissolved in 40 mL of deionized water to prepare a cobalt ion solution. Separately, 1.32 g of 2-methylimidazole (2-MIM) is added to 40 mL of deionized water and ultrasonicated to obtain a homogeneous solution.
[0062] A carbon cloth measuring 1×2 cm² was first immersed in a cobalt nitrate solution and allowed to stand at room temperature for 1 h. Then, a 2-MIM solution was poured into the same container and soaked at 60 °C for 4 h. After soaking, the cloth was allowed to cool naturally to room temperature. The product was then rinsed with deionized water to remove residual solution and impurities and dried at 60 °C to obtain rod-shaped CC@Co-MOFs grown on CC.
[0063] Step 2: Dissolve 0.0376 g of thioacetamide (TAA) in 10 mL of ethanol by ultrasonication. Transfer the resulting homogeneous solution and the prepared 1×2 cm² CC@Co-MOF into a 25 mL polytetrafluoroethylene-lined high-pressure reactor. React at 160℃ for 6 h. After the reactor cools naturally to room temperature, rinse several times with anhydrous ethanol and deionized water, and dry at 60℃ overnight to obtain hollow tubular cobalt sulfide CC@CoS.
[0064] Step 3: Dissolve 0.436 g Ni(NO3)2·6H2O, 0.146 g Co(NO3)2·6H2O, 0.094 g Al(NO3)3·9H2O, and 0.506 g KNO3 in 50 mL of deionized water and sonicate until dissolved. A standard three-electrode system was used, with Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and a 1×2 cm² carbon cloth-supported cobalt sulfide (CC@CoS) as the working electrode. NiCoAl-LDH was deposited on the CC@CoS surface using chronoamperometry (it) at a constant potential of -1.1 V for 300 s. After deposition, the sample was repeatedly rinsed with deionized water and dried at 60 °C to obtain the CC@CoS / NiCoAl-LDH composite electrode. Finally, the composite electrode was immersed in a nitrogen-doped graphene quantum dot (NGQD) dispersion to obtain CC@CoS / NiCoAl-LDH / NGQDs.
[0065] The results of the cycle stability test of the CC@CoS / NiCoAl-LDH / NGQDs composite material prepared in this embodiment as the positive electrode of the supercapacitor show that its specific capacitance remains at 70.2% of the initial capacitance after 7000 cycles.
[0066] Example 5
[0067] A method for preparing a CC@CoS / NiCoAl-LDH / NGQDs heterostructure electrode material includes the following steps:
[0068] Step 1: A piece of carbon cloth (CC) is ultrasonically pretreated and dried in deionized (DI) water to serve as the substrate. 0.582 g of Co(NO3)2·6H2O is weighed and dissolved in 40 mL of deionized water to prepare a cobalt ion solution. Separately, 1.32 g of 2-methylimidazole (2-MIM) is added to 40 mL of deionized water and ultrasonicated to obtain a homogeneous solution.
[0069] A carbon cloth measuring 1×2 cm² was first immersed in a cobalt nitrate solution and allowed to stand at room temperature for 1 h. Then, a 2-MIM solution was poured into the same container and soaked at 60 °C for 4 h. After soaking, the cloth was allowed to cool naturally to room temperature. The product was then rinsed with deionized water to remove residual solution and impurities and dried at 60 °C to obtain rod-shaped CC@Co-MOFs grown on CC.
[0070] Step 2: Dissolve 0.0376 g of thioacetamide (TAA) in 10 mL of ethanol by ultrasonication. Transfer the resulting homogeneous solution and the prepared 1×2 cm² CC@Co-MOF into a 25 mL polytetrafluoroethylene-lined high-pressure reactor. React at 120℃ for 4 h. After the reactor cools naturally to room temperature, rinse several times with anhydrous ethanol and deionized water, and dry at 60℃ overnight to obtain hollow tubular cobalt sulfide CC@CoS.
[0071] Step 3: Dissolve 0.436 g Ni(NO3)2·6H2O, 0.146 g Co(NO3)2·6H2O, 0.094 g Al(NO3)3·9H2O, and 0.506 g KNO3 in 50 mL of deionized water and sonicate until dissolved. A standard three-electrode system was used, with Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and a 1×2 cm² carbon cloth-supported cobalt sulfide (CC@CoS) as the working electrode. NiCoAl-LDH was deposited on the CC@CoS surface using chronoamperometry (it) at a constant potential of -1.1 V for 300 s. After deposition, the sample was repeatedly rinsed with deionized water and dried at 60 °C to obtain the CC@CoS / NiCoAl-LDH composite electrode. Finally, the composite electrode was immersed in a nitrogen-doped graphene quantum dot (NGQD) dispersion to obtain CC@CoS / NiCoAl-LDH / NGQDs.
[0072] The results of the cycle stability test of the CC@CoS / NiCoAl-LDH / NGQDs composite material prepared in this embodiment as the positive electrode of the supercapacitor show that after 7000 cycles, its specific capacitance remains at 68.2% of the initial capacitance.
[0073] Example 6
[0074] A method for preparing a CC@CoS / NiCoAl-LDH / NGQDs heterostructure electrode material includes the following steps:
[0075] Step 1: A piece of carbon cloth (CC) is ultrasonically pretreated and dried in deionized (DI) water to serve as the substrate. 0.582 g of Co(NO3)2·6H2O is weighed and dissolved in 40 mL of deionized water to prepare a cobalt ion solution. Separately, 1.32 g of 2-methylimidazole (2-MIM) is added to 40 mL of deionized water and ultrasonicated to obtain a homogeneous solution.
[0076] A carbon cloth measuring 1×2 cm² was first immersed in a cobalt nitrate solution and allowed to stand at room temperature for 1 h. Then, a 2-MIM solution was poured into the same container and soaked at 60 °C for 4 h. After soaking, the cloth was allowed to cool naturally to room temperature. The product was then rinsed with deionized water to remove residual solution and impurities and dried at 60 °C to obtain rod-shaped CC@Co-MOFs grown on CC.
[0077] Step 2: Dissolve 0.0376 g of thioacetamide (TAA) in 10 mL of ethanol by ultrasonication. Transfer the resulting homogeneous solution and the prepared 1×2 cm² CC@Co-MOF into a 25 mL polytetrafluoroethylene-lined high-pressure reactor. React at 120℃ for 6 h. After the reactor cools naturally to room temperature, rinse several times with anhydrous ethanol and deionized water, and dry at 60℃ overnight to obtain hollow tubular cobalt sulfide CC@CoS.
[0078] Step 3: Dissolve 0.436 g Ni(NO3)2·6H2O, 0.146 g Co(NO3)2·6H2O, 0.094 g Al(NO3)3·9H2O, and 0.506 g KNO3 in 50 mL of deionized water and sonicate until dissolved. A standard three-electrode system was used, with Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and a 1×2 cm² carbon cloth-supported cobalt sulfide (CC@CoS) as the working electrode. NiCoAl-LDH was deposited on the CC@CoS surface using chronoamperometry (it) at a constant potential of -1.1 V for 300 s. After deposition, the sample was repeatedly rinsed with deionized water and dried at 60 °C to obtain the CC@CoS / NiCoAl-LDH composite electrode. Finally, the composite electrode was immersed in a nitrogen-doped graphene quantum dot (NGQD) dispersion to obtain CC@CoS / NiCoAl-LDH / NGQDs.
[0079] The results of the cycle stability test of the CC@CoS / NiCoAl-LDH / NGQDs composite material prepared in this embodiment as the positive electrode of the supercapacitor show that its specific capacitance remains at 72.3% of the initial capacitance after 7000 cycles.
[0080] Example 7
[0081] A method for preparing a CC@CoS / NiCoAl-LDH / NGQDs heterostructure electrode material includes the following steps:
[0082] Step 1: A piece of carbon cloth (CC) is ultrasonically pretreated and dried in deionized (DI) water to serve as the substrate. 0.582 g of Co(NO3)2·6H2O is weighed and dissolved in 40 mL of deionized water to prepare a cobalt ion solution. Separately, 1.32 g of 2-methylimidazole (2-MIM) is added to 40 mL of deionized water and ultrasonicated to obtain a homogeneous solution.
[0083] A carbon cloth measuring 1×2 cm² was first immersed in a cobalt nitrate solution and allowed to stand at room temperature for 1 h. Then, a 2-MIM solution was poured into the same container and soaked at 60 °C for 4 h. After soaking, the cloth was allowed to cool naturally to room temperature. The product was then rinsed with deionized water to remove residual solution and impurities and dried at 60 °C to obtain rod-shaped CC@Co-MOFs grown on CC.
[0084] Step 2: Dissolve 0.0376 g of thioacetamide (TAA) in 10 mL of ethanol by ultrasonication. Transfer the resulting homogeneous solution and the prepared 1×2 cm² CC@Co-MOF into a 25 mL polytetrafluoroethylene-lined high-pressure reactor. React at 120℃ for 8 h. After the reactor cools naturally to room temperature, rinse several times with anhydrous ethanol and deionized water, and dry at 60℃ overnight to obtain hollow tubular cobalt sulfide CC@CoS.
[0085] Step 3: Dissolve 0.436 g Ni(NO3)2·6H2O, 0.146 g Co(NO3)2·6H2O, 0.094 g Al(NO3)3·9H2O, and 0.506 g KNO3 in 50 mL of deionized water and sonicate until dissolved. A standard three-electrode system was used, with Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and a 1×2 cm² carbon cloth-supported cobalt sulfide (CC@CoS) as the working electrode. NiCoAl-LDH was deposited on the CC@CoS surface using chronoamperometry (it) at a constant potential of -1.1 V for 300 s. After deposition, the sample was repeatedly rinsed with deionized water and dried at 60 °C to obtain the CC@CoS / NiCoAl-LDH composite electrode. Finally, the composite electrode was immersed in a nitrogen-doped graphene quantum dot (NGQD) dispersion to obtain CC@CoS / NiCoAl-LDH / NGQDs.
[0086] The results of the cycle stability test of the CC@CoS / NiCoAl-LDH / NGQDs composite material prepared in this embodiment as the positive electrode of the supercapacitor show that after 7000 cycles, its specific capacitance remains at 71.3% of the initial capacitance.
[0087] Example 8
[0088] A method for preparing a CC@CoS / NiCoAl-LDH / NGQDs heterostructure electrode material includes the following steps:
[0089] Step 1: A piece of carbon cloth (CC) is ultrasonically pretreated and dried in deionized (DI) water to serve as the substrate. 0.582 g of Co(NO3)2·6H2O is weighed and dissolved in 40 mL of deionized water to prepare a cobalt ion solution. Separately, 1.32 g of 2-methylimidazole (2-MIM) is added to 40 mL of deionized water and ultrasonicated to obtain a homogeneous solution.
[0090] A carbon cloth measuring 1×2 cm² was first immersed in a cobalt nitrate solution and allowed to stand at room temperature for 1 h. Then, a 2-MIM solution was poured into the same container and soaked at 60 °C for 4 h. After soaking, the cloth was allowed to cool naturally to room temperature. The product was then rinsed with deionized water to remove residual solution and impurities and dried at 60 °C to obtain rod-shaped CC@Co-MOFs grown on CC.
[0091] Step 2: Dissolve 0.0376 g of thioacetamide (TAA) in 10 mL of ethanol by ultrasonication. Transfer the resulting homogeneous solution and the prepared 1×2 cm² CC@Co-MOF into a 25 mL polytetrafluoroethylene-lined high-pressure reactor. React at 200℃ for 6 h. After the reactor cools naturally to room temperature, rinse several times with anhydrous ethanol and deionized water, and dry at 60℃ overnight to obtain hollow tubular cobalt sulfide CC@CoS.
[0092] Step 3: Dissolve 0.436 g Ni(NO3)2·6H2O, 0.146 g Co(NO3)2·6H2O, 0.094 g Al(NO3)3·9H2O, and 0.506 g KNO3 in 50 mL of deionized water and sonicate until dissolved. A standard three-electrode system was used, with Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and a 1×2 cm² carbon cloth-supported cobalt sulfide (CC@CoS) as the working electrode. NiCoAl-LDH was deposited on the CC@CoS surface using chronoamperometry (it) at a constant potential of -1.1 V for 300 s. After deposition, the sample was repeatedly rinsed with deionized water and dried at 60 °C to obtain the CC@CoS / NiCoAl-LDH composite electrode. Finally, the composite electrode was immersed in a nitrogen-doped graphene quantum dot (NGQD) dispersion to obtain CC@CoS / NiCoAl-LDH / NGQDs.
[0093] The results of the cycle stability test of the CC@CoS / NiCoAl-LDH / NGQDs composite material prepared in this embodiment as the positive electrode of the supercapacitor show that its specific capacitance remains at 65.4% of the initial capacitance after 7000 cycles.
[0094] Example 9
[0095] A method for preparing a CC@CoS / NiCoAl-LDH / NGQDs heterostructure electrode material includes the following steps:
[0096] Step 1: A piece of carbon cloth (CC) is ultrasonically pretreated and dried in deionized (DI) water to serve as the substrate. 0.582 g of Co(NO3)2·6H2O is weighed and dissolved in 40 mL of deionized water to prepare a cobalt ion solution. Separately, 1.32 g of 2-methylimidazole (2-MIM) is added to 40 mL of deionized water and ultrasonicated to obtain a homogeneous solution.
[0097] A carbon cloth measuring 1×2 cm² was first immersed in a cobalt nitrate solution and allowed to stand at room temperature for 1 h. Then, a 2-MIM solution was poured into the same container and soaked at 60 °C for 4 h. After soaking, the cloth was allowed to cool naturally to room temperature. The product was then rinsed with deionized water to remove residual solution and impurities and dried at 60 °C to obtain rod-shaped CC@Co-MOFs grown on CC.
[0098] Step 2: Dissolve 0.038 g of thiourea (TU) in 10 mL of ethanol using ultrasound. Transfer the resulting homogeneous solution and the prepared 1×2 cm² CC@Co-MOF into a 25 mL polytetrafluoroethylene-lined high-pressure reactor. React at 160℃ for 6 h. After the reactor has cooled naturally to room temperature, rinse it several times with anhydrous ethanol and deionized water. Dry it overnight at 60℃ to obtain hollow tubular cobalt sulfide CC@CoS.
[0099] Step 3: Dissolve 0.436 g Ni(NO3)2·6H2O, 0.146 g Co(NO3)2·6H2O, 0.094 g Al(NO3)3·9H2O, and 0.506 g KNO3 in 50 mL of deionized water and sonicate until dissolved. A standard three-electrode system was used, with Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and a 1×2 cm² carbon cloth-supported cobalt sulfide (CC@CoS) as the working electrode. NiCoAl-LDH was deposited on the CC@CoS surface using chronoamperometry (it) at a constant potential of -1.1 V for 300 s. After deposition, the sample was repeatedly rinsed with deionized water and dried at 60 °C to obtain the CC@CoS / NiCoAl-LDH composite electrode. Finally, the composite electrode was immersed in a nitrogen-doped graphene quantum dot (NGQD) dispersion to obtain CC@CoS / NiCoAl-LDH / NGQDs.
[0100] The results of the cycle stability test of the CC@CoS / NiCoAl-LDH / NGQDs composite material prepared in this embodiment as the positive electrode of the supercapacitor show that its specific capacitance remains at 77.6% of the initial capacitance after 7000 cycles.
[0101] Example 10
[0102] A method for preparing a CC@CoS / NiCoAl-LDH / NGQDs heterostructure electrode material includes the following steps:
[0103] Step 1: A piece of carbon cloth (CC) is ultrasonically pretreated and dried in deionized (DI) water to serve as the substrate. 0.582 g of Co(NO3)2·6H2O is weighed and dissolved in 40 mL of deionized water to prepare a cobalt ion solution. Separately, 1.32 g of 2-methylimidazole (2-MIM) is added to 40 mL of deionized water and ultrasonicated to obtain a homogeneous solution.
[0104] A carbon cloth measuring 1×2 cm² was first immersed in a cobalt nitrate solution and allowed to stand at room temperature for 1 h. Then, a 2-MIM solution was poured into the same container and soaked at 60 °C for 4 h. After soaking, the cloth was allowed to cool naturally to room temperature. The product was then rinsed with deionized water to remove residual solution and impurities and dried at 60 °C to obtain rod-shaped CC@Co-MOFs grown on CC.
[0105] Step 2: Dissolve 0.0376 g of thioacetamide (TAA) in 10 mL of ethanol by ultrasonication. Transfer the resulting homogeneous solution and the prepared 1×2 cm² CC@Co-MOF into a 25 mL polytetrafluoroethylene-lined high-pressure reactor. React at 160℃ for 6 h. After the reactor cools naturally to room temperature, rinse several times with anhydrous ethanol and deionized water, and dry at 60℃ overnight to obtain hollow tubular cobalt sulfide CC@CoS.
[0106] Step 3: Dissolve 0.436 g Ni(NO3)2·6H2O, 0.146 g Co(NO3)2·6H2O, 0.094 g Al(NO3)3·9H2O, and 0.506 g KNO3 in 50 mL of deionized water and sonicate until dissolved. A standard three-electrode system was used, with Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and a 1×2 cm² carbon cloth-supported cobalt sulfide (CC@CoS) as the working electrode. NiCoAl-LDH was deposited on the CC@CoS surface using chronoamperometry (it) at a constant potential of -1.1 V for 250 s. After deposition, the sample was repeatedly rinsed with deionized water and dried at 60 °C to obtain the CC@CoS / NiCoAl-LDH composite electrode. Finally, the composite electrode was immersed in a nitrogen-doped graphene quantum dot (NGQD) dispersion to obtain CC@CoS / NiCoAl-LDH / NGQDs.
[0107] The results of the cycle stability test of the CC@CoS / NiCoAl-LDH / NGQDs composite material prepared in this embodiment as the positive electrode of the supercapacitor show that its specific capacitance remains at 80.8% of the initial capacitance after 7000 cycles.
[0108] Example 11
[0109] A method for preparing CC@CoS / NiCoAl-LDH / NGQDs electrode material includes the following steps:
[0110] Step 1: A piece of carbon cloth (CC) is ultrasonically pretreated and dried in deionized (DI) water to serve as the substrate. 0.582 g of Co(NO3)2·6H2O is weighed and dissolved in 40 mL of deionized water to prepare a cobalt ion solution. Separately, 1.32 g of 2-methylimidazole (2-MIM) is added to 40 mL of deionized water and ultrasonicated to obtain a homogeneous solution.
[0111] A carbon cloth measuring 1×2 cm² was first immersed in a cobalt nitrate solution and allowed to stand at room temperature for 1 h. Then, a 2-MIM solution was poured into the same container and soaked at 60 °C for 4 h. After soaking, the mixture was allowed to cool naturally to room temperature, and the product was rinsed with deionized water to remove residual solution and impurities. The product was then dried at 60 °C to obtain rod-shaped CC@Co-MOFs grown on CC.
[0112] Step 2: Dissolve 0.0376 g of thioacetamide (TAA) in 10 mL of ethanol by ultrasonication. Transfer the resulting homogeneous solution and the prepared 1×2 cm² CC@Co-MOF into a 25 mL polytetrafluoroethylene-lined high-pressure reactor. React at 160℃ for 6 h. After the reactor cools naturally to room temperature, rinse several times with anhydrous ethanol and deionized water, and dry at 60℃ overnight to obtain hollow tubular cobalt sulfide CC@CoS.
[0113] Step 3: Dissolve 0.436 g Ni(NO3)2·6H2O, 0.146 g Co(NO3)2·6H2O, 0.094 g Al(NO3)3·9H2O, and 0.506 g KNO3 in 50 mL of deionized water and sonicate until dissolved. A standard three-electrode system was used, with Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and a 1×2 cm² carbon cloth-supported cobalt sulfide (CC@CoS) as the working electrode. NiCoAl-LDH was deposited on the CC@CoS surface using chronoamperometry (it) at a constant potential of -1.1 V for 350 s. After deposition, the sample was repeatedly rinsed with deionized water and dried at 60 °C to obtain the CC@CoS / NiCoAl-LDH composite electrode. Finally, the composite electrode was immersed in a nitrogen-doped graphene quantum dot (NGQD) dispersion to obtain CC@CoS / NiCoAl-LDH / NGQDs.
[0114] The results of the cycle stability test of the CC@CoS / NiCoAl-LDH / NGQDs composite material prepared in this embodiment as the positive electrode of the supercapacitor show that its specific capacitance remains at 73.6% of the initial capacitance after 7000 cycles.
[0115] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made using the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.
Claims
1. A method for preparing a ternary CoS / NiCoAl-LDH / NGQDs heterostructure electrode material, characterized in that, Includes the following steps: A. A piece of carbon cloth was ultrasonically pretreated and dried in deionized water to serve as a substrate; 0.582 g of Co(NO3)2·6H2O was weighed and dissolved in 40 mL of deionized water to prepare a cobalt ion solution; 1.32 g of 2-methylimidazole was added to 40 mL of deionized water and ultrasonicated to obtain a homogeneous solution. A carbon cloth with a size of 1×2 cm² was first immersed in a cobalt nitrate solution and left to stand at room temperature for 1 h. Then, a 2-methylimidazole solution was poured into the same container and soaked at 60°C for 2–6 h. After soaking, the cloth was naturally cooled to room temperature, and the product was rinsed with deionized water to remove residual solution and impurities. The product was then dried at 60°C to obtain rod-shaped CC@Co-MOFs grown on CC. B. Dissolve 0.0376 g of thioacetamide in 10 mL of ethanol using ultrasound. Transfer the resulting homogeneous solution and the prepared 1×2 cm² CC@Co-MOF into a 25 mL polytetrafluoroethylene-lined high-pressure reactor. React at 120~200℃ for 4~8 h. After the reactor cools naturally to room temperature, rinse several times with anhydrous ethanol and deionized water, and dry at 60℃ overnight to obtain hollow tubular cobalt sulfide CC@CoS. C. Dissolve 0.436 g Ni(NO3)2·6H2O, 0.146 g Co(NO3)2·6H2O, 0.094 g Al(NO3)3·9H2O, and 0.506 g KNO3 in 50 mL of deionized water and sonicate until dissolved. Use a standard three-electrode system with Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and a 1×2 cm² carbon cloth loaded with cobalt sulfide as the working electrode. Deposit NiCoAl-LDH on the CC@CoS surface using a chronoamperometry method at a constant potential of -1.1V for 250~350 s. After deposition, rinse the sample repeatedly with deionized water and dry at 60℃ to obtain the CC@CoS / NiCoAl-LDH composite electrode. Finally, immerse the composite electrode in a nitrogen-doped graphene quantum dot dispersion to obtain CC@CoS / NiCoAl-LDH / NGQDs.
2. The method for preparing a ternary CoS / NiCoAl-LDH / NGQDs heterostructure electrode material according to claim 1, characterized in that: In step A, it is preferable to soak at 60 ℃ for 4 hours.
3. The method for preparing a ternary CoS / NiCoAl-LDH / NGQDs heterostructure electrode material according to claim 1, characterized in that: In step A, the cobalt source is Co(NO3)2 or CoCl2, preferably Co(NO3)2.
4. The method for preparing a ternary CoS / NiCoAl-LDH / NGQDs heterostructure electrode material according to claim 1, characterized in that: In step B, the reaction is preferably carried out at 160°C for 6 hours.
5. The method for preparing a ternary CoS / NiCoAl-LDH / NGQDs heterostructure electrode material according to claim 1, characterized in that: In step B, the sulfur source is thioacetamide or thiourea, preferably thioacetamide.
6. The method for preparing a ternary CoS / NiCoAl-LDH / NGQDs heterostructure electrode material according to claim 1, characterized in that: In step C, it is preferable to deposit using the chronoamperometry method for 300 s at a constant potential of -1.1 V.
7. A method for preparing a ternary CoS / NiCoAl-LDH / NGQDs heterostructure electrode material according to any one of claims 1-6, characterized in that: CoS hollow nanotubes serve as a conductive scaffold, supporting the uniformly grown NiCoAl-LDH nanosheets, while nitrogen-doped graphene quantum dots are tightly anchored to their surface through electrostatic interactions.
8. A ternary CoS / NiCoAl-LDH / NGQDs heterostructure electrode material as described in claim 7, applied to the positive electrode material of a supercapacitor.