CN114507786B

CN114507786B - Method for utilizing quantum dots to assist dissociation, concentration and in-situ monitoring of low-concentration diluted noble elements of supercapacitor

Info

Publication number: CN114507786B
Application number: CN202111657453.8A
Authority: CN
Inventors: 曹晏
Original assignee: Guangzhou Institute of Energy Conversion of CAS
Current assignee: Guangzhou Institute of Energy Conversion of CAS
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2023-06-09
Anticipated expiration: 2041-12-30
Also published as: CN114507786A

Abstract

The invention discloses a method for utilizing quantum dots to assist a super capacitor to dissociate, concentrate and in-situ monitor rare earth elements with low concentration. The method comprises the following steps: putting mineral solid waste raw materials into a super capacitor, wherein the super capacitor comprises a cathode, an anode, a mixed solution of an electrolyte and quantum dots, when a stage capacitor is charged, an acidic water environment is generated, rare earth element ions on the surface of the mineral solid waste raw materials are promoted to carry out ion exchange dissociation, the rare earth element ions are transferred into the mixed solution and combined with the quantum dots to form quantum dot-rare earth element aggregates, and the aggregates move to the surface of the cathode to be further enriched under the action of an electric field of the super capacitor; when the super capacitor is operated reversely, the aggregate is separated from the surface of the cathode, and the aggregate separated from the cathode naturally subsides in a solution environment, so that rare earth rare elements are concentrated. The invention constructs a working mechanism of the quantum dot auxiliary super capacitor for rare earth rare element ion migration, adsorption, enrichment and fluorescence emission.

Description

Method for utilizing quantum dots to assist dissociation, concentration and in-situ monitoring of low-concentration diluted noble elements of supercapacitor

Technical Field

The invention relates to the technical field of environmental protection and mining and metallurgy, in particular to a method for utilizing quantum dots to assist a supercapacitor to dissociate, concentrate and in-situ monitor low-concentration diluted noble elements.

Background

The symbiotic companion of mineral products is the main cause of complex solid waste components, wherein rare and rare elements or technical key elements such as rare earth, lithium, cobalt, copper, gallium, germanium, indium and other nonferrous metal varieties which are significant to the economic development of national economy in China, especially the high technical field are not consumed, but the low concentration occurrence makes the mineral products abandoned by the existing mining and metallurgy process, and high-value resources are lost along with the solid waste of mining and metallurgy. Among them, rare earth elements are the total name of seventeen elements of lanthanide series, scandium and yttrium, and the unique light, electricity and magnetism of rare earth elements are used for obtaining the reputation of 'industrial vitamins', so as to support the development of a plurality of emerging industries. Wherein, the rare earth accounting for 60 percent of the total consumption and 91 percent of the total consumption is used for permanent magnetic materials (praseodymium, neodymium, terbium, dysprosium, holmium and the like) and catalysts (lanthanum, cerium, yttrium and the like); other aspects can also be used for laser and fluorescence, color display (terbium, europium, etc.), ultra-high temperature and super magnetostrictive alloys (praseodymium, terbium, dysprosium, scandium, etc.), batteries, sensing materials, etc.

China gradually forms the only country with the whole industrial chain of rare earth, and occupies the first position of the world all the year round in the aspects of rare earth storage, production, smelting separation, consumption, export total amount and the like. However, the rapid consumption results in the rapid decrease of the rare earth ratio in the well-established reserves worldwide from 2000. The strategic, limited and nonrenewable nature of rare earth resources promotes China to implement protective rare earth limited production. In view of the important strategic position of rare earth resources affecting global future development, china needs to further maintain the dominant position of global rare earth reserve, production and application so as to maintain the strategic consideration of self development needs and international supply. Because the accompaniment of minerals to numerous solid wastes and tailings contains a large amount of low-concentration rare earth resources, the technical problems to be solved are how to realize rapid secondary rare earth raw material detection census (> 100 mug/g, ppm), efficient low-occurrence rare earth dissociation extraction and concentration, lower process energy consumption, environmental hazard avoidance and the like.

The prior related industrialization technology inevitably adopts acid leaching extraction, has larger environmental and energy consumption load and requires more existing rare and noble element raw materials (the concentration of solid waste rare earth elements is hundreds of times or more), and environmental pollution and ecological damage are industrial problems. Other extraction methods include ionic liquid, ion exchange, solvent extraction, resin extraction, membrane separation and the like, which are in research and development states, and have different requirements on the chemical state, structure and grade of an extraction object, and the extraction efficiency, energy efficiency and economy are required to be improved. The rarefaction of rare elements presents challenges for concentration, and currently relies primarily on organic chelates, which are cost and environmental impact considerations, and need to find effective alternatives.

Therefore, the method can accelerate the promotion of the mineral metallurgical industry chain of China by extracting high-value accompanying elements from the tailings or mining and metallurgy solid wastes, has great significance for the high-value resource supply and the high-value utilization of the solid wastes such as rare and noble elements, saves the mining steps, and reduces the environmental pollution and ecological damage caused by the solid wastes and the tailings stacking related to the mining steps.

Disclosure of Invention

Aiming at the problems existing in the prior art, the invention aims to provide a method for utilizing quantum dots to assist the dissociation, concentration and in-situ monitoring of low-concentration rare elements, and the method provided by the invention constructs a dissociation, concentration and in-situ analysis integrated technology of the low-concentration rare elements, so that a new mechanism of quantum dot adsorption, electrochemical enhanced fluorescence spectrum analysis and super capacitor electrolyte regulation is expanded; the development of integrated framework integration solves the dissociation, concentration and in-situ analysis screening of low-occurrence rare elements, exploits a new separation engineering technology, and has innovative technical teaching for the dissociation-enrichment-detection of all low-occurrence and high-value substances.

The technical scheme adopted by the invention is as follows:

the invention provides a method for utilizing quantum dots to assist a super capacitor to dissociate, concentrate and in-situ monitor low-concentration and diluted noble elements, which comprises the following steps: crushing mineral solid waste raw materials into powder, and placing the powder into a super capacitor, wherein the super capacitor comprises a cathode, an anode, a mixed solution of electrolyte and quantum dots, when the super capacitor is charged, the super capacitor generates an acidic water environment to promote low-occurrence rare-noble element ions adsorbed on the surface of the mineral solid waste raw materials to carry out ion exchange dissociation, and the rare-noble element ions are transferred into the mixed solution to be combined with the quantum dots to form quantum dot-rare-noble element aggregates, so that the aggregates move to the surface of the cathode to be further enriched under the action of an electric field of the super capacitor; when the super capacitor is operated reversely, the aggregate is separated from the surface of the cathode, and the electrode is regenerated, so that the aggregate separated from the cathode naturally subsides in a solution environment, and the concentration of rare and noble elements is realized; according to the optical effect, the electrical effect and the magnetic effect of the quantum dot-rare element, the in-situ analysis screening and the enrichment capacity of the rare element are realized.

The quantum dot can be an excellent candidate material, has nanoscale, controllable scale, low toxicity, easy synthesis and good dispersion in water, and the functional groups such as carbonyl, hydroxyl and the like on the surface of the quantum dot can produce the rare element adsorption and enrichment function similar to chelating agent, and the quantum dot is easy to agglomerate and separate to form rare earth enrichment concentration; meanwhile, the quantum fluorescent characteristics of the quantum dots and the rare elements respectively enable the quantum dots and the rare elements to generate excellent rare element detection performance after being combined. The invention relates to a quantum chemistry, electrochemistry and optical spectrum analysis coupling synergistic mechanism for rare earth enrichment and noble element set detection, which is used for constructing a super capacitor framework technology integrating dissociation, concentration and in-situ analysis screening of low-concentration rare earth, meets various application requirements of in-situ online detection of low-concentration rare earth, efficient cleaning and low-energy enrichment of low-concentration rare earth and the like, has higher economic and application values, and also has innovative technical revenues for dissociation-enrichment-detection of all low-concentration and high-value substances.

Preferably, the method specifically comprises the following steps:

(1) The method comprises the steps of (1) placing mineral solid waste raw materials into a supercapacitor, wherein when the supercapacitor is charged, the concentration of hydrogen ions in electrolyte is increased, so that the acidity of the electrolyte is improved, and an acidic water environment is formed; ion exchange dissociation is carried out on low-occurrence rare element ions adsorbed on the surface of the mineral solid waste raw material, hydrogen ions are neutralized, and the ion exchange dissociated rare element ions enter an electrolyte solution to become free rare element ions; the quantum dots and rare element ions in the super capacitor electrolyte are combined to form quantum dot-rare element aggregate, so that the dissociated rare element ions are trapped by the quantum dots and complete primary enrichment, and the aggregate moves to the surface of a cathode under the action of an electric field of the super capacitor to complete further enrichment of the rare element;

(2) Reversely operating the super capacitor to separate the aggregate from the surface of the cathode and simultaneously regenerating the electrode; naturally settling the quantum dot-rare noble element aggregate separated from the cathode in an electrolyte solution environment to finish a round of circulating operation;

(3) According to the optical effect, the electrical effect and the magnetic effect of the quantum dot-rare element, the in-situ analysis and screening of the rare element are realized, the dynamics and the enrichment capacity of the rare element ion enrichment process are tracked in real time, and the in-situ acidolysis, concentration and monitoring of the integrated low-concentration rare element are realized.

The carbon dot-rare noble element aggregate separated from the cathode can accelerate the sedimentation of the carbon dot-rare noble element aggregate in the electrolyte solution environment by adding a sedimentation agent, wherein the sedimentation agent can be any substance which can enable the pH value of the electrolyte solution to be between 5 and 12, such as strong alkali, weak alkali strong acid salt, strong acid weak alkali salt and the like.

The optical effect comprises the combined use of detection means such as fluorescence spectrum, absorption spectrum, infrared spectrum, raman spectrum, X-ray energy spectrum and the like; the electrical effects include electrochemical spectrum, electrochemical impedance, electrochemical power generation, etc., and the magnetic effects include magnetoresistance effects, magneto luminescence, etc.

Due to the optical effect, the electrical effect and the magnetic effect of the quantum dot-rare and noble element, the system can also realize in-situ analysis and screening of rare earth, track the dynamics and the enrichment capacity of the rare earth ion enrichment process in real time, finally realize in-situ acidolysis, concentration and detection of the integrated low-concentration rare and noble element, and get rid of the dependence on the heavy ICP-MS off-line detection technology.

Preferably, the mineral solid waste raw material in the step (1) comprises coal-based solid waste and waste tailings, wherein the coal-based solid waste is selected from one of fly ash, coal slime and coal gangue, the waste tailings are selected from one of iron slag, phosphate rock, red mud and composite associated slag, and the content of rare elements in the mineral solid waste raw material is 10-50000 mug/g.

Preferably, the super capacitor consists of a cathode and an anode immersed in a mixed solution of electrolyte and quantum dots, wherein the ratio of the quantum dots to the electrolyte is 1-1000 mg of quantum dots per gram of electrolyte, and the anode and the cathode are made of metal oxide, metal sulfide, metal nitride or a composite of the metal oxide, the metal sulfide and the metal nitride; the pH value of the electrolyte solution is 0-7. The electrolyte is an organic acid, an inorganic acid, an organic salt or an inorganic salt.

Preferably, the anode material is a metal oxide or metal sulfide, and the metal is at least one selected from the group consisting of iron, manganese, cobalt, nickel, magnesium and zinc.

Further preferably, the anode material is selected from FeCo ₂ O ₄ 、Ni Co ₂ O ₄ 、ZnCo ₂ O ₄ 、CoFeO ₄ 、Ni ₂ S ₃ And Co ₂ S ₃ One of them. Further preferably, the anode material is a composite metal oxide, i.e. FeCo ₂ O ₄ @MnO ₂ 。

Preferably, the quantum dot material is selected from carbon quantum dots, metal sulfur and metal nitrogen quantum dots and composite quantum dots of the quantum dots, and the particle size of the quantum dots is 1-50 nm; the carbon quantum dots are an aggregate of oxygen, sulfur, nitrogen and modified metal taking carbon element as a core.

Further preferably, the carbon quantum dots are folic acid or multi-element nitrogen-phosphorus-sulfur doped semiconductor carbon quantum dots.

Preferably, the charging energy of the super capacitor is supplied by renewable solar energy.

Preferably, the supercapacitor operates at a temperature in the range of 5 ℃ to 300 ℃ and at a pressure in the range of 0.01 to 30 MPa.

Compared with the prior art, the invention has the advantages that:

(1) In theory, the invention fuses and applies related theories of material chemistry, electrochemistry, thermodynamics, physical field and separation engineering; the working mechanism of the quantum dot auxiliary supercapacitor with rare and noble element ion migration, adsorption, enrichment and fluorescence emission can be constructed in a narrow sense, and the synergistic action mechanism of intermolecular force dissociation and adsorption balance, electric field effect charge ion migration, electrochemical electron transfer and fluorescence spectrum fusion can be constructed in a broad sense;

(2) In the invention, a dissociation, concentration and in-situ analysis integrated technology of low-occurrence rare elements is constructed, and a new mechanism of quantum dot adsorption, electrochemical enhanced fluorescence spectrum analysis and supercapacitor electrolyte regulation is expanded; the development of integrated framework integration solves the dissociation, concentration and in-situ analysis screening of low-occurrence rare elements, exploits a new separation engineering technology, and has innovative technical revenues for the dissociation-enrichment-detection of all low-occurrence and high-value substances;

(3) In application, the invention takes rare elements as an example, and shows double application prospects in the fields of analysis detection or detection and separation engineering, such as a novel low-occurrence rare earth in-situ enrichment detection method and a novel low-occurrence rare element high-efficiency cleaning low-energy enrichment technology, wherein the former refers to a portable or in-situ instrument framework, the latter refers to a large industrial separation engineering technology, the formation of secondary industries facing to the recovery and enrichment of low-occurrence rare elements and other high-value substances is promoted, the development of in-situ detection means and separation engineering technology paths is promoted, and the integration and high-quality development of the dissociation-enrichment-detection related operations of the solid waste industry are led.

Drawings

FIG. 1 is a diagram of a low concentration rare earth technology route for utilizing quantum dots to assist in dissociation, concentration and in situ monitoring of a supercapacitor in accordance with the present invention;

FIG. 2 is a composite metal oxide electrode material according to example 1 of the present invention; FIG. 2a is a schematic diagram of a supercapacitor lighting diode light emitter assembled based on a synthetic composite metal oxide electrode material; FIG. 2b is a graph showing the capacitance characteristics of a composite metal oxide; FIG. 2c is a schematic diagram of lighting more LED emitters;

FIG. 3 is an electron microscope image of the composite metal oxide electrode material according to embodiment 1 of the present invention, wherein FIGS. 3a-d are electron microscope images of the same composite metal oxide electrode material with different microscopic dimensions (see drawing notation), i.e. different magnifications;

FIG. 4 is a graph showing the particle size distribution of (a) NPS-GQDs in example 1 of the present invention; (b) NPS-GQDs high resolution projection electron micrographs; (c) NPS-GQDs solution addition Tb ³⁺ (0-50. Mu.M) fluorescence spectrum; (d) Fluorescence intensity and Tb ³⁺ A linear plot of concentration;

FIG. 5 is a diagram of the process of preparing sour water from the super capacitor of example 2;

FIG. 6 shows the addition of Eu with different concentrations to a folic acid raw material carbon quantum dot solution in example 3 (a) ³⁺ A fluorescence spectrum; (b) Fluorescence intensity and Eu ³⁺ A linear plot of concentration; (c) 1-1200 mu M Eu ³⁺ A plot of current response to concentration change, (d) a plot of the corresponding linear fit of (c); (e) Current response plot of CDs/GCE electrode for Ce (III) ions; (f) For Ce (III) ionLinear plot of sub-and fluorescence intensity.

Detailed Description

The following examples are further illustrative of the invention and are not intended to be limiting thereof. Reagents and apparatus proposed by the present invention are commercially available, unless otherwise specified. Each of the gas or liquid flow paths in the embodiments described below is provided with a valve for controlling the entry or exit of the gas or liquid.

Example 1

As shown in fig. 1, the method for utilizing quantum dots to assist the dissociation, concentration and in-situ monitoring of low-concentration and diluted noble elements of the supercapacitor comprises the following steps: crushing coal-based solid waste raw materials into powder, putting the powder into a super capacitor, wherein the operating temperature range of the super capacitor is 50-100 ℃, the pressure is 0.5-5 MPa, the content of rare and noble elements in the coal-based solid waste raw materials is 10 mug/g, the super capacitor comprises two electrodes and a mixed solution of electrolyte and quantum dots, and the anode material is FeCo ₂ O ₄ @MnO ₂ The cathode material is FeCo ₂ O ₄ @MnO ₂ The electrolyte is 1M sodium phosphate solution, the quantum dots are multi-element nitrogen phosphorus sulfur doped semiconductor type carbon quantum dots (NPS-GQDs), the ratio of the electrolyte to the quantum dots is that 10 mg of quantum dots are added into each gram of electrolyte, when the super capacitor is charged at normal temperature and normal pressure, the super capacitor generates an acidic water environment, low-occurrence rare element ions adsorbed on the surface of a mineral solid waste raw material are subjected to ion exchange dissociation, the rare element ions are transferred into a mixed solution and combined with the quantum dots to form quantum dot-rare element aggregates, and the aggregates move to the surface of a cathode to be further enriched under the effect of an electric field of the super capacitor (the electrode which can be adsorbed with the quantum dots is shown as a cathode in FIG. 1); when the super capacitor is operated reversely, the aggregate is separated from the surface of the cathode, and the electrode is regenerated, so that the aggregate separated from the cathode naturally subsides in a solution environment, and the concentration of rare and noble elements is realized. The rare earth extraction efficiency reaches 80%, and the enrichment rate is more than 300 times.

FeCo is selected as anode and cathode ₂ O ₄ The electrode (160-10 hours hydrothermal method from 1M ferric nitrate and cobalt nitrate) showed the maximum power storage capacity of 182.8 Cg ⁻ (39.7 Wh kg ⁻. Mu.),the matching current is 0.5A g ⁻, the performance is improved by 21.1% even after 500 cycles in a life test, and OH is found by research ^-1 The mass transfer of (2) is a speed control step, and the application of the related electrode material in the acid water production test shows that the minimum pH value can reach 3-4. As shown in fig. 2 and 3, the prepared supercapacitor of the iron-based electrode material has good performance, and the electron microscope photograph shows that the supercapacitor has a regular and fine nano structure.

According to the optical effect, the electrical effect and the magnetic effect of the quantum dot-rare element, the in-situ analysis screening and the enrichment capacity of the rare element are realized.

The molecular structure of anthracite is C ₄₀ H ₁₅ N ₃ O ₇ S ₂ P ₂ The preparation method of the multi-element nitrogen phosphorus sulfur doped semiconductor type carbon quantum dots (NPS-GQDs) is shown in a document Applied Surface Science 445 (2018) 519-526. As shown in fig. 4. The fluorescent dye has obvious fluorescence emission, lead ions can cause fluorescence quenching (the detection limit reaches 0.75 mu M) and is not interfered by most ions; NPS-GQDs can be applied to rare earth ions Tb ³⁺ Plays a role in antenna sensitization and bloom and sends out Tb ³⁺ Fluorescence spectrum of the ion itself.

Example 2

In this example, three electrode materials CoFeO were used to produce acidic water using the supercapacitor of example 1 as shown in FIG. 5 ₄ 、Ni ₂ S ₃ And Co ₂ S ₃ The pH value in the neutral electrolyte solution changes, and the pH value can be reduced to 4-5, so that the super capacitor provided by the invention enables the solution to be in an acidic water environment, and is beneficial to the extraction of rare and noble elements in mineral solid waste raw materials.

Example 3

The same as in example 1, except that: the carbon quantum dots are folic acid.

FIG. 6 shows the addition of Eu with different concentrations to a folic acid raw material carbon quantum dot solution in example 3 (a) ³⁺ A fluorescence spectrum; (b) Fluorescence intensity and Eu ³⁺ A linear plot of concentration; (c) 1-1200 mu M Eu ³⁺ A plot of current response to concentration change, (d) a plot of the corresponding linear fit of (c); (e) Current response of CDs/GCE electrode to Ce (III) ionsA map is formed; (f) Is a linear relation graph of Ce (III) ions and fluorescence intensity.

Various fluorescence mechanisms (fluorescence quenching, antenna sensitization fluorescence, spectral line red shift effect and the like) of the carbon quantum dot-rare earth taking folic acid as a carbon source are successfully established, and an indirect method (carbon quantum dot fluorescence quenching) and a direct method (rare earth characteristic fluorescence generated by transferring absorption energy) rare earth element detection method utilizing the carbon quantum dot are successfully utilized, so that typical light, medium and heavy rare earth ions such as Ce, eu, tb and the like can be detected in a wider linear range (0-50 mu M) and a lower detection limit (0.3 mu M); further, the electrochemical scanning of the electrode loaded with the carbon quantum dots generates voltage response peaks to typical light and medium rare earth ions such as Ce, eu and the like, the linear detection range (Ce: 1-100 mu M, eu:1-1200 mu M) is widened under the lower detection limit (Ce: 0.72 mu M and Eu:0.68 mu M), and the stable working life of the electrode exceeds 5 months; in the research, the physical and chemical information of the carbon point is characterized by adopting a transmission electron microscope, an X-ray diffractometer, a Fourier infrared transformation spectrum, an X-ray photoelectron spectrometer, a cyclic voltammetry, electrochemical impedance and the like. Meanwhile, a plasma fluorescence enhancement mechanism of the quantum dots is also studied.

The total extraction efficiency of rare earth is 80%.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that the above-mentioned preferred embodiment should not be construed as limiting the invention, and the scope of the invention should be defined by the appended claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the invention, and such modifications and adaptations are intended to be comprehended within the scope of the invention.

Claims

1. The method for utilizing quantum dots to assist the dissociation, concentration and in-situ monitoring of the low-concentration diluted noble elements of the super capacitor is characterized by comprising the following steps:

(1) Crushing solid waste raw materials of mineral products, and then placing the crushed solid waste raw materials into a super capacitor, wherein the super capacitor comprises a cathode, an anode, a mixed solution of an electrolyte and a quantum dot, and when the super capacitor is charged, the concentration of hydrogen ions in the electrolyte is increased, so that the acidity of the electrolyte is improved, and an acidic water environment is formed; ion exchange dissociation is carried out on low-occurrence rare element ions adsorbed on the surface of the mineral solid waste raw material, hydrogen ions are neutralized, and the ion exchange dissociated rare element ions enter an electrolyte solution to become free rare element ions; the quantum dots and rare element ions in the super capacitor electrolyte are combined to form quantum dot-rare element aggregate, so that the dissociated rare element ions are trapped by the quantum dots and complete primary enrichment, and the aggregate moves to the surface of a cathode under the action of an electric field of the super capacitor to complete further enrichment of the rare element;

the quantum dot material is selected from carbon quantum dots, metal sulfur and metal nitrogen quantum dots and composite state quantum dots of the quantum dots, wherein the carbon quantum dots are an aggregate of oxygen, sulfur, nitrogen and modified metal taking carbon element as a core, and the anode and cathode materials are metal oxides, metal sulfides, metal nitrides or a composite of the metal oxides, the metal sulfides and the metal nitrides; the electrolyte is inorganic acid, organic acid, inorganic salt or organic salt, and the pH value of the electrolyte solution is 0-7;

(3) According to the optical effect, the electrical effect and the magnetic effect of the quantum dot-rare element, the in-situ analysis and screening of the rare element are realized, the dynamics and the enrichment capacity of the rare element ion enrichment process are tracked in real time, the in-situ acidolysis, concentration and monitoring of the integrated low-concentration rare element are realized, and the content of the rare element in the mineral solid waste raw material is 10-50000 mug/g.

2. The method of claim 1, wherein the mineral solid waste raw material in step (1) comprises coal-based solid waste selected from one of fly ash, coal slime and coal gangue and waste tailings selected from one of iron ore slag, phosphate ore, red mud and composite associated slag.

3. The method of claim 1, wherein the supercapacitor is comprised of a cathode and an anode immersed in a mixed solution of electrolyte and quantum dots, the quantum dots and electrolyte being present in a ratio of 1-1000 milligrams quantum dots per gram of electrolyte.

4. A method according to claim 3, wherein the anode and cathode materials are metal oxides or metal sulfides, and the metal is selected from at least one of iron, manganese, cobalt, nickel, magnesium and zinc.

5. The method of claim 3 or 4, wherein the anode and cathode materials are selected from FeCo ₂ O ₄ 、NiCo ₂ O ₄ 、ZnCo ₂ O ₄ 、CoFeO ₄ 、Ni ₂ S ₃ And Co ₂ S ₃ One of them.

6. The method of claim 1, wherein the quantum dots have a particle size of 1-50 nm.

7. The method of claim 6, wherein the carbon quantum dots are folic acid or multi-element nitrogen-phosphorus-sulfur doped semiconductor type carbon quantum dots.

8. The method of claim 1, wherein the supercapacitor is charged with energy supplied by renewable solar energy.

9. The method of claim 1, wherein the supercapacitor is operated at a temperature in the range of 5 ℃ to 300 ℃ and at a pressure in the range of 0.01 MPa to 30 MPa.