Preparation method of nitrogen-doped carbon quantum dot loaded ruthenium-based hydrogen evolution electrocatalyst

Abstract

The application belongs to the technical field of hydrogen production catalysts for electrolysis of water, and particularly relates to a preparation method of a nitrogen-doped carbon quantum dot loaded ruthenium-based hydrogen evolution electrocatalyst, which comprises the following steps: (1) taking alkali lignin and urea, adding them into deionized water, mixing uniformly, then adding ruthenium trichloride, mixing uniformly, and performing hydrothermal reaction to obtain a precursor; (2) after the precursor is reduced to room temperature, freeze-drying and annealing are performed to obtain the nitrogen-doped carbon quantum dot loaded ruthenium-based hydrogen evolution electrocatalyst. The electrocatalyst prepared by the method has high catalytic activity and stability, and can particularly exhibit excellent catalytic performance in a full pH range (including acid, neutral and alkaline conditions, i.e. 0-14 pH values).

Description

Technical Field

[0001] This invention belongs to the field of hydrogen production catalyst technology through water electrolysis, specifically relating to a method for preparing a ruthenium-based hydrogen evolution electrocatalyst supported on nitrogen-doped carbon quantum dots. Background Technology

[0002] Hydrogen (H2) is considered an ideal alternative energy source due to its cleanliness, efficiency, and abundant reserves, and hydrogen evolution reaction (HER) is an effective way to obtain H2. However, the widespread application of noble metal Pt-based catalysts is limited by their high cost and limited resources. Therefore, there is an urgent need to develop novel catalysts with low cost and high performance. To address the problem of Ru nanoparticle agglomeration and deactivation, selecting a suitable substrate for support is crucial to improving its HER performance. Carbon quantum dots show great potential as a support material, mainly due to their abundant functional groups on the surface and numerous defects in the structure. These properties can effectively disperse Ru nanoparticles, prevent their agglomeration, and thus improve the stability and activity of the catalyst. In addition, the preparation cost of carbon quantum dots is low, especially when using alkali lignin as a carbon source, which not only reduces the synthesis cost but also provides new possibilities for large-scale applications. The synergistic effect of carbon quantum dots and ruthenium provides a new approach and direction for designing efficient and inexpensive HER catalysts.

[0003] Lavanya Korampattu and others (Lavanya Korampattu, Sidharth Barik, AjmalPandikassala, Rajashri R. Urkude, Sreekumar Kurungot, Paresh L. Dhepe. Chemistry of Materials A ruthenium-based catalyst (Ru-CCP) was synthesized via nitrogen-doped carbon materials, using chitosan as the source of nitrogen and carbon. Nitrogen doping plays a crucial role in enhancing the catalytic performance of carbon materials because it generates defects and active sites, strengthening the interaction between ruthenium and carbon. The Ru-CCP catalyst, prepared via a single-step pyrolysis process, exhibited excellent electrocatalytic performance in HER in alkaline media, reaching 25 mA cm⁻¹ at overpotentials as low as 46 mV. -2 The Ru-CCP exhibits a current density exceeding that of commercial Pt / C catalysts under the same conditions. Furthermore, the highly efficient catalytic performance of the Ru-CCP benefits from the unique interaction between ruthenium and surface nitrogen groups (especially pyridine and pyrrole nitrogen). Nitrogen doping significantly modulates the electronic environment of the ruthenium nanoparticles, thereby enhancing catalytic activity. This catalyst not only demonstrates excellent hydrogen evolution activity but also proves the potential of sustainable materials (such as chitosan) in clean H2 production.

[0004] Liu et al (Liu, L., Liu, N., Dai, C., Xu, R., Yu, G., Wang, N., & Chen, B. Catalysis Today A ruthenium nanoparticle catalyst (5Ru@MoS2) based on MoS2 as a support and rich in sulfur vacancies was synthesized (2024, 436, 114751). 2-1.4 The electrocatalytic performance of HER was improved by controlling the structural properties of MoS2 and the ruthenium loading. Specifically, using CO gas as a structure-directing agent, MoS2 supports with different sulfur vacancy contents were synthesized, in which MoS2... 2-1.4 It exhibits the best alkaline hydrogen evolution performance. Subsequently, ruthenium nanoparticles (average particle size of 2 nm) were uniformly loaded onto MoS2 using a wet impregnation method. 2-1.4 superior.

[0005] The presence of ruthenium nanoparticles, in synergy with sulfur vacancies in the MoS2-1.4 support, effectively enhances hydrogen evolution activity and exhibits a low overpotential (55 mV). @10 mA cm-2 ) and a smaller Tafel slope (68.6 mV dec) -1 This catalyst exhibits excellent catalytic performance in alkaline media and shows significant advantages compared to other MoS2-based HER catalysts. Furthermore, sulfur vacancies not only promote the dispersion of ruthenium nanoparticles but also inhibit particle aggregation, further enhancing reaction efficiency. This study provides a novel strategy for improving the performance of MoS2-based hydrogen evolution catalysts by optimizing the synergistic effect between the support and ruthenium, effectively addressing the problems of ruthenium catalyst particle aggregation and insufficient support activity.

[0006] While the catalysts mentioned above are active under alkaline conditions, they do not maintain activity across a wide pH range, meaning they do not exhibit excellent catalytic performance across the entire pH spectrum. Therefore, it is crucial to research and develop a ruthenium-based catalyst supported on nitrogen-doped carbon quantum dots that demonstrates excellent catalytic performance across the entire pH range, filling a gap in current technology. Summary of the Invention

[0007] The present invention aims to solve the above-mentioned technical problems and provides a method for preparing a nitrogen-doped carbon quantum dot supported ruthenium-based hydrogen evolution electrocatalyst. The electrocatalyst prepared by this method has high catalytic activity and stability, and in particular, it can exhibit excellent catalytic performance in the full pH range (including acidic, neutral and alkaline conditions, i.e., pH value of 0-14).

[0008] The technical solution of this invention is as follows:

[0009] A method for preparing a nitrogen-doped carbon quantum dot-supported ruthenium-based hydrogen evolution electrocatalyst includes the following steps:

[0010] (1) Take alkali lignin and urea, add them to deionized water and mix them evenly, then add ruthenium trichloride and mix evenly. Perform hydrothermal reaction to obtain the precursor;

[0011] (2) After the precursor cools to room temperature, it is freeze-dried and annealed to prepare a nitrogen-doped carbon quantum dot-supported ruthenium-based hydrogen evolution electrocatalyst. The structure of the catalyst is as follows: nano-sized and highly dispersed nitrogen-doped carbon quantum dots serve as the supporting material, and the nitrogen-doped carbon quantum dots support the ruthenium-based catalyst. The carbon quantum dots form a carbon-based material with good conductivity. The ruthenium species are combined with the carbon quantum dot matrix through strong interactions. The nitrogen-doped structure helps to optimize the electron distribution and enhance the electron transfer ability of the catalytic active sites. The raw materials work synergistically under the method of the present invention to improve the hydrogen evolution reaction activity of the catalyst.

[0012] The crystal structure, morphology, and electronic structure of a catalyst affect its hydrogen evolution performance at different pH values. Nitrogen doping directly impacts the active sites of the catalyst; increasing the nitrogen source provides more active sites. However, excessive nitrogen doping can lead to over-concentration or uneven distribution of active sites, thus affecting the catalyst's stability and activity at different pH values. Furthermore, carbon quantum dots, as a support material, possess surface functional groups such as −COOH, −C−O, and −C−N, which can adsorb water molecules, facilitating water molecule splitting and promoting electrocatalytic hydrogen evolution. However, in a given catalyst structure, excessive carbon quantum dots can reduce the dispersion of ruthenium nanoparticles within the carbon quantum dots. However, altering the overall structural stability of the catalyst and reducing its active sites reduces catalytic activity, leading to structural changes or collapse during the reaction. Insufficient carbon quantum dots, lacking sufficient support to disperse and stabilize ruthenium nanoparticles, also reduce active sites, further decreasing catalytic activity. This also results in an imperfect conductive network, affecting electron transport rates within the catalyst and impacting its structure, potentially causing deactivation due to catalyst damage or wear. Therefore, strictly controlling the proportions of alkali lignin, urea, and ruthenium trichloride is crucial for preparing a catalyst with high catalytic activity, stability, and excellent catalytic performance across the entire pH range. To prepare the catalyst of this invention, the preferred mass ratio of alkali lignin, urea, and ruthenium trichloride in step (1) is 6:8:1.

[0013] In the system of this invention, in order to ensure that the ruthenium nanoparticles can be uniformly dispersed and to prevent catalyst particle agglomeration, preferably, the ratio of the total mass of alkali lignin, urea, and ruthenium trichloride to deionized water is 70-80:1 mg / ml. If the ratio is too large, it may cause catalyst particle agglomeration, reducing the dispersibility of the catalyst and the number of active sites. If the ratio is too low, it may prevent the catalyst particles from forming or growing sufficiently, which will also affect the dispersibility and catalytic performance of the catalyst system.

[0014] In the method of the present invention, the hydrothermal reaction time and temperature have a significant impact on the structure, morphology, crystallinity and catalytic performance of the catalyst. In order to obtain the catalyst of the present invention, preferably, in step (1) of the present invention, the hydrothermal reaction conditions are: the reaction is carried out at 100-200℃ for 7.5-8.5 h.

[0015] To ensure the structural integrity of the reaction products and obtain a catalyst with high catalytic activity and stability, especially one exhibiting excellent catalytic performance across the entire pH range (including acidic, neutral, and alkaline conditions, i.e., pH 0-14), preferably, in step (2) of this invention, the catalyst is freeze-dried for 46-50 hours. If the freeze-drying time is less than 46 hours, the water in the catalyst will not be completely sublimated, and the residual water will affect the catalyst's activity. If the drying time is more than 50 hours, it will cause changes in the catalyst structure, leading to the destruction of active sites. Therefore, to ensure the performance of the catalyst, the freeze-drying time needs to be carefully controlled.

[0016] To promote structural transformation and the formation of active sites, and to ensure the catalytic activity and stability of the catalyst, it is crucial to control the annealing conditions. Preferably, in step (2) of this invention, the specific annealing step is as follows: under an argon atmosphere, at 5-10℃ min... -1 The temperature is increased to 500-900℃ at a heating rate, and then held for 2-2.5 hours. In the catalyst of this invention, controlling the heating rate within the range specified in this invention ensures the catalyst's activity and stability. If the heating rate is too high, it will lead to uneven crystal growth, increased or concentrated internal stress affecting the formation of microporous structures and reducing mechanical strength. It will also cause the aggregation or covering of active sites, reducing their exposure. If the heating rate is too low, it will also lead to uneven crystal growth, excessive development of microporous structures, and the catalyst remaining at high temperatures for an extended period, thus affecting the long-term stability of the catalyst. During annealing, if the holding time is too long, the crystals will grow too large, reducing the specific surface area and affecting catalytic activity. If the holding time is too short, the active components of the catalyst cannot be fully formed or dispersed, thus affecting the catalyst's activity. Furthermore, the crystals will not grow uniformly, also affecting the catalyst's specific surface area and the number of active sites. Therefore, to obtain the catalyst of this invention, it is necessary to strictly control the degradation conditions.

[0017] This invention also provides the application of the catalyst prepared by the method of preparing nitrogen-doped carbon quantum dot supported ruthenium-based hydrogen evolution electrocatalyst in water electrolysis for hydrogen production. Preferably, the water is alkaline seawater or water with a pH value in the range of 0-14. That is, the catalyst of this invention can exhibit excellent catalytic performance in a wide pH range (including acidic, neutral and alkaline conditions), and is particularly suitable for alkaline seawater environments. It can exhibit high catalytic activity in alkaline seawater electrolysis and is suitable for industrial applications of actual seawater electrolysis for hydrogen production.

[0018] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0019] 1. The electrocatalyst prepared by the method of the present invention has high catalytic activity and stability, especially exhibiting excellent catalytic performance in a wide pH range (including acidic, neutral and alkaline conditions, i.e., pH value of 0-14), with low hydrogen evolution overpotential, achieving efficient hydrogen evolution reaction under low overvoltage, and showing good current density.

[0020] 2. The electrocatalyst prepared by the method of the present invention is particularly suitable for alkaline seawater environments and can exhibit high catalytic activity in alkaline seawater electrolysis. Chloride ions and other impurities under alkaline conditions have little impact on the catalyst. The catalyst of the present invention still maintains a highly efficient hydrogen evolution reaction in such a complex environment, making it suitable for industrial applications of actual seawater electrolysis for hydrogen production.

[0021] 3. The method of the present invention has simple and efficient process steps. Nitrogen-doped carbon quantum dot supported ruthenium-based catalysts can be prepared by a one-step hydrothermal method. By strictly controlling the addition ratio of alkali lignin, urea and ruthenium trichloride, and by strictly controlling the hydrothermal conditions, the catalyst can be synthesized in a one-step hydrothermal reaction, which greatly simplifies the preparation process, reduces intermediate steps and energy consumption, and has good prospects for industrial application.

[0022] 4. This invention uses alkali lignin as a carbon source, which is a widely available and inexpensive renewable resource. It avoids the problems of high cost and environmental pollution in the preparation of traditional carbon sources, and has the characteristics of being clean, environmentally friendly and sustainable, as well as having strong economic benefits.

[0023] 5. The method of the present invention only requires strict control of the addition ratio of alkali lignin, urea, and ruthenium trichloride and the hydrothermal reaction conditions. No other raw materials need to be added. The hydrothermal reaction can be completed in one step to prepare the catalyst of the present invention, which has high catalytic activity and stability and can exhibit excellent catalytic performance in the entire pH range.

[0024] 6. The preparation method of the present invention is clean, environmentally friendly, pollution-free, and sustainable. Attached Figure Description

[0025] Figure 1 This is a transmission electron microscope (TEM) image of the catalyst prepared in Example 1.

[0026] Figure 2 Polarization curves of the catalysts prepared for Example 1, Comparative Example 1, Comparative Example 2 and 20 wt% Pt / C in 1 M KOH solution as tested electrochemically.

[0027] Figure 3 Polarization curves of the catalysts prepared in Example 1 and Comparative Examples 1-3 in 1 M PBS solution were obtained for electrochemical testing.

[0028] Figure 4 Polarization curves of the catalysts prepared in Example 1 and Comparative Examples 1-3 in 0.5 M H2SO4 solution were obtained for electrochemical testing.

[0029] Figure 5 Polarization curves of the catalysts prepared in Example 1 and Comparative Examples 1-3 in alkaline seawater solution for electrochemical testing.

[0030] Figure 6 Polarization curves of the catalysts prepared for Example 1, Comparative Example 4 and 20wt% Pt / C in 1 M KOH solution were obtained through electrochemical testing.

[0031] Figure 7 Polarization curves of the catalysts prepared for Example 1, Comparative Example 5, Comparative Example 6 and 20 wt% Pt / C in 1 M KOH solution as tested electrochemically. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0033] A method for preparing a nitrogen-doped carbon quantum dot-supported ruthenium-based hydrogen evolution electrocatalyst, comprising the following steps:

[0034] (1) Dissolve alkali lignin and urea in 10 mL of deionized water to obtain a uniform mixed solution. Then add ruthenium trichloride to the solution and stir for 30 min until completely dispersed. Transfer the solution to a 50 mL reaction vessel, seal it, and carry out a hydrothermal reaction at 150 °C for 8 h to obtain the precursor. The mass ratio of alkali lignin, urea, and ruthenium trichloride is 6:8:1. The total mass of alkali lignin, urea, and ruthenium trichloride added is 75 mg.

[0035] (2) After the reaction is completed, the reaction vessel is allowed to cool naturally to room temperature. The product is then taken out and freeze-dried for 48 hours to obtain the dried product.

[0036] (3) The dried product is placed in a tube furnace and heated at 5°C for 5 min under an argon atmosphere. -1 The temperature was raised to 500℃ and held for 2.5 hours. After cooling to room temperature, the product was ground into a uniform powder to obtain a black powder, which is the nitrogen-doped carbon quantum dot-supported ruthenium-based hydrogen evolution electrocatalyst, hereinafter referred to as Ru / NC. The transmission electron microscopy (TEM) image of the catalyst is shown below. Figure 1 As shown, from Figure 1 It can be seen that ruthenium nanoparticles are well supported by carbon quantum dots, and the lattice fringes of the ruthenium (101) crystal plane and the graphite carbon (100) crystalline wafers supporting the carbon quantum dots can be clearly seen. The small-sized crystalline nanoparticles have a relatively high density of catalytic active sites, and the Ru nanoparticles are uniformly supported on the carbon quantum dots, exhibiting a highly uniform size distribution. Example 2

[0037] A method for preparing a nitrogen-doped carbon quantum dot-supported ruthenium-based hydrogen evolution electrocatalyst, comprising the following steps:

[0038] (1) Dissolve alkali lignin and urea in 10 mL of deionized water to obtain a uniform mixed solution. Then add ruthenium trichloride to the solution and stir for 30 min until completely dispersed. Transfer the solution to a 50 mL reaction vessel, seal it, and carry out a hydrothermal reaction at 100 °C for 8.5 h to obtain the precursor. The mass ratio of alkali lignin, urea, and ruthenium trichloride is 6:8:1. The total mass of alkali lignin, urea, and ruthenium trichloride added is 80 mg.

[0039] (2) After the reaction is completed, the reactor is allowed to cool naturally to room temperature. The product is then taken out and freeze-dried for 50 hours to obtain the dried product.

[0040] (3) The dried product is placed in a tube furnace and heated at 8°C for 8 min under an argon atmosphere. -1 The product was heated to 700℃, held for 2.5 hours, and then cooled to room temperature. The product was then ground into a uniform powder, which is the nitrogen-doped carbon quantum dot-supported ruthenium-based hydrogen evolution electrocatalyst. Example 3

[0041] A method for preparing a nitrogen-doped carbon quantum dot-supported ruthenium-based hydrogen evolution electrocatalyst, comprising the following steps:

[0042] (1) Dissolve alkali lignin and urea in 10 mL of deionized water to obtain a homogeneous mixed solution. Then add ruthenium trichloride to the solution and stir for 30 min until completely dispersed. Transfer the solution to a 50 mL reaction vessel, seal it, and carry out a hydrothermal reaction at 200 °C for 7.5 h to obtain the precursor. The mass ratio of alkali lignin, urea, and ruthenium trichloride is 6:8:1. The total mass of alkali lignin, urea, and ruthenium trichloride is 70 mg.

[0043] (2) After the reaction is completed, the reaction vessel is allowed to cool naturally to room temperature. The product is then taken out and freeze-dried for 46 hours to obtain the dried product.

[0044] (3) The dried product is placed in a tube furnace and heated at 10°C for 10 min under an argon atmosphere. -1 The product was heated to 900℃ and held for 2 hours. After cooling to room temperature, the product was ground into a uniform powder, which is the nitrogen-doped carbon quantum dot-supported ruthenium-based hydrogen evolution electrocatalyst.

[0045] Comparative Example 1

[0046] The difference from Example 1 is that no alkali lignin and urea are added, that is, the amount of alkali lignin and urea added in step 1) is 0 mg, and the rest is the same as in Example 1. The resulting catalyst is denoted as Ru NPs.

[0047] Comparative Example 2

[0048] The difference from Example 1 is that no ruthenium source is added, that is, the amount of ruthenium trichloride added in step 1) is 0 mg, and the rest is the same as in Example 1. The resulting catalyst is denoted as CDs.

[0049] Comparative Example 3

[0050] The difference from Example 1 is that this comparative example directly uses hydrophilic carbon paper without adding a catalyst, that is, it directly tests the hydrophilic carbon paper without adding electrode materials, denoted as CP.

[0051] Comparative Example 4

[0052] The difference from Example 1 is that the mass ratio of alkali lignin, urea, and ruthenium trichloride is 3:4:1, and the rest is the same as in Example 1.

[0053] Comparative Example 5

[0054] The difference from Example 1 is that the hydrothermal reaction was carried out at 150°C for 10 hours, and the rest is the same as Example 1.

[0055] Comparative Example 6

[0056] The difference from Example 1 is that the hydrothermal reaction was carried out at 150°C for 6 hours, and the rest is the same as Example 1.

[0057] In this invention, the catalysts prepared in Example 1, Comparative Example 1, Comparative Example 2, and 20 wt% Pt / C are loaded onto hydrophilic carbon paper as electrode materials, corresponding to a catalyst loading of 1 mg / cm³. 2 The electrocatalytic hydrogen evolution performance was tested using a three-electrode system, and the results are shown in [Figure number missing]. Figure 2 .

[0058] like Figure 2 As shown, Ru / NC exhibits excellent hydrogen evolution activity in 1 M KOH, yielding 10 mA cm⁻¹. -2 The current density required is only 32 mV overpotential, significantly lower than the 49 mV and 117 mV of 20 wt% Pt / C and Ru NPs, respectively. This indicates that Ru / NC has considerable potential in industrial applications, while CDs only achieve a current density of 3.16 mA cm⁻¹ at an overpotential of 293 mV. -2 This indicates that the active site is not located on the carbon quantum dot.

[0059] In this invention, the catalysts prepared in Example 1 and Comparative Examples 1-3 are loaded onto hydrophilic carbon paper as electrode materials, corresponding to a catalyst loading of 1 mg / cm³. 2 Its electrocatalytic hydrogen evolution performance was tested using a three-electrode system, and the results are as follows: Figure 3-5 As shown.

[0060] like Figure 3 As shown, Ru / NC also exhibits good catalytic performance in a neutral environment of 1 M PBS, reaching 10 mA cm⁻¹. -2 The current density required is only 38 mV at a low overpotential, lower than the 121 mV required by Ru NPs. Meanwhile, in a neutral environment, CDs achieve a current density of only 1.02 mA cm⁻¹ at an overpotential of 336 mV. -2 The current density indicates that it is also not an active site.

[0061] like Figure 4 As shown, the hydrogen evolution performance in an acidic 0.5 M H₂SO₄ solution reaches 10 mA cm⁻¹. -2 With a current density of 47 mV, Ru / NC requires only a low overpotential of 47 mV, while Ru NPs require a low overpotential of 79 mV. The difference between Ru / NC and RuNPs is significant, indicating that Ru / NC maintains higher catalytic activity.

[0062] like Figure 5 As shown, the hydrogen evolution performance was tested in an alkaline seawater environment, achieving a current density of 10 mA cm⁻¹. -2At that time, the overpotential of Ru / NC was 35 mV, the overpotential of Ru NPs was 45 mV, and the overpotential of CDs was 152 mV. The overpotential of Ru / NC was significantly lower than that of Ru NPs and CDs, indicating that Ru / NC of the present invention exhibits excellent catalytic activity in alkaline seawater.

[0063] In this invention, the catalysts prepared in Example 1, Comparative Example 4, and 20wt% Pt / C are loaded onto hydrophilic carbon paper as electrode materials, corresponding to a catalyst loading of 1 mg / cm³. 2 Its electrocatalytic hydrogen evolution performance was tested using a three-electrode system, and the results are as follows: Figure 6 As shown.

[0064] like Figure 6 As shown, the 6:8:1 ratio used in Example 1 exhibited excellent hydrogen evolution activity in 1 M KOH, yielding 10 mAcm. -2 The current density only requires an overpotential of 32 mV, which is significantly lower than the 90 mV and 49 mV of 20 wt% Pt / C with 3:4:1 and Pt / C, respectively, proving that the selected ratio of 6:8:1 is the optimal ratio.

[0065] In this invention, the catalysts prepared in Example 1, Comparative Example 5, Comparative Example 6, and 20wt% Pt / C are loaded onto hydrophilic carbon paper as electrode materials, corresponding to a catalyst loading of 1 mg / cm³. 2 Its electrocatalytic hydrogen evolution performance was tested using a three-electrode system, and the results are as follows: Figure 7 As shown.

[0066] like Figure 7 As shown, the hydrothermal catalyst in Example 1, designated Ru / NC-8 in this figure, exhibited excellent hydrogen evolution activity in 1 M KOH, achieving a yield of 10 mA cm⁻¹. -2 The current density only requires an overpotential of 32 mV, which is significantly lower than the 49 mV, 48 mV and 45 mV of 20 wt% Pt / C, 6 h annealing in Comparative Example 6 (Ru / NC-6) and 5 (Ru / NC-10), respectively, proving that the selected 8 h is the optimal hydrothermal time.

[0067] In summary, the nitrogen-doped carbon quantum dot-supported ruthenium-based hydrogen evolution electrocatalyst prepared by the synergistic effect of each step in the method of the present invention exhibits excellent HER activity in alkaline seawater across the entire pH range (including acidic, neutral and alkaline conditions, i.e., pH value 0-14), thereby significantly expanding its applicability.

[0068] The above description is a detailed description of the preferred embodiments of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modifications made under the technical spirit of the present invention should fall within the patent scope covered by the present invention.

Claims

1. A method for preparing a nitrogen-doped carbon quantum dot-supported ruthenium-based hydrogen evolution electrocatalyst, characterized in that, Includes the following steps: (1) Take alkali lignin and urea, add them to deionized water and mix them evenly, then add ruthenium trichloride and mix evenly. Perform hydrothermal reaction to obtain the precursor; (2) After the precursor cools to room temperature, freeze-dry and anneal to prepare nitrogen-doped carbon quantum dot-supported ruthenium-based hydrogen evolution electrocatalyst; In step (1), the mass ratio of alkali lignin, urea, and ruthenium trichloride is 6:8:1; In step (1), the hydrothermal reaction conditions are: the reaction is carried out at 100-200℃ for 7.5-8.5 h.

2. The method for preparing nitrogen-doped carbon quantum dot-supported ruthenium-based hydrogen evolution electrocatalyst as described in claim 1, characterized in that: In step (2), the freeze-drying process is carried out for 46-50 hours.

3. The method for preparing nitrogen-doped carbon quantum dot-supported ruthenium-based hydrogen evolution electrocatalyst as described in claim 1, characterized in that: In step (2), the annealing process specifically involves annealing at 5-10℃ for 1 minute under an argon atmosphere. -1 The temperature is increased to 500-900℃ at a heating rate, and then held at that temperature for 2-2.5 hours.

4. The application of the catalyst prepared by the method according to any one of claims 1-3 in the electrolysis of water to produce hydrogen.

5. The application as described in claim 4, characterized in that; The water is alkaline seawater or water with a pH value in the range of 0-14.

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