Preparation method of Ru-RuOx / graphene aerogel composite material and application of Ru-RuOx / graphene aerogel composite material in multifunctional electrocatalysis

Abstract

The invention relates to the technical field of preparation of inorganic materials and functional materials, and discloses a preparation method of a Ru-RuOx / graphene aerogel composite material and application of the Ru-RuOx / graphene aerogel composite material in multifunctional electrocatalyst.The preparation method comprises the following steps that S1, gelatin and sodium chloride are fully mixed to be uniform according to a certain mass ratio, then the mixture is heated to be fully melted, and then freezing overnight treatment is conducted; freeze-drying the obtained solid, then carrying out high-temperature calcination to completely graphitize the solid, and then carrying out multiple times of cleaning to completely remove sodium chloride, thus finally obtaining the porous graphene aerogel GA. According to the preparation method of the Ru-RuOx / graphene aerogel composite material, the reaction efficiency of water electrolysis hydrogen production and a metal air battery is improved to the maximum extent, and an advanced single catalyst suitable for various clean energy related applications is developed; the process equipment is simple, the production cost is low, large-scale industrial production and preparation are easy to realize, and the method has a good industrial prospect.

Description

Technical Field

[0001] This invention relates to the field of inorganic materials and functional materials preparation technology, specifically a Ru-RuO x Preparation method of graphene aerogel composite material and its application in multifunctional electrocatalysis. Background Technology

[0002] The global energy crisis and environmental pollution have forced the acceleration of the development of green and sustainable energy storage and conversion technologies. Water electrolysis and metal-air batteries are promising solutions. The former provides a green and scalable strategy for converting renewable electricity into hydrogen, while the latter plays an indispensable role in environmentally friendly fuel cell energy storage. However, the hydrogen evolution reaction (HER), oxygen reduction reaction (ORR), and oxygen evolution reaction (OER) involved in these processes are inherently slow. Therefore, high-performance electrocatalysts are indispensable to accelerate reaction kinetics and improve catalytic activity and stability. Currently, monofunctional catalysts cannot meet the needs of multiple electrocatalytic reactions, and designing multiple catalysts inevitably increases material costs and introduces the risk of catalyst cross-contamination. Furthermore, balancing catalytic performance with multiple reactions is extremely difficult for a single catalyst. Therefore, developing an advanced single catalyst with excellent HER, OER, and ORR performance remains a major scientific challenge.

[0003] Currently, platinum (Pt) is considered the most effective catalyst for HER and ORR due to its superior catalytic activity. However, its high cost hinders its widespread application. In contrast, ruthenium (Ru)-based catalysts offer comparable performance to platinum in HER / OER / ORR catalysis while being more cost-effective. Metallic Ru has a high charge density, leading to excessive adsorption of reaction intermediates such as HER and ORR. Reducing the charge density of Ru helps decrease the adsorption of electrophilic groups and improve reaction kinetics. Studies have found that electron-rich Ru sites (strong covalent bonds) in RuO2 can activate lattice oxygen and create defects, while electron-deficient states (weak covalent bonds) tend to oxidize to higher oxidation states and dissolve. By appropriately adjusting the covalent nature of the Ru-O bond, the electron distribution of the Ru-O bond can be optimized, following a relatively stable adsorption evolution mechanism. Designing catalysts with moderate Ru-O bond covalent nature can meet the balance requirements of activity and stability in OER, while Ru sites with charge deficiencies relative to metallic Ru can solve the problem of excessive adsorption of reaction intermediates in processes such as HER and ORR. Amorphous RuOx has been widely recognized as an effective strategy for modulating the covalent nature of Ru-O bonds. Lattice expansion and elongation of Ru-O bonds help weaken the covalent nature of Ru-O bonds and reduce structural damage caused by lattice oxygen precipitation. Appropriate Ru-O bond covalent nature not only significantly enhances activity and stability but also induces charge rearrangement and shifts the d-band center towards a negative potential, thereby weakening the adsorption of reaction intermediates and activating the entire reaction pathway.

[0004] Graphene has been extensively studied due to its large surface area and excellent electrical conductivity. As a substrate material supporting Ru, it holds promise for improving the catalytic activity of Ru sites and reducing Ru aggregation. However, the weak interaction between graphene and Ru, as well as the π-coating mechanism, remain challenges. Irreversible aggregation of graphene sheets caused by π stacking reduces the stability and atom utilization of Ru. Graphene aerogels (GAs) have attracted increasing attention due to their large surface area, interconnected three-dimensional network structure, and ordered hierarchical porosity. Ordered hierarchical porous carbon as a substrate can fully expose Ru active sites, optimize mass transfer and hydrogen / oxygen spillover and adsorption, thus exhibiting excellent HER / OER / ORR multifunctional activity. Summary of the Invention

[0005] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a Ru-RuO x This paper presents a method for preparing graphene aerogel composite materials and their application in multifunctional electrocatalysis, aiming to address the challenges posed by the fact that most current reference catalysts for HER and ORR are Pt-based, and OER catalysts are Ru-based. The low activity, poor stability, complex synthesis routes, and risk of cross-contamination of these catalysts hinder the development of hydrogen production through water electrolysis and metal-air batteries.

[0006] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: a Ru-RuO x The preparation method of graphene aerogel composite material includes the following steps: S1. Mix gelatin and sodium chloride in a certain mass ratio thoroughly, then heat to melt completely, and then freeze overnight; freeze-dry the obtained solid, then calcine at high temperature to completely graphitize it, then wash it multiple times to completely remove sodium chloride, and finally obtain porous graphene aerogel GA. S2. A certain mass of porous graphene aerogel GA, ruthenium trichloride, water and ethanol mixed solution are thoroughly mixed, and the solvent is evaporated in a water bath at 50°C to obtain a black powder. S3. The black powder was subjected to high-temperature reduction in an Ar / H2 mixed gas environment at 850℃ for 2 hours to obtain the reduced Ru / graphene aerogel Ru / GA-H. S4. Oxidize Ru / GA-H in air at 250–450℃ for 2 hours to obtain Ru-RuO. x / Graphene aerogel composite Ru-RuO x / GA.

[0007] Preferably, the ratio of gelatin to sodium chloride in S1 is 1:1.8 by mass.

[0008] Preferably, the heating temperature in step S1 is 50°C; The overnight freezing treatment conditions were 0°C for 24 hours. The high-temperature calcination conditions were 900℃ for 2 hours.

[0009] Preferably, in S2, the porous graphene aerogel is 150 mg, the ruthenium trichloride is 50 mg, the volume of the water and ethanol mixed solution is 20 mL, and the volume ratio of water to ethanol is 1:1.

[0010] Preferably, the oxidation temperature in step S4 is 350°C.

[0011] Preferably, in the resulting composite material, Ru has a crystalline metal core and amorphous RuO. x The shell is formed into core-shell heterojunction nanoparticles, which are uniformly loaded into the channels of mesoporous graphene aerogel with a pore size of 2.1–4.1 nm.

[0012] Preferably, the Ru-RuO x / Preparation method of graphene aerogel composite material to prepare Ru-RuO x / Graphene aerogel composite material.

[0013] Preferably, the Ru-RuO x / The application of graphene aerogel composites as trifunctional electrocatalysts for HER, OER, and ORR in alkaline electrolytes.

[0014] Preferably, the Ru-RuO x / Application of graphene aerogel composites as anode and / or cathode catalyst layers in alkaline water electrolysis hydrogen production devices.

[0015] Preferably, the Ru-RuO x / Application of graphene aerogel composites as air cathode catalyst layers in rechargeable metal-air batteries.

[0016] (III) Beneficial Effects Compared with the prior art, the present invention provides a Ru-RuO x The preparation method of graphene aerogel composite materials and their application in multifunctional electrocatalysis have the following beneficial effects: The Ru-RuO synthesized in this invention x The synthesis steps of graphene aerogel composite materials are simple, and a single catalyst exhibits trifunctional catalytic activity of HER / OER / ORR, which helps to further reduce the cost of water electrolysis and metal-air battery applications.

[0017] This invention utilizes a template method to obtain a three-dimensional porous graphene aerogel structure with abundant pores, capable of withstanding a weight nearly 1200 times its own weight without damaging its structure; it can also maximally and uniformly load Ru-RuO. x Nanoparticles enable maximum contact between reactants and active sites, while also allowing for the timely removal of gases generated during the reaction, thus accelerating the entire reaction process.

[0018] The Ru-RuO synthesized in this invention x The graphene aerogel composite material exhibits excellent electrocatalytic performance in HER, OER, and ORR, as well as long-term stability under alkaline conditions. The assembled water electrolysis device and metal-air battery far surpass commercial catalysts in terms of activity and stability. Attached Figure Description

[0019] Figure 1 The present invention is Ru-RuO x / Schematic diagram of the preparation method of graphene aerogel composite material; Figure 2 This is a schematic optical photograph of the graphene aerogel of the present invention; Figures 3-6 The images show SEM images of Ru-based graphene aerogel composites synthesized under different synthesis conditions according to this invention. Figures 7-8 This is the BET diagram of the Ru-based graphene aerogel composite material of the present invention; Figure 9 XRD patterns of Ru-based graphene aerogel composites under different synthesis conditions of the present invention; Figure 10 The present invention is Ru-RuO x / TEM and HRTEM images of graphene aerogel composites; Figure 11 The present invention is Ru-RuO x / Selection of electron diffraction (SEAD) pattern and elemental mapping diagram of graphene aerogel composite material; Figure 12 The present invention is Ru-RuO x XPS image of graphene aerogel composite material; Figure 13 The present invention is Ru-RuO x / Graphene aerogel composite material HER and OER electrochemical performance test curves in 1 M KOH electrolyte, and a schematic diagram of stability test curves; Figure 14 The present invention is Ru-RuO xThe ORR electrochemical performance test curves and stability test curves of the graphene aerogel composite material in 0.1 M KOH electrolyte are shown in the figure. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0021] Example 1: See attached document Figures 1 to 14 A method for preparing a Ru-RuOx / graphene aerogel composite material includes the following steps: Includes the following steps: S1. Mix gelatin and sodium chloride in a certain mass ratio thoroughly, then heat to melt completely, and then freeze overnight; freeze-dry the obtained solid, then calcine at high temperature to completely graphitize it, then wash it multiple times to completely remove sodium chloride, and finally obtain porous graphene aerogel GA. S2. A certain mass of porous graphene aerogel GA, ruthenium trichloride, water and ethanol mixed solution are thoroughly mixed, and the solvent is evaporated in a water bath at 50°C to obtain a black powder. S3. The black powder was subjected to high-temperature reduction in an Ar / H2 mixed gas environment at 850℃ for 2 hours to obtain the reduced Ru / graphene aerogel Ru / GA-H. S4. Oxidize Ru / GA-H in air at 250–450℃ for 2 hours to obtain Ru-RuO. x / Graphene aerogel composite Ru-RuO x / GA.

[0022] Specifically, in S1, the ratio of gelatin to sodium chloride by mass is 1:1.8.

[0023] Specifically, the heating temperature in S1 is 50°C; The overnight freezing treatment conditions were 0°C for 24 hours. The high-temperature calcination conditions were 900℃ for 2 hours.

[0024] Specifically, in S2, the porous graphene aerogel is 150 mg, ruthenium trichloride is 50 mg, and the volume of the water and ethanol mixed solution is 20 mL, with a water to ethanol volume ratio of 1:1.

[0025] Specifically, the oxidation temperature in step S4 is 350°C.

[0026] Specifically, in the resulting composite material, Ru has a crystalline metal core and an amorphous RuO core. x The shell is formed into core-shell heterojunction nanoparticles, which are uniformly loaded into the channels of mesoporous graphene aerogel with a pore size of 2.1–4.1 nm.

[0027] The Ru-RuO x / Preparation method of graphene aerogel composite material to prepare Ru-RuO x / Graphene aerogel composite material.

[0028] The Ru-RuO x / The application of graphene aerogel composites as trifunctional electrocatalysts for HER, OER, and ORR in alkaline electrolytes.

[0029] The Ru-RuO x / Application of graphene aerogel composites as anode and / or cathode catalyst layers in alkaline water electrolysis hydrogen production devices.

[0030] The Ru-RuO x / Application of graphene aerogel composites as air cathode catalyst layers in rechargeable metal-air batteries.

[0031] Example 2: The difference from Example 1 is that; A Ru-RuO x The preparation of graphene aerogel composite materials includes the following steps: Step 1: Preparation of graphene aerogel composite material: 1g of gelatin and 1.8g of sodium chloride were thoroughly mixed and heated in a water bath at 50°C until fully melted. Then, the mixture was frozen overnight at 0°C. The resulting solid was freeze-dried and then calcined at 900°C under Ar conditions to completely graphitize it. After repeated washing, sodium chloride was completely removed, and finally, porous graphene aerogel (GA) was obtained. Step 2, Ru-RuO x Preparation of graphene aerogel composite material: 50 mg of ruthenium trichloride and 20 mL of a mixed solution of water and ethanol (volume ratio 1:1) were added to 150 mg of porous graphene aerogel and stirred until homogeneous; the solution was transferred and heated in a water bath at 50 °C until it was completely evaporated, yielding a black solid powder; the solid powder obtained in the previous step was calcined at 850 °C under Ar / H2 conditions for 2 h to obtain the reduced Ru / graphene aerogel (Ru / GA-H). Step 3: The reduced Ru / graphene aerogel is then oxidized in air at 250°C to obtain the final Ru-RuO. x / Graphene aerogel composite material (Ru-RuO x / GA-1).

[0032] Example 3: The difference from Example 1 is that; A Ru-RuO x The preparation of graphene aerogel composite materials includes the following steps: Step 1: Preparation of graphene aerogel composite material: 1g of gelatin and 1.8g of sodium chloride were thoroughly mixed and heated in a water bath at 50°C until fully melted. Then, the mixture was frozen overnight at 0°C. The resulting solid was freeze-dried and then calcined at 900°C under Ar conditions to completely graphitize it. After repeated washing, sodium chloride was completely removed, and finally, porous graphene aerogel (GA) was obtained. Step 2, Ru-RuO x Preparation of graphene aerogel composite material: 50 mg of ruthenium trichloride and 20 mL of a mixed solution of water and ethanol (volume ratio 1:1) were added to 150 mg of porous graphene aerogel and stirred until homogeneous; the solution was transferred and heated in a water bath at 50 °C until it was completely evaporated, yielding a black solid powder; the solid powder obtained in the previous step was calcined at 850 °C under Ar / H2 conditions for 2 h to obtain the reduced Ru / graphene aerogel (Ru / GA-H). Step 3: The reduced Ru / graphene aerogel is then oxidized in air at 350°C to obtain the final Ru-RuO. x / Graphene aerogel composite material (Ru-RuO x / GA-2).

[0033] Example 4: The difference from Example 1 is that; A Ru-RuO x The preparation of graphene aerogel composite materials includes the following steps: Step 1: Preparation of graphene aerogel composite material: 1g of gelatin and 1.8g of sodium chloride were thoroughly mixed and heated in a water bath at 50°C until fully melted. Then, the mixture was frozen overnight at 0°C. The resulting solid was freeze-dried and then calcined at 900°C under Ar conditions to completely graphitize it. After repeated washing, sodium chloride was completely removed, and finally, porous graphene aerogel (GA) was obtained. Step 2, Ru-RuO xPreparation of graphene aerogel composite material: 50 mg of ruthenium trichloride and 20 mL of a mixed solution of water and ethanol (volume ratio 1:1) were added to 150 mg of porous graphene aerogel and stirred until homogeneous; the solution was transferred and heated in a water bath at 50 °C until it was completely evaporated, yielding a black solid powder; the solid powder obtained in the previous step was calcined at 850 °C under Ar / H2 conditions for 2 h to obtain the reduced Ru / graphene aerogel (Ru / GA-H). Step 3: The reduced Ru / graphene aerogel is then oxidized in air at 450°C to obtain the final Ru-RuO. x / Graphene aerogel composite material (Ru-RuO x / GA-3).

[0034] In this invention, Figure 2 An optical photograph of the product obtained in Example 1. GA has an extremely low mass density; a dandelion can easily support the weight of a piece of carbon aerogel (~6 cm³) without deformation. Figure 2 a). Furthermore, GA possesses excellent compressive properties, capable of withstanding pressure 1200 times its own weight without deformation. Figure 2 (b, c). This indicates that the GA prepared by this method has a rich porous structure, which can serve as a substrate material and help reduce catalyst agglomeration.

[0035] In this invention, Figure 3-6 SEM images of the products obtained in Examples 1-4, such as Figure 3 As shown in a and b, the NaCl template-guided sample produced a GA substrate with an ordered and mutually supporting three-dimensional porous structure. Through solution loading and Ar / H2 calcination, Ru metal particles (…) were clearly observed. Figure 3 b); After oxidation treatment, Ru species remained uniformly dispersed, and the GA skeletal structure did not change significantly. Figure 3-6 ).

[0036] like Figure 4-5 As shown, the morphology of GA remained largely unchanged within the oxidation temperature range of 250 to 350°C; however, after oxidation treatment at 450°C, the structure of GA showed significant cracking, as detailed in the appendix. Figure 6 As shown.

[0037] In this invention, Figure 7-8 The BET test results for the products obtained in Examples 1-4 show that the specific surface area of ​​Ru / GA-H is 68.26 m². 2 g -1 Please refer to the appendix for details. Figure 7When the temperature rises to 250 and 350°C, the specific surface area shows a gradual increasing trend, with the corresponding pore size range of 2.1~4.1nm. When the oxidation temperature reaches 450°C, the specific surface area decreases significantly and the pore size also increases. This is due to the destruction of the GA structure at high temperature, which leads to the oxidation of the graphene substrate. See Appendix 8 for details.

[0038] In this invention, Figure 9 The XRD test results of the products obtained in Examples 1-4 confirm the presence of crystalline Ru and amorphous RuO on GA. x .like Figure 9 As shown, the broad diffraction peak (~24°) is a characteristic peak of graphene. The diffraction peaks at 38.4°, 42.1°, 44.0°, 58.3°, 69.4° and 78.4° correspond to the characteristic peaks of Ru (JCPDSno.06-0663).

[0039] As the oxidation temperature increases, the intensity of the diffraction peak of metallic Ru decreases, but no diffraction peak of Ru oxide is observed, indicating that the obtained Ru oxide is amorphous.

[0040] In this invention, Figure 10-11 The TEM and EDS-mapping test results of the product obtained in Example 3 are shown. The TEM results further confirmed the structural changes of the Ru species before and after oxidation. Figure 10-11 As shown, ruthenium species were successfully loaded onto a graphene substrate. After oxidation, a distinct heterogeneous interface appeared, exhibiting a Ru-RuO₂ structure. x The core-shell structure, with inner lattice fringes consistent with crystalline Ru metal and no obvious lattice fringes observed in the outer layer, indicates the formation of amorphous RuOx ( Figure 10 ).

[0041] By comparing the Ru(002) lattice spacing (0.214 nm) with the standard card, it can be seen that the Ru(002) crystal planes are significantly widened after oxidation treatment, which is consistent with the XRD results. Figure 11 Selected area electron diffraction in a further confirmed the above analysis, with only diffraction rings of metallic Ru observed, and no diffraction rings of Ru oxide seen.

[0042] Elemental mapping analysis based on energy-dispersive X-ray spectroscopy (EDS) measurements and EDS-mapped line scans further indicated that O species are mainly present on the ruthenium surface, which further confirms that an amorphous RuOx (RuOx) is formed on the outer layer of the Ru metallic core. Figure 11 b, c).

[0043] In this invention, Figure 12 Raman and XPS tests were performed on the products obtained in Examples 1-4. The Raman spectra showed that Ru / GA-H had a strong Raman spectroscopy. ID and I G peak / ( I D / I G =1.147). After oxidation treatment, the ID and IG peaks gradually weakened or even disappeared, and the ratio of ID to IG also decreased accordingly. Figure 12 a).

[0044] Besides changes in spectral peak intensity, temperature variations also cause shifts in the peak positions of the Raman spectrum. The blue shift of the D and G peaks further indicates an increased degree of graphitization of graphene, which helps improve the conductivity of the catalyst. Figure 12 a).

[0045] Ru / GA-H, Ru-RuO x / GA-1、Ru-RuO x / GA-2 and Ru-RuO x The composition and surface chemical environment of / GA-3 can be reflected by X-ray photoelectron spectroscopy (XPS).

[0046] like Figure 12 As shown in b, Ru / GA-H exhibits a single peak at 461.51 eV, which is attributed to Ru 0 The signal indicates that Ru exists in the metallic state and is unoxidized; after oxidation treatment, two main peaks appear, located at 461.60 eV and 463.98 eV, corresponding to Ru 0 and Ru4 + The signal.

[0047] As the oxidation temperature gradually increases, Ru4 + The content of Ru4 increases from low to high. + With Ru 0 The ratio increased from 0.62 to 0.80; the binding energy peak of Ru3p shifted to a higher binding energy position, indicating that Ru lost electrons during oxidation. Figure 12 c shows Ru / GA-H, Ru-RuO x / GA-1、Ru-RuO x / GA-2 and Ru-RuO x O1sXPS results for / GA-3.

[0048] Three fitting peaks were observed in Ru / GA-H, located at 530.72, 532.34, and 533.57 eV, corresponding to the signals of H2O, C=O, and CO, respectively; after oxidation, the Ru-O chemical bond was in the Ru-RuO phase. x This can be clearly observed in the fitting results of / GA-2.

[0049] By comparing samples at different oxidation temperatures, it was found that the content of Ru-O metallic bonds increased, indicating that the content of oxidized Ru also increased. In addition, the binding energy of the O1s spectral peak showed a significant negative shift with increasing oxidation temperature, indicating that O gradually gained electrons.

[0050] Figure 13 The HER, OER, stability tests, and total water splitting performance test curves for the products obtained in Examples 1-4, commercial Pt / C, and commercial RuO2 in 1 M KOH solution are shown. Figure 13 The linear sweep voltammetry (LSV) curve shown in figure a indicates that Ru-RuO x / GA-2 requires only a 17mV overpotential to reach 10mAcm -2 The current density is much lower than that of Ru / GA-H (39mV) and Ru-RuO. x / GA-1 (24mV), Ru-RuO x Overpotentials of / GA-3 (37mV) and commercial Pt / C (39mV).

[0051] Stability tests also demonstrated excellent commercial potential at 100 mA cm⁻¹. -2 Under high current density, the potential decay rate is only 0.3mV / h over 200 hours, highlighting its excellent durability. Figure 13 b). Furthermore, Ru-RuO was further investigated. x OER performance of / GA samples, such as Figure 13 As shown in c, Ru-RuO x / GA-2 exhibits a low OER overpotential, and its catalytic performance changes from excellent to poor with changes in oxidation temperature.

[0052] Specifically, Ru-RuO x The overpotential of / GA-2 is 268mV, which is superior to Ru / GA-H (518mV) and Ru-RuO. x / GA-1(399mV)Ru-RuO x / GA-3 (300mV) and commercial RuO2 (345mV). Furthermore, measurements were taken at 10mAcm. -2 The constant potential method under the following conditions ( Figure 13 d) Stability was evaluated, with an overpotential decay rate of 0.1 mV / h. To further verify the potential of this catalyst in practical hydrogen energy applications, Ru-RuO was prepared. x / GA-2 is a laboratory-assembled membrane electrode assembly (MEA) using electrode material ( Figure 13 e).

[0053] Using Ru-RuOx An electrolyzer using GA-2 as a catalyst achieved 500 mA / cm² at 1.9 V. -2 The current density is much lower than that of electrolytic cells using Pt / C-RuO2. In durability testing, the MEA device operated at 500 mA / cm² at room temperature. -2 The current density was continuously operated for 200 hours.

[0054] Figure 14 To assess the ORR catalytic performance of the products obtained in Examples 1-4 and commercial Pt / C, linear sweep voltammetry (LSV) curves were used to show ( Figure 14 a), Ru-RuO x / GA-2 exhibits excellent ORR performance, with an onset potential of 0.95V and a half-wave potential (E1 / 2) of 0.84V, both higher than Ru / GA-H (0.73V) and Ru-RuO. x / GA-1 (0.72V), Ru-RuO x Performance of / GA-3 (0.71V) and Pt / C (0.83V).

[0055] In addition, Ru-RuO is adopted. x A homemade rechargeable ZAB was assembled using GA-2 catalyst as the cathode and a 6.0 M KOH solution containing 0.2 M zinc acetate as the electrolyte. For comparison, the performance of the Pt / C||RuO2 catalyst was also tested under the same conditions. Figure 14 As shown in b, based on Ru-RuO x The open-circuit voltage (OCV) of ZAB in / GA-2 reached 1.56V, higher than that of the Pt / C||RuO2 catalyst (1.50V). This was achieved at a current density of 10 mA / cm². -2 After standardizing the mass of the consumed Zn plates, the assembled ZAB has a mass of 946.4 mAh g. -1 The discharge capacity is higher than that of ZAB assembled with Pt / C||RuO2 (886.7 mAh g). -1 () Figure 14 c). Furthermore, the operational stability of ZAB was evaluated. Ru-RuO x The initial discharge and charge voltages of / GA-2 base ZAB are 1.985V and 1.130V, respectively. Figure 14 e), its charge-discharge voltage difference (0.82V) is narrower than that of Pt / C||RuO2 (1.01V). Even after 150 hours and 300 hours of continuous operation, the Ru-RuO2-based... x The / GA-2's ZAB still exhibits an ultra-stable operating window and smaller voltage gap variations (0.88V and 0.97V, respectively).

[0056] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A Ru-RuO x The preparation method of graphene aerogel composite material is characterized by, Includes the following steps: S1. Mix gelatin and sodium chloride in a certain mass ratio thoroughly, then heat to melt completely, and then freeze overnight; freeze-dry the obtained solid, then calcine at high temperature to completely graphitize it, then wash it multiple times to completely remove sodium chloride, and finally obtain porous graphene aerogel GA. S2. A certain mass of porous graphene aerogel GA, ruthenium trichloride, water and ethanol mixed solution are thoroughly mixed, and the solvent is evaporated in a water bath at 50°C to obtain a black powder. S3. The black powder was subjected to high-temperature reduction in an Ar / H2 mixed gas environment at 850℃ for 2 hours to obtain the reduced Ru / graphene aerogel Ru / GA-H. S4. Oxidize Ru / GA-H in air at 250-450℃ for 2 hours to obtain Ru-RuO. x / Graphene aerogel composite Ru-RuO x / GA.

2. A Ru-RuO according to claim 1 x The method for preparing graphene aerogel composite materials is characterized by: The ratio of gelatin to sodium chloride in S1 is 1:1.8 by mass.

3. A Ru-RuO according to claim 1 x The method for preparing graphene aerogel composite materials is characterized by: The heating temperature in S1 is 50°C; The overnight freezing treatment conditions were 0°C for 24 hours. The high-temperature calcination conditions were 900℃ for 2 hours.

4. A Ru-RuO according to claim 1 x The method for preparing graphene aerogel composite materials is characterized by: The S2 contains 150 mg of porous graphene aerogel, 50 mg of ruthenium trichloride, and 20 mL of a mixed solution of water and ethanol, with a water to ethanol volume ratio of 1:

1.

5. A Ru-RuO according to claim 1 x The method for preparing graphene aerogel composite materials is characterized by: The oxidation temperature in step S4 is 350°C.

6. A Ru-RuO according to claim 1 x The method for preparing graphene aerogel composite materials is characterized by: In the resulting composite material, Ru has a crystalline metal core and an amorphous RuO x The shell is formed into core-shell heterojunction nanoparticles, which are uniformly loaded into the channels of mesoporous graphene aerogel with a pore size of 2.1-4.1 nm.

7. The Ru-RuO prepared by the method according to any one of claims 1-6 x / Graphene aerogel composite material.

8. The Ru-RuO according to claim 7 x / The application of graphene aerogel composites as trifunctional electrocatalysts for HER, OER, and ORR in alkaline electrolytes.

9. The Ru-RuO according to claim 7 x / Application of graphene aerogel composites as anode and / or cathode catalyst layers in alkaline water electrolysis hydrogen production devices.

10. The Ru-RuO according to claim 7 x / Application of graphene aerogel composites as air cathode catalyst layers in rechargeable metal-air batteries.

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