Method for depositing nanoparticles on modified electrochemical graphene oxide and products and applications thereof

Abstract

The application discloses a method for depositing and modifying electrochemical graphene oxide with nanoparticles and a product and application thereof, and belongs to the technical field of electrocatalysts, and comprises the following steps: adding a noble metal salt solution and a sacrificial agent into an electrochemical graphene oxide dispersion solution to obtain a mixed solution, then performing ultraviolet irradiation reduction, performing suction filtration after reaction, and drying to obtain reduced electrochemical graphene oxide powder loaded with nanoparticles. The application also discloses the reduced electrochemical graphene oxide powder loaded with nanoparticles prepared by the method, and the application of the product in catalyst ink. The prepared reduced electrochemical graphene oxide powder has good reduction degree, and the nanoparticles loaded on the reduced electrochemical graphene oxide powder are uniformly distributed. The ultraviolet light induced reduction method has the advantages of simple operation, green environmental protection, simple process and the like.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalyst technology, and particularly relates to a method for nanoparticle deposition modification of electrochemically oxidized graphene, its products, and applications. Background Technology

[0002] The urgent need for sustainable and clean energy in today's era has spurred tremendous development in the field of energy storage and conversion. As an intermediate in energy storage and power generation, hydrogen has long been considered one of the most promising alternatives to non-renewable fossil fuels. In hydrogen-based energy systems, hydrogen can be converted into and out of electricity via zero-emission electrochemical pathways, thus integrating into other energy sectors. Simply put, water electrolysis technology converts water into hydrogen and oxygen through the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The resulting hydrogen can be stored and transported using hydrogen storage technology, and when needed, it can be converted into electricity using fuel cell systems. Fuel cell systems involve the electrochemical oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR). Currently, the slow reaction kinetics of these electrochemical reactions severely limit the widespread application of hydrogen energy. Developing high-performance electrocatalysts to achieve specified current densities with minimal overpotential, thereby maximizing the energy conversion efficiency of water electrolysis for hydrogen production and hydrogen fuel cells, is key to realizing the widespread application of hydrogen energy.

[0003] Graphene possesses excellent electrical conductivity and a large specific surface area, making it a potential support material for developing high-performance electrocatalysts. Among various types of graphene materials, graphene oxide (GO), with oxygen functional groups, exhibits excellent solution dispersibility, solution processability, and conductivity after reduction, making it suitable for supporting various types of functional nanoparticles, including noble metal electrocatalyst nanoparticles. Graphene oxide typically refers to traditional chemically prepared graphene oxide, primarily prepared using the Hummers method (Hummers, W. Setal., Preparation of graphitic oxide. J. Am. Chem. Soc., 1958, 80, 1339-1339.). This preparation process is highly environmentally polluting, and the mixture of potassium permanganate and concentrated sulfuric acid used poses an explosion risk. Furthermore, traditional graphene oxide contains numerous carbonyl and carboxyl functional groups, resulting in reduced graphene oxide with many in-plane defects and poor conductivity, which is detrimental to achieving excellent electrocatalytic performance when used as a support for noble metal electrocatalysts.

[0004] Electrochemical graphene oxide was prepared using an electrochemical intercalation-oxidation technique. This process does not use strong oxidants, and the subsequent cleaning and purification are simpler than traditional methods. Furthermore, by controlling the preparation process, weakly produced graphene oxide with an oxygen content not exceeding 30 at.% and carbon-based and carboxyl-based functional groups not exceeding 5 at.% can be obtained (Cao, J., et al., Two-step electrochemical intercalation and oxidation of graphite for the mass production of graphene oxide. J. Am. Chem. Soc., 2017, 139, 17446-17456.). After low-temperature chemical reduction (<100℃), the electrochemical graphene oxide exhibits a conductivity as high as 54600 S m. -1 It is an order of magnitude higher than that of traditional graphene oxide reduced under the same conditions.

[0005] Based on the ease of reduction and excellent conductivity of electrochemical graphene oxide, the academic journal *Advanced Functional Materials* (Peng, Y., et al., Laser assisted solution synthesis of high performance graphene supported electrocatalysts. Adv. Funct. Mater., 2020, 30, 2001756.) disclosed a method for preparing noble metal nanoparticle-modified reduced electrochemical graphene oxide using an excimer laser (wavelength 248 nm). The prepared platinum and ruthenium oxide nanoparticle-modified reduced electrochemical graphene oxide exhibits excellent electrocatalytic performance. However, the excimer laser equipment used in the above-mentioned laser-assisted method is expensive, and its operation and maintenance costs are high, making it difficult to widely apply. Furthermore, existing methods for depositing nanoparticles on the surface of graphene, graphene oxide, or reduced graphene oxide (rGO), including wet chemical deposition, electrochemical deposition, thermal decomposition, and plasma-assisted synthesis, are often cumbersome, lack universality, or require harsh conditions such as high temperature, high vacuum, and protective atmospheres.

[0006] Therefore, developing a simple, universally applicable synthesis and preparation technique that can simultaneously reduce electrochemically oxidized graphene and deposit and modify it with various noble metal nanoparticles is of great significance for developing high-performance graphene-supported noble metal electrocatalyst materials. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention proposes a method for nanoparticle deposition modification of electrochemically oxidized graphene, along with its products and applications.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A method for modifying electrochemically oxidized graphene by nanoparticle deposition includes the following steps:

[0010] A noble metal salt solution and a sacrificial agent were added to an electrochemical graphene oxide dispersion to obtain a mixture. The mixture was then subjected to ultraviolet light irradiation for reduction. After the reaction was completed, the mixture was filtered and dried to obtain reduced electrochemical graphene oxide powder loaded with nanoparticles.

[0011] Beneficial effects: This invention employs ultraviolet light-induced deposition of noble metal nanoparticles to modify electrochemical graphene oxide. Compared to traditional reduction methods, ultraviolet light reduction is based on photoelectrochemical / photochemical reactions, utilizing photons to excite photogenerated electrons generated by the semiconductor electrochemical graphene oxide, achieving rapid and efficient reduction of noble metal ions and electrochemical graphene oxide. Furthermore, ultraviolet light reduction of noble metal salts and electrochemical graphene oxide does not use expensive and toxic strong reducing agents, exhibiting better environmental friendliness and low toxicity. Compared to other reduction methods, the preferred ultraviolet light reduction method employed in this invention has advantages such as high efficiency, easy control, and environmental friendliness.

[0012] Preferably, the electrochemical graphene oxide is prepared by a two-step electrochemical intercalation-oxidation method and belongs to a weak graphene oxide with an oxygen content of no more than 30 at.% and carbon-based and carboxyl-based functional groups of no more than 5 at.%.

[0013] Beneficial effects: The internal defect concentration of the optimized electrochemical graphene oxide is significantly lower than that of traditional graphene oxide after reduction by the same method, exhibiting excellent conductivity (10). 4 S m -1 When used as an electrocatalyst support, it is beneficial to improve catalytic performance.

[0014] Preferably, the noble metal salt solution includes potassium chloroplatinate solution, chloroiridic acid solution, ammonium chloropalladate solution, and one or more of other salt solutions containing platinum, palladium, ruthenium, iridium, and rhodium noble metal ions.

[0015] Beneficial effects: PtCl4 in this invention 2- IrCl4 2- PdCl4 2- The standard reduction potentials for noble metal ions to be reduced to elemental metals are all greater than the potential of the standard hydrogen electrode. In other words, these noble metal ions can be effectively reduced to metal nanoparticles by photoexcited electrons.

[0016] Preferably, the sacrificial agent includes acetone and / or isopropanol.

[0017] Beneficial effects: Under ultraviolet light irradiation, acetone and isopropanol in this invention can generate (CH3)2C. · (OH) radicals, which have strong reducing properties and a redox potential of -1.8V vs NHE, can rapidly reduce electrochemically oxidized graphene and noble metal ions in a short time. Furthermore, acetone and isopropanol have good water solubility and chemical stability, are not prone to side reactions, and can better protect the surface of nanoparticles and prolong their stability.

[0018] Preferably, the concentration of the noble metal salt solution is 0.1-1 mg / mL.

[0019] Beneficial effects: Excessively high concentrations of precious metal salts can easily lead to the aggregation of nanoparticles, forming large particles and reducing the stability of nanoparticles. The nanoparticles obtained by the concentration of precious metal salts in this invention are smaller in size, which can achieve the purpose of controlling the size of nanoparticles and improving the stability of the catalyst; and avoids the situation where the sacrificial agent (acetone, isopropanol) is excessively consumed, resulting in the remaining sacrificial agent undergoing side reactions and reducing the yield of nanoparticles.

[0020] Preferably, the concentration of the electrochemical graphene oxide dispersion is 0.001-10 mg / mL.

[0021] Beneficial effects: The electrochemical graphene oxide dispersion at the above concentration can maintain good light transmittance, allowing ultraviolet light to penetrate the electrochemical graphene solution and reach its interior, thereby improving the reduction efficiency; and the electrochemical graphene oxide solution at the selected concentration can ensure the uniformity of light irradiation, thereby ensuring the consistency of reduction of electrochemical graphene oxide and noble metal ions in different regions.

[0022] Preferably, the mass ratio of the noble metal salt to the electrochemical graphene oxide is (0.01-0.1):1; and the volume fraction of the sacrificial agent in the mixture is 0.1-10%.

[0023] Beneficial effects: The mass ratio of the aforementioned noble metal salt to electrochemical graphene oxide can improve the utilization rate of the noble metal salt, ensuring the relative purity and uniformity of the catalyst; simultaneously, the prepared nanoparticles have uniform size, which can improve the catalytic efficiency of the catalyst. Furthermore, the aforementioned volume fraction of sacrificial agent can effectively improve the reduction degree of electrochemical graphene oxide and the loading of noble metals, while also ensuring the dispersion of electrochemical graphene oxide and the dissolution of noble metal salts.

[0024] Preferably, the ultraviolet light irradiation wavelength is 180-350 nm and the intensity is 0.5-1.5 mW / cm². -2 The temperature is 0-20℃, and the time is 0.1-5h;

[0025] More preferably, the ultraviolet light irradiation wavelength is 254 nm;

[0026] The freeze-drying temperature is -80℃, the vacuum degree is 30-50Pa, and the time is 24h.

[0027] Beneficial effects: The photoreduction rate induced at the above wavelength is significantly higher than at other wavelengths. This is because the absorbance of acetone at the preferred wavelength is much higher than at other wavelengths, at which wavelength the sacrificial agents acetone and isopropanol react more readily to form (CH3)2C. · (OH) radicals, thereby increasing the photoreduction rate; the optimal intensity can avoid photodegradation of electrochemically oxidized graphene; at the optimal temperature, the radicals can be preserved for a longer period of time, which is conducive to the full progress of the reduction reaction.

[0028] A method for preparing reduced electrochemical graphene oxide powder loaded with nanoparticles by nanoparticle deposition modification of electrochemical graphene oxide.

[0029] Beneficial effects: Compared with chemical or laser-assisted reduction of graphene oxide, the preparation method provided by this invention has the advantages of environmental friendliness, low cost, and high safety. Furthermore, the catalyst prepared has catalytic properties such as low overpotential, small Tafel slope, extremely high mass activity, and excellent durability, indicating its great potential as an electrocatalyst.

[0030] Application of a reduced electrochemical graphene oxide powder loaded with nanoparticles in catalyst ink.

[0031] Preferably, it includes the following steps:

[0032] The reduced electrochemical graphene oxide powder loaded with nanoparticles, water, isopropanol, and Nafion solution were mixed evenly and then ultrasonicated in an ice-water bath to obtain the catalyst ink.

[0033] The ratio of the amount of the reduced electrochemical graphene oxide powder loaded with nanoparticles, water, isopropanol and Nafion solution added is 5 mg: 450 μL: 500 μL: 50 μL.

[0034] The ultrasonic power is 10-15 W / L, and the ultrasonic time is 1 hour.

[0035] Beneficial effects: Under the above-mentioned dispersant ratio and ultrasonic power, ultrasonication can effectively suppress the aggregation of catalyst, thereby achieving the best dispersibility and fully exerting the catalytic performance of the catalyst.

[0036] This invention discloses a method for nanoparticle deposition modification of electrochemical graphene oxide, its products, and applications. The reduced electrochemical graphene oxide powder prepared by this invention exhibits good reduction degree and uniform distribution of the supported nanoparticles. Its OER and HER performance show higher quality activities than commercial catalysts. Compared with other methods, the UV-induced reduction method in this invention has advantages such as low equipment requirements, environmental friendliness, and simple process flow. Attached Figure Description

[0037] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0038] Figure 1 This is a schematic diagram of the process flow in Example 1;

[0039] Figure 2 This is a field emission scanning electron microscope (SEM) comparison image of electrochemical graphene oxide and Ir-rEGO in Example 1;

[0040] In the image, a is a field emission scanning electron microscope image of electrochemical graphene oxide, and b is a field emission scanning electron microscope image of Ir-rEGO.

[0041] Figure 3 This is a transmission electron microscope (TEM) image of Ir-rEGO in Example 1;

[0042] Figure 4 This is a high-angle annular dark-field transmission electron microscopy (HAADF-STEM) image of Ir-rEGO in Example 1;

[0043] Figure 5 EDS surface scanning imaging of Ir-rEGO in Example 1;

[0044] Figure 6 This is a comparison of the Raman spectra of electrochemical graphene oxide and Ir-rEGO in Example 1;

[0045] Figure 7 This is a comparison of the X-ray photoelectron spectroscopy (XPS) spectra of electrochemical graphene oxide and Ir-rEGO in Example 1.

[0046] Figure 8 The graph shows the HER catalytic performance and mass activity of Ir-rEGO in Example 1;

[0047] Where a is the catalytic performance diagram and b is the mass activity diagram;

[0048] Figure 9The graph shows the OER catalytic performance and mass activity of Ir-rEGO in Example 1;

[0049] Where a is the catalytic performance diagram and b is the mass activity diagram;

[0050] Figure 10 The image shows a field emission scanning electron microscope (SEM) image of Pt-rEGO in Example 2.

[0051] Figure 11 The EDS energy distribution mapping diagram of Pt-rEGO in Example 2;

[0052] Figure 12 The graph shows the HER catalytic performance of Pt-rEGO in Example 2;

[0053] Figure 13 The image shows a field emission scanning electron microscope (SEM) image of Pt / Pd-rEGO in Example 3.

[0054] Figure 14 The EDS energy distribution mapping diagram of Pt / Pd-rEGO in Example 3;

[0055] Figure 15 The graph shows the HER catalytic performance of Pt / Pd-rEGO in Example 3. Detailed Implementation

[0056] 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.

[0057] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0058] The electrochemical graphene oxide in this invention is prepared using the electrochemical two-step intercalation-oxidation method described in reference (J.Am.Chem.Soc.2017,139,17446).

[0059] Example 1

[0060] A method for depositing and modifying electrochemically oxidized graphene with Ir nanoparticles, such as Figure 1 As shown, it includes the following steps:

[0061] (1) Prepare an electrochemical graphene oxide dispersion with a concentration of 1 mg / mL and a suspension color of brownish-yellow; prepare an Ir noble metal solution with a concentration of 1 mg / mL using chloroiridium acid;

[0062] (2) Using acetone and isopropanol as sacrificial agents, 1 mL of acetone, 2 mL of isopropanol, 2 mL of Ir noble metal solution, and 87 mL of deionized water were added to 10 mL of electrochemical graphene oxide dispersion to prepare a mixed solution. The mixed solution was then irradiated with ultraviolet light at a low temperature (0-5℃), where the ultraviolet light wavelength was 254 nm and the intensity was 0.9 mW / cm². -2 The time was 1 hour, and a reduced electrochemical graphene oxide suspension loaded with nanoparticles was obtained, the color of which changed from brownish-yellow to black.

[0063] (3) The reduced electrochemical graphene oxide suspension loaded with nanoparticles was filtered and washed, and then freeze-dried to obtain reduced electrochemical graphene oxide loaded with nanoparticles (denoted as Ir-rEGO powder); wherein the freeze-drying temperature was -80℃, the vacuum degree was 30-50Pa, and the time was 24h.

[0064] Technical effects:

[0065] Field emission scanning electron microscopy was performed on the electrochemically oxidized graphene and the Ir-rEGO powder obtained in step (3), such as... Figure 2 As shown, the reduced electrochemical graphene oxide exhibits a wrinkled sheet-like structure, with nanoparticles uniformly loaded onto the reduced electrochemical graphene oxide.

[0066] The Ir-rEGO powder obtained in step (3) was scanned by transmission electron microscopy, such as... Figure 3 , Figure 4 As shown, nanoparticles and single atoms are uniformly loaded on the surface of reduced electrochemical graphene oxide, and the average particle size of the nanoparticles is 1.7 nm.

[0067] The Ir-rEGO powder obtained in step (3) was subjected to EDS energy dispersive spectroscopy analysis, such as... Figure 5 As shown, it can be seen that Ir nanoparticles are uniformly loaded on reduced electrochemical graphene oxide.

[0068] Raman spectroscopy was performed on the electrochemically oxidized graphene and the Ir-rEGO powder obtained in step (3) to evaluate the degree of reduction of the electrochemically oxidized graphene, such as... Figure 6 As shown, Ir-rEGO has a low defect concentration and a high degree of reduction.

[0069] X-ray photoelectron spectroscopy was performed on the electrochemically oxidized graphene and the Ir-rEGO powder obtained in step (3) to evaluate the degree of reduction of the electrochemically oxidized graphene, such as... Figure 7 As shown, the content of O in the reduced Ir-rEGO is significantly reduced, indicating a good reduction effect.

[0070] Example 2

[0071] A method for depositing and modifying electrochemically oxidized graphene with Pt nanoparticles includes the following steps:

[0072] (1) Prepare an electrochemical graphene oxide solution with a concentration of 1 mg / mL and a suspension color of brownish-yellow; prepare a Pt noble metal solution with a concentration of 1 mg / mL using potassium chloroplatinate.

[0073] (2) Using acetone and isopropanol as sacrificial agents, 1 mL of acetone, 2 mL of isopropanol, 2 mL of Pt noble metal solution, and 87 mL of deionized water were added to 10 mL of electrochemical graphene oxide solution and mixed thoroughly to prepare a mixed solution. The mixed solution was then irradiated with ultraviolet light at a low temperature (0-5℃), where the ultraviolet light wavelength was 254 nm and the intensity was 0.9 mW / cm². -2 An electrochemically reduced graphene oxide suspension loaded with nanoparticles was prepared by irradiating the sample for 1 hour. The color of the suspension changed from brownish-yellow to black.

[0074] (3) The reduced electrochemical graphene oxide suspension loaded with nanoparticles was filtered and washed, and then freeze-dried to obtain reduced electrochemical graphene oxide powder loaded with nanoparticles (denoted as Pt-rEGO powder). The freeze-drying temperature was -80℃, the vacuum degree was 30-50Pa, and the time was 24h.

[0075] The obtained Pt-rEGO powder was scanned using a field emission scanning electron microscope, such as... Figure 10 As shown, the reduced electrochemical graphene oxide exhibits a wrinkled sheet-like structure, with nanoparticles uniformly loaded onto the reduced electrochemical graphene oxide.

[0076] The obtained Pt-rEGO powder was subjected to EDS energy dispersive spectroscopy analysis, such as... Figure 11 As shown, Pt nanoparticles are uniformly loaded onto reduced electrochemical graphene oxide.

[0077] Example 3

[0078] A method for depositing and modifying electrochemically oxidized graphene with Pt / Pd nanoparticles includes the following steps:

[0079] (1) Prepare an electrochemical graphene oxide solution with a concentration of 1 mg / mL and a suspension color of brownish-yellow; prepare a Pt noble metal solution with a concentration of 1 mg / mL using potassium chloroplatinate and a Pd noble metal solution with a concentration of 1 mg / mL using ammonium chloropalladate.

[0080] (2) Using acetone and isopropanol as sacrificial agents, 1 mL of acetone, 2 mL of isopropanol, 0.7 mL of Pt noble metal solution, 1.3 mL of Pd noble metal solution, and 87 mL of deionized water were added to 10 mL of electrochemical graphene oxide solution and mixed thoroughly to prepare a mixed solution. The mixed solution was then irradiated with ultraviolet light at a low temperature (0-5℃), where the ultraviolet light wavelength was 254 nm and the intensity was 0.9 mW / cm². -2 An electrochemically reduced graphene oxide suspension loaded with nanoparticles was prepared by irradiating the sample for 1 hour. The color of the suspension changed from brownish-yellow to black.

[0081] (3) The reduced electrochemical graphene oxide suspension loaded with nanoparticles was filtered and washed, and then freeze-dried to obtain reduced electrochemical graphene oxide powder loaded with nanoparticles (denoted as Pt / Pd-rEGO). The freeze-drying temperature was -80℃, the vacuum degree was 30-50Pa, and the time was 24h.

[0082] Field emission scanning electron microscopy was performed on Pt / Pd-rEGO powder, such as... Figure 13 As shown, the reduced electrochemical graphene oxide exhibits a wrinkled sheet-like structure with nanoparticles uniformly loaded onto it.

[0083] The obtained Pt / Pd-rEGO powder was subjected to EDS energy dispersive spectroscopy analysis, such as... Figure 14 As shown, the composition of the nanoparticles is Pt / Pd, and Pt / Pd alloy nanoparticles have been successfully prepared.

[0084] Application Example 1

[0085] The application of a reduced electrochemical graphene oxide powder loaded with nanoparticles in a catalyst ink includes the following steps:

[0086] Take 5 mg of Ir-rEGO powder obtained in Example 1, 450 μL of deionized water, 500 μL of isopropanol, and 50 μL of Nafion solution to prepare a coating ink; sonicate in an ice-water bath for 1 h to obtain a uniformly dispersed catalyst ink.

[0087] The electrochemical catalytic performance of reduced electrochemical graphene oxide powder loaded with nanoparticles was evaluated using a Shanghai Chenhua electrochemical workstation and a rotating disk electrode. 10 μL each of the electrochemical graphene oxide dispersion from step (1) of Example 1 and the catalyst ink from Application Example 1 were dropped onto a glassy carbon electrode. Pt was used as the counter electrode, AgCl as the reference electrode, and a 0.5 M N2-saturated H2SO4 solution as the electrolyte. The HER performance of the catalyst was then tested.

[0088] Take 10 μL each of the electrochemical graphene oxide dispersion from step (1) of Example 1 and the catalyst ink from Application Example 1, and drop them onto a glassy carbon electrode. Use Pt as the counter electrode, AgCl as the reference electrode, and 1M KOH solution saturated with O2 as the electrolyte to test the OER performance of the catalyst.

[0089] The HER and OER performance of the catalyst are as follows: Figure 8-9 As shown, in the HER performance test, Ir-rEGO requires only a very low overpotential (70.51mV) to drive a 50mA cm⁻¹. -2 It has a high current density and extremely high mass activity, far exceeding that of commercial Pt / C 20% catalysts;

[0090] In OER performance testing, Ir-rEGO performed at 10 mA cm⁻¹ -2 It exhibits excellent catalytic performance at a current density of only 294 mV and has a mass activity that is 20% higher than that of commercial Pt / C catalysts, indicating that Ir-rEGO has excellent bifunctional performance in both HER and OER.

[0091] Application Example 2

[0092] The application of a reduced electrochemical graphene oxide powder loaded with nanoparticles in catalyst ink differs from Application Example 1 in that the Ir-rEGO powder obtained in Example 1 is replaced with the Pt-rEGO powder obtained in Example 2, while the remaining steps and parameters are the same as in Application Example 1.

[0093] Technical effects: The HER performance of the catalyst is as follows Figure 12 As shown, it can be seen that Pt-rEGO at 50mA cm -2 It exhibits excellent catalytic performance at a current density of only 83.5 mV.

[0094] Application Example 3

[0095] The application of a reduced electrochemical graphene oxide powder loaded with nanoparticles in catalyst ink differs from Application Example 1 in that the Ir-rEGO powder obtained in Example 1 is replaced with the Pt / Pd-rEGO obtained in Example 3, while the remaining steps and parameters are the same as in Application Example 1.

[0096] Technical effects: The HER performance of the catalyst is as follows Figure 15 As shown, it can be seen that Pt / Pd-rEGO at 50 mA cm -2 It exhibits excellent catalytic performance at a current density of only 134.4 mV.

[0097] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for modifying electrochemically oxidized graphene by nanoparticle deposition, characterized in that, Includes the following steps: A noble metal salt solution and a sacrificial agent were added to an electrochemical graphene oxide dispersion to obtain a mixture. Then, the mixture was reduced by ultraviolet light irradiation. After the reaction was completed, the mixture was filtered and freeze-dried to obtain reduced electrochemical graphene oxide powder loaded with nanoparticles. The ultraviolet light irradiation wavelength is 180-350 nm, and the intensity is 0.5-1.5 mW / cm². -2 The temperature is 0-20 ℃, and the time is 0.1-5 h.

2. The method for nanoparticle deposition modification of electrochemically oxidized graphene according to claim 1, characterized in that, The electrochemical graphene oxide raw material is prepared by electrochemical intercalation-oxidation method, and its oxygen content is not higher than 30 at.%, and the carbonyl and carboxyl content is not higher than 5 at.%.

3. The method for nanoparticle deposition modification of electrochemically oxidized graphene according to claim 1, characterized in that, The precious metal salt solution includes potassium chloroplatinate solution, chloroiridic acid solution, ammonium chloropalladate solution, and one or more other salt solutions containing platinum, palladium, ruthenium, iridium, and rhodium precious metal ions. The sacrificial agent includes acetone and / or isopropanol.

4. The method for nanoparticle deposition modification of electrochemically oxidized graphene according to claim 1, characterized in that, The concentration of the noble metal salt solution is 0.1-1 mg / mL.

5. The method for nanoparticle deposition modification of electrochemically oxidized graphene according to claim 1, characterized in that, The concentration of the electrochemical graphene oxide dispersion is 0.001-10 mg / mL.

6. The method for nanoparticle deposition modification of electrochemically oxidized graphene according to claim 1, characterized in that, The mass ratio of the noble metal salt to the electrochemically oxidized graphene is (0.01-0.1):1; The volume fraction of the sacrificial agent in the mixture is 0.1-10%.

7. The method for nanoparticle deposition modification of electrochemically oxidized graphene according to claim 1, characterized in that, The freeze-drying temperature is -80 ℃, the vacuum degree is 30-50 Pa, and the time is 24 h.

8. Reduced electrochemical graphene oxide powder loaded with nanoparticles prepared by the method of nanoparticle deposition modification of electrochemical graphene oxide as described in claims 1-7.

9. The application of the reduced electrochemical graphene oxide powder with supported nanoparticles as described in claim 8 in catalyst ink.

10. The application according to claim 9, characterized in that, Includes the following steps: The reduced electrochemical graphene oxide powder loaded with nanoparticles, water, isopropanol, and Nafion solution were mixed evenly and then ultrasonicated in an ice-water bath to obtain the catalyst ink. The ratio of the amount of the reduced electrochemical graphene oxide powder loaded with nanoparticles, water, isopropanol and Nafion solution added is 5 mg: 450 μL: 500 μL: 50 μL. The ultrasonic power is 10-15 W / L, and the ultrasonic time is 1 h.

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