Nano Ag-based alloy film catalyst with iodine functionalized surface as well as preparation method and application of nano Ag-based alloy film catalyst

Abstract

The invention discloses a surface iodine functionalized nano Ag-based alloy film catalyst as well as a preparation method and application thereof, and belongs to the technical field of carbon dioxide reduction electro-catalysis. The preparation method comprises the following steps: firstly, forming an Ag-Cu-Ce alloy film on a carbonaceous carrier, then carrying out surface electrochemical dealloying on the Ag-Cu-Ce alloy film to prepare a nano Ag-based alloy film catalyst, and then carrying out surface modification on the catalyst with a nano structure by using an electrolyte containing I <-> through a constant potential electrolysis method to obtain the nano Ag-based alloy film catalyst with the iodine functionalized surface. The iodine functionalization can further improve the carbon dioxide electrocatalytic reduction performance of the catalyst. The functionalization method provided by the invention is simple, controllable in process and high in reproducibility.

Description

Technical Field

[0001] This invention belongs to the field of carbon dioxide reduction electrocatalysis technology, specifically relating to a surface-functionalized iodine nano-Ag-based alloy film catalyst, its preparation method, and its application. Background Technology

[0002] With the development of global industry, carbon dioxide (CO2) emissions have triggered numerous problems such as the greenhouse effect and global climate change. Electrocatalytic reduction of CO2 (CO2RR) technology, as an efficient, environmentally friendly, and sustainable solution, can convert atmospheric CO2 into high-value-added chemicals, such as carbon monoxide (CO), methane (CH4), and ethylene (C2H4).

[0003] Ag is considered the most active and selective catalyst in the CO2RR to CO production process. It exhibits moderate adsorption energy for the ·COOH intermediate and weak adsorption energy for the ·CO intermediate. This is the decisive factor in the significantly higher selectivity of Ag in CO2RR compared to other products. Once CO is formed, it rapidly desorbs from the Ag surface and leaves as a gaseous product, thus avoiding further CO reduction. In addition, Ag can suppress competing reactions and can further enhance its electron transport performance and lower the activation energy by alloying with transition metals (such as Cu). In recent years, halogens have been proven in electrocatalysis research to be an effective strategy for finely controlling the electronic structure and surface microenvironment of silver nanoalloys. They can form strong bonds with Ag, exhibiting strong electronic effects and significant site isolation effects, and the resulting halogen-modified layers are highly stable within the electrochemical window.

[0004] In the preparation of catalyst films, Chinese patent CN116804279A prepared a single-metal thin-film catalyst using magnetron sputtering, achieving efficient product conversion. However, the catalyst surface morphology was dense with few active sites. Chinese patent CN116695172A prepared Ag-modified Cu2O foam catalyst using hydrazine hydrate as a reducing agent and copper foam as a substrate via a one-step hydrothermal method. Due to the synergistic effect of Ag and Cu, the prepared catalyst exhibited good electrocatalytic carbon dioxide reduction performance, but its preparation process was relatively cumbersome. Chinese patent CN116676631A synthesized AgX (X=Cl, Br, I) nanoparticle precursors using a precipitation method. By reducing AgX nanoparticles in situ under ECR conditions, X-modified Ag nanocatalysts were finally formed. The prepared catalyst showed significant improvement in electrochemical performance, but its preparation process was difficult to control and highly reproducible. Summary of the Invention

[0005] The purpose of this invention is to provide a surface-functionalized iodine-containing nano-Ag-based alloy film catalyst, its preparation method, and its application. The nano-Ag-based alloy film catalyst is prepared by first forming an Ag-Cu-Ce alloy film on a carbonaceous support, then performing surface electrochemical dealloying on the Ag-Cu-Ce alloy film, and finally using an iodine-containing nano-Ag-based alloy film catalyst via a constant potential electrolysis method. - The surface of the nanostructured catalyst was modified with an electrolyte to obtain an iodine-functionalized nano-Ag-based alloy film catalyst. Iodine functionalization can further improve the catalyst's carbon dioxide electrocatalytic reduction performance. The functionalization method provided by this invention is simple, the process is controllable, and it has high reproducibility.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] One of the technical solutions of this invention is to provide a method for preparing a surface-functionalized iodine-based nano-Ag-based alloy film catalyst, comprising the following steps:

[0008] Ion beam-assisted cleaning of carbonaceous supports was performed using N2. + Doping is performed, followed by ion sputtering to form an Ag-Cu-Ce alloy film on the treated carbonaceous support surface, yielding an Ag-Cu-Ce alloy film catalyst. The Ag-Cu-Ce alloy film catalyst is then subjected to electrochemical surface dealloying in a solution containing NaCl and citric acid, resulting in an Ag-based alloy film catalyst with a nanoparticle-like surface structure. This Ag-based alloy film catalyst with a nanoparticle-like surface structure is then placed in a solution containing I... - A constant potential electrolysis treatment was performed in the solution to obtain a nano-Ag-based alloy film catalyst with iodine functionalization on the surface;

[0009] The concentration of NaCl in the solution containing NaCl and citric acid is 0.1–0.3 M, and the concentration of citric acid is 0.01–0.02 M; the dealloying potential of the electrochemical surface dealloying is 0.5–0.65 V (relative to the reversible hydrogen electrode), the dealloying time is 10–60 s, and the dealloying temperature is 20–40 °C.

[0010] Alternatively, the carbonaceous carrier may comprise graphite fiber cloth or carbon paper.

[0011] Preferably, the carbonaceous support is subjected to ion beam-assisted cleaning and N... + Before doping, a pretreatment step of surface cleaning is also included.

[0012] Preferably, the ion beam-assisted cleaning and N + Doping was carried out in a high-vacuum multifunctional ion sputtering apparatus with the following parameters set: sample stage temperature 200–220 °C, vacuum degree 7.0 × 10⁻⁶. -4 ~7.5×10 -4Pa, N2 flow rate 9.0–10 sccm, plate voltage 0.35–0.40 kV, beam current 45–55 mA, time 8–15 min.

[0013] Preferably, the ion sputtering is performed in a high-vacuum multifunctional ion sputtering apparatus, with the following parameters set: sample stage temperature 210°C, vacuum degree 7.5 × 10⁻⁶. -4 Pa, Ar flow rate 5.4 sccm, plate voltage 2.5 kV, beam current 80 mA, time 25 min.

[0014] Preferably, the thickness of the Ag-Cu-Ce alloy film is 70-90 nm, wherein the relative atomic contents of Ag, Cu and Ce are 50-70 at.%, 25-45 at.% and 1-10 at.%.

[0015] Optionally, the I - Provided by KI.

[0016] Preferably, in the constant potential electrolysis treatment, the Ag-based alloy film catalyst with a nanoparticle structure on its surface serves as the working electrode, the carbon rod as the counter electrode, and Ag / AgCl as the reference electrode, with the parameters set as follows: I - The concentration is 0.1–0.2 M, the electrolysis potential is 0.1–0.2 V (relative to the reversible hydrogen electrode), the electrolysis temperature is 20–30 °C, and the electrolysis time is 10–15 min. N2 or Ar is introduced for protection during the electrolysis process to avoid photoelectrolysis.

[0017] The present invention introduces N2 or Ar for protection during electrolysis to prevent I during the reaction. - It is oxidized to I2, which corrodes metals and contaminates surfaces. Because AgI is photosensitive, the reactor is wrapped in aluminum foil to protect it from light during electrolysis.

[0018] The second technical solution of the present invention provides a surface-iodine-functionalized nano-Ag-based alloy film catalyst prepared according to the above-mentioned preparation method of surface-iodine-functionalized nano-Ag-based alloy film catalyst.

[0019] The third technical solution of the present invention provides an application of the above-mentioned surface iodine-functionalized nano-Ag-based alloy film catalyst in the electrocatalytic reduction of CO2.

[0020] The beneficial technical effects of the present invention are as follows:

[0021] This invention enhances the CO2 RR performance of a catalyst through the synergistic effect of three metal components: Ag, Cu, and Ce. Ag primarily activates CO2 efficiently and selectively generates CO intermediates; Cu utilizes its strong adsorption capacity for carbon-containing intermediates to promote carbon-carbon (CC) coupling; and Ce, typically existing as CeO2, provides oxygen vacancies to strengthen CO2 adsorption and activation, and also modulates the electronic structure of Ag and Cu through strong metal-carbon support interactions, optimizing the adsorption energy of reaction intermediates and acting as a structural stabilizer to improve the overall durability of the catalyst. These three components synergistically construct a highly efficient "activation-conversion-stabilization" catalytic system, achieving a synergistic improvement in both selectivity and reaction stability for the target product.

[0022] This invention employs a NaCl and citric acid system to perform dealloying treatment on the catalyst surface, enabling the direct one-step preparation of nanofilms with a three-dimensional bicontinuous structure. The process primarily involves etching away some of the transition metal Cu to increase the Ag content. This technique is simple, efficient, and allows for precise control over the nanostructure of the prepared catalyst film. The catalyst film material possesses a high specific surface area, exposing numerous active sites. The interconnected channels within the catalyst film material promote mass transfer efficiency between reactants and products, significantly enhancing the catalyst's activity, selectivity, and durability in electrochemical applications.

[0023] The constant potential electrolysis method used in this invention is in the presence of I - The reaction is carried out in an electrolytic solution. By forming AgI on the catalyst surface to precisely control the electronic structure of active sites, the adsorption free energy of key reaction intermediates is optimized, thereby significantly improving the selectivity and formation efficiency of target products (especially CO). The steric hindrance effect of iodide ions is used to selectively block the active sites of hydrogen evolution reaction, effectively suppressing side reactions. The formation of a stable AgI chemical bond layer on the metal surface can significantly enhance the structural stability and anti-dissolution performance of the catalyst under long-term electrochemical operating conditions. The constant potential electrolysis method is simple, mild, and requires no complex equipment, making it suitable for large-scale preparation. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 Scanning electron microscope (SEM) image (a) and transmission electron microscope (TEM) image (b) of the surface-functionalized iodine nano-Ag-based alloy film catalyst prepared in Example 1.

[0026] Figure 2 Scanning electron microscope (SEM) image (a) and transmission electron microscope (TEM) image (b) of the Ag-based alloy thin film catalyst with a nanoparticle structure on the surface prepared in Example 2.

[0027] Figure 3 The XRD patterns are of the catalysts prepared in Example 1, Comparative Example 4, and Comparative Example 5.

[0028] Figure 4 Scanning electron microscope image of the Ag-Cu-Ce alloy thin film catalyst prepared in Comparative Example 1.

[0029] Figure 5 Scanning electron microscope image of the Ag-based alloy thin film catalyst with a nanoparticle structure on the surface prepared for Comparative Example 2.

[0030] Figure 6 Scanning electron microscope image of Ag-based alloy thin film catalyst with a surface nanoparticle structure prepared for Comparative Example 3.

[0031] Figure 7 LSV curves for the catalysts prepared in Examples 1 and 2.

[0032] Figure 8 LSV curves of the catalysts prepared for comparative examples 1-5.

[0033] Figure 9 The it curves are for the catalysts prepared in Examples 1, 2, 4, and 5.

[0034] Figure 10 The Faraday efficiency diagrams are for the catalysts prepared in Examples 1, 2, 4, and 5. Detailed Implementation

[0035] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0036] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0037] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0038] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this invention.

[0039] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0040] Unless otherwise specified, room temperature in this invention refers to a temperature of 20±10℃.

[0041] Example 1

[0042] (1) Pretreatment of carbonaceous support: First, 16cm×16cm graphite fiber cloth is placed in 0.5M H2SO4 solution for ultrasonic cleaning for 20min, then placed in acetone solution for ultrasonic cleaning for 20min, then placed in ultrapure water for ultrasonic cleaning for 20min, and finally placed in anhydrous ethanol for 10min. The carbonaceous support is then removed and placed in a vacuum drying oven to dry, resulting in a clean carbonaceous support.

[0043] (2) Vacuum ion beam sputtering-assisted cleaning: First, the Ag, Cu, and Ce targets are mounted on the target stage. The sample stage temperature is raised to 210℃ and kept constant, and the vacuum degree is 7.5×10⁻⁶. -4 Pa. The treated carbonaceous support was placed on the sample stage, and the carbonaceous support on the sample stage was subjected to N2 ion beam assisted cleaning and N. + The doping parameters were as follows: N2 flow rate of 9.6 sccm, plate voltage of 0.35 kV, beam current of 50 mA, and time of 10 min.

[0044] (3) Vacuum ion beam sputtering: auxiliary cleaning and N + After doping, Ag, Cu, and Ce targets were sputtered by ion beam under the protection of inert gas Ar. The Ar flow rate was 5.4 sccm, the plate voltage was 2.5 kV, the beam current was 80 mA, and the sputtering time was 25 min. Then, the vacuum was reduced to room temperature to obtain Ag-Cu-Ce alloy thin film catalyst. The thickness of Ag-Cu-Ce alloy film was 75 nm, and the relative atomic contents of Ag, Cu, and Ce were 60 at.%, 35 at.%, and 5 at.%, respectively.

[0045] (4) The obtained Ag-Cu-Ce alloy thin film catalyst was cut into 2cm×2cm pieces and placed in a solution of 0.15M NaCl and 0.01M citric acid for electrochemical surface dealloying. The dealloying time was 30s, the dealloying potential was 0.6V (relative to the reversible hydrogen electrode), and the dealloying temperature was 30℃. Then, the catalyst surface was washed with ultrapure water, avoiding ultrasonic cleaning to prevent damage to the nanoporous structure. The catalyst was then dried in a vacuum drying oven to obtain an Ag-based alloy thin film catalyst with a nanoparticle structure on the surface.

[0046] (5) Using the dried Ag-based alloy film as the working electrode, constant potential electrolysis was performed in 0.1M KI electrolyte for 10 min. The treatment potential was controlled at 0.2V (relative to the reversible hydrogen electrode), the temperature was 25℃, and N2 was introduced into the reaction tank for protection. The reaction vessel was wrapped with aluminum foil to protect it from light. After the constant potential electrolysis was completed, the catalyst surface was cleaned and dried in a vacuum drying oven to obtain the surface iodine-functionalized nano Ag-based alloy film catalyst.

[0047] Example 2

[0048] Compared with Example 1, without the constant potential electrolysis treatment in step (5), an Ag-based alloy thin film catalyst with a nanoparticle structure on the surface is prepared.

[0049] Comparative Example 1

[0050] Compared with Example 1, steps (4) and (5) are omitted, and an Ag-Cu-Ce alloy thin film catalyst is prepared.

[0051] Comparative Example 2

[0052] Compared with Example 1, the solution used for electrochemical surface dealloying in step (4) is a 0.15M NaCl solution, and the constant potential electrolysis treatment in step (5) is not performed. The resulting catalyst is an Ag-based alloy thin film catalyst with a nanoparticle structure on the surface.

[0053] Comparative Example 3

[0054] Compared with Example 1, the solution used for electrochemical surface dealloying in step (4) is a 0.25M NaCl solution, and the constant potential electrolysis treatment in step (5) is not performed. The resulting catalyst is an Ag-based alloy thin film catalyst with a nanoparticle structure on its surface.

[0055] Comparative Example 4

[0056] Compared with Example 1, the KI electrolyte was replaced with a 0.1M KF solution to prepare a nano-Ag-based alloy film catalyst.

[0057] Comparative Example 5

[0058] Compared with Example 1, the KI electrolyte was replaced with a 0.1M KBr solution to prepare a nano-Ag-based alloy film catalyst.

[0059] Scanning electron microscope (SEM) image (a) and transmission electron microscope (TEM) image (b) of the surface-functionalized iodine nano-Ag-based alloy film catalyst prepared in Example 1 are shown below. Figure 1 .

[0060] Depend on Figure 1 It can be seen that the catalyst is composed of nanoparticles with a size of 30–50 nm.

[0061] Scanning electron microscope (SEM) image (a) and transmission electron microscope (TEM) image (b) of the Ag-based alloy thin film catalyst with a nanoparticle structure on the surface prepared in Example 2 are shown below. Figure 2 .

[0062] Depend on Figure 2 It can be seen that the morphology obtained is similar to that of Example 1, indicating that the constant potential electrolysis treatment did not significantly change the catalyst morphology.

[0063] The XRD patterns of the catalysts prepared in Example 1, Comparative Example 4, and Comparative Example 5 are shown in the figure. Figure 3 .

[0064] Depend on Figure 3 It can be seen that the catalyst after constant-potential electrolysis exhibited an AgI phase, indicating that after constant-potential electrolysis, AgI formed a stable compound layer on the Ag nanostructure surface, which will significantly alter the surface electronic structure of the catalyst. The presence of Cu diffraction peaks indicates that the dealloying process is partial rather than complete, preserving the Ag-Cu interface and providing a structural basis for tandem catalysis. In contrast, no new phases appeared on the catalyst surface after constant-potential electrolysis using KBr or KI electrolytes, suggesting that KBr or KI treatment may only induce physical adsorption or surface defect modification, and will not generate new silver halide phases.

[0065] The scanning electron microscope image of the Ag-Cu-Ce alloy thin film catalyst prepared in Comparative Example 1 is shown below. Figure 4 .

[0066] Depend on Figure 4 It can be seen that the surface of the catalyst without dealloying is relatively smooth, and its inherent low active site density and mass transfer limitations cannot meet the high-performance requirements of practical applications. Therefore, constructing nanostructures through surface dealloying technology to significantly increase active sites and optimize mass transfer pathways is a necessary means to achieve highly efficient catalysts.

[0067] The scanning electron microscope image of the Ag-based alloy thin film catalyst with a nanoparticle structure on the surface prepared in Comparative Example 2 is shown below. Figure 5 .

[0068] Depend on Figure 5It can be seen that the catalyst surface has particles with uneven size and irregular crystal structure, which will lead to uneven contact between the electrolyte and the electrode surface, thereby causing instability of the electrochemical interface, reducing charge transfer efficiency, and affecting the stability and catalytic performance of the membrane catalyst.

[0069] The scanning electron microscope image of the Ag-based alloy thin film catalyst with a nanoparticle structure on the surface prepared in Comparative Example 3 is shown below. Figure 6 .

[0070] Depend on Figure 6 It can be seen that the etching degree of the catalyst surface is limited, and the high concentration of NaCl solution crystallizes more on the catalyst surface, making it difficult to remove and masking the active sites of the catalyst. Its morphology is mainly "willow catkin-like", which is an inefficient and unstable morphology with poor conductivity and mass transfer efficiency, resulting in poor electrochemical performance of the catalyst.

[0071] Electrochemical characterization of the catalysts prepared in Examples 1-2 and Comparative Examples 1-5 was performed using a standard three-electrode system. An H-type electrolytic cell was used as the electrolytic cell, the prepared catalyst as the working electrode, a graphite rod as the counter electrode, and Ag / AgCl as the reference electrode. Linear sweep voltammetry (LSV) was used to characterize the catalyst activity. The LSV test scan range was -0.6 to 0.2 V (relative to the reversible hydrogen electrode), and the scan rate was 20 mV / s.

[0072] Figure 7 These are the LSV curves of the catalysts prepared in Examples 1 and 2; Figure 8 The LSV curves of the catalysts prepared in Comparative Examples 1–5 are shown in Table 1. The maximum current density in the LSV curves is shown in Table 1.

[0073] from Figure 7 As can be seen, the catalyst current density in Example 1 after constant potential electrolysis can reach -10.10 mA·cm⁻¹. -2 The catalyst current density in Example 2, which did not undergo constant potential electrolysis, was -5.20 mA·cm⁻¹. -2 This represents a 94.23% increase compared to the previous year.

[0074] Table 1

[0075]

[0076] Electrochemical characterization of the catalysts prepared in Examples 1-2, Comparative Examples 4 and 5 was performed using a standard three-electrode system. An H-type electrolytic cell was used as the electrolytic cell, the prepared catalyst as the working electrode, a graphite rod as the counter electrode, and Ag / AgCl as the reference electrode. Catalyst stability was evaluated using the chronoamperometry (it) method, continuously tested for 5 hours at a constant potential of -0.8V (relative to the reversible hydrogen electrode). The collected gas after the stability test was passed through a gas chromatograph equipped with a thermal conductivity detector (TCD) and a flame ionization detector (FID), using argon (Ar) as the carrier gas. The content of gaseous products (CO, H2, CH4) was detected. The Faradaic efficiency (FE) of each product was calculated using the following formula.

[0077]

[0078] In the above formula: z represents the number of electrons transferred during product formation; F represents the Faraday constant (96485 C·mol⁻¹). -1 ); n represents the amount of substance of the product (mol); Q represents the total amount of charge transferred (C).

[0079] Figure 9 The it curves for the catalysts prepared in Examples 1, 2, 4, and 5 are shown below. Figure 9 As can be seen, the catalyst in Example 1 remained stable at a relatively high current density after 5 hours of reaction, indicating that the catalyst maintained strong stability after 5 hours of reaction.

[0080] Figure 10 The Faraday efficiency for detecting the main gaseous products (H2, CO, and CH4) using gas chromatography. Figure 10 This indicates that CO2RR and the hydrogen evolution reaction (HER) are competing reactions. The Faraday efficiency of CH4 in Example 1 (13.44%) was increased by 122.52%, 71.43%, and 74.77% compared to Example 2, Comparative Example 4, and Comparative Example 5, respectively. The Faraday efficiency of CO in Example 1 (32.58%) was also increased by 108.31%, 20.49%, and 19.17% compared to Example 2, Comparative Example 4, and Comparative Example 5, respectively. However, the Faraday efficiency of H2 in Example 1 decreased by 45.64%, 20.64%, and 22.21% compared to Example 2, Comparative Example 4, and Comparative Example 5, respectively. This shows that the catalyst in Example 1 exhibits excellent electrocatalytic performance in CO2RR, promoting the generation of CO and CH4 and inhibiting the hydrogen evolution reaction.

[0081] In summary, the surface-functionalized iodine-based nano-Ag-based alloy film catalyst prepared in Example 1 exhibits significant electrocatalytic performance in CO2RR, with a current density of -10.10 mA·cm⁻¹ in the LSV test. -2The activity was significantly higher than that of the catalysts in Examples 2 and Comparative Examples 1-5. Scanning electron microscopy (SEM) images showed that the catalyst surfaces of Examples 1 and 2 consisted of uniformly distributed nanocubic particles and lamellar structures. These morphological features provided more active sites and optimized the diffusion channels of reactants, promoting CO2RR. XRD patterns further confirmed the formation of an AgI phase on the surface of the catalyst in Example 1, indicating that surface iodization treatment effectively improved the electronic structure of the catalyst and enhanced its stability. Through surface modification and morphology optimization, the stability and catalytic activity of the catalyst in Example 1 were significantly improved in electrochemical reactions. In contrast, the catalysts in Comparative Examples 1-3 had relatively smooth surfaces or exhibited particle agglomeration, resulting in less exposure of active sites and thus poorer electrocatalytic performance. Furthermore, the lack of effective surface modification and structural optimization, coupled with their failure to achieve a nanoparticle-like morphology, led to lower catalytic efficiency in Comparative Examples 1-3. However, comparing the LSV data of Comparative Examples 4 and 5 with those of Examples 1 and 2, these catalysts, after surface modification with KBr and KF solutions, still demonstrated certain advantages in electrocatalytic performance, particularly in the LSV tests showing current densities of -6.66 mA·cm⁻¹. -2 and -6.52mA·cm -2 Although lower than -10.10 mA·cm in Example 1 -2 However, it is significantly higher than -5.20 mA·cm⁻¹ in Example 2. -2 And Comparative Example 1 (-2.52 mA·cm -2 Comparative Example 2 (-3.75 mA·cm) -2 ) and Comparative Example 3 (-3.04 mA·cm -2 Secondly, the Faraday efficiency calculations showed that the catalyst of Example 1 effectively reduced CO2 and suppressed the hydrogen evolution reaction during the electrocatalytic reduction of CO2. Comparative Examples 4 and 5 showed higher Faraday efficiencies for CO and CH4 compared to Example 2. This indicates that the catalysts of Comparative Examples 4 and 5 improved their surface structure through constant-potential electrolysis treatment. Although they did not achieve the highly efficient iodine functionalization modification as in Example 1, and may have only induced physical adsorption or surface defect modification, they still effectively improved electrocatalytic performance. Overall, the catalyst of Example 1, with its excellent morphology, surface modification, and electronic structure tuning, exhibited superior electrocatalytic performance in CO2RR.

[0082] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing a surface-functionalized iodine-based nano-Ag-based alloy film catalyst, characterized in that, Includes the following steps: Ion beam-assisted cleaning of carbonaceous supports was performed using N2. + Doping is performed, followed by ion sputtering to form an Ag-Cu-Ce alloy film on the treated carbonaceous support surface, yielding an Ag-Cu-Ce alloy film catalyst. The Ag-Cu-Ce alloy film catalyst is then subjected to electrochemical surface dealloying in a solution containing NaCl and citric acid, resulting in an Ag-based alloy film catalyst with a nanoparticle-like surface structure. This Ag-based alloy film catalyst with a nanoparticle-like surface structure is then placed in a solution containing I... - A constant potential electrolysis treatment was performed in the solution to obtain a nano-Ag-based alloy film catalyst with iodine functionalization on the surface; The concentration of NaCl in the solution containing NaCl and citric acid is 0.1–0.3 M, and the concentration of citric acid is 0.01–0.02 M; the dealloying potential of the electrochemical surface dealloying is 0.5–0.65 V, the dealloying time is 10–60 s, and the dealloying temperature is 20–40 °C.

2. The method for preparing the surface-functionalized iodine-based nano-Ag-based alloy film catalyst according to claim 1, characterized in that, The carbonaceous carrier includes graphite fiber cloth or carbon paper.

3. The method for preparing the surface-functionalized iodine-based nano-Ag-based alloy film catalyst according to claim 1, characterized in that, The carbonaceous support undergoes ion beam-assisted cleaning and N... + Before doping, a pretreatment step of surface cleaning is also included.

4. The method for preparing the surface-functionalized iodine-based nano-Ag-based alloy film catalyst according to claim 1, characterized in that, The ion beam-assisted cleaning and N + Doping was carried out in a high-vacuum multifunctional ion sputtering apparatus with the following parameters set: sample stage temperature 200–220 °C, vacuum degree 7.0 × 10⁻⁶. -4 ~7.5×10 -4 Pa, N2 flow rate 9.0–10 sccm, plate voltage 0.35–0.40 kV, beam current 45–55 mA, time 8–15 min.

5. The method for preparing the surface-functionalized iodine-based nano-Ag-based alloy film catalyst according to claim 1, characterized in that, The ion sputtering was performed in a high-vacuum multifunctional ion sputtering apparatus with the following parameters: sample stage temperature 200–220°C, vacuum degree 7.0 × 10⁻⁶. -4 ~7.5×10 -4 Pa, Ar flow rate 5.0–6.5 sccm, plate voltage 2.3–2.6 kV, beam current 75–90 mA, time 20–30 min.

6. The method for preparing the surface-functionalized iodine-based nano-Ag-based alloy film catalyst according to claim 1, characterized in that, The thickness of the Ag-Cu-Ce alloy film is 70-90 nm, wherein the relative atomic contents of Ag, Cu and Ce are 50-70 at.%, 25-45 at.% and 1-10 at.%.

7. The method for preparing the surface-functionalized iodine-based nano-Ag-based alloy film catalyst according to claim 1, characterized in that, The I - Provided by KI.

8. The method for preparing the surface-functionalized iodine-based nano-Ag-based alloy film catalyst according to claim 1, characterized in that, In the constant potential electrolysis process, the Ag-based alloy film catalyst with a nanoparticle structure on its surface serves as the working electrode, the carbon rod as the counter electrode, and Ag / AgCl as the reference electrode. The parameters are set as follows: I - Concentration 0.1-0.2M, electrolysis potential 0.1-0.2V, electrolysis temperature 20-30℃, electrolysis time 10-15min, N2 or Ar is introduced for protection during electrolysis, and photoelectrolysis is avoided.

9. A surface-iodine-functionalized nano-Ag-based alloy film catalyst prepared by the method of preparing the surface-iodine-functionalized nano-Ag-based alloy film catalyst according to any one of claims 1 to 8.

10. The application of the surface-functionalized iodine nano-Ag-based alloy film catalyst of claim 9 in the electrocatalytic reduction of CO2.

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