Nanometer flower-shaped electrocatalyst synthesized based on pulse CO2 laser induction as well as preparation method and application of nanometer flower-shaped electrocatalyst

Abstract

The invention discloses a nano flower-shaped electrocatalyst synthesized based on pulse CO2 laser induction and a preparation method and application thereof, and the preparation method comprises the following steps: dissolving copper nitrate and magnesium nitrate in a mixed solution of distilled water and ethanol at room temperature to obtain a solution A; adding an ethanolamine solution into the solution A, and after blue precipitates appear, standing, centrifuging and drying to obtain an electrocatalyst precursor material; grinding the precursor material into powder, uniformly laying the powder on a PI film, placing the PI film in an air atmosphere for CO2 laser induction, cooling the product to room temperature after the CO2 laser induction is finished, washing the product, drying and grinding the product into powder, and finally obtaining the nano flower-shaped electrocatalyst Ly-Mg / CuxO. According to the method, instantaneous pulse CO2 laser induction is utilized, the method is novel, the preparation process is simple, and the magnesium-doped multivalent copper oxide (L4-Mg / CuxO) electrocatalyst synthesized by the method can be used as a dual catalyst applied to preparation of ethanol from eCO2RR and a lithium carbon dioxide battery and has important practical significance.

Description

Technical Field

[0001] This invention relates to the field of eCO2RR electrocatalysis technology, and specifically provides a nanoflower-like electrocatalyst based on pulsed CO2 laser-induced synthesis, its preparation method, and its application. Background Technology

[0002] Against the backdrop of accelerating global energy consumption, electricity, as a sustainable and eco-friendly new energy source, is gradually gaining attention. Unlike traditional fossil fuels, it does not produce large amounts of carbon dioxide and other harmful gases, resulting in less environmental pollution. Furthermore, the renewable nature of electricity makes it a reliable energy choice, as it can be generated from renewable energy sources such as solar and wind power, thus reducing dependence on finite resources. In addition, with continuous technological advancements, the efficiency of electricity storage and transmission is constantly improving, making its application more widespread and convenient. Therefore, the research and technological innovation of electricity storage devices are urgently needed.

[0003] Combining electrocatalytic carbon dioxide reduction (eCO2RR) with renewable electricity to produce value-added chemicals is a promising method for achieving a closed-loop carbon cycle. Ethanol (C2H5OH), as a high-quality liquid and industrial chemical, has received considerable attention. Lithium-carbon dioxide (Li-CO2) batteries, with their unique carbon dioxide fixation and conversion capabilities, hold promise for opening up new avenues for development in energy storage and carbon dioxide utilization. The core electrochemical process of Li-CO2 batteries involves two key steps: during discharge, lithium reacts with carbon dioxide to generate lithium carbonate (Li2CO3) and undergoes carbon dioxide reduction (CO2RR); during charging, Li2CO3 is decomposed into lithium ions and carbon dioxide through the reverse carbon dioxide evolution reaction (CEOR). However, the main challenge facing this system is that the discharge product Li2CO3 has high insulation and chemical stability. Its continuous deposition on the electrode surface significantly hinders gas transport and electron transfer at the reaction interface, resulting in large overpotentials during charging and discharging. In particular, the slow reaction kinetics of CO2RR and CEOR at the positive electrode severely limit the energy efficiency and cycle life of the battery, fundamentally restricting the practical application potential of Li-CO2 batteries.

[0004] In polyvalent copper oxide (Cu) x Doping electrocatalysts with heteroatoms, especially metals, is a key pathway to enhance the formation of C2 from eCO2RR. This promotes the emergence of active sites, modulates electronic properties, and ultimately achieves superior stability. Among these, Mg, due to its unique physicochemical properties, has become a promising dopant for improving the selectivity of C2H5OH. As a light alkaline earth metal, it can significantly modulate the selectivity of Cu. x The electronic structure of O, which is embedded in the nanostructure Cux The active Mg sites in the O matrix optimize the adsorption energy of key intermediates, thereby improving the CC coupling kinetics and C2H5OH selectivity. However, traditional synthesis strategies often face bottlenecks in achieving uniform Mg distribution and precise control of dopant-induced defects, thus limiting product selectivity.

[0005] Therefore, developing a high-performance Li-CO2 battery cathode catalyst with high catalytic activity is of great practical significance. Summary of the Invention

[0006] Therefore, the purpose of this invention is to provide a nano-flower-like electrocatalyst based on pulsed CO2 laser-induced synthesis, its preparation method, and its application, in order to solve the above-mentioned technical problems.

[0007] The technical solution provided by this invention is as follows: Firstly, this invention provides a method for preparing nano-flower-like electrocatalysts based on pulsed CO2 laser-induced synthesis, comprising: At room temperature, copper nitrate and magnesium nitrate are dissolved in a mixed solution of distilled water and ethanol to obtain solution A; An ethanolamine solution was added to solution A. After a blue precipitate appeared, the product was collected by standing and centrifugation. The product was then dried to obtain the electrocatalyst precursor material. The precursor material was ground into powder, uniformly spread on a PI film, and subjected to CO2 laser induction in an air atmosphere. After the induction, the product was allowed to cool to room temperature, washed, dried, and ground into powder to obtain the nanoflower-like electrocatalyst L4-Mg / Cu. x O.

[0008] Preferably, the molar ratio of magnesium nitrate to copper nitrate is 4:1.

[0009] Preferably, the settling time is 18 hours.

[0010] Preferably, the centrifuged product is collected by first washing with distilled water 2-3 times and then filtering with ethanol once.

[0011] Preferably, the drying method for obtaining the electrocatalyst precursor material after drying the product is: vacuum drying at room temperature for 12 h.

[0012] Preferably, the CO2 laser induction is performed twice, with a power of 2-8 W and a scan rate of 150 mm / s. -1 .

[0013] Preferably, the product is then washed, dried, and ground into powder, wherein the drying method is forced air drying, the drying temperature is 80±10 ℃, and the drying time is 10-12 h.

[0014] Secondly, the present invention also provides a nanoflower-like electrocatalyst based on pulsed CO2 laser-induced synthesis obtained by the preparation method.

[0015] Thirdly, the present invention provides the application of the aforementioned nano-flower-like electrocatalyst, which is used as an electrocatalyst for eCO2RR to ethanol production and for the cathode of Li-CO2 batteries.

[0016] This invention provides a nano-flower-like electrocatalyst synthesized based on pulsed CO2 laser induction, its synthesis method, and its applications. This method utilizes instantaneous pulsed CO2 laser induction, is novel, and has a simple preparation process. Compared to the slow and energy-intensive traditional high-temperature pyrolysis method, it offers a faster reaction rate and lower energy consumption. The L4-Mg / Cu nano-flower-like electrocatalyst synthesized by this method... x O electrocatalysts exhibit excellent selectivity for eCO2RR to ethanol production and can serve as dual catalysts for both eCO2RR to ethanol production and Li-CO2 battery applications, which has significant practical implications.

[0017] The Mg-doped Cu-based catalyst of this invention exhibits excellent ethanol selectivity. L4-Mg / Cu is synthesized by varying the pyrolysis method and controlling the laser power. x The O electrocatalyst has a unique nanosheet structure and is assembled into intertwined nanoflowers, which can further improve electron transfer in the catalytic process and is beneficial to ion diffusion and catalytic reaction. L4-Mg / Cu x O electrocatalysts all exhibited excellent electrocatalytic activity in eCO2RR; specifically, L4-Mg / Cu x O electrocatalyst, used as the cathode electrocatalyst in Li-CO2 batteries, exhibited high specific capacity and excellent cycle stability. The assembled Li-CO2 battery achieved a cycle stability of 0.2 mA cm⁻¹. -2 At a current density of 0.1 mA cm⁻¹, 187 stable cycles can be achieved. -2 At current densities, it has a high capacity of 20480 mAh g. -1 With its high discharge specific capacity, this electrocatalyst shows great promise for application as a cathode electrocatalyst in Li-CO2 batteries. Attached Figure Description

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments: Figure 1 This invention (corresponding to Example 1) uses L4-Mg / Cu. xO's process flow diagram; Figure 2 Here is a SEM image of L4-CuO from the present invention (corresponding to Example 1); Figure 3 The image shows the FE bar chart of L4-CuO in this invention (corresponding to Example 1); the electrolyte solution is: 1 mol L... -1 KOH; Figure 4 The graph shows the cycle performance of L4-CuO as the cathode electrocatalyst in a Li-CO2 battery (corresponding to Example 1) of this invention; the current density is 0.2 mA cm⁻¹. -2 The capacity is limited to 500 mAh g. -1 ; Figure 5 In this invention (corresponding example 1), L4-CuO was used as the cathode electrocatalyst for a Li-CO2 battery at a current density of 0.1 mA cm⁻¹. -2 The initial discharge curve is shown below. Figure 6 This invention (corresponding to Example 1) uses L4-Mg / Cu. x SEM image of the O electrocatalyst; Figure 7 This invention (corresponding to Example 1) uses L4-Mg / Cu. x TEM image of O electrocatalyst; Figure 8 This invention (corresponding to Example 1) uses L4-Mg / Cu. x HRTEM image of O electrocatalyst; Figure 9 This invention (corresponding to Example 1) uses L4-Mg / Cu. x FE histogram for O; electrolyte solution: 1 mol L - 1 KOH; Figure 10 This invention (corresponding to Example 1) uses L4-Mg / Cu. x Cycle performance curve of O as cathode electrocatalyst in Li-CO2 battery; current density 0.2 mA cm⁻¹ -2 The capacity is limited to 500 mAh g. -1 ; Figure 11 This invention (corresponding to Example 1) uses L4-Mg / Cu. x O was used as a cathode electrocatalyst in Li-CO2 batteries at a current density of 0.1 mA cm⁻¹. -2 The initial discharge curve is shown below. Figure 12 For the present invention (counterpart 2) C 300SEM image of Mg / CuO; Figure 13 For the present invention (counterpart 2) C 300 -FE bar chart of Mg / CuO; electrolyte solution: 1 mol L - 1 KOH; Figure 14 For the present invention (counterpart 2) C 300 Cycle performance curves of Mg / CuO as a cathode electrocatalyst in Li-CO2 batteries; current density: 0.2 mA cm⁻¹ -2 The capacity is limited to 500 mAh g. -1 ; Figure 15 For the present invention (counterpart 2) C 300 -Mg / CuO was used as a cathode electrocatalyst in Li-CO2 batteries at a current density of 0.1 mA cm⁻¹. -2 The initial discharge curve is shown below. Figure 16 This invention (corresponding to Example 2) uses L2-Mg / Cu. x SEM image of O; Figure 17 This invention (corresponding to Example 2) uses L2-Mg / Cu. x FE histogram for O; electrolyte solution: 1 mol L - 1 KOH; Figure 18 This invention (corresponding to Example 2) uses L2-Mg / Cu. x Cycle performance curve of O as cathode electrocatalyst in Li-CO2 battery; current density 0.2 mA cm⁻¹ -2 The capacity is limited to 500 mAh g. -1 ; Figure 19 This invention (corresponding to Example 2) uses L2-Mg / Cu. x O was used as a cathode electrocatalyst in Li-CO2 batteries at a current density of 0.1 mA cm⁻¹. -2 The initial discharge curve is shown below. Figure 20 This invention (corresponding to Example 3) uses L6-Mg / Cu. x SEM image of O; Figure 21 This invention (corresponding to Example 3) uses L6-Mg / Cu. x FE histogram for O; electrolyte solution: 1 mol L - 1 KOH; Figure 22 This invention (corresponding to Example 3) uses L6-Mg / Cu. x Cycle performance curve of O as cathode electrocatalyst in Li-CO2 battery; current density 0.2 mA cm⁻¹ -2 The capacity is limited to 500 mAh g. -1 ; Figure 23 This invention (corresponding to Example 3) uses L6-Mg / Cu. x O was used as a cathode electrocatalyst in Li-CO2 batteries at a current density of 0.1 mA cm⁻¹. -2 The initial discharge curve is shown below. Figure 24 This invention (corresponding to Example 4) uses L8-Mg / Cu. x SEM image of O; Figure 25 This invention (corresponding to Example 4) uses L8-Mg / Cu. x FE histogram for O; electrolyte solution: 1 mol L - 1 KOH; Figure 26 This invention (corresponding to Example 4) uses L8-Mg / Cu. x Cycle performance curve of O as cathode electrocatalyst in Li-CO2 battery; current density 0.2 mA cm⁻¹ -2 The capacity is limited to 500 mAh g. -1 ; Figure 27 This invention (corresponding to Example 4) uses L8-Mg / Cu. x O was used as a cathode electrocatalyst in Li-CO2 batteries at a current density of 0.1 mA cm⁻¹. -2 The initial discharge curve is shown below. Figure 28 For the present invention (counterpart 3) C 300 SEM image of CuO; Figure 29 For the present invention (counterpart 3) C 300 -FE histogram of CuO; electrolyte solution: 1 mol L -1 KOH; Figure 30 For the present invention (counterpart 3) C 300 Cycle performance curve of CuO as cathode electrocatalyst in Li-CO2 battery; current density: 0.2 mA cm⁻¹ -2 The capacity is limited to 500 mAh g. -1 ; Figure 31 For the present invention (counterpart 3) C300 CuO was used as a cathode electrocatalyst in Li-CO2 batteries at a current density of 0.1 mA cm⁻¹. -2 The initial discharge curve is shown below. Detailed Implementation

[0019] In the existing technology, the traditional synthesis strategy of doping heteroatoms in electrocatalysts often faces bottlenecks in achieving uniform Mg distribution and precise control of dopant-induced defects, thus limiting the selectivity of products.

[0020] To this end, the present invention utilizes cost-effective light alkaline earth metal Mg doping technology to reduce the cost of material synthesis, while using transient CO2 pulsed laser synthesis technology to achieve precise morphology control, obtain a unique nanosheet structure, and assemble it into intertwined nanoflowers, so that the synthesized electrocatalyst has excellent eCO2RR electrocatalytic performance and good charge-discharge performance in Li-CO2 batteries.

[0021] Specifically, this embodiment provides a method for synthesizing nanoflower-like electrocatalysts induced by pulsed CO2 laser, comprising the following steps: 1) Dissolve copper nitrate and magnesium nitrate in a mixed solution of distilled water and ethanol; 2) Add ethanolamine solution to the above solution. A blue precipitate appears, and after standing for 18 hours, collect it by centrifugation. After centrifugation, dry under vacuum overnight at room temperature to obtain the electrocatalyst precursor.

[0022] 3) The electrocatalyst precursor was ground into powder and evenly spread on a 100 mm thick PI film. CO2 laser induction was performed twice in air at a power of 2-8 W. After the process, the product was allowed to cool to room temperature, washed, dried by forced air, and ground into powder to obtain nanoflower-like L... y -Mg / Cu x O electrocatalyst. Preferably, the CO2 laser-induced power is 4 W; Furthermore, the molar ratio of magnesium nitrate to copper nitrate is 4:1. This invention relates to the preparation of L4-Mg / Cu xIn O electrocatalysis, Mg atoms are incorporated into the Cu lattice, transferring electrons to Cu and making the Cu surface electron-rich. This electronic effect fine-tunes the d-band center of Cu, thereby altering its adsorption strength for key reaction intermediates (such as CO and COOH). Too low a doping level or no doping (e.g., a molar ratio of magnesium nitrate to copper nitrate of 0:1 or 2:1) results in a weak electron transfer effect, insufficient to alter the strong adsorption of CO by Cu, leading to CO poisoning of the catalyst surface and hindering subsequent reactions. Conversely, too high a doping level (e.g., a molar ratio of magnesium nitrate to copper nitrate of 6:1) may cause the d-band center to shift excessively downwards, resulting in weak CO adsorption, insufficient CO coverage, or ineffective activation of CO2 molecules. The ratio (4:1) used in this application finds the optimal balance between strong and weak adsorption, ensuring a moderate CO adsorption energy that guarantees sufficient CO coverage while facilitating subsequent hydrogenation or CC coupling steps.

[0023] Furthermore, the CO2 laser-induced power was 4 W, and the CO2 laser-induced scan speed was 150 mm / s. -1 .

[0024] Furthermore, during centrifugation in step 2), wash the sample 2-3 times with distilled water, and finally filter it once with ethanol.

[0025] Furthermore, in step 3), the drying temperature is 80±10 ℃ and the drying time is 10-12 h.

[0026] This invention utilizes transient CO2 pulsed laser irradiation to synthesize L4-Mg / Cu. x The O electrocatalyst exhibits excellent selectivity for ethanol production via eCO2RR. The Mg doping strategy suppresses the hydrogen evolution reaction, increases the local pH, accelerates H2O dissociation, and facilitates proton supply in eCO2RR.

[0027] Meanwhile, Mg-doped Cu-based catalysts exhibit excellent ethanol selectivity. L4-Mg / Cu catalysts were synthesized by varying the pyrolysis method and controlling the laser power. x The O electrocatalyst possesses a unique nanosheet structure, assembled into interwoven nanoflowers, which can further improve electron transfer during the catalytic process, facilitating ion diffusion and catalytic reactions. This invention, based on the elemental composition of the electrocatalyst and combined with laser processing technology, utilizes its localized, instantaneous ultrafast heating and cooling characteristics. For example, laser energy is absorbed by the material surface within milliseconds, microseconds, or even nanoseconds, generating extremely high local temperatures. Subsequently, the heat is rapidly dissipated into the surrounding cold matrix, achieving ultrafast quenching. This process forms a metastable, non-equilibrium state, yielding a unique electrocatalyst structure unattainable in traditional tube furnaces. L4-Mg / Cu xThe formation of the nanoflower morphology in the O electrocatalyst is a result of the "burst nucleation-gas transport-electrostatic self-assembly" pathway under the extreme non-equilibrium environment created by laser, ultimately locked by the kinetics of "ultrafast cooling." During this process, Mg tends to form MgO nanoclusters. These clusters serve as heterogeneous nucleation sites, and due to their different crystal structure from Cu, strain occurs at the interface, preventing the random fusion and growth of nuclei, thus laying the foundation for the formation of fine, plate-like primary structures. The synergistic effect of laser induction and Mg doping results in the nanoflower morphology. This unique morphology endows the catalyst with a larger specific surface area, more active sites, and superior mass transfer capacity, thereby significantly improving its electrocatalytic performance.

[0028] The present invention will be further explained below with reference to specific implementation schemes, but this explanation does not limit the scope of the invention.

[0029] The instruments used in the following examples and comparative examples are as follows: The morphology of the electrocatalyst was characterized using scanning electron microscopy (SEM, Hitachi S-4800). Transmission electron microscopy (TEM) was performed using a Talos F200S G2 at 220 kV. A CO2 laser cutting system (SC-CO2-B30, total power 30 W, laser wavelength 10.6 µm) was purchased from Shanghai Suochang Optoelectronic Equipment Co., Ltd. A tube furnace (OTF-1200X) was purchased from Suzhou Qiaoshi Tube Furnace Co., Ltd. Gas chromatography (GC 9560), equipped with a flame ionization detector (FID, for carbon-containing product detection) and a thermal conductivity detector (TCD, for H2 detection), using high-purity argon as the carrier gas, was used to analyze the gaseous products of eCO2RR. Dimethyl sulfoxide (DMSO) and phenol (PhOH) were used as internal standards (400 MHz, Bruker AV-400), and nuclear magnetic resonance (NMR) was used for analysis. 1 H) spectroscopy was used to identify and quantify the liquid phase products. The battery assembly was performed in a glove box (M1200S / D) purchased from Chengdu Delis Industrial Co., Ltd., and the charge-discharge test was conducted in a charge-discharge tester (Neware CT3008W) purchased from Shenzhen Xinwei Electronics Co., Ltd.

[0030] All electrochemical tests were performed on a CHI660E electrochemical workstation (Shanghai Chenhua). All potentials in this paper were calibrated to the reversible hydrogen electrode (RHE) according to the Nernst equation (E(V vs. RHE) = E(V vs. Hg / HgO) + 0.098 V + 0.059 × pH).

[0031] Example 1 1) First, 0.2250 g Cu(NO3)2 and 0.9552 g Mg(NO3)2 were dissolved in a mixed solution of water (15 mL) and ethanol (15 mL) at room temperature. Then, 56 µL of ethanolamine solution was added to the above solution. A blue precipitate formed, and after standing for 18 h, it was collected by centrifugation. The electrocatalyst was then vacuum dried at room temperature for 12 h to obtain the electrocatalyst precursor. 2) After grinding the electrocatalyst precursor into powder, it is evenly spread on a 100 mm thick PI film, and then marked with a CO2 laser at a laser power of 4 W and a scanning speed of 150 mm / s. -1 Under the specified conditions, CO2 laser induction was performed twice in an air atmosphere. After the process, the mixture was ground uniformly, washed twice with distilled water, dried at 80℃ for 10 h, and then ground into powder to obtain L4-Mg / Cu. x O electrocatalyst.

[0032] L4-Mg / Cu prepared in Example 1 of this invention x Scanning electron microscope image of O electrocatalyst as follows Figure 6 As shown, a thinner and more delicate structure is presented, which is a nanoflower ball assembled from nanosheets.

[0033] L4-Mg / Cu prepared in Example 1 of this invention x Transmission electron microscopy image of O electrocatalyst as follows Figure 7 The image shows the morphology of nanoparticles anchored on nanosheets.

[0034] L4-Mg / Cu prepared in Example 1 of this invention x High-magnification transmission electron microscopy image of the O electrocatalyst as follows: Figure 8 As shown, clear and distinct lattice fringes can be seen, and the lattice spacing of 0.210 nm corresponds to the (111) crystal plane of Cu.

[0035] L4-Mg / Cu prepared in Example 1 of this invention x The eCO2RR performance of O electrocatalysts is as follows: Figure 9 As shown, the Faraday efficiency (FE) of the C2 product is 74.1% at a voltage of -1.1V vs. RHE, while that of ethanol is 52.2%, exhibiting the highest FE and excellent eCO2RR activity.

[0036] The cycle performance curves of the Li-CO2 battery assembled according to Example 1 are as follows: Figure 10 As shown, at a current density of 0.2 mA cm⁻¹ -2 And the specific capacity is limited to 500 mAh g -1 Under these conditions, L4-Mg / Cu xThe O heterojunction electrocatalyst can achieve a maximum of 187 stable cycles.

[0037] The first discharge curve measured according to Example 1 of the Li-CO2 battery assembly is as follows: Figure 11 As shown, at 0.1 mA cm -2 At current density, L4-Mg / Cu x O has a capacity of up to 20480 mAh g -1 The specific discharge capacity.

[0038] Example 2 1) First, 0.2250 g Cu(NO3)2 and 0.9552 g Mg(NO3)2 were dissolved in a mixed solution of water (15 mL) and ethanol (15 mL) at room temperature. Then, 56 µL of ethanolamine solution was added to the above solution. A blue precipitate formed, and after standing for 18 h, it was collected by centrifugation. The electrocatalyst was then vacuum dried at room temperature for 12 h to obtain the electrocatalyst precursor. 2) After grinding the electrocatalyst precursor into powder, it is evenly spread on a 100 mm thick PI film, and then marked with a CO2 laser at a laser power of 2 W and a scanning speed of 150 mm / s. -1 Under the specified conditions, CO2 laser induction was performed twice in an air atmosphere. After the process, the mixture was ground until homogeneous, washed twice with distilled water, dried at 80℃ for 10 h, and then ground into powder to obtain L2-Mg / Cu. x O electrocatalyst.

[0039] L2-Mg / Cu prepared in Example 2 of this invention x Scanning electron microscope image of O electrocatalyst as follows Figure 16 As shown, the surface morphology of loose nanosheets is exhibited. In this embodiment, insufficient power energy leads to incomplete reaction of the precursor. The heat generated by the low-power laser is only sufficient to slightly activate the particle surface, but far from enough to cause particle fusion or densification sintering. This "weak connection" causes the particles to form a loose nanoflower morphology with low structural strength in order to reduce surface energy during growth.

[0040] L2-Mg / Cu prepared in Example 2 of this invention x The eCO2RR performance of O electrocatalysts is as follows: Figure 17 As shown, the FE of the C2 product is 62.0% and that of ethanol is 38.8% at a voltage of -1.1 V vs. RHE.

[0041] The cycle performance curves of the Li-CO2 battery assembled according to Example 2 are as follows: Figure 18 As shown, at a current density of 0.2 mA cm⁻¹ -2And the specific capacity is limited to 500 mAh g -1 Under these conditions, L2-Mg / Cu x The O electrocatalyst can achieve 115 stable cycles.

[0042] The first discharge curve measured according to Example 2 of the Li-CO2 battery assembly is as follows: Figure 19 As shown, at 0.1 mA cm -2 At current density, L2-Mg / Cu x O has 12482 mAh g -1 The specific discharge capacity.

[0043] Example 3 1) First, 0.2250 g Cu(NO3)2 and 0.9552 g Mg(NO3)2 were dissolved in a mixed solution of water (15 mL) and ethanol (15 mL) at room temperature. Then, 56 µL of ethanolamine solution was added to the above solution. A blue precipitate formed, and after standing for 18 h, it was collected by centrifugation. The electrocatalyst was then vacuum dried at room temperature for 12 h to obtain the electrocatalyst precursor. 2) After grinding the electrocatalyst precursor into powder, it is evenly spread on a 100 mm thick PI film, and then marked with a CO2 laser at a laser power of 6 W and a scanning speed of 150 mm / s. -1 Under the specified conditions, CO2 laser induction was performed twice in an air atmosphere. After the process, the mixture was ground until homogeneous, washed twice with distilled water, dried at 80℃ for 10 h, and then ground into powder to obtain L6-Mg / Cu. x O electrocatalyst.

[0044] L6-Mg / Cu prepared in Example 3 of this invention x Scanning electron microscope image of O electrocatalyst as follows Figure 20 As shown, the surface morphology of nanoflowers assembled from nanosheets is revealed. The nanosheets are more aggregated because the high heat input provides sufficient kinetic energy for the nanoparticles, causing them to migrate and fuse, with small particles merging into larger particles.

[0045] L6-Mg / Cu prepared in Example 3 of this invention x The eCO2RR performance of O electrocatalysts is as follows: Figure 21 As shown, at a voltage of -1.1 V vs. RHE, the FE of the C2 product is 70.4%, and the FE of ethanol is 42.6%. High laser power generates high temperatures, causing the catalyst material itself to ablate, evaporate, or even plasmaify. This directly leads to material mass loss, thinning of the physical thickness, and thus a reduction in the total number of active sites.

[0046] The cycle performance curves of the Li-CO2 battery assembled according to Example 3 are as follows: Figure 22 As shown, at a current density of 0.2 mA cm⁻¹ -2 And the specific capacity is limited to 500 mAh g -1 Under these conditions, L6-Mg / Cu x The O electrocatalyst can achieve 144 stable cycles.

[0047] The first discharge curve measured according to Example 3 of the Li-CO2 battery assembly is as follows: Figure 23 As shown, at 0.1 mA cm -2 At current density, L6-Mg / Cu x O has 16576 mAh g -1 The specific discharge capacity.

[0048] Example 4 1) First, 0.2250 g Cu(NO3)2 and 0.9552 g Mg(NO3)2 were dissolved in a mixed solution of water (15 mL) and ethanol (15 mL) at room temperature. Then, 56 µL of ethanolamine solution was added to the above solution. A blue precipitate formed, and after standing for 18 h, it was collected by centrifugation. The electrocatalyst was then vacuum dried at room temperature for 12 h to obtain the electrocatalyst precursor. 2) After grinding the electrocatalyst precursor into powder, it is evenly spread on a 100 mm thick PI film, and then marked with a CO2 laser at a laser power of 8 W and a scanning speed of 150 mm / s. -1 Under the specified conditions, CO2 laser induction was performed twice in an air atmosphere. After the process, the mixture was ground until homogeneous, washed twice with distilled water, dried at 80℃ for 10 h, and then ground into powder to obtain L8-Mg / Cu. x O electrocatalyst.

[0049] L8-Mg / Cu prepared in Example 4 of this invention x Scanning electron microscope image of O electrocatalyst as follows Figure 24 As shown, the surface morphology of nanoflowers assembled from nanosheets is presented, and the nanoflowers are completely aggregated. The reason for this morphology is that the excess energy provided by the high power breaks the balance of maintaining the fine nano morphology, activates processes such as particle fusion and atomic migration to reduce the total surface energy of the system, and ultimately leads to a sharp transformation from a highly dispersed nanostructure to a thermodynamically stable state (aggregate) with low surface area and large size. Aggregate greatly reduces the surface area of ​​the material, resulting in a decrease in performance.

[0050] L8-Mg / Cu prepared in Example 4 of this invention x The eCO2RR performance of O electrocatalysts is as follows: Figure 25As shown, at a voltage of -1.1 V vs. RHE, the FE of the C2 product is 67.1%, and the FE of ethanol is 39.7%. Excessive laser power will generate extreme high temperatures, resulting in greater loss of the catalyst material itself and further reducing the total number of active sites.

[0051] The cycle performance curves of the Li-CO2 battery assembled according to Example 4 are as follows: Figure 26 As shown, at a current density of 0.2 mA cm⁻¹ -2 And the specific capacity is limited to 500 mAh g -1 Under these conditions, L8-Mg / Cu x The O electrocatalyst can achieve 93 stable cycles.

[0052] The first discharge curve measured according to Example 4 of the Li-CO2 battery assembly is as follows: Figure 27 As shown, at 0.1 mA cm -2 At current density, L8-Mg / Cu x O has 11016 mAh g -1 The specific discharge capacity.

[0053] Comparative Example 1 1) First, 0.2250 g of Cu(NO3)2 was dissolved in a mixed solution of water (15 mL) and ethanol (15 mL) at room temperature. Then, 56 µL of ethanolamine solution was added to the above solution. A blue precipitate formed, and after standing for 18 h, it was collected by centrifugation. The electrocatalyst was then vacuum dried at room temperature for 12 h to obtain the electrocatalyst precursor. 2) After grinding the electrocatalyst precursor into powder, it is evenly spread on a 100 mm thick PI film, and then marked with a CO2 laser at a laser power of 4 W and a scanning speed of 150 mm / s. -1 Under the given conditions, CO2 laser induction was performed twice in an air atmosphere. After the process, the mixture was ground until homogeneous, washed twice with distilled water, dried at 80 °C for 10 h, and then ground into powder to obtain the L4-CuO electrocatalyst.

[0054] The scanning electron microscope image of the L4-CuO electrocatalyst prepared in Comparative Example 1 of this invention is shown below. Figure 2 As shown, the morphology of stacked nanoparticles is presented.

[0055] The eCO2RR performance of the L4-CuO electrocatalyst prepared in Comparative Example 1 of this invention is as follows: Figure 3 As shown, the FE of the C2 product is 53.8% and that of ethanol is 22.4% at a voltage of -1.1 V vs. RHE.

[0056] The cycle performance curves of the Li-CO2 batteries assembled according to Comparative Example 1 are as follows: Figure 4 As shown, at a current density of 0.2 mA cm⁻¹ -2 And the specific capacity is limited to 500 mAh g -1 Under certain conditions, the L4-CuO electrocatalyst can achieve 80 stable cycles.

[0057] The initial discharge curve of the Li-CO2 battery assembled according to Comparative Example 1 is shown below. Figure 5 As shown, at 0.1 mA cm -2 At a current density, L4-CuO exhibits a current density of 9346 mAh g. -1 The specific discharge capacity.

[0058] In this comparative example, the L4-CuO catalyst in eCO2RR is limited by its poor intermediate adsorption energy and severe HER side reactions.

[0059] Comparative Example 2 1) First, 0.2250 g Cu(NO3)2 and 0.9552 g Mg(NO3)2 were dissolved in a mixed solution of water (15 mL) and ethanol (15 mL) at room temperature. Then, 56 µL of ethanolamine solution was added to the above solution. A blue precipitate formed, and after standing for 18 h, it was collected by centrifugation. The electrocatalyst was then vacuum dried at room temperature for 12 h to obtain the electrocatalyst precursor. 2) After grinding the electrocatalyst precursor into powder, it was evenly spread in a ceramic boat and placed in a tube furnace under air atmosphere for high-temperature pyrolysis treatment at 300℃ for 30 min, with a heating rate of 2℃ / min. -1 After grinding, the mixture was homogeneous, yielding C. 300 -Mg / CuO electrocatalyst.

[0060] The C prepared in Comparative Example 2 of this invention 300 Scanning electron microscope image of the Mg / CuO electrocatalyst is shown below. Figure 12 As shown, the surface morphology exhibits thick nanosheets and a small number of nanoparticles.

[0061] The C prepared in Comparative Example 2 of this invention 300 The eCO2RR performance of the Mg / CuO electrocatalyst is as follows: Figure 13 As shown, the FE of the C2 product is 57.5% and that of ethanol is 35.6% at a voltage of -1.1 V vs. RHE.

[0062] The cycle performance curves of the Li-CO2 batteries assembled according to Comparative Example 2 are as follows: Figure 14 As shown, at a current density of 0.2 mA cm⁻¹ -2And the specific capacity is limited to 500 mAh g -1 In the case of C 300 The Mg / CuO electrocatalyst can achieve 152 stable cycles.

[0063] The initial discharge curve of the Li-CO2 battery assembled according to Comparative Example 2 is shown below. Figure 15 As shown, at 0.1 mA cm -2 At current density, C 300 -Mg / CuO has 14375 mAh g -1 The specific discharge capacity.

[0064] The high-temperature calcination in the tubular furnace used in this comparative example is a holistic and slow heating method, which easily causes nanoparticles to sinter and agglomerate into a stable state, resulting in a reduction in surface energy, a significant decrease in the specific surface area of ​​the material, and a reduction in active sites.

[0065] Comparative Example 3 1) First, 0.2250 g of Cu(NO3)2 was dissolved in a mixed solution of water (15 mL) and ethanol (15 mL) at room temperature. Then, 56 µL of ethanolamine solution was added to the above solution. A blue precipitate formed, and after standing for 18 h, it was collected by centrifugation. The electrocatalyst was then vacuum dried at room temperature for 12 h to obtain the electrocatalyst precursor. 2) After grinding the electrocatalyst precursor into powder, it was evenly spread in a ceramic boat and placed in a tube furnace under air atmosphere for high-temperature pyrolysis treatment at 300℃ for 30 min, with a heating rate of 2℃ / min. -1 After grinding, the mixture was homogeneous, yielding C. 300 -CuO electrocatalyst.

[0066] C prepared in Comparative Example 3 of this invention 300 Scanning electron microscope image of CuO electrocatalyst as follows: Figure 28 As shown, the surface morphology of small, fragmented nanosheets is revealed.

[0067] C prepared in Comparative Example 3 of this invention 300 - The eCO2RR performance of CuO electrocatalyst is as follows: Figure 29 As shown, the FE of C2 product is 46.8% and that of ethanol is 25.6% at a voltage of -1.1V vs. RHE.

[0068] The cycle performance curves of the Li-CO2 batteries assembled according to Comparative Example 3 are as follows: Figure 30 As shown, at a current density of 0.2 mA cm⁻¹ -2 And the specific capacity is limited to 500 mAh g -1 In the case of C 300-CuO electrocatalyst can achieve 74 stable cycles.

[0069] The initial discharge curve of the Li-CO2 battery assembled according to Comparative Example 3 is shown below. Figure 31 As shown, at 0.1 mA cm -2 At current density, C 300 CuO has 7670 mAh g -1 The specific discharge capacity.

[0070] C obtained by calcination in a tubular furnace 300 -CuO catalyst is a thermodynamically stable electrocatalyst with a simple structure, which cannot effectively solve the key problems in eCO2RR (such as HER competition and high CC coupling energy barrier), resulting in poor electrocatalytic and battery performance.

[0071] In summary, this invention develops a method for synthesizing L by transient CO2 pulsed laser irradiation. 4- Mg / Cu x O electrocatalyst was used as a high-performance Li-CO2 battery cathode catalyst to achieve efficient electrocatalytic activity. L4-Mg / Cu x O-type electrocatalysts exhibit excellent eCO2RR catalytic efficiency, effectively producing ethanol. Meanwhile, the practical application of Li-CO2 batteries, which possess excellent discharge specific capacity and cycle stability, requires stable and efficient electrocatalyst materials. L4-Mg / Cu x O was used as a cathode electrocatalyst in Li-CO2 batteries at a current density of 0.2 mA cm⁻¹. -2 It can achieve 187 stable cycles at 0.1 mA cm⁻¹. -2 At current density, L4-Mg / Cu x O has a capacity of up to 20480 mAh g -1 The discharge specific capacity. Therefore, the novel synthesis method proposed in this invention, namely the method of synthesizing electrocatalysts using pulsed CO2 laser technology, has the advantages of being fast and simple, and the synthesized L4-Mg / Cu x The O electrocatalyst provides insights for the design and fabrication of high-performance Li-CO2 batteries. Furthermore, the method's simple synthesis and preliminary results indicate that the prepared electrocatalyst is a promising eCO2RR electrocatalyst suitable for metal-air batteries and electrocatalysis.

[0072] The specific embodiments of the present invention are written in a progressive manner, emphasizing the differences between the various implementation schemes, and the similar parts can be referred to each other.

[0073] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for preparing nanoflower-like electrocatalysts based on pulsed CO2 laser-induced synthesis, characterized in that, include: At room temperature, copper nitrate and magnesium nitrate are dissolved in a mixed solution of distilled water and ethanol to obtain solution A; An ethanolamine solution was added to solution A. After a blue precipitate appeared, the product was collected by standing and centrifugation. The product was then dried to obtain the electrocatalyst precursor material. The precursor material was ground into powder, uniformly spread on a PI film, and subjected to CO2 laser induction in an air atmosphere. After the induction, the product was allowed to cool to room temperature, washed, dried, and ground into powder to obtain the nanoflower-like electrocatalyst L. y -Mg / Cu x O.

2. The method for preparing the nanoflower-like electrocatalyst based on pulsed CO2 laser-induced synthesis according to claim 1, characterized in that, The molar ratio of magnesium nitrate to copper nitrate is 4:

1.

3. The method for preparing the nanoflower-like electrocatalyst based on pulsed CO2 laser-induced synthesis according to claim 1, characterized in that, The settling time is 18 hours.

4. The method for preparing the nanoflower-like electrocatalyst based on pulsed CO2 laser-induced synthesis according to claim 1, characterized in that, The centrifuged product is first washed 2-3 times with distilled water, and then filtered once with ethanol.

5. The method for preparing the nanoflower-like electrocatalyst based on pulsed CO2 laser-induced synthesis according to claim 1, characterized in that, The drying method for obtaining the electrocatalyst precursor material after drying the product is: vacuum drying at room temperature for 12 h.

6. The method for preparing the nanoflower-like electrocatalyst based on pulsed CO2 laser-induced synthesis according to claim 1, characterized in that, The CO2 laser induction was performed twice, with a power of 2-8 W and a scan rate of 150 mm / s. -1 .

7. The method for preparing the nanoflower-like electrocatalyst based on pulsed CO2 laser-induced synthesis according to claim 1, characterized in that, The product is then washed, dried, and ground into powder. The drying method is forced air drying, the drying temperature is 80±10 ℃, and the drying time is 10-12 h.

8. The nanoflower-like electrocatalyst based on pulsed CO2 laser-induced synthesis obtained by any of the preparation methods described in claims 1-7.

9. The application of the nano-flower-like electrocatalyst according to claim 8, characterized in that, The catalyst is used as an electrocatalyst for eCO2RR to ethanol production and as a cathode catalyst for Li-CO2 batteries.

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