A method for constructing a heterostructure based on thermally induced electron transfer

Abstract

The application relates to a method for constructing a heterostructure based on thermally induced electron transfer, which comprises the following steps: step one, respectively dissolving an alkaline earth metal salt compound and a platinum group metal salt compound in a solvent to obtain two solutions, mixing the two solutions in equal volumes to obtain a precursor solution; step two, immersing a substrate in the precursor solution at room temperature, taking out and drying to obtain an impregnated substrate; step three, using direct current to perform non-equilibrium transient high-temperature treatment on the impregnated substrate obtained in step two at room temperature in an air atmosphere, realizing electron rearrangement transfer, and obtaining a heterostructure constructed based on thermally induced electron transfer. The application realizes rapid oxidation-reduction reaction, electron reconstruction and lattice distortion, constructs a heterostructure of two or more oxides, and ensures that the heterostructure has super-long-time load stability and performance stability.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to a method for constructing heterostructures based on thermally induced electron transfer. Background Technology

[0002] Alkaline earth metal oxides mainly include oxides of beryllium, magnesium, calcium, strontium, barium, and radium. Due to their excellent electrical conductivity, alkaline earth oxide materials are considered potential candidates for water splitting electrocatalysts, effectively promoting electron transfer and accelerating water molecule splitting reactions. On the other hand, they are also widely used in the field of semiconductor electronic devices. For example, calcium oxide is used as a getter to remove harmful gases generated during semiconductor device manufacturing. Barium oxide is used as a photoelectric material to achieve photoelectric conversion or optical signal detection. Strontium oxide can be used in solid capacitors, electronic measuring instruments, and other fields; its high melting point and stability make it an indispensable component of these devices.

[0003] Platinum group metal nanomaterials, as sensing materials, can accelerate electrode reactions, thereby improving sensitivity. When introduced into suitable solid supports, they not only serve as carriers but also significantly influence surface chemistry and electronic structure, facilitating the stable construction of heterogeneous interfaces and enhancing electrochemical activity.

[0004] However, single oxides often face performance bottlenecks in practical applications, such as limited activity, high internal transport resistance, and insufficient stability, making it difficult to meet the stringent requirements of high efficiency and durability in industrial applications. Meanwhile, the composite process of multiple oxides faces challenges such as difficulty in achieving simultaneous uniformity, weak interfacial bonding, and susceptibility to detachment or phase transition under prolonged operation. These challenges severely hinder the development and application of high-performance composite oxides.

[0005] Therefore, there is an urgent need for a method to construct heterostructures based on thermally induced electron transfer. By combining alkaline earth metals with platinum group metals, electron reconstruction is effectively achieved to form oxide heterostructures. Utilizing the difference in thermal expansion between the metal support and the substrate, non-equilibrium Joule thermal radiation treatment is applied to the material to achieve electron reconstruction and lattice distortion, thereby improving the stability of the connection between the heterostructure and the substrate. Summary of the Invention

[0006] To address the aforementioned problems, this invention proposes a method for constructing heterostructures based on thermally induced electron transfer.

[0007] This invention relates to a method for constructing heterostructures based on thermally induced electron transfer, comprising the following steps:

[0008] Step 1: Dissolve the salt compounds of alkaline earth metals and the salt compounds of platinum group metals in solvents to prepare two solutions. Mix the two solutions in equal volumes to prepare the precursor solution.

[0009] Step 2: Immerse the substrate in the precursor solution at room temperature, remove it and dry it to obtain the impregnated substrate;

[0010] Step 3: At room temperature and in an air atmosphere, the substrate obtained in Step 2 after impregnation is subjected to non-equilibrium instantaneous high temperature treatment using direct current to achieve electron rearrangement and transfer, thereby obtaining a heterostructure constructed based on thermally induced electron transfer.

[0011] Furthermore, in step one, the alkaline earth metal salt compound is a strontium salt, and the platinum group metal salt compound is a ruthenium salt.

[0012] Furthermore, in step one, the strontium salt or ruthenium salt is one of the following: chloride salt, nitrate salt, sulfate salt, or acetate salt.

[0013] Furthermore, in step one, the concentration of strontium salt is 0.5 mol / L to 2.0 mol / L, and the concentration of ruthenium salt is 1 mmol / L to 3 mmol / L.

[0014] Furthermore, in step one, the solvent is deionized water or ethanol.

[0015] Furthermore, in step two, the substrate is carbon cloth, carbon paper, nickel foam, or nickel mesh.

[0016] Furthermore, in step two, the time for immersing the substrate in the precursor solution is 2 min to 10 min.

[0017] Furthermore, in step two, the substrate is dried in an air atmosphere at a temperature of 60℃~70℃ for 1h~2h.

[0018] Furthermore, in step three, the temperature for non-equilibrium instantaneous high-temperature treatment of the substrate is 800℃~1000℃, and the treatment time is 1s~10s.

[0019] Beneficial effects

[0020] This invention designs a rapid redox reaction to achieve electronic reconstruction and lattice distortion, constructing a heterostructure of two or more oxides, and ensuring that the heterostructure has ultra-long-term load stability and performance stability.

[0021] 1. This invention effectively achieves electronic reconstruction to form an oxide heterostructure by combining alkaline earth metal elements with platinum group metal elements, thereby enhancing the stability of the heterostructure and achieving performance retention over an ultra-long period of time.

[0022] 2. This invention utilizes the difference in thermal expansion between the metal support and the substrate. By subjecting the material to non-equilibrium Joule thermal radiation treatment, the compound is oxidized and stably composited, achieving electronic reconstruction and lattice distortion, and improving the stability of the connection between the heterostructure and the substrate.

[0023] 3. This invention develops a heterostructure material and its preparation method that can stably coexist with multiple oxide components, possess excellent performance, and maintain long-term performance stability. This has significant scientific and practical value for promoting the commercialization of electrocatalytic water splitting hydrogen production technology, improving the sensitivity of metal oxide-based gas-sensitive resistor sensors, and accelerating the rapid development of the semiconductor electronic device industry. Attached Figure Description

[0024] Figure 1a This is a microscopic morphology image of a heterostructure constructed based on thermally induced electron transfer, prepared according to Example 1 of the present invention.

[0025] Figure 1b This is a microscopic morphology image of a heterostructure constructed based on thermally induced electron transfer, prepared according to Example 2 of the present invention.

[0026] Figure 1c This is a microscopic morphology image of a heterostructure constructed based on thermally induced electron transfer, prepared in Example 3 of the present invention.

[0027] Figure 2 The images show the X-ray diffraction (XRD) results of the heterostructures constructed based on thermally induced electron transfer prepared in Examples 1 to 3 of this invention.

[0028] Figure 3a The spectrum of Sr 3d prepared based on thermally induced electron transfer to construct a heterostructure is shown in Example 1 of this invention.

[0029] Figure 3b The spectra of C1s and Ru 3d based on thermally induced electron transfer to construct heterostructures are shown in Example 1 of this invention.

[0030] Figure 3c The spectrum of Ru 3p, a heterostructure constructed based on thermally induced electron transfer, prepared according to Example 1 of the present invention;

[0031] Figure 4 The polarization curve of the heterostructure constructed based on thermally induced electron transfer prepared in Example 1 of the present invention is shown.

[0032] Figure 5 This is an overpotential histogram prepared based on thermally induced electron transfer to construct a heterostructure, as shown in Example 1 of the present invention.

[0033] Figure 6This refers to the long-term stable test chronopotential results of the heterostructure constructed based on thermally induced electron transfer prepared in Embodiment 1 of the present invention;

[0034] Figure 7a This is a graph showing the distribution of alkaline earth metal Sr elements in the heterostructure constructed based on thermally induced electron transfer prepared in Example 1 of the present invention after a long-term stability test.

[0035] Figure 7b This is a graph showing the distribution of Ru, a platinum group metal, in a heterostructure constructed based on thermally induced electron transfer, after a long-term stability test, as shown in Example 1 of the present invention.

[0036] Figure 7c This is a graph showing the O element distribution of the heterostructure constructed based on thermally induced electron transfer prepared in Embodiment 1 of the present invention after a long-term stability test.

[0037] Figure 7d The distribution of Ni elements in the substrate of the heterostructure constructed based on thermally induced electron transfer prepared in Embodiment 1 of the present invention after long-term stability testing is shown.

[0038] Figure 8a The image shows a bright-field transmission electron microscope image of a heterostructure constructed based on thermally induced electron transfer, prepared according to Example 1 of the present invention.

[0039] Figure 8b Selected-area electron diffraction results under a transmission electron microscope for the heterostructure constructed based on thermally induced electron transfer prepared in Embodiment 1 of the present invention;

[0040] Figure 8c This is a high-resolution transmission electron microscope image of a heterostructure constructed based on thermally induced electron transfer, prepared according to Embodiment 1 of the present invention.

[0041] Figure 9 Impedance map of a heterostructure constructed based on thermally induced electron transfer, prepared according to Embodiment 1 of the present invention. Detailed Implementation

[0042] The following describes this embodiment in detail with reference to Figures 1 to 9.

[0043] This invention relates to a method for constructing heterostructures based on thermally induced electron transfer, comprising the following steps:

[0044] Step 1: Dissolve the salt compounds of alkaline earth metals and platinum group metals in solvents to prepare two solutions. Mix the two solutions in equal volumes to obtain the precursor solution.

[0045] The alkaline earth metal salt is a strontium salt, and the platinum group metal salt is a ruthenium salt; the type of strontium salt or ruthenium salt is one of chloride, nitrate, sulfate or acetate; the concentration of strontium salt is 0.5 mol / L to 2.0 mol / L, and the concentration of ruthenium salt is 1 mmol / L to 3 mmol / L.

[0046] The solvent used in step one is deionized water or ethanol.

[0047] Step 2: Immerse the substrate in the precursor solution at room temperature, remove it and dry it to obtain the impregnated substrate.

[0048] The substrate is carbon cloth, carbon paper, nickel foam, or nickel mesh.

[0049] The substrate is immersed in the precursor solution for 2 to 10 minutes.

[0050] The substrate was dried in an air atmosphere at a temperature of 60℃~70℃ for 1h~2h.

[0051] Step 3: At room temperature and in an air atmosphere, the substrate obtained in Step 2 after impregnation is subjected to non-equilibrium instantaneous high temperature treatment using direct current to achieve electron rearrangement and transfer, thereby obtaining a heterostructure constructed based on thermally induced electron transfer.

[0052] The temperature for non-equilibrium instantaneous high-temperature treatment of the substrate is 800℃~1000℃, and the treatment time is 1s~10s.

[0053] Example 1

[0054] A method for constructing heterostructures based on thermally induced electron transfer includes the following steps:

[0055] Step 1: Dissolve strontium chloride and ruthenium chloride separately in deionized water to prepare two solutions. Mix the two solutions in equal volumes to prepare the precursor solution.

[0056] The concentration of strontium chloride in the precursor solution was 1.0 mol / L, and the concentration of ruthenium chloride was 3 mmol / L.

[0057] Step 2: Immerse the substrate in the precursor solution for 5 minutes at room temperature, then remove it and dry it in an air atmosphere at 60°C for 2 hours to obtain the impregnated substrate.

[0058] The substrate used in step two is nickel foam, with dimensions of 2cm×1cm×1.6mm.

[0059] Step 3: Under normal temperature and air atmosphere, the impregnated substrate is subjected to non-equilibrium instantaneous high temperature treatment with a DC voltage of 20-30V and a current of 30A-50A. The treatment temperature is 800℃ and the time is 10s to obtain a heterostructure based on thermally induced electron transfer.

[0060] Example 2

[0061] The difference between this embodiment and Embodiment 1 is that the non-equilibrium instantaneous high-temperature treatment in step three is performed at a temperature of 900°C. Everything else is the same as in Embodiment 1.

[0062] Example 3

[0063] The difference between this embodiment and Embodiment 1 is that the non-equilibrium instantaneous high-temperature treatment in step three is performed at a temperature of 1000℃. Everything else is the same as in Embodiment 1.

[0064] Example 4

[0065] The difference between this embodiment and Embodiment 1 is that the concentration of ruthenium chloride in the precursor solution in step one is 1 mmol / L. Everything else is the same as in Embodiment 1.

[0066] Example 5

[0067] The difference between this embodiment and Embodiment 1 is that the concentration of ruthenium chloride in the precursor solution in step one is 2 mmol / L. Everything else is the same as in Embodiment 1.

[0068] Figure 1a This is a microscopic morphology diagram of Embodiment 1 of the present invention. Figure 1b These are microscopic morphology images of Example 2. Figure 1c This is a microstructure diagram of Example 3. The microstructures obtained from each example are basically consistent, indicating that the change in the maximum temperature during the instantaneous high-temperature process has little impact on the microstructure. The products obtained from impregnation loading are all distributed in dense and uniform fine blocky form. This morphological characteristic effectively increases the specific surface area, which is conducive to the full occurrence of surface chemical reactions.

[0069] Figure 2 The figures show the X-ray diffraction (XRD) results of heterostructures constructed based on thermally induced electron transfer prepared in Examples 1 to 3. As can be seen from the figures, the samples treated at 800℃, 900℃, and 1000℃ as the highest instantaneous temperatures exhibit the same diffraction peaks, which are consistent with the JDPSD cards 21-1172RuO2 and 01-1113SrO2, indicating that the simultaneous presence of oxides was successfully prepared through short-duration high-temperature thermal radiation, forming a heterostructure.

[0070] Figure 3 shows the X-ray photoelectron spectroscopy (XPS) results of a heterostructure constructed based on thermally induced electron transfer prepared in Example 1. The lower left corner of each sample in the figure is labeled with the metal element contained in the precursor solution, and the single metal element is the control sample. Figure 3a This is the Sr 3d spectrum. Both Example 1 and the control sample show two peaks, corresponding to Sr... 2+ 3D 3 / 2 and Sr 2+ 3D 5 / 2 In the control sample containing only Sr as the precursor solution, the binding energies of the two peaks were ~135.89 eV and ~134.11 eV. However, in the sample with added Ru, i.e. Example 1, the peak position of Sr 3d showed a significant negative shift, with binding energies at ~134.77 eV and ~133.04 eV, respectively. Figure 3a This indicates that the Sr oxidation state is lower in the heterostructure, suggesting a tendency to gain electrons. The addition of platinum group elements modulates the electron distribution in the heterostructure.

[0071] Figure 3b These are the spectra of C1s and Ru 3d. Because a specific amount of C is added to the sample surface for calibration, the samples all exhibit characteristic C1s signals, containing three peaks attributed to O–C–O (~289.31 eV), C=O (~286.12 eV), and C–C (~284.80 eV). Figure 3b Fitting was performed at the Ru 3d peak position. Compared with the control sample, the Ru 3d peak position in Example 1 showed a significant positive shift. The fitting results showed that ~282.21 eV and ~278.99 eV corresponded to Ru 3d peaks, respectively. 0 3D 3 / 2 and Ru 0 3D 5 / 2 In addition, ~283.01 eV and ~280.47 eV correspond to Ru respectively. 4+ 3D 3 / 2 and Ru 4+ 3D 5 / 2 .

[0072] Figure 3c This is the spectrum of Ru 3p. The Ru 3p spectrum of Example 1 can be fitted and divided into four peaks, with binding energies of ~484.07 eV and ~461.66 eV, corresponding to Ru 0 3p 1 / 2 and Ru 0 3p 3 / 2 The binding energies are ~485.89 eV and ~463.85 eV, corresponding to Ru 4+ 3p 1 / 2 and Ru 4+ 3p 3 / 2 .

[0073] comprehensive Figure 3b and Figure 3c The results indicate that Ru in the sample does not exist as a pure element, but rather as Ru in a higher valence state. From the precursor, Ru... 3+ Analysis of the results after transient high-temperature treatment shows that both oxidation and reduction processes occur during the non-equilibrium transient high-temperature process, and electron transfer processes are evident, constructing heterostructures and enriching the valence and ionic states of Ru.

[0074] Figure 4 The polarization curve of the heterostructure constructed based on thermally induced electron transfer prepared in Example 1; Figure 5 This is a histogram of overpotentials for the heterostructure constructed based on thermoinduced electron transfer prepared in Example 1. Chronopotential analysis was performed on this heterostructure in 1M KOH electrolyte. For the OER reaction, the overpotential reached 10 mA / cm². 2 The current density required only an overpotential of 199.84 mV indicates that the composite heterostructure of multiple oxides, as an electrocatalyst, effectively reduces the overpotential of the water electrolysis reaction and reduces energy consumption. Figure 4 and Figure 5 The data results fully demonstrate that the heterostructure prepared by the method in Example 1 can be effectively applied in the field of electrocatalysis.

[0075] Figure 6 This is the time-lapse potential result for a long-term stable test of the heterostructure constructed based on thermally induced electron transfer, prepared in Example 1. To verify the service stability of the heterostructure, a constant current density (10 mA cm⁻¹) was used. -2 Chronopotential data were collected. Since the reaction process consumes electrolyte, the arrows in the figure indicate where electrolyte is replenished; electrolyte is replenished approximately every 900 hours to ensure the reaction continues. The potential stabilized at 1.575V vs. RHE, and this performance lasted for at least 3790 hours (approximately 157 days), indicating that this heterostructure possesses good electrochemical stability.

[0076] Figure 7 shows the surface scan energy dispersive spectroscopy results of the heterostructure constructed based on thermally induced electron transfer prepared in Example 1 after long-term stability testing. Figure 7a This is the distribution result of the alkaline earth metal Sr element; Sr element still exists and is evenly distributed. Figure 7b This is the distribution result of the platinum group metal Ru. Ru has been confirmed to exist and its distribution is uniform. Figure 7c This is the distribution result of element O; element O exists and is evenly distributed. Figure 7dThe results show the distribution of Ni in the substrate, which exhibits a uniform distribution, demonstrating the integrity of the substrate material. Continuous long-term constant-current testing proves that the heterostructure formed by the prepared alkaline earth metal oxide and platinum group metal oxide is stable under load and will not change or detach due to reaction.

[0077] Figure 8 shows the characterization results of a heterostructure constructed based on thermally induced electron transfer prepared in Example 1 under a transmission electron microscope. Figure 8a This is the result of a transmitted bright-field image. From Figure 8a It can be seen that the sample has a nanorod morphology with a diameter of about 30 nm, and the rod structure has good homogeneity.

[0078] Figure 8b These are selected area electron diffraction results. The characterization results show a ring-shaped pattern, which is characteristic of polycrystalline materials. The diffraction rings (from the inside to the outside) in the figure can be attributed to the (0 0 2) and (1 0 3) crystal planes of SrO2, and the (2 2 0) and (3 0 1) crystal planes of RuO2, respectively, further confirming that both alkaline earth metal oxides and platinum group metal oxides exist in the sample phase.

[0079] Figure 8c This is a high-resolution transmission electron microscope image. As can be seen from the image, by calculating the crystal planes with different orientations within the same selected area, we can obtain a crystal plane spacing of 0.330 nm from the (0 0 2) plane of SrO2 and a lattice spacing of 0.317 nm corresponding to the (1 1 0) plane of RuO2, which further confirms the formation of the oxide heterostructure.

[0080] The characterization results in Figure 8 indicate that the heterostructure exhibits a near-parallel, unidirectional arrangement of nanorods, effectively increasing the microscopic specific surface area, exposing more active sites, and thus improving the efficiency of material transport. The large overall bonding sites between the nanorods and the substrate are the reason for the stable loading and resistance to detachment.

[0081] Figure 9 This is an impedance diagram of the heterostructure constructed based on thermally induced electron transfer prepared in Example 1. The sample names in the diagram represent the metal elements contained in the precursor solution, and the single metal element is the control sample. Charge transfer resistance can be reflected by the impedance diagram; at open-circuit potential, the steeper the slope of the curve, the smaller the transfer resistance. Figure 9 As shown, the impedance curves of heterostructures formed by multiple oxides have a steeper slope, indicating that designing a heterogeneous interface reduces the interfacial charge transfer resistance, which is more conducive to charge transport. Secondly, even small changes in impedance can significantly affect the output signal; therefore, a smaller initial impedance improves the sensitivity of the gas-sensitive resistor sensor to changes in gas concentration. A smaller intrinsic resistance expands the adjustment range and also facilitates more precise resistance adjustment, improving sensing accuracy.

[0082] The above description of the present invention is only a preferred embodiment of the present invention and is not intended to limit the implementation of the present invention. Those skilled in the art can easily make corresponding modifications or alterations based on the main concept and spirit of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of protection claimed in the claims.

Claims

1. A method for constructing heterostructures based on thermally induced electron transfer, characterized in that, Includes the following steps: Step 1: Dissolve the salt compounds of alkaline earth metals and platinum group metals in solvents to prepare two solutions, respectively. Mix these two solutions in equal volumes to prepare a precursor solution. The alkaline earth metal salt compound is a strontium salt, and the platinum group metal salt compound is a ruthenium salt. The concentration of the strontium salt is 0.5 mol / L to 2.0 mol / L, and the concentration of the ruthenium salt is 1 mmol / L to 3 mmol / L. Step 2: Immerse the substrate in the precursor solution at room temperature, remove it and dry it to obtain the impregnated substrate; Step 3: At room temperature and in an air atmosphere, the substrate obtained in Step 2 after impregnation is subjected to non-equilibrium instantaneous high temperature treatment using direct current to achieve electron rearrangement and transfer, thereby obtaining a heterostructure constructed based on thermally induced electron transfer.

2. The method for constructing heterostructures based on thermally induced electron transfer according to claim 1, characterized in that, In step one, the strontium or ruthenium salt is one of the following: chloride, nitrate, sulfate, or acetate.

3. The method for constructing heterostructures based on thermally induced electron transfer according to claim 1, characterized in that, In step one, the solvent is deionized water or ethanol.

4. The method for constructing heterostructures based on thermally induced electron transfer according to claim 1, characterized in that, In step two, the substrate is carbon cloth, carbon paper, nickel foam, or nickel mesh.

5. The method for constructing heterostructures based on thermally induced electron transfer according to claim 1, characterized in that, In step two, the substrate is immersed in the precursor solution for 2 to 10 minutes.

6. The method for constructing heterostructures based on thermally induced electron transfer according to claim 1, characterized in that, In step two, the substrate is dried in an air atmosphere at a temperature of 60℃~70℃ for 1h~2h.

7. The method for constructing heterostructures based on thermally induced electron transfer according to claim 1, characterized in that, In step three, the temperature for non-equilibrium instantaneous high-temperature treatment of the substrate is 800℃~1000℃, and the treatment time is 1s~10s.

Images