Metal / alloy micro-nano three-dimensional structure preparation method based on complexation reaction

Abstract

The invention discloses a metal / alloy micro-nano three-dimensional structure preparation method based on complex reaction, and relates to the technical field of micro-nano three-dimensional structure preparation, and the specific method comprises the following steps: S1, synthesizing photoresist by taking acrylic acid as a polymerization monomer; s2, processing and forming photoresist through a femtosecond laser two-photon polymerization technology to obtain a three-dimensional polymer bracket; and S3, the three-dimensional polymer support is subjected to a complexation reaction in a metal salt solution, a sample is sintered after the reaction, and the metal / alloy micro-nano three-dimensional structure is obtained. The method is compatible with various metal elements, the machining resolution reaches the submicron level, and a solid foundation is laid for application of a metal / alloy micro-nano three-dimensional structure in the fields of nano optics, micro robots, mechanical metamaterials and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-nano three-dimensional structure preparation, and particularly to a method for preparing metal / alloy micro-nano three-dimensional structures based on complexation reactions. Background Art

[0002] Metal / alloy micro-nano three-dimensional structures have broad application prospects in advanced technical fields such as mechanical metamaterials, nano-optics, and microrobots. However, current metal and alloy preparation technologies still have some limitations. First, traditional additive manufacturing technologies are limited by the physical size of the nozzle and the rheological properties of the material, and their processing resolution is generally limited to dozens to hundreds of micrometers, making it difficult to meet the requirements for high-precision structures in the field of micro-nano devices. Second, deposition-based processing methods, such as template-assisted methods, have high requirements for the properties (electrical conductivity, thermal stability, chemical compatibility) of the processing substrate, and the structure is easily damaged during the demolding stage. Although focused electron and ion beam deposition has high precision, the point-by-point scanning efficiency is low, and the high-energy beam during the deposition process may damage the substrate, introducing thermal stress or contamination, resulting in limited material purity. The material compatibility of optical force trapping and photoreduction methods is poor, and there are special requirements for the surface plasmon resonance frequency or reducibility of metals, and only inert metals such as gold and silver can be processed.

[0003] Emerging preparation technologies that have emerged in recent years, such as the method of two-photon polymerization combined with sintering post-treatment, can prepare high-fidelity metal micro-nano three-dimensional structures with feature sizes in the nanometer range. However, due to the special chemical properties of some metals, such as the strong oxidizing property of iron ions that quenches free radicals during the two-photon polymerization process, it is impossible to process this type of metal. The method based on scaffold adsorption avoids the above problems by introducing metal ions after printing. However, this type of method only uses the physical diffusion of metal ions to enter the scaffold, resulting in a weak binding force between it and the scaffold, limiting the metal ion loading capacity of the scaffold and causing a large number of defects inside the sintered structure. Summary of the Invention

[0004] Based on the technical problems existing in the background art, the present invention proposes a method for preparing metal / alloy micro-nano three-dimensional structures based on complexation reactions. This method is compatible with a variety of metal elements, and the processing resolution reaches the sub-micron level, laying a solid foundation for the application of metal / alloy micro-nano three-dimensional structures in fields such as nano-optics, microrobots, and mechanical metamaterials.

[0005] The method for preparing metal / alloy micro-nano three-dimensional structures based on complexation reactions proposed by the present invention is as follows:

[0006] S1: Synthesize a photoresist using acrylic acid as a polymerization monomer;

[0007] S2: Process and form the photoresist through femtosecond laser two-photon polymerization technology to obtain a three-dimensional polymer scaffold;

[0008] S3: Complex the three-dimensional polymer scaffold in a metal salt solution, and after the reaction, sinter the sample to obtain a metal / alloy micro-nano three-dimensional structure.

[0009] Preferably, a crosslinking agent, a photoinitiator, and a thickening agent are further added in S1.

[0010] Preferably, the crosslinking agent is one or more of pentaerythritol triacrylate, polyethylene glycol diacrylate, and trimethylolpropane triacrylate.

[0011] Preferably, the photoinitiator is one or more of tetraethyl rhodamine ketone, coumarin, and photoinitiator 369.

[0012] Preferably, the thickening agent is polyvinylpyrrolidone.

[0013] Preferably, the metal salt in S3 is one or more of iron nitrate, nickel nitrate, cobalt nitrate, copper nitrate, chromium nitrate, silver nitrate, and gold chloride.

[0014] Preferably, the temperature of the complexation reaction is 80 - 90 °C, and the time is not less than 120 min.

[0015] Preferably, the sintering conditions in S3 are as follows:

[0016] Heat up to 140 - 160 °C at a rate of 1 - 2 °C / min and hold for 60 min;

[0017] Continue to heat up to 280 - 320 °C at a rate of 1 - 2 °C / min;

[0018] Continue to heat up to 400 °C at a rate of 0.5 °C / min and hold for 60 min;

[0019] Continue to heat up to 580 - 620 °C at a rate of 1 - 2 °C / min and hold for 120 min;

[0020] Finally, cool to room temperature.

[0021] Preferably, when the metal after sintering in S3 is an oxide, a reduction treatment is further carried out, and the reduction conditions are: reducing the metal oxide in the sintered polymer scaffold with a mixed gas of hydrogen and an inert gas.

[0022] Preferably, the reduction conditions are as follows:

[0023] The hydrogen content in the mixed gas is 3 - 5%, and the ventilation rate of the mixed gas is 0.2 - 0.4 SLM (standard liter per minute);

[0024] Heat it up to 800 - 1300 °C at a rate of 1 - 2 °C / min, keep it for more than 120 min, and then cool it to room temperature.

[0025] Advantageous technical effects of the present invention:

[0026] The present invention introduces metal ions into the polymerized scaffold through complexation reactions, overcoming the problem that certain metal ions (such as iron ions and copper ions) quench free radicals in the two-photon polymerization process and hinder the formation of three-dimensional structures. It has good compatibility with various metals, broadening the material selection range for metal / alloy nano-additive manufacturing. Description of the drawings

[0027] Figure 1 Schematic diagram of the preparation method of the metal / alloy micro-nano three-dimensional structure proposed by the present invention;

[0028] Figure 2 Schematic diagram of the femtosecond laser two-photon polymerization processing optical path proposed by the present invention;

[0029] Figure 3 Schematic diagram of the polymerization process and optical microscope image of the metal / alloy micro-nano three-dimensional structure proposed by the present invention, where a is the schematic diagram of the polymerization process and b is the optical microscope image;

[0030] Figure 4 Scanning electron microscope images of different metal / alloy micro-nano three-dimensional structures proposed by the present invention, where a is Fe, b is Co, c is Ni, d is Au, e is Ag, f is Cu, g is Cr, h is Ni, Co alloy, and i is Ni, Co, Cu alloy;

[0031] Figure 5 Scanning electron microscope images of the surface morphology of different morphologies of nickel-cobalt alloy micro-nano three-dimensional structures proposed by the present invention, where a is octahedral truss lattice, b is orthorhombic nanowires, c is cubic lattice, and d is octahedral truss unit;

[0032] Figure 6 EDS element distribution map and energy spectrum diagram of the sintered metal / alloy micro-nano three-dimensional structure proposed by the present invention, where a is NiO micro-nano three-dimensional structure, b is Ni element distribution map of NiO micro-nano three-dimensional structure, c is O element distribution map of NiO micro-nano three-dimensional structure, d is C element distribution map of NiO micro-nano three-dimensional structure, e is CoO micro-nano three-dimensional structure, f is Co element distribution map of CoO micro-nano three-dimensional structure, g is O element distribution map of CoO micro-nano three-dimensional structure, h is C element distribution map of NiO micro-nano three-dimensional structure, and i is Ni 0.5 Co 0.5 O micro-nano three-dimensional structure, j is Ni 0.5 Co 0.5Ni element distribution map of the O micro-nano three-dimensional structure, where k is Ni 0.5 Co 0.5 Co element distribution map of the O micro-nano three-dimensional structure, where l is Ni 0.5 Co 0.5 O element distribution map of the O micro-nano three-dimensional structure, m is the energy spectrum diagram of the NiO micro-nano three-dimensional structure, n is the energy spectrum diagram of the CoO micro-nano three-dimensional structure, and o is Ni 0.5 Co 0.5 Energy spectrum diagram of the O micro-nano three-dimensional structure;

[0033] Figure 7 EDS element distribution map and energy spectrum diagram after reduction of the metal / alloy micro-nano three-dimensional structure proposed by the present invention. Among them, a is the Co micro-nano three-dimensional structure and Co element distribution map, b is the Cu micro-nano three-dimensional structure and Cu element distribution map, c is the Ni-Co alloy micro-nano three-dimensional structure and Ni, Co, O element distribution map, d is the Ni-Co-Cu alloy micro-nano three-dimensional structure and Ni, Co, Cu element distribution map, e is the energy spectrum diagram of the Co micro-nano three-dimensional structure, f is the energy spectrum diagram of the Cu micro-nano three-dimensional structure, g is the energy spectrum diagram of the Ni-Co alloy micro-nano three-dimensional structure, and h is the energy spectrum diagram of the Ni-Co-Cu alloy micro-nano three-dimensional structure;

[0034] Figure 8 XRD pattern of the metal / alloy micro-nano three-dimensional structure proposed by the present invention. a is the sintered NiO micro-nano three-dimensional structure, b is the sintered CoO micro-nano three-dimensional structure, c is the sintered Ni-CoO micro-nano three-dimensional structure, d is the reduced Ni micro-nano three-dimensional structure, e is the reduced Co micro-nano three-dimensional structure, and f is the reduced Ni-Co alloy micro-nano three-dimensional structure. Detailed implementation manners

[0035] The present invention will be further explained below in conjunction with specific embodiments.

[0036] Example 1

[0037] Mix acrylic acid (AAc) and pentaerythritol triacrylate (PETA, crosslinking agent) in a mass ratio of 10:1 to form a prepolymer solution. Subsequently, add ethyl methyl ketone (EMK, photoinitiator, 1.1 wt%) and polyvinylpyrrolidone (PVP, thickener, 10 wt%) to it in sequence and shake well to obtain a mixed solution. Finally, ultrasonicate the mixed solution for 2 hours to ensure that the solute is fully dispersed, and finally obtain a uniform and transparent photoresist.

[0038] Use a pipette to take a portion of the prepared photoresist and drop it onto a sapphire glass slide. The sapphire material can withstand temperatures above 2000 °C, which can meet the requirements of subsequent sintering and reduction processes. To avoid interference of the polymerized part with the laser, we adopt an inverted processing method. Stick double-sided tape on both sides of the sapphire glass slide and paste a cover glass on top of it. Then place the sample upside down on the piezoelectric displacement stage. The light emitted by the femtosecond laser passes through the preset optical path, the scanning galvanometer, and finally is focused inside the photoresist through a 60x oil immersion objective. The femtosecond laser two-photon polymerization processing optical path is as shown in Figure 2 ; The exposed area will undergo a polymerization reaction to form a polymer. The laser changes with the movement of the piezoelectric platform and the rotation of the scanning galvanometer, thereby guiding the laser scanning path, and a three-dimensional structure can be printed. The processing and polymerization process are as shown in Figure 3 .

[0039] Place the sapphire glass slide processed by the femtosecond laser in ethanol for development for more than 30 minutes to remove the unexposed photoresist and obtain polymer scaffolds of different shapes. Immerse the developed sample in a metal salt solution (0.3 mol / L) to complete the complexation reaction. Set the soaking conditions as follows: the soaking time is controlled to be more than 120 minutes, the solution temperature is 90 °C, and the pH value is 5 (the pH of the metal salt solution is the precipitation limit pH of metal ions, and the concentration of the metal salt solution is 0.3 mol / L). Under these conditions, the best complexation reaction effect can be obtained, and the structural shape fidelity is the highest. The metal salt can be selected from iron salts, cobalt salts, nickel salts, gold salts, silver salts, copper salts, chromium salts, mixtures of nickel salts, cobalt salts, and copper salts, nickel salts, cobalt salts, and copper salts. Figure 4 It is the polymer scaffold after the complexation reaction.

[0040] Place the sapphire glass slide with the complexed metal / alloy scaffold in a tube furnace. Under an air atmosphere, set the sintering temperature conditions: raise the temperature to 150 °C at a heating rate of 2 °C / min and hold for 60 minutes to remove the crystal water in the scaffold. Then raise the temperature to 300 °C at a heating rate of 2 °C / min, and then raise the temperature to 400 °C at a heating rate of 0.5 °C / min to inhibit the formation of pores and hold at this temperature for 60 minutes to ensure complete pyrolysis of the organic matter. Subsequently, raise the temperature to 600 °C at a heating rate of 2 °C / min and hold for 120 minutes to remove the remaining amorphous carbon in the structure, and then cool naturally to room temperature.

[0041] After sintering, the polymer scaffold is transformed into a metal oxide scaffold, so further high-temperature reduction is required. The reduction conditions are as follows: A mixed gas of 5% H2 + 95% N2 is introduced into the tubular furnace, the gas flow rate is set to 0.3 SLM (standard liters per minute), the starting temperature is 20 °C, the heating rate is 2 °C / min, and the ending temperature is 800 °C or 1300 °C (the specific ending temperature is determined according to the metal properties, 800 °C for nickel, cobalt, copper, and iron, 1300 °C for chromium, and gold and silver do not require reduction). And keep it at the highest temperature for more than 120 min to ensure sufficient reduction. Then cool it naturally to room temperature, and a metal and alloy micro-nano three-dimensional structure with sub-micron resolution and high fidelity can be obtained.

[0042] The sintered nickel-cobalt alloy micro-nano three-dimensional structures with different morphologies were characterized by scanning electron microscopy (SEM), as Figure 5 shown. Part a is the nickel-cobalt alloy micro-nano three-dimensional structure of the octahedral truss lattice. The lattice structure combines two-photon polymerization and an optimized sintering process to achieve an ultra-fine feature size of 220 nm. This index has approached the theoretical limit of two-photon polymerization technology; Part b is the nickel-cobalt alloy micro-nano three-dimensional structure of the orthogonal nanowires with an ultra-low line width of 132 nm processed by the present invention, which is nearly an order of magnitude higher than that of traditional micro-nano processing technology, fully demonstrating the unique advantages of this process in sub-micron scale processing; Part c is the enlarged view of the surface of the nickel-cobalt alloy micro-nano three-dimensional structure of the cubic lattice structure, showing that the prepared structure has a low surface roughness; Part d is the nickel-cobalt alloy micro-nano three-dimensional structure diagram of the octahedral truss unit. The FIB is used to cut the structure, and the cross-sectional view is observed to analyze the internal situation of the structure. Through Figure 5 it is shown that the formed metal / alloy micro-nano three-dimensional structure prepared by the present invention has good forming effect and high fidelity.

[0043] Figure 6 and Figure 7 are respectively the EDS element distribution map and energy spectrum diagram of the metal / alloy micro-nano three-dimensional structure after sintering and reduction. After EDS analysis and measurement, the sintered and reduced structure has a very high metal content.

[0044] Figure 8 are the XRD patterns of the metal / alloy micro-nano three-dimensional structure after sintering and reduction. The XRD pattern results of the sintered samples show that no other diffraction peaks are observed in the patterns of all samples, successfully realizing the complete oxidation and decomposition of the metal-containing polymer; the diffraction peak positions of the XRD patterns of the reduced samples correspond to the standard cards, proving that the product obtained after reduction is a metal single substance.

[0045] Example 2

[0046] Acrylic acid (AAc) and pentaerythritol triacrylate (PETA, crosslinker) were mixed at a mass ratio of 10:1 to form a prepolymer solution. Subsequently, ethyl Michler's ketone (EMK, photoinitiator, 1.0 wt%) and polyvinylpyrrolidone (PVP, thickener, 8 wt%) were added thereto in sequence and shaken well to obtain a mixed solution. Finally, the mixed solution was sonicated for 2 hours to ensure the complete dispersion of the solute, and a uniform and transparent photoresist was finally obtained.

[0047] A portion of the prepared photoresist was taken with a pipette and dropped onto a sapphire glass slide. Using the inverted processing method, double-sided tape was attached to both sides of the sapphire glass slide, and a cover glass was pasted above it. Then the sample was placed upside down on a piezoelectric displacement stage. The light emitted by the femtosecond laser passed through the preset optical path, a scanning galvanometer, and finally was focused inside the photoresist through a 60× oil immersion objective lens; the polymerized reaction occurred in the exposed area to form a polymer. The laser was changed with the movement of the piezoelectric stage and the rotation of the scanning galvanometer, thereby guiding the laser scanning path, and a three-dimensional structure could be printed.

[0048] The sapphire glass slide after femtosecond laser processing was placed in ethanol for development for more than 30 min to remove the unexposed photoresist, and polymer scaffolds with different shapes were obtained; the developed sample was immersed in a metal salt solution (0.1 mol / L) to complete the complexation reaction. The immersion conditions were set as follows: the immersion time was controlled to be more than 120 min, the solution temperature was 85 °C, and the pH value was 5 (the pH of the metal salt solution was the precipitation limit pH of metal ions, and the concentration of the metal salt solution was 0.1 mol / L). The best complexation reaction effect and the highest structural shape fidelity could be obtained under these conditions. The metal salt could be selected from iron salts, cobalt salts, nickel salts, gold salts, silver salts, copper salts, chromium salts, mixtures of nickel salts, cobalt salts and copper salts, nickel salts, cobalt salts and copper salts.

[0049] The sapphire glass slide with the metal / alloy scaffold after the completion of complexation was placed in a tubular sintering furnace. Under an air atmosphere, the sintering temperature conditions were set: the temperature was raised to 140 °C at a heating rate of 1 °C / min and held for 60 min to remove the crystal water in the scaffold. Subsequently, the temperature was raised to 280 °C at a heating rate of 1 °C / min, and then the temperature was raised to 400 °C at a heating rate of 0.5 °C / min to inhibit the formation of pores, and held at this temperature for 60 min to ensure the complete pyrolysis of the organic matter. Subsequently, the temperature was raised to 580 °C at a heating rate of 1 °C / min and held for 120 min to remove the remaining amorphous carbon in the structure, and then it was naturally cooled to room temperature.

[0050] After sintering, the polymer scaffold is transformed into a metal oxide scaffold, so further high-temperature reduction is required. The reduction conditions are as follows: A mixed gas of 5% H2 + 95% N2 is introduced into a tube furnace, the gas flow rate is set at 0.2 SLM (standard liters per minute), the starting temperature is 20 °C, the heating rate is 1 °C / min, and the ending temperature is 800 °C or 1300 °C (the specific ending temperature is determined according to the metal properties, 800 °C for nickel, cobalt, copper, and iron, 1300 °C for chromium, and gold and silver do not require reduction). Keep the temperature at the highest temperature for more than 120 minutes to ensure sufficient reduction, and then naturally cool to room temperature to obtain metal and alloy micro-nano three-dimensional structures with sub-micron resolution and high fidelity.

[0051] Example 3

[0052] Mix acrylic acid (AAc) and pentaerythritol triacrylate (PETA, cross-linking agent) in a mass ratio of 10:1 to form a prepolymer solution. Subsequently, add ethyl Michler's ketone (EMK, photoinitiator, 1.2 wt%) and polyvinylpyrrolidone (PVP, thickening agent, 12 wt%) to it in sequence and shake well to obtain a mixed solution. Finally, ultrasonicate the mixed solution for 2 hours to ensure sufficient dispersion of the solute, and finally obtain a uniform and transparent photoresist.

[0053] Use a pipette to take a portion of the prepared photoresist and drop it on a sapphire glass slide. Adopt an inverted processing method, stick double-sided tape on both sides of the sapphire glass slide, and paste a cover glass on top of it. Then place the sample upside down on a piezoelectric displacement stage. The light emitted by the femtosecond laser passes through a preset optical path, a scanning galvanometer, and finally focuses inside the photoresist through a 60x oil immersion objective lens; the exposed area will undergo a polymerization reaction to form a polymer. The laser changes with the movement of the piezoelectric stage and the rotation of the scanning galvanometer, thereby guiding the laser scanning path, and a three-dimensional structure can be printed.

[0054] Place the sapphire glass slide after femtosecond laser processing in ethanol for development for more than 30 minutes to remove the unexposed photoresist and obtain polymer scaffolds of different shapes; immerse the developed sample in a metal salt solution (0.5 mol / L) to complete the complexation reaction. Set the immersion conditions as follows: the immersion time is controlled to be more than 120 minutes, the solution temperature is 95 °C, and the pH value is 5 (the pH of the metal salt solution is the precipitation limit pH of metal ions, and the concentration of the metal salt solution is 0.5 mol / L). Under these conditions, the best complexation reaction effect can be obtained, and the structural shape fidelity is the highest. The metal salt can be selected from iron salts, cobalt salts, nickel salts, gold salts, silver salts, copper salts, chromium salts, mixtures of nickel salts, cobalt salts, mixtures of nickel salts, cobalt salts, and copper salts.

[0055] Place the sapphire glass slide with the metal / alloy stent after complexation completion into a tube sintering furnace. Under an air atmosphere, set the sintering temperature conditions: raise the temperature to 160 °C at a heating rate of 2 °C / min and hold for 60 min to remove the crystal water in the stent. Subsequently, raise the temperature to 320 °C at a heating rate of 2 °C / min, and then raise the temperature to 400 °C at a heating rate of 0.5 °C / min to inhibit the formation of pores, and hold at this temperature for 60 min to ensure complete pyrolysis of the organic matter. Subsequently, raise the temperature to 620 °C at a heating rate of 2 °C / min and hold for 120 min to remove the remaining amorphous carbon in the structure, and then cool naturally to room temperature.

[0056] After sintering, the polymer stent is transformed into a metal oxide stent, so further high-temperature reduction is required. The reduction conditions are as follows: introduce a mixed gas of 5% H2 + 95% N2 into the tube furnace, set the gas flow rate to 0.4 SLM (standard liters per minute), the starting temperature is 20 °C, the heating rate is 2 °C / min, and the ending temperature is 800 °C or 1300 °C (the specific ending temperature is determined according to the metal properties, 800 °C for nickel, cobalt, copper, and iron, 1300 °C for chromium, and gold and silver do not require reduction), and hold at the highest temperature for more than 120 min to ensure sufficient reduction. Then cool naturally to room temperature, and a metal and alloy micro-nano three-dimensional structure with sub-micron resolution and high fidelity can be obtained.

[0057] Although the embodiments of the present application have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present application. The scope of the present application is defined by the appended claims and their equivalents, and all should be included within the protection scope of the present application.

Claims

1. A method for preparing metal / alloy micro-nano three-dimensional structures based on complexation reactions, characterized in that, The method steps are as follows: S1: Synthesize a photoresist using acrylic acid as a polymerization monomer; S2: Process and form the photoresist through femtosecond laser two-photon polymerization technology to obtain a three-dimensional polymer scaffold; S3: Carry out a complexation reaction of the three-dimensional polymer scaffold in a metal salt solution, and after the reaction, sinter the sample to obtain a metal / alloy micro-nano three-dimensional structure.

2. The method for preparing a metal / alloy micro-nano three-dimensional structure based on a complexation reaction according to claim 1, wherein A crosslinking agent, a photoinitiator, and a thickening agent are also added in S1.

3. The method for preparing a metal / alloy micro-nano three-dimensional structure based on a complexation reaction according to claim 2, wherein The crosslinking agent is one or more of pentaerythritol triacrylate, polyethylene glycol diacrylate, and trimethylolpropane triacrylate.

4. The preparation method of the metal / alloy micro-nano three-dimensional structure based on the complexation reaction according to claim 2, wherein, The photoinitiator is one or more of tetraethyl rhodamine, coumarin, and photoinitiator 369.

5. The method for preparing a metal / alloy micro-nano three-dimensional structure based on a complexation reaction according to claim 2, characterized in that, The thickening agent is polyvinylpyrrolidone.

6. The method for preparing a metal / alloy micro-nano three-dimensional structure based on a complexation reaction according to claim 1, wherein, The metal salt in S3 is one or more of iron nitrate, nickel nitrate, cobalt nitrate, copper nitrate, chromium nitrate, silver nitrate, and gold chloride.

7. The preparation method of the metal / alloy micro-nano three-dimensional structure based on complexation reaction according to claim 1, wherein, The temperature of the complexation reaction is 80 - 90 °C, and the time is not less than 120 min.

8. The preparation method of the metal / alloy micro-nano three-dimensional structure based on complexation reaction according to claim 1, characterized in that, The sintering conditions in S3 are: Heat up to 140 - 160 °C at a rate of 1 - 2 °C / min and hold for 60 min; Continue to heat up to 280 - 320 °C at a rate of 1 - 2 °C / min; Continue to heat up to 400 °C at a rate of 0.5 °C / min and hold for 60 min; Continue to heat up to 580 - 620 °C at a rate of 1 - 2 °C / min and hold for 120 min; Finally, cool to room temperature.

9. The method for preparing a metal / alloy micro-nano three-dimensional structure based on a complexation reaction according to claim 1, wherein When the metal after sintering in S3 is an oxide, a reduction treatment is also carried out. The reduction conditions are: reducing the metal oxide in the sintered polymer scaffold with a mixture of hydrogen and an inert gas.

10. The method for preparing a metal / alloy micro-nano three-dimensional structure based on a complexation reaction according to claim 9, characterized in that, The reduction conditions are: The hydrogen content in the mixture gas is 3 - 5%, and the gas flow rate of the mixture gas is 0.2 - 0.4 SLM (standard liters per minute); Heat up to 800 - 1300 °C at a rate of 1 - 2 °C / min, hold for more than 120 min, and then cool to room temperature.

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