Preparation method of metal material with multi-scale nano-porous
Technical Field
The invention belongs to the field of multi-scale nano-porous metal materials, and particularly relates to a preparation method of a multi-scale nano-porous metal material.
Background
The multi-scale nano porous structure material refers to a material with porous structures with different size orders, from nanometer to submicron to micron. Such structures are widely present in biological matrices, such as silk, charcoal, wood fibers, etc., and are most directly characterized by having particular optical properties. The artificial multi-scale nano porous structure material structure can be used in the fields of catalytic reaction, photocatalysis, energy storage, filtration/separation, drug release and the like.
The fabrication (synthesis) method of multi-scale nanoporous structural materials typically requires multiple steps, each of which produces an order of magnitude structure. The method used at present comprises the following steps: surfactant templating, replication, sol-gel, post-treatment, emulsion templating, phase separation, zeolitization, self-assembly, colloid templating, biomimetic, polymer templating, supercritical fluid, lyophilization, respiratory patterning, and selective extraction (dissolution). Although the synthetic methods are numerous, each is a "start-from-scratch" technique. The surface modification technology which can process the surface of the existing material is lacked. The "phase separation method" and the "selective extraction (dissolution) method" can be used to some extent for surface porous treatment of the existing material, but there are certain requirements (type of component, proportion of component, etc.) for the material components.
In the case of a metal material, the "phase separation method" corresponds to the "dealloying method" and the "ion crystal reduction method", which are techniques for producing a porous metal material by selectively dissolving a part of alloy components. Under certain technological parameters, the multi-scale nano porous structure can be realized through multiple phase separation. Similarly, both the dealloying method and the ion crystal reduction method have a large limitation on the composition of the raw material. Within the knowledge of the pen practitioner, there is no technique that can reprocess an existing surface on a metal surface to produce a multi-scale nanoporous structure.
Disclosure of Invention
Aiming at the problems in the prior art, the invention aims to provide a preparation method of a metal material with multi-scale nano-porosity.
The invention is realized by the following technical scheme:
the preparation method of the metal material with the multi-scale nano-pores is characterized by comprising the following steps of:
1) carrying out oxidation treatment on the surface of the metal material to generate an oxide layer on a target surface area to be treated;
2) soaking the metal material with the oxidized surface in a sodium borohydride solution at room temperature;
3) and taking out the soaked metal material, washing the metal material by using alcohol and deionized water in turn for surface seconds, and then drying and storing the metal material to avoid the appearance change.
The oxidation treatment in step 1) can adopt any process which causes surface/integral oxidation of the material, such as: high-temperature oxidation, liquid-phase reaction and vacuum plasma furnace.
The concentration of the sodium borohydride solution in the step 2) is 0.1-0.01 mol/L.
The soaking time in the step 2) is not less than 1min, stirring is carried out along with the soaking process, and the stirring speed is less than 500 r/min.
The metal material is copper, aluminum, nickel metal and alloy material.
The multi-scale nano porous structure is prepared by carrying out secondary processing on the existing surface on the metal surface, the method of oxidation before reduction is adopted, the requirements on the components of the metal material are low, only the oxidation characteristic of the metal material needs to be considered, and the process simplicity and the wide applicability are greatly improved.
Drawings
FIG. 1 shows the process of the brass surface from plane to multi-scale nano-porous through treatment;
(a) an original surface; (b) soaking the brass flocculent porous surface for 24 hours at 40 ℃ in 1 MNaOH; (c) 0.1M NaBH4Soaking for 1min to obtain a brass double-layer sheet-porous surface;
fig. 2 is a multi-scale nano-layer sheet-porous surface of brass after reduction;
FIG. 3 is a schematic flow chart of the preparation of the multi-scale nano-porous structure by a reduction method.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings, and specific embodiments are given.
Hair brushA process for preparing the multi-scale nano-porous metallic material includes such steps as oxidizing by high-temp oxidizing, liquid-phase reaction, and vacuum plasma furnace to generate a uniform oxide layer on the surface of metallic specimen to be treated for covering the target surface. The original surface topography of the metal sample can be retained or changed according to the oxidation mode. Then using sodium borohydride (NaBH)4) The water solution reduces the oxide layer on the surface of the porous metal, and then a secondary porous structure with the pore diameter of about 60nm is manufactured on the basis that most of the original oxidized morphology is reserved.
Examples
The brass will be specifically described as an example. And carrying out secondary processing on the basis of the original porous copper, and manufacturing a secondary porous structure on the basis of the original appearance. Compared with other manufacturing methods of multi-scale nano porous materials, the method is suitable for manufacturing the secondary porous structure with the size smaller than 100nm on the metal surface with the original surface structure size not smaller than 100 nm. The specific flow diagram is shown in fig. 3.
The preparation process comprises the following steps: performing surface oxidation treatment on brass as a sample, wherein the original surface of the flavone of the sample is shown in figure 1 (a), and an oxide layer is generated on the target surface area to be treated; the step adopts an oxidant oxidation method for oxidation treatment: placing the brass sample in 1M sodium hydroxide solution (40 ℃), soaking for 24h at room temperature without stirring, taking out and airing to obtain the flocculent porous surface of the flavone, as shown in figure 1 (b), soaking the oxidized brass sample in 0.1 mol/L sodium borohydride solution for 3 min at a stirring speed of less than 500r/min to obtain the two-layer laminar-porous surface of the brass, as shown in figure 1 (c), and the enlarged view of the two-layer laminar-porous surface of the brass is shown in figure 2.