阅读说明：本技术 一种提高镍钛合金催化性能的表面粗糙化方法 (Surface roughening method for improving catalytic performance of nickel-titanium alloy ) 是由 侯广亚 王贵 梅杰 唐谊平 曹华珍 郑国渠 张惠斌 于 2019-12-30 设计创作，主要内容包括：本发明涉及电极材料处理方法领域,尤其涉及一种提高镍钛合金催化性能的表面粗糙化方法。所述方法包括以下步骤：对平板镍钛合金进行预处理后,对其进行金相打磨粗造化处理和后续的去合金化处理；所述金相打磨粗造化处理处理为砂纸打磨处理；所述砂纸打磨处理至少选用2种不同目数的砂纸各进行至少一次打磨,且第N+1次打磨所用砂纸目数不低于第N次打磨所用砂纸目数。所述去合金化处理为氢氟酸(HF)溶液的腐蚀处理,去除部分钛元素,暴露出活性位点。本发明处理方法简洁高效,适用于产业化处理；处理成本低；借助材料表面粗糙化能够有效提高镍钛合金的对甲醇的电催化氧化性能。(The invention relates to the field of electrode material treatment methods, in particular to a surface roughening method for improving the catalytic performance of nickel-titanium alloy. The method comprises the following steps: after the flat nickel-titanium alloy is pretreated, the flat nickel-titanium alloy is subjected to metallographic phase polishing and roughing treatment and subsequent dealloying treatment; the metallographic polishing and roughening treatment is sand paper polishing treatment; the abrasive paper polishing treatment at least selects 2 kinds of abrasive paper with different meshes for polishing at least once, and the mesh number of the abrasive paper used for polishing for the (N + 1) th time is not less than that of the abrasive paper used for polishing for the nth time. The dealloying treatment is a corrosion treatment of hydrofluoric acid (HF) solution, a part of titanium elements are removed, and active sites are exposed. The treatment method is simple and efficient, and is suitable for industrial treatment; the treatment cost is low; the electro-catalytic oxidation performance of the nickel-titanium alloy to methanol can be effectively improved by roughening the surface of the material.)

1. A surface roughening method for improving the catalytic performance of nickel-titanium alloy is characterized in that,

the method comprises the following steps:

after the flat nickel-titanium alloy is pretreated, the surface of the flat nickel-titanium alloy is subjected to metallographic polishing and surface roughening treatment and dealloying treatment.

2. The surface roughening method of claim 1, wherein said nickel titanium alloy surface roughening method further comprises the step of applying a chemical composition to said nickel titanium alloy surface,

the pre-treatment comprises polishing;

the polishing is any one or more of mechanical polishing, chemical polishing, electrolytic polishing, ultrasonic polishing, fluid polishing and magnetic grinding polishing.

3. The surface roughening method of claim 1, wherein said nickel titanium alloy surface roughening method further comprises the step of applying a chemical composition to said nickel titanium alloy surface,

and the metallographic polishing surface roughening treatment is sand paper polishing treatment.

4. The surface roughening method of claim 3 wherein said nickel titanium alloy surface roughening method further comprises the step of applying a chemical composition to said nickel titanium alloy surface,

and the sand paper polishing treatment is carried out by using 240-2000-mesh sand paper.

5. The method of claim 3 or 4, wherein the sanding treatment comprises at least one sanding of at least 2 different sizes of sandpaper, and the number of sandpaper used for the N +1 th sanding is not less than the number of sandpaper used for the N th sanding;

and N is a positive integer.

6. The surface roughening method of claim 5 wherein said nickel titanium alloy surface roughening method further comprises the step of applying a chemical composition to said nickel titanium alloy surface,

and the last grinding of the sand paper grinding treatment adopts 2000-mesh sand paper for grinding.

7. The surface roughening method of claim 1, wherein said nickel titanium alloy surface roughening method further comprises the step of applying a chemical composition to said nickel titanium alloy surface,

and performing dealloying corrosion treatment after the metallographic polished surface is roughened.

8. The method of claim 7, wherein the surface roughening is performed by a chemical vapor deposition process,

and the dealloying corrosion treatment is to partially remove titanium element by utilizing hydrofluoric acid solution to perform constant-temperature corrosion.

Technical Field

The invention relates to the field of electrode material treatment methods, in particular to a surface roughening method for improving the catalytic performance of nickel-titanium alloy.

Background

Nickel titanium alloy is a commonly used alloy material, and has a series of special and excellent properties such as shape memory property, superelasticity, sensitivity to temperature change in the oral cavity, corrosion resistance, toxicity resistance, soft correcting force, good damping performance and the like, so that the nickel titanium alloy has very wide application. In recent years, with the increasing worldwide demand for energy, the continuous and rapid consumption of fossil fuels, and the dramatic increase in greenhouse gas concentrations, large-scale research and development of "green" energy sources have been promoted to replace traditional fossil energy sources. Thus, low or even zero emissions of harmful greenhouse gases (e.g., CO)₂、NO_x、SO_xEtc.) have attracted considerable attention from the scientific and engineering communities. Today, fuel cells are widely regarded as an efficient, pollution-free energy source with higher energy density and energy efficiency than other existing cells. The emergence of fuel cells has also led to the development of new applications of nitinol as an electrode material for fuel cells.

Currently, there are six major types of fuel cells, namely (1) Proton Exchange Membrane Fuel Cells (PEMFC) including Direct Methanol Fuel Cells (DMFC), (2) alkaline fuel cells (sub), (3) Phosphoric Acid Fuel Cells (PAFC) (4) Molten Carbonate Fuel Cells (MCFC), (5) Solid Oxide Fuel Cells (SOFC) and (6) Microbial Fuel Cells (MFC). PEMFCs, DMFCs, AFCs, PAFCs and MFCs operate at low temperatures (50-200 ℃ C.), and MCFCs and SOFCs operate at high temperatures (650-.

Among various fuel cells, DMFC has been widely studied in the past two decades or so. These have become one of the potential systems to provide not only clean energy, but also good commercial viability (e.g., Ballard and smart fuel cells). A number of successful applications for PEMFCs and DMFCs, such as passenger cars, generators (APUs), chargers and other portable and handheld devices, including mobile phones and laptops, are currently commercialized. Nickel titanium alloy is also used mainly as an electrode material of DMFC. However, the existing nickel-titanium alloy has the problem of limited catalytic activity when being directly used in the DMFC, and the existing method for improving the catalytic performance of the nickel-titanium alloy in the DMFC mainly comprises surface nanocrystallization, metal doping and other modes, wherein the optimization mode of the surface nanocrystallization can greatly improve the catalytic performance of the nickel-titanium alloy, but the nickel-titanium alloy has a series of problems of high cost, complex preparation process, long preparation period, poor stability in the preparation process and the like.

For example, the patent application of the invention of the nanotube/porous Ti/W/Ni oxide in-situ supported platinum/palladium nanoparticle thin film catalytic electrode and the preparation method thereof, which is disclosed by the Chinese patent office in 2016, 1, 20 and has the application publication number of CN 105261763A. The method comprises the steps of depositing a Ti/W/Ni-Pt/Pd alloy film on the surface of a titanium sheet, a tungsten sheet, a nickel-titanium alloy sheet or conductive glass, then taking a metal sheet or conductive glass on which the Ti/W/Ni-Pt/Pd alloy film is deposited as an anode and a graphite rod/sheet or a platinum wire/sheet as a cathode, and carrying out anodic oxidation treatment to obtain the nanotube/porous Ti/W/Ni oxide in-situ supported platinum/palladium nanoparticle film catalytic electrode, wherein metal Pt/Pd atoms in the electrode are embedded in the nanotube/porous Ti/W/Ni oxide tube/pore wall in situ and exist as metal nanoparticles. The technical scheme combines the surface nanocrystallization process and the metal doping process, and the catalytic performance of the nickel-titanium alloy electrode is improved, but the process is complex, the manufacturing period is long, and the cost is high, so that the practical use and popularization value are limited.

Disclosure of Invention

The invention provides a surface roughening method for improving the catalytic performance of nickel-titanium alloy, aiming at solving a series of problems that the catalytic performance of the existing nickel-titanium alloy is limited when the existing nickel-titanium alloy is directly used as a catalytic electrode, and the existing technological method for optimizing the catalytic performance of the nickel-titanium alloy is complex, high in operation difficulty, high in cost, long in preparation period and the like. The invention aims to: firstly, the treatment method of the nickel-titanium alloy is simplified; secondly, the catalytic performance of the nickel-titanium alloy when used in a battery can be effectively improved; thirdly, the treatment cost is reduced; fourthly, the treatment efficiency is improved.

In order to achieve the purpose, the invention adopts the following technical scheme.

A surface roughening method for improving the catalytic performance of nickel-titanium alloy,

the method comprises the following steps:

after the flat nickel-titanium alloy is pretreated, the surface roughening treatment of metallographic phase polishing and the subsequent dealloying treatment are carried out on the flat nickel-titanium alloy.

Metallography is polished and is handled and is included artifical and polish with machinery usually, and artifical and polish and have higher flexibility, are applicable to the research and development and the test of few appearance, and machinery is polished and is had high-efficient, quick and polish the equal advantage of quality. Generally, the surface of a flat nickel-titanium alloy has extremely high flatness, so the roughness of the surface of the nickel-titanium alloy is gradually increased in the grinding process, and the increase of the roughness indicates that the surface of the nickel-titanium alloy has the appearances of scratches, small protrusions and the like, which are generally harmful to the nickel-titanium alloy and can affect the mechanical property and the like of the nickel-titanium alloy.

As a preference, the first and second liquid crystal compositions are,

the pre-treatment comprises polishing;

the polishing is any one or more of mechanical polishing, chemical polishing, electrolytic polishing, ultrasonic polishing, fluid polishing and magnetic grinding polishing.

Pretreatment usually includes conventional steps such as washing, deoiling, descaled skin, but the most important polishing among this application technical scheme, polishing can effectively promote nickel titanium alloy surface smoothness, so at first can improve follow-up metallography and polish the effect of handling, is favorable to the evenly distributed of mar and the control of mar degree of depth, and then can form multi-level active point position, improves nickel titanium alloy's catalytic effect by a wide margin.

As a preference, the first and second liquid crystal compositions are,

and the metallographic polishing surface roughening treatment is sand paper polishing treatment.

The abrasive paper is polished in the same direction as much as possible, the largest deflection angle of the polishing direction is ensured to be less than or equal to 20 degrees as much as possible, otherwise, the polishing marks of multiple layers are mutually staggered, obvious pits appear on the surface of the nickel-titanium alloy, the polishing effect is poor or the rest of the nickel-titanium alloy is not beneficial to the improvement of the catalytic performance, the scratches are overlapped after polishing in the same direction, the uniformity of the formation of active points is higher, and the specific surface area is also higher.

As a preference, the first and second liquid crystal compositions are,

and the sand paper polishing treatment is carried out by using 240-2000-mesh sand paper.

The effect after above-mentioned mesh number abrasive paper is polished is more excellent, and the mesh number is too big after the abrasive paper is polished to the low surface roughness to can lead to too much alloy to lose at the in-process of polishing, and the mesh number is too big then polish the activity position smoothly easily, can't produce the optimization effect on the contrary.

As a preference, the first and second liquid crystal compositions are,

the abrasive paper polishing treatment at least selects 2 abrasive papers with different meshes for polishing at least once, and the mesh number of the abrasive paper used for the N +1 th polishing is not less than that of the abrasive paper used for the N th polishing;

and N is a positive integer.

The grinding of different sand paper with different meshes is carried out at least twice, and the mesh of the sand paper used in the previous grinding is not more than that of the sand paper used in the next grinding.

As a preference, the first and second liquid crystal compositions are,

and the last grinding of the sand paper grinding treatment adopts 2000-mesh sand paper for grinding.

The active point positions can be effectively formed on the surface of the nickel-titanium alloy by carrying out ending and polishing through 2000-mesh sand paper.

As a preference, the first and second liquid crystal compositions are,

and performing dealloying corrosion treatment after the metallographic phase is polished.

The dealloying corrosion etch process can further form etch marks on the surface of the nitinol alloy and remove portions of the titanium to expose more nickel active sites. And when the nickel-titanium alloy is corroded after being polished, the scratch part can be corroded at an accelerated speed to form more active sites, so that the catalytic performance of the nickel-titanium alloy is further improved.

As a preference, the first and second liquid crystal compositions are,

and the dealloying corrosion treatment is to partially remove titanium element by utilizing hydrofluoric acid solution to perform constant-temperature corrosion.

The dealloying treatment is carried out for 10-50 min by adopting 0.8-1.5 wt% hydrofluoric acid aqueous solution to carry out constant-temperature corrosion treatment at 40-55 ℃, and a better corrosion effect can be achieved.

The invention has the beneficial effects that:

1) the treatment method is simple and efficient, and is suitable for industrial treatment;

2) the treatment cost is low;

3) the catalytic performance of the nickel-titanium alloy can be effectively improved.

Drawings

FIG. 1 is a gold phase diagram of a 1-2 flat nickel-titanium alloy of example 1;

FIG. 2 is a gold phase diagram of the flat nickel-titanium alloy of examples 1-4;

FIG. 3 is a graph of CV curves for a portion of the flat nickel titanium alloy of example 1 tested in a 1M KOH system;

FIG. 4 is a CV diagram of a portion of the flat nickel titanium alloy of example 1 tested in a 1M KOH +0.5M aqueous methanol system;

FIG. 5 is a graph of CV curves for a portion of the flat nickel titanium alloy of example 2 tested in a 1M KOH system;

FIG. 6 is a CV diagram of a portion of the flat nickel titanium alloy of example 2 tested in a 1M KOH +0.5M aqueous methanol system;

FIG. 7 is a CV diagram of a portion of the flat nickel titanium alloy of example 3 tested in a 1M KOH system;

FIG. 8 is a CV diagram of a portion of the flat nickel titanium alloy of example 3 tested in a 1M KOH +0.5M aqueous methanol system;

FIG. 9 is a CV diagram of a portion of the flat nickel titanium alloy of example 4 tested in a 1M KOH system;

FIG. 10 is a CV diagram of the test of a portion of the flat nickel titanium alloy of example 4 in a 1M KOH +0.5M aqueous methanol system

FIG. 11 is a SEM characterization of the flat nickel titanium alloy of example 5, accession number 5-1;

FIG. 12 is an SEM representation of the plate nickel titanium alloy of example 5, accession number 5-2.

Detailed Description

The invention is described in further detail below with reference to specific embodiments and the attached drawing figures. Those skilled in the art will be able to implement the invention based on these teachings. Moreover, the embodiments of the present invention described in the following description are generally only some embodiments of the present invention, and not all embodiments. Therefore, all other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.

Unless otherwise specified, the raw materials used in the examples of the present invention are all commercially available or available to those skilled in the art; unless otherwise specified, the methods used in the examples of the present invention are all those known to those skilled in the art.