TW202016362A - Method for the layered double hydroxide growing on the surface of stainless steel - Google Patents

Abstract

The present disclosure provides a method for the layered double hydroxide growing on the surface of stainless steel, wherein a method of sandblasting is used to roughen the surface of stainless steel and provide the surface which is good for growth of layered double hydroxide. Herein, an electrodeposition method is used to grow the layered double hydroxide with a high specific surface area on the surface of stainless steel as a good catalyst carrier.

Description

Method for coating layered double metal hydroxide on stainless steel surface

The invention relates to a method for coating a layered double metal hydroxide on a surface of stainless steel, in particular to a method for nanometer roughening of a stainless steel surface and coating a layered double metal hydroxide.

Stainless steel has the advantages of strong corrosion resistance, good mechanical strength, and good properties under high and low temperature environments. It is widely used in industries such as chemical, food, machinery, decoration, household appliances, and environmental protection.

Conventional catalytic reactors need to use a substrate with sufficient mechanical strength at high temperature as the flow channel, and stainless steel is an excellent substrate choice. In the past research, try to coat the surface of the stainless steel substrate with a high specific surface area by electrochemical methods The layered bimetallic hydroxide serves as a catalyst carrier, but the surface potential of the stainless steel substrate is too stable, which makes it difficult to form a layered bimetallic hydroxide.

In view of this, how to improve the surface of the stainless steel substrate so that the layered bimetallic hydroxide can coat the stainless steel substrate to facilitate the growth of catalysts for future mass production has become the goal of the efforts of the relevant industry.

An object of the present invention is to provide a method for coating a layered bimetallic hydroxide on a surface of stainless steel. Through the treatment of the surface of stainless steel, the layered bimetallic hydroxide can be coated on the surface of the stainless steel as a good contact Medium catalytic reactor.

One embodiment of the present invention provides a method for coating a layered bimetal hydroxide on a stainless steel surface, which includes providing a surface treatment of a stainless steel substrate and subjecting the stainless steel substrate to sandblasting with an abrasive material to obtain a Rough stainless steel substrate, of which one surface of the rough stainless steel substrate is rough; provide a rough stainless steel substrate pretreatment, put the rough stainless steel substrate after sandblasting into a solvent for cleaning, take it out and dry it; prepare an electrochemical plating The electrochemical plating solution is a clear aqueous solution of a layered bimetallic hydroxide; providing an electrochemical method by placing a rough stainless steel substrate in the electrochemical plating solution to obtain a coated layered bimetallic hydroxide Of stainless steel.

According to the aforementioned method for coating the layered bimetal hydroxide on the surface of the stainless steel, the stainless steel substrate may be Austenite stainless steel or Ferrite stainless steel.

According to the aforementioned method of coating the layered bimetal hydroxide on the surface of the stainless steel, the abrasive material may be a gold steel grit with a particle size of 106 μm to 125 μm.

According to the aforementioned method of coating the layered double metal hydroxide on the surface of the stainless steel, the solvent may be an organic solvent.

According to the aforementioned method of coating the layered double metal hydroxide on the surface of the stainless steel, wherein the rough stainless steel substrate is pretreated by the rough stainless steel substrate After that, a plating area and an electrode fixture position can be reserved, and the rest is covered with a waterproof glue.

According to the aforementioned method for coating the layered double metal hydroxide on the surface of the stainless steel, wherein the layered double metal hydroxide may be a lithium-aluminum layered double metal hydroxide, and an intermediate layer ion may be a carbonate ion.

According to the aforementioned method of coating the layered double metal hydroxide on the surface of the stainless steel, wherein the electrochemical method may be an electrodeposition method for preparing a thin film of the lithium-aluminum layered double metal hydroxide, the electrodeposition method may include application A direct current, and after a period of time, the lithium-aluminum layered bimetallic hydroxide is deposited on the surface of the rough stainless steel substrate.

In this way, the method for coating the layered bimetal hydroxide on the surface of the stainless steel of the present invention is to provide a growth interface of the layered bimetal hydroxide by sandblasting on the surface of the stainless steel, and the electrodeposition method is used to make the layered The double metal hydroxide coats the stainless steel surface. The advantages of sandblasting are convenience, cheapness, and the use of toxic chemical sensitizers or expensive vacuum equipment to complete the roughening of the stainless steel surface.

100‧‧‧Method for coating stainless steel surface with layered double metal hydroxide

110, 120, 130, 140 ‧‧‧ steps

200‧‧‧plate stainless steel substrate

300‧‧‧Round tube stainless steel substrate

400‧‧‧Rough stainless steel substrate

410‧‧‧Electroplating area

420‧‧‧Position of electrode fixture

430‧‧‧Waterproof adhesive

500‧‧‧Electrodeposition device

510‧‧‧Anode

520‧‧‧Cathode

530‧‧‧Electrolyzer

In order to make the above and other objects, features, advantages and examples of the present invention more obvious and understandable, the drawings are described as follows: FIG. 1 illustrates a stainless steel surface coating according to an embodiment of the present invention Step flow chart of the method of bimetallic hydroxide; Figure 2A, Figure 2B and Figure 2C respectively show the preparation process of the method of coating the layered double metal hydroxide on the surface of stainless steel according to Figure 1 Figures; Figures 3A and 3B are FESEM surface morphologies of a sheet stainless steel substrate according to an embodiment of the invention; Figures 3C and 3D are drawings of a rough sheet stainless steel substrate according to an embodiment of the invention FESEM surface morphology of the material; Figures 4A and 4B illustrate the FESEM surface morphology of the lithium-aluminum layered bimetallic hydroxide deposited on the surface of the rough plate stainless steel substrate according to an embodiment of the present invention; FIG. 6 is an XRD diffraction analysis diagram of a lithium-aluminum layered bimetal hydroxide deposited on a rough plate stainless steel substrate according to an embodiment of the present invention; and FIG. 6 is an embodiment of the present invention. Fourier transform infrared spectroscopy analysis of lithium-aluminum layered bimetallic hydroxide deposited on the surface of a rough plate stainless steel substrate.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. For clarity, many practical details will be explained in the following description. However, the reader should understand that these practical details should not be used to limit the present invention. That is to say, in some embodiments of the present invention, these practical details are unnecessary. In addition, for the sake of simplifying the drawings, some conventionally used structures and elements will be shown in a simple schematic manner in the drawings; and repeated elements may be indicated by the same number.

Please refer to FIG. 1, FIG. 2A, FIG. 2B, and FIG. 2C, wherein FIG. 1 illustrates a step flow of a method 100 for coating a layered double metal hydroxide on a stainless steel surface according to an embodiment of the present invention FIG. 2, FIG. 2A, FIG. 2B and FIG. 2C respectively illustrate the preparation process of the method 100 for coating the layered double metal hydroxide on the surface of the stainless steel according to FIG. 1. The method 100 for coating the layered double metal hydroxide on the surface of the stainless steel includes steps 110, 120, 130 and 140.

Step 110 is to provide a surface treatment of a stainless steel substrate, change the size and type of the stainless steel substrate according to the sample requirements of different analysis tests, as shown in Figure 2A, when the surface morphology analysis (SEM) and diffraction analysis are tested (XRD) and Fourier Transform Infrared Spectroscopy (FTIR), the sample needs to be kept flat and without special warpage. Therefore, the stainless steel substrate can be a plate stainless steel substrate 200. The stainless steel substrate may be a round tube stainless steel substrate 300, wherein the stainless steel substrate may be Austenite stainless steel or ferrite stainless steel, wherein the Woustian iron stainless steel may be 304 or 306 stainless steel The fat iron stainless steel can be 420 stainless steel, but not limited to this disclosure. However, this embodiment is mainly to observe the surface roughening state of the stainless steel substrate and the surface morphology and element analysis of the coated layered double metal hydroxide, so the type of stainless steel substrate of this embodiment is the plate stainless steel substrate 200, The size is 10mm×20mm×2mm, but not limited to this disclosure.

The types of surface treatment of the stainless steel substrate include mechanical method, metallurgical method, chemical method, surface coating, inorganic coating and organic coating, etc., and the method of coating the layered bimetal hydroxide on the surface of the stainless steel of this embodiment 100 is a destructive processing method for the stainless steel surface by sand blasting, using a small abrasive material to wear the stainless steel surface, so that the stainless steel surface produces a granulated depression to form a matte surface or an eroded surface. Application of rust, friction coefficient adjustment, high adhesion and atomization to improve the roughness of the stainless steel surface.

The abrasive material for sand blasting may include gold steel sand, silicon carbide, alumina, glass beads, ceramic beads, plastic sand, zirconium sand and other sand materials. The abrasive material in this embodiment may be gold steel sand with a particle size of 106 μm to 125 μm. The stainless steel substrate is surface blasted with gold steel sand to obtain a rough stainless steel substrate 400, wherein one surface of the rough stainless steel substrate 400 is rough, and the above-mentioned abrasive materials are not limited to this content disclosure.

Step 120 is to provide a rough stainless steel substrate pretreatment. The sandblasted rough stainless steel substrate 400 is placed in a solvent and cleaned to remove residual sand, organic matter, grease, etc. on the surface, and then taken out and dried. The cleaning solvent may be common organic solvents such as acetone, ethanol, isopropanol, etc. The solvent in this embodiment is acetone, but not limited thereto. Next, the cleaned rough stainless steel substrate 400 is reserved with an electroplating area 410 and an electrode fixture position 420, and the rest is covered with a waterproof glue 430, as shown in FIG. 2B, as an electrode of the electrochemical system.

其中，M^Ⅱ為Li²⁺、Mg²⁺、Zn²⁺、Fe²⁺、Ni²⁺等二價金屬陽離子，M^Ⅲ為Al³⁺、Cr³⁺、Fe³⁺、Sc³⁺等三價金屬陽離子，A^n-為中間層離子，如CO₃ ^2-、Cl^-、NO₃ ^-、SO₄ ^2-、C₆H₄(COO^-)₂等無機或有機陰離子。本實施方式之層狀雙金屬氫氧化物為一鋰-鋁層狀雙金屬氫氧化物，其中間層離子為一碳酸根離子，但層狀雙金屬氫氧化物不以此內容揭示為限。 Step 130 is to prepare an electrochemical plating solution which is a clear aqueous solution of layered double metal hydroxide (LDH). The layered double metal hydroxide is composed of several layers of positively charged ions It is composed of anions with balanced charge in the middle. The anions in the middle are exchangeable due to the weak force between the layers. The structure of the layered double metal hydroxide is as follows:

Among them, M ^Ⅱ is Li ²⁺ , Mg ²⁺ , Zn ²⁺ , Fe ²⁺ , Ni ²⁺ and other divalent metal cations, M ^Ⅲ is Al ³⁺ , Cr ³⁺ , Fe ³⁺ , Sc ³⁺ and other three divalent metal cation, A ^n- is an intermediate layer of ions, such as _{^{CO 3 2-, Cl -, NO}} 3 -, SO 4 2-, C 6 H 4 (COO -) 2 and other inorganic or organic anion. The layered double metal hydroxide of this embodiment is a lithium-aluminum layered double metal hydroxide, wherein the interlayer ion is a carbonate ion, but the layered double metal hydroxide is not limited to this disclosure.

Step 140 is to provide an electrochemical method by placing the rough stainless steel substrate 400 in an electrochemical plating solution to obtain a stainless steel coated with layered bimetal hydroxide. The electrochemical method is an electrodeposition method, and the device 500 of the electrodeposition method, as shown in FIG. 2C, includes an anode 510, a cathode 520, and an electrolytic cell 530, wherein the anode 510 is a platinum titanium mesh and the cathode 520 is Rough stainless steel substrate 400, the plating bath of lithium-aluminum layered bimetal hydroxide is poured into electrolytic cell 530, and then a constant current is applied, and after a period of time, the lithium-aluminum layered bimetal hydroxide can be removed Deposited on the surface of rough stainless steel substrate 400.

Layered bimetallic hydroxides have a large specific surface area and have been widely used in academic research and industrial applications, such as catalysis, photochemistry, electrochemistry, polymer polymerization and other applications. In this way, in the present invention, the surface of the stainless steel substrate is subjected to sandblasting to roughen the surface nano, and then the lithium-aluminum layered bimetallic hydroxide is grown on the rough stainless steel surface by electrodeposition method As a carrier for the catalyst, it can provide a process that is fast and not affected by the shape of the substrate to facilitate mass production in the future.

Examples

Please refer to FIGS. 3A, 3B, 3C, 3D, 4A, and 4B, wherein FIGS. 3A and 3B illustrate the FESEM surface of the plate stainless steel substrate according to the embodiment of the present invention Appearance, in which the magnification of Figure 3A is 1000 times, and the magnification of Figure 3B is 5000 times. FIGS. 3C and 3D illustrate the FESEM surface morphology of a rough plate stainless steel substrate according to an embodiment of the present invention, wherein the magnification of FIG. 3C is 1000 times and the magnification of FIG. 3D is 5000 times. FIGS. 4A and 4B illustrate the FESEM surface morphology of the lithium-aluminum layered bimetallic hydroxide deposited on the surface of a rough plate stainless steel substrate according to an embodiment of the present invention, wherein the magnification of FIG. 4A is 1000 times The magnification of Figure 4B is 5000 times. The surface morphology of FESEM in Figures 3A to 4B is obtained using a field-emission scanning electron microscope (FESEM) model JEOL JSM-6700F.

The embodiment of the present invention prepares the stainless steel coated with the layered double metal hydroxide according to the method 100 for coating the layered double metal hydroxide on the surface of the stainless steel according to the embodiment of FIG. 1. Firstly, the 304 stainless steel substrate is cut into a plate stainless steel substrate with a size of 10mm×20mm×2mm, and then the plate stainless steel substrate is sandblasted with gold steel sand with a particle size of 106μm~125μm to roughen the surface of the plate stainless steel substrate. A rough plate stainless steel substrate is formed, and the working pressure is 52.5 kg/cm ² . Then put the rough plate stainless steel substrate in acetone, clean it for 10 minutes by ultrasonic method, take it out and dry it, and reserve the plating area and the position of the electrode fixture area. The rest is covered with waterproof glue to obtain a rough plate stainless steel electrode.

When preparing the electrochemical plating solution, first pass 200 ml of deionized water into argon gas for 10 minutes to remove the carbonate in the water, and then crush the AlLi intermetallic compound in a mortar, in which the aluminum lithium The intermetallic compound contains 19±0.5% lithium and 81±0.5% aluminum, and 0.4g of the powder is added to water and stirred vigorously for 4 minutes, then poured into 5A filter paper for suction filtration to form a lithium-rich and aluminum-rich A clear aqueous solution of ions.

Finally, the device of the electrodeposition method is set up. The anode is a platinum titanium mesh, the cathode is a rough plate stainless steel electrode, the plating solution of lithium-aluminum layered bimetal hydroxide is poured into the electrolytic cell, and the instrument is a potentiostat machine (Princeton) Applied Research model273A), test with a fixed potential of 1.5 volt DC for 60 minutes, then take out the rough plate stainless steel electrode and wash it with water, then dry it at room temperature for 8 hours to obtain a stainless steel coated with layered double metal hydroxide. As a catalytic reactor.

From the results of Figure 3B and Figure 3D, it can be seen that the surface of the stainless steel substrate of the sheet material is converted into a rough surface after sandblasting, which can increase its surface area. In addition, as can be seen from the results in Figure 4B, after the sandblasting of the roughened stainless steel substrate by electrodeposition, the layered bimetal hydroxide was grown, and its rough surface was observed to be covered by a dense sheet structure. The size of the structure is 1~1.5μm, and the thickness is 20~50nm. In addition, from the specific surface area analysis of the sheet stainless steel substrate, rough sheet stainless steel substrate and electrodeposited lithium-aluminum layered bimetal hydroxide of the rough sheet stainless steel substrate in Table 1 below, it can be seen that the original sheet stainless steel substrate The specific surface area is 0.00023m ² /g. The specific surface area of the rough plate stainless steel substrate after sandblasting is increased by 118 times to 0.0272m ² /g, and the specific surface area of the rough plate stainless steel substrate after electrodeposition is further increased to 0.1972m ² /g. Therefore, from the results in Table 1, it can be seen that the surface of the stainless steel sheet material after blasting can increase its surface area, and can provide a better growth interface of the layered double metal hydroxide.

Please refer to FIG. 5. FIG. 5 shows the XRD diffraction analysis diagram of the lithium-aluminum layered bimetal hydroxide deposited on the surface of the rough plate stainless steel substrate according to the embodiment of the present invention, and the XRD diffraction diagram of FIG. 5 The radiographic analysis chart was obtained using an X-ray diffraction model Bruker MXP-Ⅲ to analyze the film structure of the lithium-aluminum layered bimetallic hydroxide deposited on the surface of the rough plate stainless steel substrate. The target material is CuKα1 (1.5405), which is diffracted by X-ray diffraction with a low glancing angle of 0.5°. The scanning rate is 3°/min, and the scanning range is 6°~90°.

It can be seen from the results in Figure 5 that the angular position (2 θ) of the triangle icon and the circle icon respectively represent the ferrite (α-Fe) and fertile phase (Austenite, γ-Fe) of stainless steel ), and the angular position (2 θ) of the square diagram represents the characteristic of the lithium-aluminum layered bimetal hydroxide film Zheng Feng (JCPDS card no 42-729), therefore, XRD diffraction analysis can confirm that the lithium-aluminum layered bimetallic hydroxide is deposited on the surface of the rough plate stainless steel substrate.

Please refer to FIG. 6, FIG. 6 shows the Fourier transform infrared spectroscopy analysis of lithium-aluminum layered bimetallic hydroxide deposited on the surface of a rough plate stainless steel substrate according to an embodiment of the present invention, and FIG. 6 The Fourier transform infrared spectroscopy analysis chart is obtained by using Fourier Transform Infrared Spectrometer (FTIR) model DIGILAB FTX3500 to analyze the chemical bonding of the thin film of lithium-aluminum layered double metal hydroxide, The analysis range is wave number 400~4000cm ^-1 .

From the results in Figure 6, it can be seen that the Fourier transform infrared spectrum of the lithium-aluminum layered bimetallic hydroxide film is an asymmetric stretching mode of carbonate ions (CO ₃ ^2- ) at a wavenumber of 1348 cm ^-1 The characteristic peak, in addition, at a wavenumber of about 3000 cm ^-1 , exhibits a characteristic peak in which carbonate ions (CO ₃ ^2- ) and water molecules (H ₂ O) form a hydrogen bond, indicating that the lithium-aluminum layered bimetal The hydroxide has the intercalation of carbonate ions and water molecules in the interlayer, and the XRD diffraction analysis chart can confirm that the film coated on the surface of the stainless steel is a lithium-aluminum layered bimetal hydroxide film.

In summary, the method of coating the layered double metal hydroxide on the surface of the stainless steel of the present invention is to roughen the nanometer of the surface of the stainless steel by sandblasting to provide a better growth interface of the layered double metal hydroxide And, using electrodeposition method, the layered bimetallic hydroxide is deposited on the surface of rough stainless steel as a carrier for catalyst catalysis. Therefore, the FESEM surface morphology, XRD diffraction analysis and Fourier transform infrared spectroscopy of the embodiments of the present invention The analysis shows that after the surface of the stainless steel is roughened by sandblasting, the layered bimetallic hydroxide can indeed be coated on the surface of the rough stainless steel. This method provides a fast and independent of the shape of the substrate, which is beneficial to the future. Mass production.

Although the present invention has been disclosed as above in an embodiment, it is not intended to limit the present invention. Anyone who is familiar with this art can make various modifications and retouching without departing from the spirit and scope of the present invention, so the protection of the present invention The scope shall be as defined in the appended patent application scope.

100‧‧‧Method for coating stainless steel surface with layered double metal hydroxide

110, 120, 130, 140 ‧‧‧ steps

Claims (10)

A method for coating a layered bimetal hydroxide on a stainless steel surface, comprising: providing a surface treatment of a stainless steel substrate, sandblasting a stainless steel substrate with an abrasive material to obtain a rough stainless steel substrate, wherein the One surface of the rough stainless steel substrate is rough; provide a rough stainless steel substrate pretreatment, put the rough stainless steel substrate after sandblasting into a solvent for cleaning, take it out and place it to dry; prepare an electrochemical plating solution, the electrochemical The plating solution is a clear aqueous solution of a layered bimetallic hydroxide; and an electrochemical method is provided to place the rough stainless steel substrate in the electrochemical plating solution to obtain a coating of the layered bimetallic hydroxide stainless steel. The method for coating the layered bimetal hydroxide on the surface of the stainless steel as described in item 1 of the scope of the patent application, wherein the stainless steel substrate is Vostian iron-based stainless steel or ferrite iron-based stainless steel. The method for coating the layered bimetal hydroxide on the surface of the stainless steel as described in item 1 of the patent application scope, wherein the abrasive material is a gold steel grit. The method for coating the layered bimetallic hydroxide on the surface of the stainless steel as described in item 3 of the patent application scope, wherein the particle size of the gold steel grit is 106 μm to 125 μm. The method for coating the layered bimetal hydroxide on the surface of stainless steel as described in item 1 of the patent application range, wherein the solvent is an organic solvent. The method for coating the layered bimetal hydroxide on the surface of the stainless steel as described in item 1 of the patent application scope, wherein the rough stainless steel substrate is pre-treated by the rough stainless steel substrate, a plating area and an electrode fixture are reserved Position, the rest is covered with a waterproof glue. The method for coating the layered bimetal hydroxide on the surface of the stainless steel as described in item 1 of the patent application scope, wherein the layered bimetal hydroxide is a lithium-aluminum layered bimetal hydroxide. The method for coating the layered bimetal hydroxide on the surface of stainless steel as described in item 7 of the patent application range, wherein one of the intermediate layer ions of the lithium-aluminum layered bimetal hydroxide is a carbonate ion. The method for coating the layered bimetal hydroxide on the surface of the stainless steel as described in item 7 of the patent scope, wherein the electrochemical method is an electrodeposition method for preparing the lithium-aluminum layered bimetal hydroxide film. The method for coating the layered bimetal hydroxide on the surface of the stainless steel as described in item 9 of the patent application scope, wherein the electrodeposition method includes: applying a DC current, and after a period of time, the lithium-aluminum layered bimetallic hydrogen Oxide is deposited on the surface of the rough stainless steel substrate.

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