CN110714212B

CN110714212B - A method for preparing super-hydrophobic nickel film by one-step method of nickel chloride in an aqueous solution system

Info

Publication number: CN110714212B
Application number: CN201910966431.6A
Authority: CN
Inventors: 王世颖; 侯超; 王文昌; 吴敏娴; 陈智栋
Original assignee: Changzhou University
Current assignee: Changzhou University
Priority date: 2019-10-12
Filing date: 2019-10-12
Publication date: 2021-04-30
Anticipated expiration: 2039-10-12
Also published as: CN110714212A

Abstract

The invention relates to the technical field of membranes, in particular to a method for preparing a super-hydrophobic nickel thin film from nickel chloride in an aqueous solution system by a one-step method. A super-hydrophobic nickel film with a micro-nano structure was obtained, and the prepared nickel film had a good bonding force with the copper substrate. The electrodeposition solution is composed of nickel chloride, boric acid and choline chloride. The deposition conditions are: 20mA-120mA constant current electrodeposition for 3min-30min at 60°C. The method to obtain a superhydrophobic nickel film is simple and efficient, and does not require any low surface area. It can be modified with organic substances, and the nickel film can be changed from superhydrophilic to superhydrophobic after standing in the air for 10 days, and the contact angle can reach 160°. The method is safe and reliable, has simple steps, is suitable for industrial production, and has the prospect of large-scale application.

Description

Method for preparing super-hydrophobic nickel film in aqueous solution system by nickel chloride one-step method

Technical Field

The invention relates to the technical field of membranes, in particular to a method for preparing a super-hydrophobic nickel film in an aqueous solution system by a nickel chloride one-step method.

Background

The wettability of the solid surface has wide application and prospect in industrial application and daily life, and the surface with a contact angle of more than 150 degrees and a rolling angle of less than 10 degrees between water and the surface is considered to be a super-hydrophobic surface. The bionic super-hydrophobic surface is started from the famous lotus leaf effect, and has important application prospects in multiple fields of self-cleaning, anti-icing, anti-fogging, anti-corrosion, oil-water separation and the like due to the special surface wettability, so that the bionic super-hydrophobic surface is increasingly valued by scientific researchers. The lotus leaf surface structure is compounded by a series of micro-nano mastoids and a layer of waxy crystals with low surface energy, so the key point for preparing the super-hydrophobic surface is to construct a rough micro surface structure and reduce the surface energy. According to the Young's equation, when the surface energy of the material is low, water drops tend to agglomerate with themselves rather than spread when contacting the surface of the material, and the low surface energy can reduce the adhesion of the water drops on the surface of the material, so that the water drops can roll on the surface of the material more easily. The rough surface structure is also important for constructing a super-hydrophobic surface, when a water drop is in contact with the rough surface, a gas cavity exists in a contact area between the water drop and the surface of a material, and the surface energy of the gas is far lower than that of a solid material, so that air in the cavity can form an air cushion to support the water drop and improve the contact angle.

At present, the preparation methods of the super-hydrophobic surface are many, and mainly comprise: chemical vapor deposition, electrodeposition, electrospinning, sol-gel, laser or plasma etching, etc., but the above methods usually require special equipment, complicated processes or expensive cost, and are difficult to realize large-scale industrial production. Therefore, the search for a simple, efficient, inexpensive and excellent overall performance preparation method has been a hot point of research in this field.

The prior electrodeposition method for preparing the super-hydrophobic surface mostly needs secondary surface modification, but the modifier has higher price and complex preparation process.

The existing electrodeposition method for preparing the super-hydrophobic nickel film takes ionic liquid as a solvent, the preparation cost is high, the deposition temperature is generally above 80 ℃, and certain potential safety hazards exist.

Disclosure of Invention

The invention aims to provide a method for preparing a super-hydrophobic nickel film by a one-step method, which is simple, efficient, safe and reliable, and the obtained film has excellent performance.

The technical scheme of the invention is as follows: a method for preparing a super-hydrophobic nickel film in an aqueous solution system by a nickel chloride one-step method comprises the following steps:

(1) dissolving nickel chloride and boric acid in deionized water, and continuously stirring until the nickel chloride and the boric acid are completely dissolved to obtain a uniform green solution, wherein the concentration of the nickel chloride is 0.3-1.5 mol/L, and the concentration of the boric acid is 0.3-1 mol/L;

(2) adding a certain amount of choline chloride solid into the solution obtained in the step (1) to ensure that the concentration of choline chloride is 0.25-1.5 mol/L, and continuously stirring to obtain uniform green electrolyte;

the choline chloride is used as an additive and has the following functions: in the electroplating process, the metal ions can be adsorbed on the surface of an electrode and play a role in inhibiting the cathode electric crystallization, so that the nucleation speed of crystals is higher than the growth speed, and the function of refining the crystal grains is played.

(3) Taking 50mL of the electrolyte obtained in the step (2), and adding 0-0.8 mL of 15 wt.% dilute hydrochloric acid to obtain a final electrolyte;

hydrochloric acid is added to reduce the pH value of the reaction system, the appearance of the plating layer is greatly different under different pH values, and the contact angle of the plating layer is larger under a lower pH value.

(4) Putting copper foil and high-purity nickel sheet into electrolyte to be used as a cathode and an anode respectively, and depositing between the cathode and the anode at a constant current of 20-120 mA, wherein the distance between the two electrodes is 10-40 mm, and the deposition time is 3-30 min;

(5) and after the deposition is finished, cleaning the cathode sample by using deionized water, and then placing the cathode sample in an oven to dry for 15-30 min to obtain the nickel film with the micro-nano hierarchical structure.

The size of the copper foil is 50mm multiplied by 10mm multiplied by 0.2mm, and the area immersed into the electrolyte is 20mm multiplied by 10 mm.

The nickel film prepared by the cathode is kept stand in the air at room temperature for 10 days, the water contact angle of the film is changed from the super-hydrophilicity (<5 ℃) of the film just prepared into the super-hydrophobicity of the film after being kept for 10 days, 5 mu L of water drop is used for representing the film, the contact angle can reach 160 +/-0.5 degrees, and the rolling angle is smaller than 10 degrees.

The super-hydrophobic nickel film prepared by the method is used for corrosion protection of metal, conductive metal substrates such as metal copper aluminum, stainless steel and the like are easy to corrode in water, and the super-hydrophobic nickel film plays a good role in protection after protection.

The invention has the beneficial effects that:

1. the invention provides a method for preparing a super-hydrophobic nickel film in an aqueous solution system by a nickel chloride one-step method. And the prepared nickel film has a large contact angle and a small rolling angle. Meanwhile, the method does not need surface modification in the second step, and only needs to be kept stand in the air at normal temperature for 10 days, and the carbon and oxygen substances in the air are attached to the surface to obtain the super-hydrophobic nickel film. Besides, the copper substrate can be replaced by other conductive metal substrates such as aluminum, stainless steel, etc.

2. The preparation method has the advantages of simplicity, high efficiency, no need of strict experimental conditions, low equipment cost, large-scale production and the like.

Drawings

FIG. 1 is a scanning electron micrograph and a water contact angle of a nickel film obtained by electrodeposition at a constant current of 80mA for 10min in a solution of 1.25M nickel chloride, 0.5M boric acid and 0.25M choline chloride at a pH of 3; a: scanning an electron microscope image; b: a water contact angle;

FIG. 2 is a scanning electron micrograph and a water contact angle of a nickel thin film obtained by adding 0.3mL of 15 wt.% diluted hydrochloric acid to a 1.25M solution of nickel chloride, 0.5M solution of boric acid and 0.25M solution of choline chloride and performing electrodeposition at a constant current of 80mA for 10 min; a: scanning an electron microscope image; b: a water contact angle;

FIG. 3 is a scanning electron micrograph and a water contact angle of a nickel thin film obtained by adding 0.3mL of 15 wt% diluted hydrochloric acid to a 1.25M solution of nickel chloride, 0.5M solution of boric acid and 0.5M solution of choline chloride and performing electrodeposition at a constant current of 80mA for 10 min; a: scanning an electron microscope image; b: a water contact angle;

FIG. 4 is a scanning electron micrograph and water contact angle of a nickel thin film obtained by electrodeposition at constant current of 80mA for 10min in a 1.25M solution of nickel chloride, 0.5M solution of boric acid and 1M solution of choline chloride, with 0.3mL of 15 wt% diluted hydrochloric acid; a: scanning an electron microscope image; b: a water contact angle;

FIG. 5 is a scanning electron micrograph and water contact angle of a nickel thin film obtained by electrodeposition at constant current of 40mA for 10min in a solution of 1.25M nickel chloride, 0.5M boric acid and 1M choline chloride, to which 0.3mL of 15 wt% diluted hydrochloric acid is added; a: scanning an electron microscope image; b: a water contact angle;

FIG. 6 is a scanning electron micrograph and a water contact angle of a nickel thin film obtained by adding 0.3mL of 15 wt.% diluted hydrochloric acid to a 1.25M nickel chloride and 0.5M boric acid solution and performing electrodeposition at a constant current of 80mA for 10 min; a: scanning an electron microscope image; b: a water contact angle;

FIG. 7 is a scanning electron micrograph and water contact angle of a nickel thin film obtained by electrodeposition at constant current of 80mA for 10min in a 1.25M solution of nickel chloride, 0.5M solution of boric acid and 1M solution of ammonium chloride, with 0.3mL of 15 wt.% dilute hydrochloric acid; a: scanning an electron microscope image; b: a water contact angle;

fig. 8 is a tafel test curve of a copper foil, a nickel film prepared in comparative example 1, and a superhydrophobic nickel thin film prepared in example 4.

Detailed Description

The technical solution of the present invention will be further illustrated and described by specific embodiments in conjunction with the accompanying drawings. The embodiments described herein are only a part of the embodiments of the present invention, and not all of them.

Example 1

14.875g NiCl was first added to 50mL of deionized water₂·6H₂O and 1.55g H₃BO₃Continuously stirring until the mixture is completely dissolved to obtain a uniform green solution; next, 1.75g of choline chloride was added to the above solution, and stirred uniformly to obtain a green electrolyte solution having a pH of about 3. The copper foil, cleaned in ethanol and activated in 15 wt.% HCl for 10 seconds, was then placed in an electrolyte with a foil size of 50mm x 10mm x 0.2mm, an area of immersion in the electrolyte was 20mm x 10mm, and the anode was a high purity nickel plate. Performing electrodeposition at constant current of 80mA for 10min at constant deposition temperature of 60 deg.C, wherein the scanning electron microscope image of copper-based nickel film formed on cathode is shown in FIG. 1, and the water contact angle is shown in Table 1 and FIG. 1.

Example 2

14.875g NiCl was first added to 50mL of deionized water₂·6H₂O and 1.55g H₃BO₃Continuously stirring until the mixture is completely dissolved to obtain a uniform green solution; then, 1.75g of choline chloride was added to the above solution, and stirred uniformly to obtain a green electrolyte, and 0.3mL of 15 wt.% diluted hydrochloric acid was added. The copper foil, cleaned in ethanol and activated in 15 wt.% HCl for 10 seconds, was then placed in an electrolyte with a foil size of 50mm x 10mm x 0.2mm, an area of immersion in the electrolyte was 20mm x 10mm, and the anode was a high purity nickel plate. Performing electrodeposition at constant current of 80mA for 10min at constant deposition temperature of 60 deg.C, wherein the scanning electron microscope image of copper-based nickel film formed on cathode is shown in FIG. 2, and the water contact angle is shown in Table 1 and FIG. 2.

Example 3

14.875g NiCl was first added to 50mL of deionized water₂·6H₂O and 1.55g H₃BO₃Continuously stirring until the mixture is completely dissolved to obtain a uniform green solution; secondly, 3.5g of choline chloride is added into the solution, and is stirred uniformly to obtain green electrolyte, and 0 is added.3mL of 15 wt.% dilute hydrochloric acid. The copper foil, cleaned in ethanol and activated in 15 wt.% HCl for 10 seconds, was then placed in an electrolyte with a foil size of 50mm x 10mm x 0.2mm, an area of immersion in the electrolyte was 20mm x 10mm, and the anode was a high purity nickel plate. Performing electrodeposition at constant current of 80mA for 10min at constant deposition temperature of 60 deg.C, wherein the scanning electron microscope image of copper-based nickel film formed on cathode is shown in FIG. 3, and the water contact angle is shown in Table 1 and FIG. 3.

Example 4

14.875g NiCl was first added to 50mL of deionized water₂·6H₂O and 1.55g H₃BO₃Continuously stirring until the mixture is completely dissolved to obtain a uniform green solution; then, 7g of choline chloride is added into the solution, the mixture is stirred uniformly to obtain a green electrolyte, and 0.3mL of 15 wt.% diluted hydrochloric acid is added. The copper foil, cleaned in ethanol and activated in 15 wt.% HCl for 10 seconds, was then placed in an electrolyte with a foil size of 50mm x 10mm x 0.2mm, an area of immersion in the electrolyte was 20mm x 10mm, and the anode was a high purity nickel plate. Performing electrodeposition at constant current of 80mA for 10min at constant deposition temperature of 60 deg.C, wherein the scanning electron microscope image of copper-based nickel film formed on cathode is shown in FIG. 4, and the water contact angle is shown in Table 1 and FIG. 4.

Example 5

14.875g NiCl was first added to 50mL of deionized water₂·6H₂O and 1.55g H₃BO₃Continuously stirring until the mixture is completely dissolved to obtain a uniform green solution; then, 7g of choline chloride is added into the solution, the mixture is stirred uniformly to obtain a green electrolyte, and 0.3mL of 15 wt.% diluted hydrochloric acid is added. The copper foil, cleaned in ethanol and activated in 15 wt.% HCl for 10 seconds, was then placed in an electrolyte with a foil size of 50mm x 10mm x 0.2mm, an area of immersion in the electrolyte was 20mm x 10mm, and the anode was a high purity nickel plate. Performing electrodeposition at constant current of 40mA for 10min at constant deposition temperature of 60 deg.C, wherein the scanning electron microscope image of copper-based nickel film formed on cathode is shown in FIG. 5, and the water contact angle is shown in Table 1 and FIG. 5.

Comparative example 1

14.875g NiCl was first added to 50mL of deionized water₂·6H₂O and 1.55g H₃BO₃Continuously stirring until the mixture is completely dissolved to obtain a uniform green solution; adding into0.3mL of 15 wt.% dilute hydrochloric acid. The copper foil, cleaned in ethanol and activated in 15 wt.% HCl for 10 seconds, was then placed in an electrolyte with a foil size of 50mm x 10mm x 0.2mm, an area of immersion in the electrolyte was 20mm x 10mm, and the anode was a high purity nickel plate. The copper-based nickel film is electrodeposited for 10min under the constant current of 80mA, the deposition temperature is constant at 60 ℃, a scanning electron microscope picture of the copper-based nickel film formed by the cathode is shown in figure 6, and the result shows that the contact angle under the condition is only 130 degrees.

Comparative example 2

14.875g NiCl was first added to 50mL of deionized water₂·6H₂O and 1.55g H₃BO₃Continuously stirring until the mixture is completely dissolved to obtain a uniform green solution; then, 7g of choline chloride is added into the solution, the mixture is stirred uniformly to obtain a green electrolyte, and 0.3mL of 15 wt.% diluted hydrochloric acid is added. The copper foil, cleaned in ethanol and activated in 15 wt.% HCl for 10 seconds, was then placed in an electrolyte with a foil size of 50mm x 10mm x 0.2mm, an area of immersion in the electrolyte was 20mm x 10mm, and the anode was a high purity nickel plate. Electrodepositing at constant current of 200 mA for 10min at constant deposition temperature of 60 deg.C. It was found that the current density was too large to cause severe bending of the copper foil.

Comparative example 3

14.875g NiCl was first added to 50mL of deionized water₂·6H₂O and 1.55g H₃BO₃Continuously stirring until the mixture is completely dissolved to obtain a uniform green solution; then 2.67 g ammonium chloride (1M concentration) was added to the above solution, stirred well to obtain a green electrolyte, and 0.3mL15 wt.% diluted hydrochloric acid was added. The copper foil, cleaned in ethanol and activated in 15 wt.% HCl for 10 seconds, was then placed in an electrolyte with a foil size of 50mm x 10mm x 0.2mm, an area of immersion in the electrolyte was 20mm x 10mm, and the anode was a high purity nickel plate. Performing electrodeposition at constant current of 80mA for 10min at 60 deg.C, and forming copper-based nickel film on cathode by using a contact angle of 146 deg. as shown in FIG. 8.

Table 1: water contact angles of examples

Sample (I)	Example 1	Example 2	Example 3	Example 4	Example 5
						Water contact angle/° c	143	150	155	160	140

And (3) performance testing: tafel curve of test specimen

Corrosion resistance represents the amount of a material's ability to resist the corrosive destructive effects of the surrounding medium. The corrosion resistance of the plating was characterized using a tafel plot in this experiment. And (5) carrying out Tafel curve test by using an electrochemical workstation. The potential interval is + -0.3V relative to the open circuit potential, and the scanning is carried out at the scanning speed of 5mV/s from negative to positive. 3.5 wt% NaCl solution as corrosive liquid, and working electrode of 1cm²The plating piece sample and the reference electrode are Ag/AgCl electrodes, and the counter electrode is a platinum piece electrode. The results are shown in FIG. 8, which are Tafel test curves for copper foil, nickel film prepared without additive, and superhydrophobic nickel film (example 4), respectively. Wherein the corrosion potential of the super-hydrophobic nickel film is corrected, which indicates that the corrosion resistance of the super-hydrophobic nickel film is optimal; and the corrosion current of the super-hydrophobic nickel film is obviously smaller than that of the other two samples, which shows that the corrosion speed is high when corrosion occursThe degree is minimal. In conclusion, the super-hydrophobic nickel film plays an obvious role in corrosion resistance.

Table 2 corrosion resistance data

In Table 2, I_CThe corrosion current is the corrosion speed when corrosion occurs, the corrosion current of the copper foil, the nickel film and the (ammonium chloride) nickel film sample is close to that of the copper foil, the nickel film and the (ammonium chloride) nickel film sample, and the corrosion current of the super-hydrophobic nickel film is obviously smaller than the corrosion current of the first two, and is lower by one order of magnitude, so that the corrosion performance of the super-hydrophobic nickel film is best.

Claims

1. the method for preparing super-hydrophobic nickel film by nickel chloride one-step method in an aqueous solution system, is characterized in that, described method steps are as follows:

(1) Dissolve nickel chloride and boric acid in deionized water and continuously stir until they are completely dissolved to obtain a uniform green solution;

(2) adding choline chloride solid to the solution of step (1), stirring constantly to obtain a uniform green electrolyte;

(3) Take 50 mL of the electrolyte in step (2), add 0.3-0.8 mL of 15 wt.% dilute hydrochloric acid, and obtain the final electrolyte;

(4) Put copper foil and high-purity nickel sheet into the electrolyte as cathode and anode, respectively, and carry out constant current deposition between the two electrodes, and the distance between the two electrodes is 10 mm to 40 mm;

The current of the constant current for deposition is 80 mA;

(5) After the deposition is completed, the cathode is washed with deionized water and then dried in an oven for 30 min to 60 min to obtain a nickel film with a micro-nano hierarchical structure;

The nickel film was left standing in the air for 10 days at room temperature, the water contact angle of the film changed from superhydrophilic <5° just prepared to superhydrophobicity after 10 days, the contact angle reached 160±0.5°, and the rolling angle was less than 10 °.

2. The method for preparing super-hydrophobic nickel film by nickel chloride one-step method according to claim 1, characterized in that: the concentration of nickel chloride in the green solution of step (1) is 0.3 mol/L～1.5 mol/L , the boric acid concentration is 0.3 mol/L to 1 mol/L.

3. The method for preparing super-hydrophobic nickel film by nickel chloride one-step method according to claim 1, characterized in that: the concentration of choline chloride in the green electrolyte of step (2) is 0.25 mol/L～1.5 mol /L.

4. the method for preparing super-hydrophobic nickel film by nickel chloride one-step method according to claim 1, is characterized in that: the copper foil size described in step (4) is 50 mm × 10 mm × 0.2 mm, and the size of the copper foil immersed in the electrolyte is 50 mm × 10 mm × 0.2 mm. The area is 20 mm × 10 mm.

5. The method for preparing a super-hydrophobic nickel thin film by a nickel chloride one-step method according to claim 1, wherein the deposition time in step (4) is 3 min to 30 min, and the deposition temperature is 60°C.

6. the application of the super-hydrophobic nickel film prepared by the method according to claim 1, is characterized in that: described super-hydrophobic nickel film is used for the corrosion protection of metal.