阅读说明：本技术 一种多孔镍基析氢电极复合材料 (Porous nickel-based hydrogen evolution electrode composite material ) 是由 杜先明 于 2021-01-03 设计创作，主要内容包括：本发明公开了一种多孔镍基析氢电极复合材料所述多孔镍基析氢电极泡沫金属为基材,通过离子液体电解沉积S-La-Ni合金,然后通过碱性溶液中腐蚀处理除去铝获得多孔电极,然后通过热处理进行硫修饰,复合材料的比表面积20-23g/m～2,析氢催化活性好,化学稳定性优良。(The invention discloses a porous nickel-based hydrogen evolution electrode composite material, wherein a foam metal of the porous nickel-based hydrogen evolution electrode is used as a base material, S-La-Ni alloy is electrolytically deposited through ionic liquid, aluminum is removed through corrosion treatment in alkaline solution to obtain a porous electrode, sulfur modification is performed through heat treatment, and the specific surface area of the composite material is 20-23g/m 2 Good catalytic activity of hydrogen evolutionHas excellent chemical stability.)

1. The porous nickel-based hydrogen evolution electrode composite material is characterized in that the porous nickel-based hydrogen evolution electrode foam metal is used as a base material, S-La-Ni alloy is deposited on the surface of the porous nickel-based hydrogen evolution electrode foam metal in situ through electrochemistry to obtain the S-La-Ni/foam metal composite material, and the specific surface area of the composite material is 20-23g/m²Hydrogen evolution potential of-0.32V and exchange current density of 37.2 mA/cm²And the Tafel slope is 67.3 mV/dec, and the hydrogen evolution potential is shifted by 12mV for continuous 24-hour stability test, wherein the electrolyte for electrochemical in-situ deposition is a molten salt ionic liquid consisting of nickel salt, aluminum salt, lanthanum salt, alkyl imidazole halide and ethane dithiol.

2. The porous nickel-based hydrogen evolution electrode composite material as claimed in claim 1, wherein the metal foam is nickel foam or copper foam.

3. The porous nickel-based hydrogen evolution electrode composite as claimed in claim 1, wherein the ratio of nickel salt: 150-200 g/L; the aluminum salt is 20-30g/L, the lanthanum salt is 15-20g/L, and the ethane dithiol is 3-5 g/L.

4. The porous nickel-based hydrogen evolution electrode composite material as claimed in claim 1, wherein the electrochemical in-situ deposition of the S-La-Ni alloy comprises the following steps:

(1) nickel salt, aluminum salt, lanthanum salt, alkyl imidazole halide and ethane dithiol are taken as electrolyte molten salt, foam metal is taken as a cathode, a high-purity aluminum plate is taken as an anode, and the electrodeposition condition is 5-15A/dm²At a temperature of 40-50 deg.C^oC, the time is 30min-4h, and the atmosphere is inert gas;

(2) putting the electrode subjected to the electrodeposition in the step (1) into an alkaline solution for corrosion treatment;

(3) placing the cathode subjected to the heat treatment in the step (2) under the inert gas condition for heat treatment;

(4) and (5) washing and drying.

5. The porous nickel-based hydrogen evolution electrode composite material as claimed in claim 4, wherein the alkaline solution in the step (2) is 30-35wt.% NaOH, and the volume ratio is 4: (1-1.5) a mixture of deionized water and ethanol.

6. The porous nickel-based hydrogen evolution electrode composite material as claimed in claim 5, wherein the corrosion process is accompanied by ultrasonic stirring at 30-40kHz, 200-300W of power and 30-35W of temperature^oC。

7. The porous nickel-based hydrogen evolution electrode composite material as claimed in claim 4, wherein the heat treatment of the step (3) is carried out for a time of 12-24 hours,temperature of 450 DEG 650 DEG C^oC。

8. The porous nickel-based hydrogen evolution electrode composite material as claimed in claim 1, wherein the foam metal is subjected to heat treatment, degreasing, alkali washing and acid washing, and the heat treatment is 200-^oC，N₂Protecting with gas for 20-60 min.

9. The porous nickel-based hydrogen evolution electrode composite material as claimed in claim 1, wherein the degreasing solution is acetone and the alkali washing is 30%^oC3-5min, 15-20wt.% NaOH, 3-5min, and 5-15wt.% HCl by acid washing for 3-5min, wherein deionized water is used for washing after degreasing, alkali washing and acid washing.

Technical Field

The invention relates to a porous nickel-based hydrogen evolution electrode composite material, and mainly relates to the field of alkaline catholyte preparation by water electrolysis.

Background

The electrolytic reduction water is safe drinking water and is alkalescent (pH is more than 7); the water molecule group is about 5-6 water molecules, the movement speed in the organism is 2 times of 11-13 water molecules of purified water or tap water, the molecular activity is relatively high, so a large amount of small molecular water has different functions; the oxygen content is high, the negative potential is high, the peroxide in vivo can be removed, and the effects of disease prevention and aging resistance are achieved; contains abundant minerals in ionic state. The electrolytic reduction water completely meets the sanitary standard of domestic drinking water in China, and researches prove that the electrolytic reduction water can be used as an auxiliary means for preventing and treating diseases after being drunk for a long time, and abnormal conditions of liver and kidney and various physiological indexes are not found. Alkaline ionized water is firstly brought into the visual field of people in the medical field, and the water ionizer is accepted by people as a medical instrument.

As drinking water, the pH value of the body fluid of a healthy human body is about 7.4, and the intestinal fluid is mostly alkalescent. At present, most of foods drunk by people are acidic foods, so that the pace of life is accelerated, the pressure of work and study is increased, and the body fluid is gradually acidified due to lack of movement, so that various functions of the body are weakened, excrement cannot be smoothly discharged, the burden of kidney and liver is increased, and various chronic diseases are caused. If people drink alkalescent ionic water frequently, harmful acidic metabolites in the body can be neutralized, the body partial acid state can be corrected, the effects of adjusting the acid-base balance of the human body and keeping the health of the body can be achieved, and the treatment effect on digestive disorder symptoms such as dyspepsia, hyperacidity, chronic diarrhea and the like caused by abnormal fermentation in intestines and stomach can be achieved. Only the weakly alkaline ionized water obtained after electrolysis has the unique function.

The micromolecule ionized water contains rich ionized oxygen, has a reducing group in a negative potential state, directly or indirectly eliminates lipid peroxidation metabolites such as malondialdehyde, lipofuscin and glycosylation end products generated in the in vivo oxidative metabolism process, and free radicals such as H2O2, ROO and the like, and simultaneously can directly or indirectly improve the activity of in vivo antioxidant enzymes such as superoxide dismutase (SOD), Catalase (CAT), glutathione peroxidase (GPx) and the like, improve the oxidation resistance of the organism, maintain the redox balance of the organism and achieve the beautifying effect.

Along with the improvement of living standard of people, the interest on health is more and more close, the electrolyzed and reduced water is accepted by people as novel functional drinking water, and the electrolyzed and reduced water conforms to six essential conditions of good drinking water proposed by the United nations, the property of the water is most close to the water quality of the longevity village, and the electrolyzed and reduced water is potential good health-care water. With the continuous and deep research on the functions of the electrolyzed water and the fact that the electrolyzed water machine is a common commodity and enters common families, the application field of the electrolyzed and reduced water is wider.

The mechanism of electrolyzing and reducing water is simple, and the water enters an electrolytic bath and reacts on the anode and the cathode as follows:

H2O=OH^-+H⁺

at the cathode: 2H₂O+2e^-=2OH^-+H₂↑

At the anode: 2H2O =4H⁺+O2↑+ 4 e^-

As the electrons pass through the circuit, the cathode progressively accumulates to include Na⁺，K⁺，Ca²⁺，Mg²⁺The pH value of the water is increased to 8-10 along with the generation of light radicals and hydrogen, the oxidation-reduction potential is reduced to a negative value, and alkaline water containing metal ions such as calcium, sodium, potassium and the like is generated in the cathode chamber, namely the beauty water produced by the invention.

In addition, as described above, the key of beauty water preparation is that electricity is applied, hydrogen is reduced at the cathode by electrons, hydroxyl groups are left, and weakly alkaline electrolyzed and reduced water is obtained as long as the conductive function is satisfied, and the threshold is extremely low, so that a cathode electrode for researching electrolyzed and reduced water is rarely available in the prior art.

As for the electrode, the present invention considers that the cathode for electrolytically reducing water should have the following functions: (1) the real specific surface area of the electrode; (2) increasing the intrinsic catalytic activity of the electrode material.

Disclosure of Invention

Aiming at the defects and problems of the research of the electrolytic reduction water electrode, the invention provides a preparation method of a cathode for alkalescent beauty water, most electrodes have porous structures and extremely high performance of catalyzing hydrogen evolution to generate alkalescent ionized water, the hydrogen evolution potential is only-310 mV, and the exchange current density is 40.3mA/cm²The alkalescent ionic water obtained by the method has the advantages of high yield, low oxidation-reduction potential and high stability.

Porous nickel-based hydrogen evolutionThe porous nickel-based hydrogen evolution electrode foam metal is used as a base material, an S-La-Ni/foam metal composite material is obtained by electrochemical in-situ deposition of an S-La-Ni alloy on the surface of the porous nickel-based hydrogen evolution electrode foam metal, and the specific surface area of the composite material is 20-23g/m²Hydrogen evolution potential of-0.32V and exchange current density of 37.2 mA/cm²And the Tafel slope is 67.3 mV/dec, and the hydrogen evolution potential is shifted by 12mV for continuous 24-hour stability test, wherein the electrolyte for electrochemical in-situ deposition is a molten salt ionic liquid consisting of nickel salt, aluminum salt, lanthanum salt, alkyl imidazole halide and ethane dithiol.

Further, the foam metal is foam nickel or foam copper.

Further, the nickel salt: 150-200 g/L; the aluminum salt is 20-30g/L, the lanthanum salt is 15-20g/L, and the ethane dithiol is 3-5 g/L.

Further, the electrochemical in-situ deposition of the S-La-Ni alloy comprises the following steps:

(1) nickel salt, aluminum salt, lanthanum salt, alkyl imidazole halide and ethane dithiol are taken as electrolyte molten salt, foam metal is taken as a cathode, a high-purity aluminum plate is taken as an anode, and the electrodeposition condition is 5-15A/dm²At a temperature of 40-50 deg.C^oC, the time is 30min-4h, and the atmosphere is inert gas;

(2) putting the electrode subjected to the electrodeposition in the step (1) into an alkaline solution for corrosion treatment;

(3) placing the cathode subjected to the heat treatment in the step (2) under the inert gas condition for heat treatment;

(4) and (5) washing and drying.

Further, the alkaline solution in the step (2) is 30-35wt.% NaOH, and the volume ratio is 4: (1-1.5) a mixture of deionized water and ethanol.

Further, ultrasonic stirring is carried out at 30-40kHz, the power is 200-300W, and the temperature is 30-35 ℃ in the corrosion process^oC。

Further, the heat treatment of the step (3) takes 12-24h at a temperature of 450-^oC。

Further, the washing 9 in the step (4) is a porous nickel-based hydrogen evolution battery as claimed in claim 1The composite material is prepared by subjecting the foam metal to heat treatment, degreasing, alkali washing and acid washing, wherein the heat treatment is 200-250-^oC，N₂Protecting with gas for 20-60 min.

Further, the degreasing solution is acetone, and the alkali washing is 30^oC3-5min, 15-20wt.% NaOH, 3-5min, and 5-15wt.% HCl by acid washing for 3-5min, wherein deionized water is used for washing after degreasing, alkali washing and acid washing.

With respect to the electrode of the present invention:

(1) pretreatment of water source: factors such as water source, seasonality, process, water sterilization and disinfection can affect the quality of the weakly alkaline electrolyzed and reduced water. The common quality problems of the alkalescent electrolytic reduction water produced by the process are mainly mouth

The quality of the water can be effectively improved by selecting a proper water source and improving the process method due to abnormal taste and smell, such as chlorine smell, soil smell, odor of byproducts possibly accompanied in the production process and the like.

The water source of the invention is drinking water, and the drinking water is pretreated as follows:

(a) a special fiber layer: the characteristic fiber layer is used for filtering large-particle impurities such as rust, dust or moss with the particle size of more than 5 microns.

(b) And (3) treating granular activated carbon: used for removing impurities such as chlorine, VOC, heavy metals, pesticides, peculiar smell and the like.

(c) And (3) calcium sulfite treatment: used for removing chlorine gas, heavy metals and the like remained in water.

(d) Silver-plated particle activated carbon treatment: can be used for sterilizing and inhibiting growth of pathogenic bacteria.

(e) 0.1 micrometer ultra-fine filtering membrane for filtering substances of 0.1 micrometer or more, including pathogenic bacteria and cyst.

The pretreated water is treated in the steps (a) to (e) in sequence.

(2) And selecting and planning electrode materials.

As described in the background above: the present invention recognizes that the cathode for electrolytically reducing water should have the following functions: the real specific surface area of the electrode; increasing the intrinsic catalytic activity of the electrode material.

First, with respect to the inherent catalytic activity, the existing electrodes for the electrolytic reduction of water are generally mainly nickel-based alloys such as Ni — Cu, Ni — Fe, Ni — Mo, and then doped by metal elements in order to obtain excellent catalytic activity.

The invention still uses nickel-based alloy, transition element selects lanthanum for doping, sulfur element is used for further improving the catalytic activity to hydrogen, theoretically

The electron distribution state of Ni element is 1s²2s²2p⁶3s²3d⁸4s²Wherein 3d⁸According to the principle of lowest energy, two unpaired electrons are distributed on the d orbit, so that the metallic nickel has better capability of dissociating and adsorbing H.

The electron distribution state of La element is [ Xe]5d¹6s²The outer layer of the lanthanum atom has four empty orbitals and one unpaired electron, which is easily paired with the 1s orbit of the hydrogen atom to form a La-H adsorption bond.

The electron distribution state of the S element is 3p4, and two unpaired electrons are distributed on the p orbital.

When Ni atoms and La atoms are alloyed according to a certain proportion and doped by S, the electrode material can show excellent catalytic adsorption and dissociation H performance. In the catalysis process, electrons are transferred from Ni to La, so that La in the electrode material forms La-H adsorption bonds, and the hydrogen evolution performance of the electrode material is influenced by the fact that the adsorption bonds are too strong and difficult to desorb or the adsorption bonds are too weak and difficult to adsorb. Ni has good desorption capacity, and compared with the strong H adsorption effect of La, the dissociation effect of nickel is limited, so that the dissociation effect of nickel ions is improved by using two unpaired electrons of S atoms, and when the La adsorption effect and the S-Ni desorption effect gradually reach the optimal state, the synergistic effect of the La adsorption effect, the S-Ni adsorption effect and the S-Ni desorption effect is highlighted.

Based on the support of the theory, the Ni-La alloy is selected and modified by S.

Secondly, with regard to the large specific surface area: porous metal substrates, such as nickel foam and copper foam, are used as the metal substrate, but commercial metal foams are usually macroporous and do not contribute significantly to the specific surface area, and the invention uses a dealloying method to prepare the porous metal substrate.

But the person skilled in the art knows that: the reduction potential of nickel is-0.25V, but the reduction potential of lanthanum ion is more negative (-2.38 Vvs. SHE), and the difference with the reduction potential of nickel ion is larger, so it is difficult to electrodeposit from aqueous solution electrodeposition, in order to simultaneously precipitate lanthanum and nickel, the dosage of nickel can be increased, the dosage of La can be reduced, or the complexing agent can be used to neutralize the reduction potentials of both, but the total effect of electrodeposition is not good, so that the ionic liquid system is adopted, the ionic liquid is an organic salt which is composed of anion and cation, is liquid at room temperature or near room temperature, has the excellent performances of wide electrochemical window, good conductivity, wide liquid range, no vapor pressure, good stability and the like, and is a green solvent. In the aspect of electrodeposition, the ionic liquid combines the advantages of high-temperature molten salt and aqueous solution: the alloy has wider electrochemical window and good conductivity, can obtain metal and alloy which can be electrodeposited only in high-temperature molten salt at room temperature, but has no strong corrosivity like the high-temperature molten salt; meanwhile, most metals which can be obtained in the aqueous solution can be obtained by electrodepositing in the ionic liquid without side reaction, so that the obtained metal has better quality and higher current efficiency, particularly for metals and alloys thereof, such as aluminum and the like, which are difficult to obtain by electrodeposition in the aqueous solution. The above characteristics and good conductivity of ionic liquid make it a new liquid for electrodeposition research, and is increasingly applied to electrodeposition of metals.

Performing electrodeposition on Ni-Al-La alloy through an ionic liquid system, and then performing alkali washing to obtain micropores and mesopores, wherein the alkaline solution is 30-35wt.% of NaOH, and the volume ratio is 4: (1-1.5) a mixture of deionized water and ethanol.

The sodium hydroxide here has two functions: (1) removing aluminum; (2) removing the effect of alkylimidazole halides, especially chlorine, aluminum as an amphoteric oxide which can be dissolved by both acid and base, removing aluminum by base, increasing the surface area of the alloy, about the specific surface areaThe area is 20-23g/m². Secondly, because the main component of the electrolytic solution is alkyl imidazole halide, part of alkyl imidazole halide ionic liquid is inevitably existed on the surface of the porous electrode, if the subsequent heat treatment is directly carried out, the halogen can be obviously adsorbed on the surface of the metal electrode to influence the capability of adsorbing and dissociating hydrogen of the electrode, the alkyl imidazole halide can be usually removed by washing, but in the process of removing the alkyl imidazole halide by washing, the ethane dithiol sulfur source can be inevitably removed by washing, which is not desired to be seen by the invention, so a method for removing the alkyl imidazole halide ionic liquid and ensuring the content of the ethane dithiol is needed.

As would be known to those skilled in the art. Mercaptan can be dissolved in an ethanol solution of sodium hydroxide to generate relatively stable salt, water-insoluble mercaptide can be formed in the presence of nickel, alkyl imidazolium halide can be dissolved in an aqueous solution of sodium hydroxide and cannot be deposited, namely, the alkyl imidazolium halide deposited in the electrolytic process can be effectively removed, the influence of chloride is avoided, namely, aluminum can be effectively removed by using an alkaline solution to obtain micro-mesopores, and the obtained specific surface area is 20-23g/m²And the content of the sulfur source is not influenced while the alkyl imidazole halide is removed.

The corrosion process is accompanied by ultrasonic stirring at 30-40kHz, power of 200-300W and temperature of 30-35 kHz^oAnd C, the ultrasonic treatment can effectively enable the corrosive liquid and the cathode to be in full contact to obtain a porous structure, and the influence of halogen is avoided.

(4) And (3) placing the cathode under the inert gas condition for heat treatment:

the time for heat treatment is 12-24h, and the temperature is 450-650-^oThermal decomposition of C, ethane dithiol to 400^oc, mercaptides are generally less than 450^oC, decomposed sulfides, e.g. hydrogen sulfide, 300^oDirectly decomposing to form sulfur and carrying out a vulcanization reaction on the La-Ni, wherein the minimum treatment temperature of the invention is 450 DEG^oC, preferably 600^oC is not particularly limited as long as melting of the nickel plating layer or the nickel base material does not occur.

The scheme of the invention has the following beneficial effects:

(1) the foamed nickel structure of the cathode for the alkalescent beautifying water endows the electrode with a macroporous structure, and is beneficial to contact with electrolyte.

(2) The nickel-aluminum-lanthanum ternary alloy structure is effectively formed through ionic liquid electroplating.

(3) Aluminum is effectively removed through alkaline corrosion to obtain a micro-mesoporous structure with a specific surface area of 20-23g/m²。

(4) The influence of halogen is effectively avoided when the aluminum material is effectively removed through the alkali corrosion.

(5) Through sulfur doping and lanthanum modification of the nickel material, the adsorption and dissociation performance of hydrogen ions is optimal, and higher hydrogen evolution activity is obtained.

Drawings

FIG. 1 is an SEM image of a nickel foam of the present invention.

FIG. 2 is an SEM image of an S-La-Ni/foamed nickel cathode of the present invention.

FIG. 3 is an SEM magnified view of an S-La-Ni/foamed nickel cathode of the present invention.

FIG. 4 is an SEM close-up view of an S-La-Ni/nickel foam cathode of the present invention.

FIG. 5 is a SEM image of a cross section of S-La-Ni/nickel foam of the present invention.

Detailed Description

Commercially available foamed three-dimensional nickel is purchased as shown in fig. 1, the pore size of the large pores of the nickel material of the three-dimensional network is about 10-400 μm, after electroplating-etching-heat treatment, the surface of the three-dimensional network structure is coated with a coating layer which has disordered micro mesopores, the pore size range is 30nm-500nm according to BET and BJH tests, as shown in fig. 3 and 4, the coating layer is further enlarged, obvious pore channel structures can be seen, the porosity of the coating layer on the surface of the nickel material of the three-dimensional network is about 20-40%, according to the doped aluminum concentration, as shown in fig. 5, the bonding degree of the substrate and the porous coating layer is good, no peeling is caused, and the method is mainly closely related to heat treatment, alkali washing and acid washing in the pretreatment.

Example 1

A preparation method of a cathode for alkalescent beautifying water comprises the following preparation methods:

(1) nickel salt, aluminum salt, lanthanum salt, alkyl imidazole halide and ethane dithiol are taken as electrolyte molten salt, a copper net or a nickel net is taken as a cathode, a high-purity aluminum plate is taken as an anode, and the electrodeposition condition is 5A/dm²Temperature 40^oC, the time is 30min, and the atmosphere is inert gas.

(2) And (3) putting the electrode subjected to the electrodeposition in the step (2) into an alkaline solution for corrosion treatment: alkaline solution is 30wt.% NaOH, volume ratio is 4: 1, deionized water and ethanol mixed solution, ultrasonic stirring is carried out at 30kHz and the temperature is 30 DEG^oC。

(3) The cathode subjected to the heat treatment in the step (2) is subjected to heat treatment under the inert gas condition, the time for heat treatment is 12 hours, and the temperature is 450 DEG^oC。

(4) Washing and drying: washing with deionized water, and air-drying with cold air.

The nickel salt is nickel sulfate or nickel nitrate, and the concentration is 150 g/L.

The aluminum salt is aluminum chloride or aluminum nitrate and is 20 g/L.

The lanthanum salt is lanthanum chloride or lanthanum nitrate and is 15 g/L.

Ethanedithiol 3 g/L.

The nickel net or the copper net is pretreated, the pretreatment comprises heat treatment, degreasing, alkali washing and acid washing, and the heat treatment is 200^oC，N₂Gas protection, 20min, the degreasing fluid is acetone, and the alkali washing is 30^oAnd C, 3min, 15wt.% NaOH, 3min, and 5wt.% HCl for acid washing, 3min, wherein deionized water is used for washing after degreasing, alkali washing and acid washing.

Example 2

A preparation method of a cathode for alkalescent beautifying water comprises the following preparation methods:

(1) nickel salt, aluminum salt, lanthanum salt, alkyl imidazole halide and ethane dithiol are taken as electrolyte molten salt, a copper net or a nickel net is taken as a cathode, a high-purity aluminum plate is taken as an anode, and the electrodeposition condition is 10A/dm²Temperature 45 ℃ of^oC, time 2h, inert gas atmosphere.

(2) And (3) putting the electrode subjected to the electrodeposition in the step (2) into an alkaline solution for corrosion treatment: alkaliThe aqueous solution was 32.5wt.% NaOH, in a volume ratio of 4: 1.25 mixture of deionized water and ethanol with ultrasonic stirring at 35kHz and 33 deg.C^oC。

(3) The cathode subjected to the heat treatment in the step (2) is subjected to heat treatment under the inert gas condition, the time for the heat treatment is 18 hours, and the temperature is 600^oC。

(4) Washing and drying: washing with deionized water, and air-drying with cold air.

The nickel salt is nickel sulfate or nickel nitrate, 175 g/L.

The aluminum salt is aluminum chloride or aluminum nitrate and is 25 g/L.

The lanthanum salt is lanthanum chloride or lanthanum nitrate and is 17.5 g/L.

Ethanedithiol 4 g/L.

The nickel net or the copper net is pretreated, the pretreatment comprises heat treatment, degreasing, alkali washing and acid washing, and the heat treatment is 225^oC，N₂Gas protection, 40min, the degreasing fluid is acetone, and the alkali washing is 30^oC, 4min, 17.5wt.% NaOH, 4min, and acid washing to 10wt.% HCl, 4min, wherein deionized water is used for washing after degreasing, alkali washing and acid washing, and the obtained sample is named as S-2.

Example 3

A preparation method of a cathode for alkalescent beautifying water comprises the following preparation methods:

(1) nickel salt, aluminum salt, lanthanum salt, alkyl imidazole halide and ethane dithiol are taken as electrolyte molten salt, a copper net or a nickel net is taken as a cathode, a high-purity aluminum plate is taken as an anode, and the electrodeposition condition is 15A/dm²Temperature 50 of^oC, time 4h, inert gas atmosphere.

(2) And (3) putting the electrode subjected to the electrodeposition in the step (2) into an alkaline solution for corrosion treatment: the alkaline solution is 35wt.% NaOH, and the volume ratio is 4: 1.5 mixture of deionized water and ethanol, with ultrasonic stirring at 40kHz and 35 deg.C^oC。

(3) The cathode subjected to the heat treatment in the step (2) is subjected to heat treatment under the inert gas condition, the heat treatment time is 24 hours, and the temperature is 650^oC。

(4) Washing and drying: washing with deionized water, and air-drying with cold air.

The nickel salt is nickel sulfate or nickel nitrate, and the concentration is 200 g/L.

The aluminum salt is aluminum chloride or aluminum nitrate and is 30 g/L.

The lanthanum salt is lanthanum chloride or lanthanum nitrate, and the concentration is 20 g/L.

3-5g/L of ethanedithiol.

The nickel net or the copper net is pretreated, the pretreatment comprises heat treatment, degreasing, alkali washing and acid washing, and the heat treatment is 250^oC，N₂Gas protection, 60min, the degreasing fluid is acetone, and the alkali washing is 30^oAnd C, 5min, 20wt.% NaOH, 5min, and 5min, wherein the acid washing is 15wt.% HCl, and the acid washing is 5min, and deionized water is used for washing after degreasing, alkali washing and acid washing.

Comparative example 1

A preparation method of a cathode for alkalescent beautifying water comprises the following preparation methods:

(1) taking nickel salt, aluminum salt, lanthanum salt and alkyl imidazole halide as electrolyte molten salt, taking a copper net or a nickel net as a cathode and taking a high-purity aluminum plate as an anode, and performing electrodeposition under the condition of 10A/dm²Temperature 45 ℃ of^oC, time 2h, inert gas atmosphere.

(2) And (3) putting the electrode subjected to the electrodeposition in the step (2) into an alkaline solution for corrosion treatment: the alkaline solution was 32.5wt.% NaOH, in a volume ratio of 4: 1.25 mixture of deionized water and ethanol with ultrasonic stirring at 35kHz and 33 deg.C^oC。

(3) The cathode subjected to the heat treatment in the step (2) is subjected to heat treatment under the inert gas condition, the time for the heat treatment is 18 hours, and the temperature is 600^oC。

(4) Washing and drying: washing with deionized water, and air-drying with cold air.

The nickel salt is nickel sulfate or nickel nitrate, 175 g/L.

The aluminum salt is aluminum chloride or aluminum nitrate and is 25 g/L.

The lanthanum salt is lanthanum chloride or lanthanum nitrate and is 17.5 g/L.

The nickel net or the copper net is pretreated, and the pretreatment comprises heat treatment, degreasing and alkali washingAnd acid washing, the heat treatment is 225^oC，N₂Gas protection, 40min, the degreasing fluid is acetone, and the alkali washing is 30^oC, 4min, 17.5wt.% NaOH, 4min, acid wash to 10wt.% HCl, 4min, and deionized water washing after degreasing, alkali wash, and acid wash, wherein the obtained sample is named as D-2.

As shown in the above table, the main element in S-2 is S-La-Ni, the hydrogen evolution potential is-0.32V, and the exchange current density is 37.2 mA/cm²The Tafel slope is 67.3 mV/dec, for which a 12mV shift in hydrogen evolution potential occurs for a continuous 24h stability test.

If the S element is not doped, such as the main element of D-1 is La-Ni, the hydrogen evolution potential is-0.63V, and the exchange current density is 19.3 mA/cm²The Tafel slope was 119.2 mV/dec, for which a 24h continuous stability test, a 23mV shift in hydrogen evolution potential occurred.

Finally, it should be noted that the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.