CN115011997B - Self-supporting hollow sugarcoated haws-end electrocatalyst and preparation method and application thereof - Google Patents

Self-supporting hollow sugarcoated haws-end electrocatalyst and preparation method and application thereof Download PDF

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CN115011997B
CN115011997B CN202210668202.8A CN202210668202A CN115011997B CN 115011997 B CN115011997 B CN 115011997B CN 202210668202 A CN202210668202 A CN 202210668202A CN 115011997 B CN115011997 B CN 115011997B
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nickel
solution
electrocatalyst
molybdenum oxide
source
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CN115011997A (en
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王刚
徐丹
刘涵丹
刘艳艳
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Shihezi University
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
    • C25B11/095—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds at least one of the compounds being organic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C25B1/01—Products
    • C25B1/02—Hydrogen or oxygen
    • C25B1/04—Hydrogen or oxygen by electrolysis of water
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/10—Process efficiency
    • Y02P20/133—Renewable energy sources, e.g. sunlight

Abstract

The invention provides a self-supporting hollow sugarcoated haws-end electrocatalyst and a preparation method and application thereof, belonging to the technical field of electrocatalytic water decomposition. The invention firstly prepares NiMoO by taking foam nickel as a substrate 4 ·xH 2 O/NF nano rod array, then taking the nano rod array as a growth framework, wrapping ZIF-67 on the surface of the nano rod through MOF participation strategy to form a sugarcoated haws-like core-shell structure, and then forming NiMoO through selective vulcanization 4 ·xH 2 O is a core, and Ni-Co-S nano cage is a shell, thereby ensuring that the electrocatalyst is in a large current density condition (350 mA cm) ‑2 ) Still has excellent hydrogen evolution and oxygen evolution performance, and is favorable for improving full hydrolysis performance.

Description

Self-supporting hollow sugarcoated haws-end electrocatalyst and preparation method and application thereof
Technical Field
The invention relates to the technical field of electrocatalytic water splitting, in particular to a self-supporting hollow sugarcoated haw-shaped electrocatalyst and a preparation method and application thereof.
Background
The growing energy and environmental crisis have attracted global attention, and therefore, it is highly desirable to develop renewable, clean, and emerging energy sources to replace traditional fossil fuels. The hydrogen energy has the characteristics of high energy density, high heat value, rich resources, zero carbon emission, easy storage and the like, is widely considered as a potential energy carrier of a future sustainable energy system, and is widely paid attention to. Compared with the traditional hydrogen production technology, the electrolytic water hydrogen production has the advantages of high conversion efficiency, zero carbon emission, high hydrogen purity and the like, and is the hydrogen production technology with the most development prospect. However, in actual electrolysis of water, an additional driving force (typically expressed in the form of an overpotential) is often required to overcome the activation energy barrier and some other resistance of the solution and electrode/electrolyte contact interface to encourage the overall reaction to occur. The search for highly active electrocatalysts is an effective way to increase the efficiency of water electrolysis.
Currently, pt-based noble metals are the best Hydrogen Evolution Reaction (HER) catalysts, whereas RuO 2 And IrO 2 Is a reference electrocatalyst for Oxygen Evolution Reaction (OER). However, the problems of small reserves, high cost, poor stability and the like of noble metals limit the large-scale application of the noble metals. Furthermore, the use of HER catalysts and OER catalysts often require different environments. HER catalysts exhibit good catalytic activity under acidic conditions while OER catalysts have better catalytic activity under basic conditions. Therefore, development and design of a non-noble metal electrocatalyst with high-efficiency hydrogen evolution and oxygen evolution dual-function characteristics in the same electrolyte are attracting attention.
Disclosure of Invention
The invention aims to provide a self-supporting hollow sugarcoated haws-end electrocatalyst, a preparation method and application thereof, and the prepared electrocatalyst has high-efficiency hydrogen evolution and oxygen evolution functions in the same electrolyte.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides a preparation method of a self-supporting hollow sugarcoated haw-shaped electrocatalyst, which comprises the following steps:
mixing foam nickel, a molybdenum source, a nickel source and water, and performing a hydrothermal reaction to obtain a nickel-molybdenum oxide-nickel composite;
mixing the nickel molybdenum oxide-nickel compound, a solution containing bivalent cobalt salt and a 2-methylimidazole solution, and carrying out coordination to obtain nickel molybdenum oxide @ ZIF-67;
mixing the nickel molybdenum oxide @ ZIF-67 with a sulfur source solution, and performing solvothermal reaction to obtain a self-supporting hollow sugarcoated haws-end electrocatalyst; the mass ratio of the sulfur source to the nickel molybdenum oxide @ ZIF-67 in the sulfur source solution is (3.5-5): 1.
Preferably, the molybdenum source comprises ammonium molybdate or sodium molybdate and the nickel source comprises nickel acetate, nickel nitrate or nickel chloride.
Preferably, the molar ratio of the nickel source to the molybdenum source is 1:1-10:1; the temperature of the hydrothermal reaction is 140-180 ℃ and the time is 6-10 h.
Preferably, the divalent cobalt salt in the divalent cobalt salt-containing solution is cobalt nitrate, cobalt chloride, cobalt acetate or cobalt sulfate; the concentration of the solution containing the bivalent cobalt salt is 0.04-0.08 mol/L; the concentration of the 2-methylimidazole solution is 0.4-0.8 mol/L.
Preferably, the molar ratio of the 2-methylimidazole to the divalent cobalt salt in the solution containing the divalent cobalt salt is (0.08-0.16): 0.8-1.6; the mass ratio of the nickel molybdenum oxide-nickel complex to the bivalent cobalt salt is 0.006 (0.23-0.46).
Preferably, the mixing of the nickel molybdenum oxide-nickel complex, the solution containing the divalent cobalt salt and the 2-methylimidazole solution comprises the steps of placing the nickel molybdenum oxide-nickel complex in the solution containing the divalent cobalt salt for first mixing, and carrying out second mixing on the obtained mixed solution and the 2-methylimidazole solution; the first mixing time is 5-10 min; the second mixing time is 15-45 min.
Preferably, the sulfur source in the sulfur source solution is thioacetamide, thiourea, sodium sulfide or cysteine, and the concentration of the sulfur source in the sulfur source solution is 0.044mol/L.
Preferably, the solvothermal reaction is carried out at a temperature of 120-150 ℃ for 4-6 hours.
The invention provides a self-supporting hollow sugarcoated haw-shaped electrocatalyst prepared by the preparation method, which comprises a nickel-molybdenum oxide-nickel composite inner core and a hollow Ni-Co-S nano cage outer shell.
The invention provides application of the self-supporting hollow sugarcoated haw-like electrocatalyst in the field of alkaline full electrolytic cell water decomposition.
The invention provides a preparation method of a self-supporting hollow sugarcoated haw-shaped electrocatalyst, which comprises the following steps: mixing foam nickel, a molybdenum source, a nickel source and water, and performing a hydrothermal reaction to obtain a nickel-molybdenum oxide-nickel composite; mixing the nickel molybdenum oxide-nickel compound, a solution containing bivalent cobalt salt and a 2-methylimidazole solution, and carrying out coordination to obtain nickel molybdenum oxide @ ZIF-67; mixing the nickel molybdenum oxide @ ZIF-67 with a sulfur source solution, and performing solvothermal reaction to obtain a self-supporting hollow sugarcoated haws-end electrocatalyst; the mass ratio of the sulfur source to the nickel molybdenum oxide @ ZIF-67 in the sulfur source solution is (3.5-5): 1.
The invention firstly prepares nickel molybdenum oxide-nickel compound (NiMoO) by taking foam nickel as a substrate 4 ·xH 2 O/NF nano rod array, x is more than or equal to 0), then taking the nano rod array as a growth framework, wrapping ZIF-67 on the surface of the nano rod through a MOF participation strategy to form a sugarcoated haw-shaped core-shell structure, and then regulating and controlling the dosage of a sulfur source to carry out selective vulcanization to realize a hollow core structure to form a NiMoO-based nano rod structure 4 ·xH 2 O is a core, and Ni-Co-S nano-cage is a self-supporting hollow sugarcoated haws-end core-shell array structure. The invention takes the foam nickel as the substrate, so that the electrocatalyst has the inherent structural advantage of the self-supporting electrocatalyst (the self-supporting structure avoids the use of a polymer adhesive, reduces the contact internal resistance of an active material and a conductive substrate, realizes the rapid desorption of gas), and the hollow sugar gourd-shaped structure enables the catalyst to have larger specific surface area, can increase the contact area of an electrode and electrolyte, expose more active sites and improve the electronic conductivity, also obviously enhances the catalytic activity and the stability of the catalyst, and is beneficial to rapid charge and quality transmission and excellent reaction kinetics; the multi-element metal sulfide formed by selective vulcanization can realize the synergistic effect among different metal ions, and enhance the intrinsic activity of the catalyst, thereby ensuring that the electrocatalyst can be used under the condition of high current density (350 mAcm -2 ) Still has excellent hydrogen evolution and oxygen evolution performance, and is favorable for improving full hydrolysis performance.
The preparation process is simple, template removal is not needed, the production cost is low, the product structure is stable, and the prepared self-supporting hollow sugarcoated haw-like electrocatalyst has the potential of being practically applied to the water electrolysis industry of an alkaline full-electrolytic cell.
Drawings
FIG. 1 is a NiMoO prepared in example 1 4 ·xH 2 XRD pattern of O@Ni-Co-S array electrocatalyst;
FIG. 2 is a NiMoO prepared in example 1 4 ·xH 2 SEM image of O@Ni-Co-S array electrocatalyst；
FIG. 3 is a NiMoO prepared in example 1 4 ·xH 2 TEM image of O@Ni-Co-S array electrocatalyst;
FIG. 4 is a NiMoO prepared in example 1 4 ·xH 2 Element mapping graph of O@Ni-Co-S array electrocatalyst;
fig. 5 is a HER polarization plot for the electrocatalyst prepared in example 1, the electrocatalyst prepared in comparative example 1, and commercial Pt;
FIG. 6 electrocatalyst prepared in example 1, electrocatalyst prepared in comparative example 1 and commercially available RuO 2 OER polarization curve plot of catalyst;
FIG. 7 is a graph showing polarization of the electrocatalyst prepared in example 1 as an alkaline water splitting cell assembled with a positive electrode and a negative electrode;
fig. 8 is a digital photograph of a huffman device for measuring faraday efficiency of example 1;
FIG. 9 shows the electrocatalyst yield H prepared in example 1 2 And O 2 A plot of the volume change of (2);
FIG. 10 is a graph showing the overall water-splitting stability test at a voltage of 1.51V (vs. RHE) for example 1.
Detailed Description
The invention provides a preparation method of a self-supporting hollow sugarcoated haw-shaped electrocatalyst, which comprises the following steps:
mixing foam nickel, a molybdenum source, a nickel source and water, and performing a hydrothermal reaction to obtain a nickel-molybdenum oxide-nickel composite;
mixing the nickel molybdenum oxide-nickel compound, a solution containing bivalent cobalt salt and a 2-methylimidazole solution, and carrying out coordination to obtain nickel molybdenum oxide @ ZIF-67;
mixing the nickel molybdenum oxide @ ZIF-67 with a sulfur source solution, and performing solvothermal reaction to obtain a self-supporting hollow sugarcoated haws-end electrocatalyst; the mass ratio of the sulfur source to the nickel molybdenum oxide @ ZIF-67 in the sulfur source solution is (3.5-5): 1.
In the present invention, the preparation materials are commercially available as known to those skilled in the art unless otherwise specified.
The invention mixes foam nickel, molybdenum source, nickel source and water, and carries out hydrothermal reaction to obtain nickel-molybdenum oxide-nickel compound.
The Nickel Foam (NF) is not particularly limited, and commercially available products known in the art can be used; the size of the foam nickel is not particularly limited, and the foam nickel can be adjusted according to actual requirements; in the present invention, the size of the nickel foam is 1.5X3 cm 2 。
In the invention, the foam nickel is preferably subjected to ultrasonic cleaning for 15min by sequentially adopting 1mol/L HCl solution, deionized water and absolute ethyl alcohol before use, and then is dried in vacuum at a low temperature. The specific process of ultrasonic cleaning and low-temperature vacuum drying is not particularly limited, and may be performed according to a process well known in the art.
In the present invention, the molybdenum source preferably includes ammonium molybdate or sodium molybdate, and the nickel source preferably includes nickel acetate, nickel nitrate or nickel chloride; the molar ratio of the nickel source to the molybdenum source is preferably 1:1 to 10:1, more preferably 8.75:1.
In the present invention, the process of mixing the foam nickel, the molybdenum source, the nickel source and the water is preferably as follows: dissolving a molybdenum source and a nickel source in water, and mixing the obtained mixed solution with foam nickel; in the mixed solution, the concentration of the molybdenum source is preferably 0.0057mol/L, and the concentration of the nickel source is preferably 0.0267mol/L.
In the invention, the temperature of the hydrothermal reaction is preferably 140-180 ℃ and the time is preferably 6-10 h; the hydrothermal reaction is preferably carried out in a teflon lined autoclave.
After the hydrothermal reaction is completed, the obtained product is preferably cooled, foam nickel is washed by deionized water and ethanol for several times, and then vacuum drying is carried out to obtain a nickel-molybdenum oxide-nickel composite, which is denoted as NiMoO 4 ·xH 2 O/NF (x is greater than or equal to 0); the number of times of the washing is not particularly limited, and the washing is performed according to the process well known in the art; the conditions of the vacuum drying are not particularly limited in the present invention, and the vacuum drying may be performed according to a process well known in the art; in an embodiment of the present invention, the temperature of the vacuum drying is 60 ℃ and the time is 12 hours.
After the nickel molybdenum oxide-nickel composite is obtained, the nickel molybdenum oxide-nickel composite, the solution containing the bivalent cobalt salt and the 2-methylimidazole solution are mixed for coordination, and the nickel molybdenum oxide@ZIF-67 is obtained. In the present invention, the divalent cobalt salt in the divalent cobalt salt-containing solution is preferably cobalt nitrate, cobalt chloride, cobalt acetate or cobalt sulfate; the concentration of the divalent cobalt salt-containing solution is preferably 0.04 to 0.08mol/L, more preferably 0.06mol/L; the molar ratio of the 2-methylimidazole to the cobalt salt in the cobalt salt-containing solution is preferably (0.08-0.16): 0.8-1.6, more preferably 0.12:1; the mass ratio of the nickel molybdenum oxide-nickel complex to the bivalent cobalt salt is preferably 0.006 (0.23-0.46).
In the present invention, the concentration of the 2-methylimidazole solution is preferably 0.4 to 0.8mol/L, more preferably 0.5mol/L; the solvent used for the solution containing the divalent cobalt salt and the solution containing the 2-methylimidazole is preferably methanol. The preparation process of the solution containing the divalent cobalt salt and the solution containing the 2-methylimidazole is not particularly limited, and the solution may be prepared according to a process well known in the art.
In the present invention, the mixing of the nickel molybdenum oxide-nickel complex, the divalent cobalt-containing salt solution and the 2-methylimidazole solution preferably comprises placing the nickel molybdenum oxide-nickel complex in the divalent cobalt-containing salt solution, performing first mixing, and performing second mixing of the obtained mixed solution and the 2-methylimidazole solution; the 2-methylimidazole solution is preferably added dropwise to the mixture under vigorous stirring. In the present invention, the time of the first mixing is preferably 5 to 10 minutes; the second mixing time is preferably 15 to 45 minutes, more preferably 30 minutes. In the present invention, the first mixing and the second mixing are preferably performed under stirring conditions, and the stirring rate is not particularly limited in the present invention, and may be performed according to a process well known in the art. The invention makes bivalent cobalt ions fully adhere to NiMoO through the first mixing 4 ·xH 2 An O/NF framework; in the second mixing process, the divalent cobalt ion coordinates with 2-methylimidazole to form ZIF-67.
After the coordination is completed, the obtained product is preferably washed and dried in sequence to obtain the nickel-molybdenum oxideZIF-67 denoted as NiMoO 4 ·xH 2 O@ZIF-67/NF; the reagent used for the washing is preferably absolute ethanol, and the drying temperature is preferably 60 ℃ and the time is preferably 6h.
After the nickel molybdenum oxide @ ZIF-67 is obtained, the self-supporting hollow sugarcoated haws-end electrocatalyst is obtained by mixing the nickel molybdenum oxide @ ZIF-67 with a sulfur source solution and performing solvothermal reaction.
In the invention, the sulfur source in the sulfur source solution is preferably thioacetamide, thiourea, sodium sulfide or cysteine, the concentration of the sulfur source in the sulfur source solution is 0.044mol/L, and the solvent used in the sulfur source solution is preferably ethanol; the mass ratio of the sulfur source to the nickel molybdenum oxide @ ZIF-67 in the sulfur source solution is preferably (3.5-5): 1, more preferably 4.16:1.
In the invention, the nickel molybdenum oxide @ ZIF-67 is mixed with the sulfur-containing source solution, preferably, the nickel molybdenum oxide @ ZIF-67 is immersed in the sulfur-containing source solution and stirred for 30min.
In the invention, the temperature of the solvothermal reaction is preferably 120-150 ℃ and the time is preferably 4-6 h; the solvothermal reaction is preferably carried out in a teflon lined stainless steel autoclave.
During the solvothermal reaction, S formed by hydrolysis of the sulfur source 2- Co of anions with the surface of the crust ZIF-67 2+ Reacting to generate cobalt sulfide; when Co is 2+ After the ions are consumed S 2- Further with NiMoO in the internal core 4 ·xH 2 Ni in the O surface portion reacts (Ni reacts preferentially with Ni due to its higher chemical activity than Mo) to give nickel sulfide but does not react with molybdenum ions to give molybdenum sulfide, the amount of the sulfur source is excessive relative to cobalt ions but insufficient to react with metallic ions Mo, and the amount of the sulfur source is insufficient to react with NiMoO 4 ·xH 2 O is completely reacted, thus not damaging NiMoO 4 ·xH 2 O structure.
After the solvothermal reaction is completed, the obtained product is preferably subjected to natural cooling, washing and drying in sequence to obtain the self-supporting hollow sugarcoated haw-like electrocatalyst which is named as NiMoO 4 ·xH 2 O@Ni-Co-S. In the present inventionThe reagent used for washing is preferably absolute ethanol; the drying mode is preferably vacuum drying, the drying temperature is preferably 60 ℃, and the drying time is preferably 12 hours.
The invention provides a self-supporting hollow sugarcoated haw-shaped electrocatalyst prepared by the preparation method, which comprises a nickel-molybdenum oxide-nickel composite inner core and a hollow Ni-Co-S nano cage outer shell. The electrocatalyst is of a hollow sugarcoated haws-end core-shell array structure.
The invention provides application of the self-supporting hollow sugarcoated haw-like electrocatalyst in the field of alkaline full electrolytic cell water decomposition. The method of application of the present invention is not particularly limited, and may be applied according to methods well known in the art.
The technical solutions of the present invention will be clearly and completely described in the following in connection with the embodiments of the present invention. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
1) Will be 1.5X3 cm 2 Sequentially ultrasonically cleaning large and small foam Nickel (NF) with 1M HCl solution, deionized water and absolute ethyl alcohol for 15min, and vacuum drying at low temperature; the cleaned NF was placed in 30mL of a mixed solution containing 0.25g of nickel acetate (0.0014 mol) and 0.2g of ammonium molybdate (0.00016 mol), and the resulting solution was transferred to a Teflon-lined autoclave and reacted at 180℃for 10 hours; after the reaction kettle is cooled, washing foam nickel with deionized water and ethanol for several times, and vacuum drying at 60 ℃ for 12 hours to obtain NiMoO 4 ·xH 2 O/NF；
2) 0.36g (0.0012 mol) Co (NO 3 ) 2 ·6H 2 O is dissolved in 20mL of methanol to obtain cobalt salt solution; 0.82g (0.01 mol) of 2-methylimidazole (2-MIM) was dissolved in 20mL of methanol to obtain a 2-methylimidazole solution; the NiMoO obtained in the step (1) is processed 4 ·xH 2 O/NF was immersed in the cobalt salt solution, stirred for 5 minutes, followed by stirring the 2-methyl groupDropwise adding imidazole solution into cobalt salt solution, stirring for 30min, cleaning electrode with absolute ethanol, and oven drying at 60deg.C for 6 hr to obtain sugar-calabash-shaped NiMoO 4 ·xH 2 O@ZIF-67；
3) 12mg of the sugarcoated haws-like NiMoO of step (2) are added 4 ·xH 2 Immersing O@ZIF-67 in 15mL of ethanol solution containing 50mg of Thioacetamide (TAA), stirring for 30min, transferring the obtained solution into a stainless steel autoclave lined with 25mL of Teflon, reacting at 120 ℃ for 6h, naturally cooling the autoclave, cleaning the electrode with absolute ethanol, and vacuum drying at 60 ℃ for 12h to obtain self-supporting hollow sugarcoated haw-like NiMoO 4 ·xH 2 O@Ni-Co-S array electrocatalyst.
Example 2:
the only difference from example 1 is that: in the step 2), the 2-methylimidazole solution is added into the cobalt salt solution dropwise, and stirring is continued for 15min.
Example 3:
the only difference from example 1 is that: in the step 2), the 2-methylimidazole solution is added into the cobalt salt solution dropwise, and stirring is continued for 45min.
Example 4:
the only difference from example 1 is that: the sulfide in the step 3) is thiourea.
Example 5:
the only difference from example 1 is that: the sulfide in step 3) is sodium sulfide.
Example 6:
the only difference from example 1 is that: the sulfide in step 3) is cysteine.
Comparative example 1
Step 1): will be 1.5X3 cm 2 Sequentially ultrasonically cleaning large and small foam Nickel (NF) with 1M HCl solution, deionized water and absolute ethyl alcohol for 15min, and vacuum drying at low temperature; placing the cleaned NF in 30mL of mixed solution containing 0.25g of nickel acetate and 0.2g of ammonium molybdate, transferring the obtained solution into a Teflon-lined autoclave, and reacting for 10 hours at 180 ℃; after the reaction kettle is cooled, washing foam nickel with deionized water and ethanol for several times, and vacuum drying at 60 ℃ for 12 hours to obtain NiMoO 4 ·xH 2 O/NF；
2) 0.36g Co (NO) 3 ) 2 ·6H 2 O is dissolved in 20mL of methanol to obtain cobalt salt solution; 0.82g of 2-methylimidazole (2-MIM) was dissolved in 20mL of methanol to obtain a 2-methylimidazole solution; the NiMoO obtained in the step (1) is processed 4 ·xH 2 Immersing O/NF in cobalt salt solution, stirring for 5min, adding 2-methylimidazole solution dropwise into cobalt salt solution under stirring, stirring for 30min, washing electrode with absolute ethanol, and oven drying at 60deg.C for 6 hr to obtain sugar-calabash-shaped NiMoO 4 ·xH 2 O@ZIF-67 array electrocatalyst.
Characterization and testing
1) Taking hollow sugarcoated haw-like NiMoO prepared in example 1 4 ·xH 2 The O@Ni-Co-S array electrocatalyst is subjected to X-ray diffraction, scanning electron microscopy, transmission electron microscopy and element mapping tests respectively, and the results are shown in fig. 1 to 4.
As can be seen from FIG. 1, the electrocatalyst prepared is mainly composed of NF, niMoO 4 ·xH 2 O、Ni 3 S 2 And Co 9 S 8 Four phase compositions, wherein Ni 3 S 2 The nickel in (a) is mainly from NiMoO 4 ·xH 2 O。
From FIGS. 2 and 3, it can be seen that the morphology of the prepared electrocatalyst is mainly composed of nanorods and nanocages, and the inside NiMoO 4 ·xH 2 The O nano-rod array provides a growing place for the outer nano-cage to form a sugarcoated haw core-shell structure, and meanwhile, figure 3 further proves that the outer nano-cage is of a hollow structure. The hollow sugarcoated haws-end structure not only ensures that the electrode material has larger specific surface area and is beneficial to exposing more active sites, but also ensures that the electrolyte can easily permeate the electrode by the abundant open space in the array, shortens the ion diffusion length and accelerates the reaction process.
Fig. 4 is an EDS spectrum of the corresponding element in the electrocatalyst prepared in example 1, and the distribution of the element in the electrocatalyst can be clearly observed from fig. 4. Co element is mainly distributed on the shell, S element is uniformly distributed in the core and the shell, and signals of Ni, mo and O elements in the core are stronger than those in the shellNumber (x). This is because when ZIF-67 is consumed, S 2- The ions are further combined with internal NiMoO 4 ·xH 2 O nanorods react and Ni is preferentially formed due to its higher chemical activity than Mo 3 S 2 . Ni, co metal ions of various conversion valence states (with Ni 2+ 、Ni 3+ 、Co 2+ And Co 3+ ) Not only more active sites are formed, but also the synergistic effect between the two is beneficial to improving the intrinsic activity of the catalyst, thereby improving the catalytic reaction of the catalyst. The test shows that the invention successfully prepares the hollow sugarcoated haws-end NiMoO 4 ·xH 2 O@Ni-Co-S array electrocatalyst.
Test example 1
The electrochemical performance test is carried out by adopting a CHI 660E electrochemical workstation produced by Shanghai Chen Hua company, a three-electrode system is adopted to test the hydrogen evolution and oxygen evolution performance of the catalyst, ag/AgCl is used as a reference electrode, a carbon rod is used as a counter electrode, and a hollow sugarcoated haw-like NiMoO is adopted 4 ·xH 2 The O@Ni-Co-S array electrocatalyst is a working electrode, and the electrolyte is 1.0M KOH solution.
HER linear voltammetric scanning is carried out on the electrocatalyst prepared in the example 1 and the comparative example 1 and the commercial Pt sheet catalyst under alkaline conditions, the voltage ranges from-1V to-1.55V, and the scanning speed is 5mV to 100mV s -1 The standing time is 1-10 s, and the measured linear voltammetric scanning curve is shown in figure 5. As can be seen from FIG. 5, the hollow sugarcoated haw-like NiMoO prepared by the present invention 4 ·xH 2 The O@Ni-Co-S array electrocatalyst shows excellent HER catalytic activity under alkaline conditions. At 10mA cm -2 The overpotential of 113mV is better than comparative example 1, even comparable to commercial Pt. In addition, the electrode can stably output 350mA cm under the overpotential of 260mV -2 Is not subjected to severe evolution of H 2 The obvious interference of bubbles is expected to be applied to industrial electrolyzed water.
Taking hollow sugarcoated haw-like NiMoO prepared in example 1 4 ·xH 2 O@Ni-Co-S array electrocatalyst, sugarcoated haw-like NiMoO prepared in comparative example 1 4 ·xH 2 O@ZIF-67 array electrocatalyst and commercial RuO 2 OER linear volt-ampere scanning is carried out on the/NF catalyst under alkaline condition, the voltage range is 0.2-0.7V, and the scanning speed is 5-100 mV s -1 The standing time is 1-10 s, and the measured linear voltammetric scanning curve is shown in FIG. 6. As can be seen from FIG. 6, the hollow sugarcoated haws-end NiMoO of the present invention 4 ·xH 2 The O@Ni-Co-S array electrocatalyst shows excellent OER catalytic activity under alkaline conditions. At 50mA cm -2 Over potential 261mV is superior to comparative example 1 and commercial RuO at current density of (C) 2 A catalyst. In addition, the electrode can stably output 350mA cm under the overpotential of 466mV -2 Is not subject to severe evolution of O 2 The bubbles interfere significantly.
Test example 2
Electrolytic water performance test: adopts a two-electrode system and adopts hollow sugarcoated haws-end NiMoO 4 ·xH 2 O@Ni-Co-S array electrocatalyst is used as a cathode and an anode, and 1M KOH solution is used as electrolyte to assemble an alkaline electrolytic water electrolyzer.
Taking the self-supporting hollow sugarcoated haws-like NiMoO prepared in example 1 respectively 4 ·xH 2 O@Ni-Co-S array electrocatalyst and sugarcoated haw-like NiMoO prepared in comparative example 1 4 ·xH 2 An O@ZIF-67 array electrocatalyst is assembled into an alkaline water decomposition electrolytic cell, polarization curve test is carried out, the voltage range is 1-2.5V, and the scanning rate is 5mV s -1 And with commercial RuO 2 the/NF catalyst was compared and the test results are shown in FIG. 7. Commercial RuO 2 The preparation process of the NF catalyst comprises the following steps: 10mg of catalyst (RuO) 2 ) Adding the mixture into a solution containing 980 mu L of ethanol and 20 mu L of 5% Nafion, and carrying out ultrasonic treatment for 30 minutes to obtain an ink solution with uniform dispersion; 200. Mu.L of the ink solution was applied to NF (1X 1 cm) 2 ) Drying the obtained sample with hot air to obtain RuO 2 /NF。
As can be seen from FIG. 7, the self-supporting hollow sugarcoated haw-like NiMoO of the present invention 4 ·xH 2 The O@Ni-Co-S array electrocatalyst shows excellent water splitting catalytic activity. When the current density is 20mAcm -2 And 100mAcm -2 When the battery voltage is higher than that of commercial Pt II RuO, the battery voltages are only 1.503V and 1.61V respectively 2 Catalytic reactionAnd (3) an agent.
Test example 3
1) NiMoO prepared in example 1 was used 4 ·xH 2 O@Ni-Co-S electrodes as positive and negative electrodes, H was measured at room temperature by a Huffman apparatus (FIG. 8) in a two-electrode system by draining 2 And O 2 Testing with 1M KOH solution as electrolyte and constant current method with current density of 50mAcm -2 The method comprises the steps of carrying out a first treatment on the surface of the In FIG. 8, 1mL indicates the corresponding starting position of the solution without starting the reaction; after 45 minutes at 20.1mL, H 2 Precipitating the corresponding volume, and after 10mL is 45 minutes, O 2 And precipitating the corresponding volume. Collecting H generated in U-shaped electrolytic cells in different time by drainage method 2 /O 2 The amounts, test results are shown in figure 9.
As can be seen from fig. 9, the cathode/anode yields H 2 And O 2 The volume ratio of (2:1) is consistent with a theoretical value, which shows that the self-supporting hollow sugarcoated haws NiMoO 4 ·xH 2 The O@Ni-Co-S array electrocatalyst is an effective electrolyzed water catalyst.
2) Full water dissolution stability test: in a two electrode cell, a self-supporting hollow sugarcoated haw-like NiMoO prepared in example 1 4 ·xH 2 O@Ni-Co-S array electrocatalyst serving as positive electrode and negative electrode, electrolyte of 1.0M KOH, and measuring NiMoO by using a transverse voltage test method 4 ·xH 2 Durability of the overall water decomposition of O@Ni-Co-S/NF at continuous potential of 1.51V, as shown in FIG. 10, the prepared electrocatalyst was durable as seen from FIG. 10.
As can be seen from the above examples and test examples, the self-supporting hollow sugarcoated haw-like NiMoO prepared by the invention 4 ·xH 2 The O@Ni-Co-S array electrocatalyst shows excellent electrolyzed water catalytic activity, and mainly benefits from the following points: (1) The active material grows on the foam nickel substrate, so that the use of a polymer adhesive is avoided, the contact internal resistance of the active material and the conductive substrate is reduced, and the rapid desorption of gas is realized; the contact area between the electrode and the electrolyte is increased, and the electronic conductivity is improved; (2) The hollow sugarcoated haws array structure not only ensures that the electrocatalyst has larger specific surface areaThe method is favorable for exposing more active sites, and the abundant open space in the array can ensure that electrolyte can easily permeate to the electrode, shorten the ion diffusion length and accelerate the reaction process; (3) The synergic action between Ni and Co ions with multiple conversion valence states can enhance the intrinsic activity of the catalyst, thereby accelerating the reaction kinetics and further improving the reaction efficiency of electrolyzed water.
The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims (9)

1. A preparation method of a self-supporting hollow sugarcoated haw-shaped electrocatalyst comprises the following specific steps:
mixing foam nickel, a molybdenum source, a nickel source and water, and performing hydrothermal reaction to obtain a nickel-molybdenum oxide-nickel compound, wherein the nickel-molybdenum oxide-nickel compound is a nanorod array;
mixing the nickel molybdenum oxide-nickel compound, a solution containing divalent cobalt salt and a 2-methylimidazole solution, carrying out coordination, and wrapping ZIF-67 on the surface of the nanorod to obtain nickel molybdenum oxide @ ZIF-67;
mixing the nickel molybdenum oxide @ ZIF-67 with a sulfur source solution, and performing solvothermal reaction to obtain a self-supporting hollow sugarcoated haws-end electrocatalyst; the mass ratio of the sulfur source to the nickel molybdenum oxide @ ZIF-67 in the sulfur source solution is (3.5-5) 1;
the concentration of the solution containing the bivalent cobalt salt is 0.04-0.08 mol/L; the concentration of the 2-methylimidazole solution is 0.4-0.8 mol/L;
the molar ratio of the 2-methylimidazole to the bivalent cobalt salt in the solution containing the bivalent cobalt salt is (0.08-0.16): 0.8-1.6; the mass ratio of the nickel molybdenum oxide-nickel composite to the bivalent cobalt salt is 0.006 (0.23-0.46);
the self-supporting hollow sugarcoated haws-end electrocatalyst comprises a nickel-molybdenum oxide-nickel composite inner core and a hollow Ni-Co-S nano cage outer shell.
2. The method of claim 1, wherein the molybdenum source comprises ammonium molybdate or sodium molybdate and the nickel source comprises nickel acetate, nickel nitrate or nickel chloride.
3. The method of claim 1, wherein the molar ratio of the nickel source to the molybdenum source is from 1:1 to 10:1; the temperature of the hydrothermal reaction is 140-180 ℃ and the time is 6-10 h.
4. The method according to claim 1, wherein the divalent cobalt salt in the divalent cobalt salt-containing solution is cobalt nitrate, cobalt chloride, cobalt acetate or cobalt sulfate.
5. The method of preparing according to claim 1, wherein the mixing of the nickel molybdenum oxide-nickel complex, the solution containing a divalent cobalt salt, and the solution of 2-methylimidazole comprises: placing the nickel molybdenum oxide-nickel composite in a solution containing bivalent cobalt salt, carrying out first mixing, and carrying out second mixing on the obtained mixed solution and a 2-methylimidazole solution; the first mixing time is 5-10 min; the second mixing time is 15-45 min.
6. The method according to claim 1, wherein the sulfur source in the sulfur source solution is thioacetamide, thiourea, sodium sulfide or cysteine, and the concentration of the sulfur source in the sulfur source solution is 0.044mol/L.
7. The method according to claim 1 or 6, wherein the solvothermal reaction is carried out at a temperature of 120 to 150 ℃ for a period of 4 to 6 hours.
8. The self-supporting hollow sugarcoated haws-end electrocatalyst prepared by the preparation method of any one of claims 1 to 7, comprising a nickel molybdenum oxide-nickel composite inner core and a hollow Ni-Co-S nanocage outer shell.
9. The use of the self-supporting hollow sugarcoated haw-like electrocatalyst according to claim 8 in the field of alkaline full cell water splitting.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109364954A (en) * 2018-11-01 2019-02-22 苏州大学 A kind of Ni-based Co-Mo-S dual-functional nanometer composite material and preparation method of foam and application
CN111054408A (en) * 2019-12-10 2020-04-24 太原理工大学 Preparation method of porous nickel-molybdenum-based nanosheet bifunctional electrocatalyst
CN113584521A (en) * 2021-05-05 2021-11-02 浙江大学杭州国际科创中心 Branch-leaf type heterostructure full-hydrolysis catalyst and preparation method thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109364954A (en) * 2018-11-01 2019-02-22 苏州大学 A kind of Ni-based Co-Mo-S dual-functional nanometer composite material and preparation method of foam and application
CN111054408A (en) * 2019-12-10 2020-04-24 太原理工大学 Preparation method of porous nickel-molybdenum-based nanosheet bifunctional electrocatalyst
CN113584521A (en) * 2021-05-05 2021-11-02 浙江大学杭州国际科创中心 Branch-leaf type heterostructure full-hydrolysis catalyst and preparation method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Acharya等."Modish Designation of Hollow-Tubular rGO-NiMoO4@Ni-Co-S Hybrid Core–shell Electrodes with Multichannel Superconductive Pathways for High-Performance Asymmetric Supercapacitors".ACS APPLIED MATERIALS & INTERFACES.2021,第13卷(第15期),第17487-17500页. *

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