CN111871421A - Nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst and preparation method thereof - Google Patents

Nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst and preparation method thereof Download PDF

Info

Publication number
CN111871421A
CN111871421A CN202010782252.XA CN202010782252A CN111871421A CN 111871421 A CN111871421 A CN 111871421A CN 202010782252 A CN202010782252 A CN 202010782252A CN 111871421 A CN111871421 A CN 111871421A
Authority
CN
China
Prior art keywords
nickel
nanowire
catalyst
hydrotalcite
molybdenum
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010782252.XA
Other languages
Chinese (zh)
Inventor
詹天荣
温永红
张朋
陈璐瑶
王泽琨
王磊
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Qingdao University of Science and Technology
Original Assignee
Qingdao University of Science and Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Qingdao University of Science and Technology filed Critical Qingdao University of Science and Technology
Priority to CN202010782252.XA priority Critical patent/CN111871421A/en
Publication of CN111871421A publication Critical patent/CN111871421A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/84—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/85—Chromium, molybdenum or tungsten
    • B01J23/88—Molybdenum
    • B01J23/883—Molybdenum and nickel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • B01J35/33—Electric or magnetic properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/03—Precipitation; Co-precipitation
    • B01J37/031—Precipitation
    • B01J37/033—Using Hydrolysis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/03—Precipitation; Co-precipitation
    • B01J37/031—Precipitation
    • B01J37/035—Precipitation on carriers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/08—Heat treatment
    • B01J37/10—Heat treatment in the presence of water, e.g. steam
    • 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

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Electrochemistry (AREA)
  • Metallurgy (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Catalysts (AREA)

Abstract

The invention provides a nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst growing on foamed nickel in situ and a preparation method and application thereof. The catalyst is prepared by taking foamed nickel as a substrate and adopting a urea hydrolysis method under a hydrothermal condition, the nanowire is composed of hydrotalcite-like nanosheets, and the nanowire forms a flower-shaped structure, so that the structure is convenient for the absorption and desorption processes of reactants, intermediates and generated gas, and can accelerate the electron transfer efficiency in the reaction process; the molybdenum is doped in a high-valence state, so that the electronic structures of the nickel element and the iron element and the appearance of the catalyst are changed, the types of catalytic active centers of the catalyst and the number of catalytic active sites of the catalyst are increased, excellent oxygen evolution and hydrogen evolution dual-functional catalytic activity is shown, and the special nanowire structure shows good stability and has potential application value in an electrolytic water technology.

Description

Nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst and preparation method thereof
The technical field is as follows:
the invention belongs to the field of new energy material technology and electrochemical catalysis, and particularly relates to a nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst; also relates to a preparation method of the catalyst and an electrocatalysis application of the catalyst in an anode oxygen evolution reaction and a cathode hydrogen evolution reaction of alkaline electrolyzed water.
Background art:
the dramatic increase in the global population has created many challenges for energy supply, and how to obtain inexpensive and pollution-free fuels has become a worldwide research hotspot. The water electrolysis is a sustainable green fuel technology and has great significance for relieving the energy crisis. Electrolyzed water consists of two half-reactions: two Oxygen Evolution Reactions (OER) and Hydrogen Evolution Reactions (HER). Since the OER process involves a plurality of adsorption and desorption processes, having a large reaction energy barrier, a catalyst having a high activity is required to lower the reaction barrier. The current commercial HER benchmark catalysts are Pt-based catalysts and the catalysts used for OER reactions are mainly metal oxides of Ir and Ru and their alloys, but these noble metal catalysts are expensive, which makes them not widely used. Therefore, it is a great trend to design non-noble metal catalysts with higher catalytic activity, both from an academic and industrial application point of view.
Transition metal hydroxides (LDHs) have potential research value due to their compositional diversity and stability. 3d transition metals (e.g., Fe, Co, Ni) are attractive to researchers as potential OER or HER catalytically active sites. These studies also demonstrate that Ni-Fe is more capable of reducing overpotential and increasing OER activity than either the Ni or Fe component alone. Researches show that partial charge transfer of Fe to Ni active center can activate the whole catalyst surface and improve the catalytic activity. However, in the OER catalyst, the synergistic enhancement effect between different metal ions may not be limited to two metals of Ni and Fe, and the addition of a third metal may also change the catalytic activity.High valence metal ions such as W6+The amorphous catalyst can be formed by adjusting the electronic structure of the transition metal when the transition metal is doped into the alloy oxide. The catalyst has outstanding ability of attracting high-valence metal electrons, and transition metals such as Fe and the like are kept in a high-valence state and are used as active centers of OER, so that the catalytic activity of the catalyst is improved. Due to Mo6+And W6+Has similar electronic structure and has obvious effect of improving HER, therefore, the invention adds Mo atom to improve the double-function catalytic performance of OER and HER of LDH nanometer.
In order to prepare the LDH catalyst material with higher catalytic performance, the invention dissolves divalent nickel, trivalent iron and hexavalent molybdenum in deionized water, urea and ammonium fluoride are added after uniform mixing, two pieces of treated foam nickel are added after uniform mixing and dissolution, and then the mixture is transferred to a reaction kettle to grow in situ under the hydrothermal condition by taking the foam nickel as a substrate to prepare the NiFeMo-LDH nanowire catalyst. The nanowire is composed of NiFeMo-LDH nanosheets with the transverse dimension of 20-50 nm and the thickness of 2-10 nm, nickel-iron elements in the NiFeMo-LDH nanosheets exist in the form of hydroxides, and molybdenum elements exist in the form of MoO3Exists in the form of (1); the nanowires constitute a flower-like structure. At present, the flower-shaped NiFeMo-LDH nanowire catalyst growing on the foam nickel in situ is prepared by adopting the method, and the research that the catalyst is used as a dual-function electrode for electrolyzing water under the alkaline condition is not reported.
According to the hydrothermal method adopted by the invention, urea is used as an alkali source, and a proper amount of ammonium fluoride is added, so that the flower-shaped NiFeMo-LDH nanowire catalyst growing on foamed nickel in situ is prepared; the catalyst not only improves the conductivity and the specific surface area of the catalyst, but also effectively reduces the overpotential of OER and HER, and is an ideal bifunctional catalyst. The catalyst obtained by the method fully exerts Mo6+The synergistic effect between the nickel ion and the nickel iron ion has important theoretical and practical significance for developing novel electrochemical catalysts and energy conversion.
The invention content is as follows:
aiming at the defects of the prior art and the requirements of research and application in the field, one of the purposes of the invention is to provide a nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst; the preparation method is characterized in that foamed nickel is used as a substrate, and the nano-wire is prepared by a urea hydrolysis method under a hydrothermal condition, wherein the nano-wire is composed of hydrotalcite-like nano-sheets, the nano-wire forms a flower-shaped structure, and the nickel-iron-molybdenum hydrotalcite-like is marked as NiFeMo-LDH;
the invention also aims to provide a preparation method of the nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst, which comprises the following steps:
(1) commercial nickel foam is cut into pieces with the specification of 2.5cm multiplied by 3cm, and the cut nickel foam is put into hydrochloric acid solution to be soaked for ten minutes. And taking out the foamed nickel after ten minutes, cleaning the foamed nickel with water and absolute ethyl alcohol for three times, and drying the foamed nickel in an oven at the temperature of 60 ℃ for 6 hours for later use.
(2) Weighing a certain amount of Ni (NO) at room temperature3)2·6H2O、Fe(NO3)3·9H2O and (NH)4)6Mo7O24·4H2O, in such a way that their molar ratio is 6:3: 1-9, dispersing the mixture into 40mL of deionized water, adding 0.840g of urea and 0.222g of ammonium fluoride, and stirring to obtain a homogeneous solution;
(3) and transferring the solution into a 80mL polytetrafluoroethylene reaction kettle, adding two pieces of processed foam nickel, carrying out hydrothermal reaction at 100 ℃ for 24 hours, naturally cooling the foam nickel to room temperature, taking out the foam nickel with changed color, washing the foam nickel with deionized water, and drying the foam nickel in an oven at 60 ℃ for 6 hours to obtain the catalyst of the NiFeMo-LDH growing in situ on the foam nickel, wherein the catalyst is marked as NiFeMo-LDH @ NF.
Wherein in step (2) of the preparation method, Ni (NO)3)2·6H2O and Fe (NO)3)3·9H2The weighing amount of O is respectively 20mmol and 10 mmol; the nickel-iron-molybdenum hydrotalcite bifunctional electrocatalyst is in a nanowire shape, the diameter of the top end of the nanowire is 80-120 nm, the diameter of the tail end of the nanowire is 200-300 nm, and the nanowire forms a flower-shaped structure; the nanowire is composed of NiFeMo-LDH nanosheets with the transverse dimension of 20-50 nm and the thickness of 2-10 nm, nickel-iron elements in the NiFeMo-LDH nanosheets exist in the form of hydroxides, and molybdenum elements exist in the form of MoO3Shape ofThe formula (I) exists.
The invention also aims to provide application of the nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst catalyst in water electrolysis anode OER and cathode HER under alkaline conditions.
According to the hydrothermal method adopted by the invention, urea is used as an alkali source, and a proper amount of ammonium fluoride is added, so that the flower-like ternary nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst growing on foamed nickel in situ is prepared; the catalyst not only improves the conductivity and the specific surface area of the catalyst, but also effectively reduces the overpotential of OER and HER, and is an ideal bifunctional catalyst.
Compared with the prior art, the invention has the following main advantages and beneficial effects:
1) the bifunctional catalyst is a non-noble metal composite material, the used raw materials are easy to purchase and prepare, the resources are rich, the price is low, and the large-scale preparation cost is low;
2) the bifunctional catalyst has good durability, and has a test curve which is not obviously changed in a constant voltage I-t test in 1mol/L KOH electrolyte at 1.46V (vs RHE), shows good long-term stability, and has huge application potential in the aspect of water electrolysis;
3) the bifunctional catalyst is a novel three-dimensional composite material, has better OER and HER activities, and has remarkable advantages compared with the unilateral OER and HER activities of noble metal/non-noble metal catalysts reported in the current research;
4) the bifunctional catalyst and the commercialized IrO2Compared with the catalyst, the stability is obviously improved, and good catalytic activity can be kept in long-term use of the electrolytic cell;
5) the OER activity of the bifunctional catalyst is obviously better than that of a non-noble metal/nonmetal catalyst reported in the current research, and the activity of the bifunctional catalyst is superior to that of commercial IrO2The catalytic activity of (a);
6) HER activity of the bifunctional catalyst of the invention, although at 10mA cm-2The overpotential is higher than commercial 20 wt% Pt/C, but at high voltageThe overpotential of the catalyst at the current density is obviously less than commercial 20 wt% Pt/C and most of the non-noble metal/non-metal catalysts reported in the research at present;
7) the preparation method of the bifunctional catalyst is simple, easy to operate and convenient for large-scale production.
Description of the drawings:
FIG. 1 is a scanning electron micrograph of NiFeMo-LDH @ NF prepared in example 1 of the present invention;
FIG. 2 is a transmission electron micrograph of NiFeMo-LDH @ NF prepared in example 1 of the present invention;
FIG. 3 is an XRD pattern of NiFeMo-LDH obtained in example 1 of the present invention and NiFe-LDH obtained in comparative example 1;
FIG. 4 is a high-resolution transmission electron micrograph of NiFeMo-LDH prepared in example 1 of the present invention;
FIG. 5 is the OER linear sweep voltammogram of different proportions of NiFeMo-LDH @ NF catalysts obtained in examples 1, 2, 3, 4, 5, 6 and 7 of the present invention in a 1mol/L KOH electrolyte;
FIG. 6 shows NiFeMo-LDH @ NF obtained in example 1, NiFe-LDH @ NF obtained in comparative example 1, and IrO obtained in comparative example 22And OER linear sweep voltammogram of the Ni foam electrode obtained in comparative example 3 in 1mol/L KOH electrolyte;
FIG. 7 is a time-current plot of NiFeMo-LDH @ NF obtained in example 1 at a constant voltage of 1.46V (vs RHE);
FIG. 8 is an electrochemical impedance spectrum of NiFeMo-LDH @ NF obtained in example 1 and NiFe-LDH @ NF obtained in comparative example 1 having an open circuit potential of 1.48V (vs RHE) in a 1mol/L KOH electrolyte;
FIG. 9 is a graph of HER linear sweep voltammograms of different proportions of NiFeMo-LDH @ NF catalysts obtained in examples 1, 2, 3, 4, 5, 6 and 7 of the present invention in a 1mol/L KOH electrolyte; (ii) a
FIG. 10 is a plot of HER linear sweep voltammograms for NiFeMo-LDH @ NF obtained in example 1, NiFe-LDH @ NF obtained in comparative example 1, Nifoam electrode pair obtained in comparative example 3, and Pt/C electrode obtained in comparative example 4 in a 1mol/L KOH electrolyte;
FIG. 11 is a time-current plot of the NiFeMo-LDH @ NF obtained in example 1 at a constant voltage of-0.125V (vs RHE);
FIG. 12 is a linear sweep voltammogram of the HER of the NiFeMo-LDH @ NF electrode obtained in example 1 in a 1mol/L KOH electrolyte before and after 1000 cycles of cyclic voltammetry;
FIG. 13 is a plot of the sweep voltammetry of NiFeMo-LDH @ NF obtained in example 1 for total electrolyzed water in a two-electrode system, with the inset being a picture of the electrolyzed water;
FIG. 14 is the I-T plot at a constant voltage of 1.671V (vsRhE) for the use of the NiFeMo-LDH @ NF catalyst obtained in example 1 as a bifunctional catalyst.
The specific implementation mode is as follows:
for a further understanding of the invention, reference will now be made to the following examples and drawings, which are not intended to limit the invention in any way.
Example 1:
preparation of NiFeMo-LDH @ NF
Commercial nickel foam is cut into pieces with the specification of 2.5cm multiplied by 3cm, and the cut nickel foam is put into hydrochloric acid solution to be soaked for ten minutes. Taking out the foamed nickel after 10 minutes, cleaning the foamed nickel with water and absolute ethyl alcohol for three times, and drying the foamed nickel in an oven at 60 ℃ for 6 hours for later use; weighing 0.5816g Ni (NO) at room temperature3)2·6H2O(20mmol)、0.404g Fe(NO3)3·9H2O (10mmol) and 3.2953g (NH)4)6Mo7O24·4H2O (2.67mmol) in such a way that their molar ratio is 6:3:8, dispersing the mixture into 40mL of deionized water, adding 0.840g of urea and 0.222g of ammonium fluoride, and stirring to obtain a homogeneous solution; and transferring the solution into a 80mL polytetrafluoroethylene reaction kettle, adding two pieces of processed foamed nickel with the specification of 2.5cm multiplied by 3cm, carrying out hydrothermal reaction at 100 ℃ for 24 hours, naturally cooling the foamed nickel to room temperature, taking out the foamed nickel with changed color, washing the foamed nickel with deionized water, and drying the foamed nickel in an oven at 60 ℃ for 6 hours to obtain the catalyst of the NiFeMo-LDH which grows in situ on the foamed nickel and is marked as NiFeMo-LDH @ NF.
Example 2
With fruitThe preparation of example 1 was essentially identical except that (NH)4)6Mo7O244H2The amount of O added was 0.4119g (0.33mmol), and Ni (NO) was added3)2·6H2O、Fe(NO3)3·9H2O and (NH)4)6Mo7O24·4H2The molar ratio of O is 6:3: 1.
example 3
Substantially the same as that of example 1, except that (NH)4)6Mo7O244H2The amount of O added was 0.8239g (0.67mmol), and Ni (NO) was added3)2·6H2O、Fe(NO3)3·9H2O and (NH)4)6Mo7O24·4H2The molar ratio of O is 6:3: 2.
example 4
Substantially the same as that of example 1, except that (NH)4)6Mo7O244H2The amount of O added was 1.2359g (1.00mmol), and Ni (NO) was added3)2·6H2O、Fe(NO3)3·9H2O and (NH)4)6Mo7O24·4H2The molar ratio of O is 6:3: 3.
example 5
Substantially the same as that of example 1, except that (NH)4)6Mo7O244H2The amount of O added was 1.6478g (1.33mmol), and Ni (NO) was added3)2·6H2O、Fe(NO3)3·9H2O and (NH)4)6Mo7O24·4H2The molar ratio of O is 6:3: 4.
example 6
Substantially the same as that of example 1, except that (NH)4)6Mo7O244H2The amount of O added was 2.4717g (2.00mmol), and Ni (NO) was added3)2·6H2O、Fe(NO3)3·9H2O and (NH)4)6Mo7O24·4H2The molar ratio of O is 6:3: 6.
example 7
Substantially the same as that of example 1, except that (NH)4)6Mo7O244H2The amount of O added was 3.7076g (3.00mmol), and Ni (NO) was added3)2·6H2O、Fe(NO3)3·9H2O and (NH)4)6Mo7O24·4H2The molar ratio of O is 6:3: 9.
comparative example 1
Preparation of NiFe-LDH @ NF
Weighing 0.5816g Ni (NO) at room temperature3)2·6H2O (20mmol) and 0.404g Fe (NO)3)3·9H2O (10mmol) is dispersed in 40mL deionized water, 0.840g of urea and 0.222g of ammonium fluoride are added, and the mixture is stirred into a uniform solution; and transferring the solution into a 80mL polytetrafluoroethylene reaction kettle, adding two pieces of processed foamed nickel, reacting for 24h at 100 ℃, naturally cooling to room temperature, taking out the foamed nickel with changed color, washing with deionized water, drying in an oven at 60 ℃ for 6h, and marking the material as NiFe-LDH @ NF.
Comparative example 2
Preparation of iridium dioxide catalyst loaded on glassy carbon electrode
To prepare an iridium dioxide electrode, 5mg of IrO was weighed2Dispersing the solution into 200 mu L of absolute ethyl alcohol in a centrifuge tube, adding 30 mu L of an acetone gel, performing ultrasonic treatment for 30min to obtain a uniformly dispersed solution, and then uniformly coating the solution on the surface of a clean glassy carbon electrode through a liquid transfer gun, wherein the loading capacity of iridium dioxide is about 0.62mg/cm-2。
Comparative example 3
Cutting the foamed nickel into pieces with the specification of 1cm multiplied by 2cm, and putting the cut foamed nickel into 3mol L-1And soaking in hydrochloric acid solution for ten minutes. Taking out the foamed nickel after ten minutes, and using water and absolute ethyl alcoholAnd (4) washing for three times, putting the material into an oven and drying for 6 hours at the temperature of 60 ℃, and marking the material as a Ni foam electrode.
Comparative example 4
Preparation of Pt/C catalyst loaded on glassy carbon electrode
For preparing the Pt/C electrode, 5mg of Pt/C is weighed and dispersed into 200 mu L of absolute ethyl alcohol in a centrifuge tube, 30 mu L of chemical fiber adhesive is added, ultrasonic treatment is carried out for 30min to obtain a uniformly dispersed solution, then the solution is uniformly smeared on the surface of a clean glassy carbon electrode through a liquid transfer gun, and the loading capacity of the Pt/C is about 0.69mg/cm-2。
Test example 1
Structural characterization is carried out on the NiFeMo-LDH @ NF obtained in the example 1, and the obtained results are shown in figures 1-4, wherein figures 1-2 are respectively a scanning electron microscope image and a transmission electron microscope image of the obtained NiFeMo-LDH @ NF; FIG. 3 is an XRD pattern of NiFeMo-LDH obtained in example 1 and an LDH obtained from NiFe-LDH obtained in comparative example 1; FIG. 4 is a high-resolution transmission electron microscope image of the obtained NiFeMo-LDH. As can be seen from the combination of the figures 1-2 and the figures 3-4, the electrocatalyst NiFeMo-LDH prepared by the invention is of a nanowire structure, the diameter of the top end of the nanowire is 80-120 nm, the end of the nanowire is 200-300 nm, and the nanowire forms a flower-shaped structure; the nanowire is composed of NiFeMo-LDH nanosheets with the transverse dimension of 20-50 nm and the thickness of 2-10 nm, nickel-iron elements in the NiFeMo-LDH nanosheets exist in the form of hydroxides, and molybdenum elements exist in the form of MoO3Exist in the form of (1).
Test example 2
FIG. 5 is a comparison of linear sweep voltammograms of the NiFeMo-LDH @ NF catalysts obtained in examples 1, 2, 3, 4, 5, 6 and 7 in a KOH electrolyte of 1 mol/L. As can be seen from the figure, when the molar mass ratio of the Ni element, the Fe element and the Mo element in the preparation raw material is 6:3:8, the obtained NiFeMo-LDH @ NF has the best OER catalytic performance.
FIG. 6 shows the NiFeMo-LDH @ NF electrode obtained in example 1, the NiFe-LDH @ NF electrode obtained in comparative example 1, and IrO obtained in comparative example 22The electrode and the Ni foam electrode obtained in comparative example 3 are respectively a comparison graph of linear sweep voltammetry curves in a KOH electrolyte of 1 mol/L. As can be seen, the in-situ growth on the nickel foamThe ternary nickel-iron-molybdenum hydrotalcite nanowire catalyst has minimum overpotential and initial potential, and shows that the doping of Mo plays a promoting role in NiFe-LDH, and high-valence metal ions Mo6+The amorphous catalyst can be formed by adjusting the electronic structure of the transition metal by being doped into the hydrotalcite. This catalyst has outstanding ability to attract electrons of high-valence metal, and transition metal such as Ni and Fe is kept in high-valence state and is used as an active center of oxygen evolution reaction. Due to the synergistic effect of Mo, Ni and Fe, the active sites of the catalyst are fully released, the structure and the property of the surface of the catalyst are improved, and the ternary nickel-iron-molybdenum hydrotalcite nanowire catalyst has better catalytic performance than a bimetallic nickel-iron hydrotalcite nanowire catalyst and a foamed nickel catalyst grown from anhydrous talc; in addition, the NiFeMo-LDH grown on the foamed nickel firmly grasps the shell layer, so that the good conductivity and mechanical stability are ensured, and the use of an additional binder is avoided; the NiFeMo-LDH nanowire vertically grows on the foamed nickel, has rich exposed edges and provides more active centers for catalytic reaction; the ordered nanowire structure can provide a large specific surface area, increase the exposure of active centers and the quick release of gas products; in addition, it promotes efficient electron transfer from nickel foam to NiFeMo-LDH; the conductivity, the integral catalytic activity and the stability of the electrocatalyst are improved.
The electrocatalytic performance test adopts a saturated calomel electrode as a reference electrode, a Pt electrode as a counter electrode, the sweep rate is 5mV/s, the electrolyte is 1mol/L KOH electrolyte, all potentials are converted into reversible hydrogen potential (RHE), and the conversion formula is
Figure BDA0002620668880000071
FIG. 7 is a constant voltage I-t test chart of the NiFeMo-LDH @ NF electrode obtained in example 1 in a 1mol/L KOH electrolyte at 1.46V (vs RHE), and it can be seen from the chart that in a 60h test, the test curve is not obviously changed, good long-term stability is shown, and the NiFeMo-LDH @ NF electrode has great application potential in the aspect of water electrolysis.
FIG. 8 is an electrochemical impedance spectrum of the NiFeMo-LDH @ NF electrode obtained in example 1 and the NiFe-LDH @ NF electrode obtained in comparative example 1 at an open circuit potential of 1.48V (vs RHE) in a 1mol/LKOH electrolyte, and the charge transfer resistance of the high frequency region is obtained from the semi-circular diameter. As can be seen from the figure, the NiFeMo-LDH @ NF electrode has the minimum transfer resistance value, which shows that the ternary nickel iron molybdenum hydrotalcite nano-wire containing molybdenum effectively improves the electron transfer rate and the Faraday process.
FIG. 9 is a comparison of linear sweep voltammograms of the NiFeMo-LDH @ NF catalysts obtained in examples 1, 2, 3, 4, 5, 6 and 7 in a KOH electrolyte of 1 mol/L. As can be seen from the figure, when the molar mass ratio of the Ni element, the Fe element and the Mo element in the preparation raw material is 6:3:8, the obtained NiFeMo-LDH @ NF has the best HER catalytic performance.
FIG. 10 is a graph comparing the linear sweep voltammograms of the NiFeMo-LDH @ NF electrode obtained in example 1, the NiFe-LDH @ NF electrode obtained in comparative example 1, the Ni foam electrode obtained in comparative example 3, and the Pt/C electrode obtained in comparative example 4 in a 1mol/L KOH electrolyte, respectively. As can be seen from the figure, the ternary nickel-iron-molybdenum hydrotalcite nanowire catalyst growing on the foamed nickel in situ has the minimum overpotential and the initial potential, and shows that the sincere doping of high-valence molybdenum is also beneficial to the hydrogen evolution reaction; due to the synergistic effect of Mo, Ni and Fe, the active sites of the material are further exposed, the surface property of the catalyst is improved, and the adsorption of more H is facilitated+So that the ternary nickel-iron-molybdenum hydrotalcite nanowire electrode has better catalytic performance than a bimetallic nickel-iron-molybdenum hydrotalcite nanowire catalyst, a Pt/C electrode and a foamed nickel electrode grown by anhydrous talc; and the hydrotalcite nanowire electrode grown in situ has better durability.
FIG. 11 is a graph showing the constant voltage I-t test at-0.125V (vsRHE) for the NiFeMo-LDH @ NF electrode obtained in example 1 in a 1mol/LKOH electrolyte, and it can be seen that the current density was from 10mA cm in a 60-hour test-2The current density is obviously improved when the current density is increased to 20mA cm < -2 >, which shows that the catalytic activity of the NiFeMo-LDH @ NF catalyst is improved to a certain extent along with the increase of the test time, and the NiFeMo-LDH @ NF catalyst has good long-term stability and has huge application potential in the aspect of water electrolysis and hydrogen evolution.
FIG. 12 is a plot of cyclic voltammetry measurements of the NiFeMo-LDH @ NF electrode obtained in example 1 in a 1mol/L KOH electrolyte at a sweep rate of 50mV s at 1.071-1.471V (vs RHE) to verify catalyst repeatability-1After 1000 cycles of cyclic voltammetry test, 10mA cm-2The overpotential of (a) is reduced by only about 10 mV. The results show that the hydrogen evolution reaction active centers are hardly reduced in the linear voltammetry scanning test process, and the NiFeMo-LDH @ NF catalyst is proved to have good stability and repeatability.
FIG. 13 shows that the NiFeMo-LDH @ NF catalyst obtained in example 1 is used as the cathode and the anode of an electrolyzed water system, and a linear sweep voltammetry test of fully electrolyzed water is performed under a two-electrode system, the two electrodes show an obvious bubble escape phenomenon, and the inset is an optical photograph of the two electrodes taken during the test process. As a result, it was found that the electric field strength was 100mA cm-2The current density of (A) corresponds to a potential of only 1.671V, which is lower than most of the reported full-electrolysis water catalysts, and more importantly, the NiFeMo-LDH @ NF electrodes only need voltages of 1.68V, 1.72V and 1.75V to reach higher 200, 300 and 400 mA-cm-2The current density of (1). The excellent full-electrolytic water performance of the catalyst is predicted, and the catalyst is expected to be applied on a large scale.
FIG. 14 is a time-current graph of the NiFeMo-LDH @ NF catalyst obtained in example 1 as the cathode and anode of an electrolyzed water system and a 60-hour fully electrolyzed water test at 1.671V under a two-electrode system. As can be seen from the graph, the current density of the fully electrolyzed water was substantially stabilized at 100mA cm in the 60-hour test-2Only slight attenuation appears, and proves that the NiFeMo-LDH @ NF catalyst fully-electrolyzed water has excellent long-term stability and great potential in commercialization and large-scale application.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (4)

1. The nickel-iron-molybdenum hydrotalcite-like nanowire bifunctional electrocatalyst is characterized in that the catalyst is prepared by using foamed nickel as a substrate and adopting a urea hydrolysis method under a hydrothermal condition, wherein the nanowire is composed of hydrotalcite-like nanosheets, the nanowire forms a flower-like structure, and the nickel-iron-molybdenum hydrotalcite-like hydrotalcite is marked as NiFeMo-LDH;
the preparation method of the nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst is characterized by comprising the following specific steps of:
(1) cutting commercial nickel foam into pieces with the specification of 2.5cm multiplied by 3cm, putting the cut nickel foam into a hydrochloric acid solution, soaking for ten minutes, taking out the nickel foam after ten minutes, washing for three times by using water and absolute ethyl alcohol, putting the nickel foam into an oven, drying for 6 hours at the temperature of 60 ℃, and keeping the nickel foam for later use;
(2) weighing a certain amount of Ni (NO) at room temperature3)2·6H2O、Fe(NO3)3·9H2O and (NH)4)6Mo7O24·4H2O, in such a way that their molar ratio is 6:3: 1-9, dispersing the mixture into 40mL of deionized water, adding 0.840g of urea and 0.222g of ammonium fluoride, and stirring to obtain a homogeneous solution;
(3) and transferring the solution into a 80mL polytetrafluoroethylene reaction kettle, adding two pieces of processed foamed nickel, carrying out hydrothermal reaction at 100 ℃ for 24 hours, naturally cooling the foamed nickel to room temperature, taking out the foamed nickel with changed color, washing the foamed nickel by deionized water, and drying the foamed nickel in an oven at 60 ℃ for 6 hours to obtain the catalyst of the NiFeMo-LDH growing in situ on the foamed nickel, wherein the catalyst is recorded as NiFeMo-LDH @ NF.
2. The nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst according to claim 1, wherein in step (2) of the preparation method, Ni (NO) is added3)2·6H2O and Fe (NO)3)3·9H2The weighed amounts of O were 20 and 10mmol, respectively.
3. The nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst according to claim 1, characterized in that the catalyst is prepared by a method comprising a step of reacting nickel-iron-molybdenum hydrotalcite nanowire with a metal oxide catalystThe nano wire is in a shape of a nano wire, the diameter of the top end of the nano wire is 80-120 nm, the diameter of the tail end of the nano wire is 200-300 nm, and the nano wire forms a flower-shaped structure; the nanowire is composed of NiFeMo-LDH nanosheets with the transverse dimension of 20-50 nm and the thickness of 2-10 nm, nickel-iron elements in the NiFeMo-LDH nanosheets exist in the form of hydroxides, and molybdenum elements exist in the form of MoO3Exist in the form of (1).
4. The nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst according to claims 1-3, characterized in that the catalyst is used for anodic oxygen evolution reaction and cathodic hydrogen evolution reaction of alkaline electrolysis water.
CN202010782252.XA 2020-08-06 2020-08-06 Nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst and preparation method thereof Pending CN111871421A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010782252.XA CN111871421A (en) 2020-08-06 2020-08-06 Nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010782252.XA CN111871421A (en) 2020-08-06 2020-08-06 Nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst and preparation method thereof

Publications (1)

Publication Number Publication Date
CN111871421A true CN111871421A (en) 2020-11-03

Family

ID=73211486

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010782252.XA Pending CN111871421A (en) 2020-08-06 2020-08-06 Nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst and preparation method thereof

Country Status (1)

Country Link
CN (1) CN111871421A (en)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112877727A (en) * 2021-01-17 2021-06-01 大连理工大学 Preparation method and application of efficient seawater full-electrolysis hydrogen production phosphide catalyst
CN113430553A (en) * 2021-07-23 2021-09-24 华北电力大学 Bifunctional catalytic electrode based on transition metal heterogeneous layered structure and preparation method thereof
CN113512738A (en) * 2021-06-24 2021-10-19 湖南师范大学 Ternary iron-nickel-molybdenum-based composite material water electrolysis catalyst, and preparation method and application thereof
CN113668013A (en) * 2021-09-28 2021-11-19 青岛科技大学 Method for preparing bifunctional electrolytic water catalyst based on mercaptobenzothiazole
CN114592209A (en) * 2022-04-06 2022-06-07 清华大学 Catalyst and scale-up preparation method and application thereof
CN115323395A (en) * 2022-08-22 2022-11-11 福州大学 Self-supporting electro-catalytic hydrogen evolution catalyst electrode with strain lattice and preparation method and application thereof
CN116161713A (en) * 2023-01-10 2023-05-26 中国矿业大学 Molybdenum doped hydrotalcite material with chloride ion intercalation and battery anode material
CN117427649A (en) * 2023-12-20 2024-01-23 陕西煤基特种燃料研究院有限公司 Pyrene hydrogenation reaction catalyst and preparation method and application thereof
CN117902641A (en) * 2024-03-19 2024-04-19 四川大学 Electrocatalyst and preparation method thereof and method for improving durability of nickel-iron-based electrocatalyst
WO2024117507A1 (en) * 2022-11-28 2024-06-06 포항공과대학교 산학협력단 Highly durable electrode catalyst for water electrolysis of seawater and method for producing same
CN115323395B (en) * 2022-08-22 2024-06-25 福州大学 Self-supporting electrocatalytic hydrogen evolution catalyst electrode with strain lattice, and preparation method and application thereof

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108283926A (en) * 2018-01-10 2018-07-17 青岛大学 A kind of growth in situ ferronickel double-metal hydroxide preparation method with laminated structure in nickel foam
CN108754532A (en) * 2018-05-29 2018-11-06 武汉工程大学 A kind of iron of molybdenum doping/nickel layer shape array@nickel foam based combined electrode materials and the preparation method and application thereof
CN110227531A (en) * 2019-05-23 2019-09-13 太原理工大学 A kind of preparation method of molybdenum doping cobalt iron oxide nanometer sheet bifunctional electrocatalyst
WO2020082443A1 (en) * 2018-10-26 2020-04-30 苏州大学 Fe-doped mos2 nanomaterial, preparation method therefor and use thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108283926A (en) * 2018-01-10 2018-07-17 青岛大学 A kind of growth in situ ferronickel double-metal hydroxide preparation method with laminated structure in nickel foam
CN108754532A (en) * 2018-05-29 2018-11-06 武汉工程大学 A kind of iron of molybdenum doping/nickel layer shape array@nickel foam based combined electrode materials and the preparation method and application thereof
WO2020082443A1 (en) * 2018-10-26 2020-04-30 苏州大学 Fe-doped mos2 nanomaterial, preparation method therefor and use thereof
CN110227531A (en) * 2019-05-23 2019-09-13 太原理工大学 A kind of preparation method of molybdenum doping cobalt iron oxide nanometer sheet bifunctional electrocatalyst

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
NA HAN等: "Ultrathin nickel–iron layered double hydroxide nanosheets intercalated with molybdate anions for electrocatalytic water oxidation", 《JOURNAL OF MATERIALS CHEMISTRY A》 *
宋梦皎: "基于Ni、Fe的双（多）金属化合物的合成及在电催化分解水中的应用研究", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅰ辑》 *
韩银凤等: "以泡沫镍为基底的镍铁类水滑石的制备及表征", 《化学工程师》 *

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112877727B (en) * 2021-01-17 2022-05-10 大连理工大学 Preparation method and application of efficient seawater full-electrolysis hydrogen production phosphide catalyst
CN112877727A (en) * 2021-01-17 2021-06-01 大连理工大学 Preparation method and application of efficient seawater full-electrolysis hydrogen production phosphide catalyst
CN113512738A (en) * 2021-06-24 2021-10-19 湖南师范大学 Ternary iron-nickel-molybdenum-based composite material water electrolysis catalyst, and preparation method and application thereof
CN113430553B (en) * 2021-07-23 2024-03-08 华北电力大学 Double-function catalytic electrode based on transition metal heterogeneous layered structure and preparation method thereof
CN113430553A (en) * 2021-07-23 2021-09-24 华北电力大学 Bifunctional catalytic electrode based on transition metal heterogeneous layered structure and preparation method thereof
CN113668013A (en) * 2021-09-28 2021-11-19 青岛科技大学 Method for preparing bifunctional electrolytic water catalyst based on mercaptobenzothiazole
CN114592209A (en) * 2022-04-06 2022-06-07 清华大学 Catalyst and scale-up preparation method and application thereof
CN114592209B (en) * 2022-04-06 2024-01-26 清华大学 Catalyst, and large-scale preparation method and application thereof
CN115323395A (en) * 2022-08-22 2022-11-11 福州大学 Self-supporting electro-catalytic hydrogen evolution catalyst electrode with strain lattice and preparation method and application thereof
CN115323395B (en) * 2022-08-22 2024-06-25 福州大学 Self-supporting electrocatalytic hydrogen evolution catalyst electrode with strain lattice, and preparation method and application thereof
WO2024117507A1 (en) * 2022-11-28 2024-06-06 포항공과대학교 산학협력단 Highly durable electrode catalyst for water electrolysis of seawater and method for producing same
CN116161713B (en) * 2023-01-10 2023-10-20 中国矿业大学 Molybdenum doped hydrotalcite material with chloride ion intercalation and battery anode material
CN116161713A (en) * 2023-01-10 2023-05-26 中国矿业大学 Molybdenum doped hydrotalcite material with chloride ion intercalation and battery anode material
CN117427649B (en) * 2023-12-20 2024-03-19 陕西煤基特种燃料研究院有限公司 Pyrene hydrogenation reaction catalyst and preparation method and application thereof
CN117427649A (en) * 2023-12-20 2024-01-23 陕西煤基特种燃料研究院有限公司 Pyrene hydrogenation reaction catalyst and preparation method and application thereof
CN117902641A (en) * 2024-03-19 2024-04-19 四川大学 Electrocatalyst and preparation method thereof and method for improving durability of nickel-iron-based electrocatalyst
CN117902641B (en) * 2024-03-19 2024-05-24 四川大学 Electrocatalyst and preparation method thereof and method for improving durability of nickel-iron-based electrocatalyst

Similar Documents

Publication Publication Date Title
CN111871421A (en) Nickel-iron-molybdenum hydrotalcite nanowire bifunctional electrocatalyst and preparation method thereof
CN110227496B (en) Microspherical Fe-doped trinickel disulfide nano-structure material composed of nanosheets, and preparation method and application thereof
Wang et al. Self-supported NiMo-based nanowire arrays as bifunctional electrocatalysts for full water splitting
Li et al. 3D self-supported porous vanadium-doped nickel nitride nanosheet arrays as efficient bifunctional electrocatalysts for urea electrolysis
Fang et al. Nickel promoted cobalt disulfide nanowire array supported on carbon cloth: an efficient and stable bifunctional electrocatalyst for full water splitting
Yang et al. An efficient bifunctional electrocatalyst for water splitting based on cobalt phosphide
CN109954503B (en) Nickel selenide and ternary nickel-iron selenide composite electrocatalyst, preparation method and application
CN110639534B (en) Oxygen evolution electrocatalytic material and preparation method and application thereof
CN113430553B (en) Double-function catalytic electrode based on transition metal heterogeneous layered structure and preparation method thereof
JP2018162515A (en) Cobalt selenide/titanium mesh electrode for water-electrolyzing oxygen generation, and producing method and application thereof
CN111118539B (en) Nickel-molybdenum oxide quantum dot loaded on nickel oxide nano sheet prepared by electrodeposition method
CN112663087A (en) Preparation method and application of iron and nitrogen doped cobalt selenide electrocatalyst
JP2020059917A (en) Tricobalt tetroxide array/titanium mesh electrode for water decomposition oxygen evolution and manufacturing method thereof
CN113481534A (en) Preparation method of zirconium-doped cobalt-iron layered double hydroxide with low crystallinity and application of zirconium-doped cobalt-iron layered double hydroxide in hydrogen production by water electrolysis
Xue et al. Spatially-controlled NiCo2O4@ MnO2 core–shell nanoarray with hollow NiCo2O4 cores and MnO2 flake shells: an efficient catalyst for oxygen evolution reaction
CN112058282A (en) Preparation method of pH-wide-range catalyst based on molybdenum-tungsten-based layered material and application of pH-wide-range catalyst to electrolytic water-evolution hydrogen reaction
CN113136587A (en) Composite catalyst with NiTe @ NiFe loaded on foamed nickel and preparation method and application thereof
CN111790416A (en) High-efficiency oxygen evolution electrocatalyst and preparation method thereof
Zhou et al. Synthesis of flower-like nickel–iron–chromium nanostructure compound deposited stainless steel foil as an efficient binder-free electrocatalyst for water splitting
CN113512738B (en) Ternary iron-nickel-molybdenum-based composite material water electrolysis catalyst, and preparation method and application thereof
Yang et al. Interfaces modulation strategy to synthesize bifunctional electrocatalyst for highly efficient overall water splitting
CN110629248A (en) Fe-doped Ni (OH)2Preparation method of/Ni-BDC electrocatalyst
CN112725774B (en) Core-shell structure full-hydrolysis catalyst stable under large current and preparation method thereof
CN109097788B (en) Double-carbon coupling transition metal nickel-based quantum dot electrocatalyst and preparation method thereof
CN111111718A (en) Preparation method of multi-metal phosphorus-doped electrocatalyst derived based on binary LDH

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20201103