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CN-116463670-B - Carbon dot doped Fe-Ni3S2Preparation method of @ NF electrocatalyst and application of @ NF electrocatalyst to urea decomposition hydrogen production

CN116463670BCN 116463670 BCN116463670 BCN 116463670BCN-116463670-B

Abstract

The invention belongs to the technical field of nanocomposite materials, and relates to a preparation method of a carbon dot doped Fe-Ni 3 S 2 @NF electrocatalyst, which comprises the steps of weighing sodium sulfide, dissolving in deionized water, adding carbon dots, uniformly stirring, putting Fe-Ni (OH) 2 (Fe-Ni(OH) 2 @NF) growing on foam nickel into the solution, transferring the solution into a reaction kettle, carrying out hydrothermal reaction for 4-10 h at 110-180 ℃, cooling to room temperature, washing with ethanol and water successively, and drying to obtain the catalyst. The prepared Fe-Ni 3 S 2 /CDs@NF is applied to hydrogen production by urea decomposition. In the vulcanizing process of the Fe-Ni (OH) 2 @NF nano sheet, a Fe-Ni 3 S 2 /CDs@NF nano composite electrocatalyst is constructed on the surface modified carbon points to enhance the electrocatalytic full-decomposition urea hydrogen production. The preparation process is simple, the raw materials are cheap and easy to obtain, the cost is low, the reaction time is short, the mass production is convenient, the preparation process is nontoxic and harmless, and the requirements of sustainable development are met. Not only can the energy consumption and the reaction cost be reduced by converting electric energy into hydrogen energy, but also the problem of urea pollution in the environment can be solved by utilizing electrocatalytic, and the method can be used for reducing the overpotential of a urea fuel cell.

Inventors

  • LIU YANHONG
  • ZHOU CHUNXING
  • LEI YUHE
  • ZHANG DONGXU
  • CHEN QITAO
  • JIANG TIANYAO
  • HOU YINGYING
  • MAO BAODONG

Assignees

  • 江苏大学

Dates

Publication Date
20260512
Application Date
20230320

Claims (8)

  1. 1. A preparation method of a carbon-point doped Fe-Ni 3 S 2 @NF electrocatalyst is characterized by comprising the steps of weighing sodium sulfide, dissolving in deionized water, adding carbon points, uniformly stirring, putting Fe-Ni (OH) 2 growing on foam nickel into the solution, transferring the solution into a reaction kettle for hydrothermal reaction at 110-180 ℃ for 4-10 hours, cooling to room temperature, washing with ethanol and water three times in sequence, drying to obtain the catalyst, The preparation method of the Fe-Ni (OH) 2 growing on the foam nickel comprises the steps of weighing nickel nitrate, ferric nitrate, urea and ammonium fluoride, dissolving in water, stirring ultrasonically, placing in a reaction kettle, adding the treated foam nickel, carrying out hydrothermal reaction for 4-10 hours in an autoclave at 110-180 ℃, cooling to room temperature, washing with ethanol and water three times successively, and drying to obtain Fe-Ni (OH) 2 , wherein the solid-liquid ratio of the nickel nitrate, the ferric nitrate, the urea, the ammonium fluoride and deionized water is 0.5815 g:0.0897-0.803 g:0.36g:0.15g:3ml; The preparation method of the carbon dots comprises the steps of dissolving citric acid and ethylenediamine in deionized water, dispersing uniformly, transferring to a reaction kettle, performing hydrothermal reaction for 4-1 h at 100-200 ℃, naturally cooling to room temperature, and dialyzing to obtain the carbon dots, wherein the solid-liquid ratio of citric acid to ethylenediamine to deionized water is 0.5-2 g:0.1-0.5 mL:5-20 mL; Sodium sulfide carbon dots and deionized water the solid-liquid ratio is 480mg to 0.5-4 mg to 30mL.
  2. 2. The method for preparing the carbon-point-doped Fe-Ni 3 S 2 @NF electrocatalyst according to claim 1, wherein Fe-Ni (OH) 2 grown on foam nickel is put in the electrocatalyst and transferred into a reaction kettle for reaction for 6 hours at 120 ℃.
  3. 3. The method for preparing the carbon dot doped Fe-Ni 3 S 2 @NF electrocatalyst according to claim 1, wherein the solid-to-liquid ratio of the sodium sulfide and the carbon dot to deionized water is 480 mg/2 mg/30 ml.
  4. 4. The method for preparing the carbon-point doped Fe-Ni 3 S 2 @NF electrocatalyst according to claim 1, wherein the method is characterized in that the nickel nitrate, the ferric nitrate, the urea and the ammonium fluoride are weighed, dissolved in water and stirred ultrasonically, placed in a reaction kettle, and added with treated foam nickel for hydrothermal reaction for 8 hours at 120 ℃.
  5. 5. The method for preparing the carbon dot doped Fe-Ni 3 S 2 @NF electrocatalyst according to claim 1, wherein the solid-to-liquid ratio of nickel nitrate, ferric nitrate, urea, ammonium fluoride and deionized water is 0.5815g:0.134g:0.36g:0.15g:3ml.
  6. 6. The preparation method of the carbon-point-doped Fe-Ni 3 S 2 @NF electrocatalyst according to claim 1, wherein citric acid and ethylenediamine are dissolved in deionized water and uniformly dispersed, the mixture is transferred to a reaction kettle for reaction for 5 hours at 180 ℃, naturally cooled to room temperature and dialyzed, and the catalyst is obtained.
  7. 7. The method for preparing the carbon dot doped Fe-Ni 3 S 2 @NF electrocatalyst according to claim 1, wherein the solid-to-liquid ratio of citric acid to ethylenediamine to deionized water is 1.05g:0.335mL:10mL.
  8. 8. The use of a carbon-dot doped Fe-Ni 3 S 2 @ NF electrocatalyst prepared by a process as claimed in any one of claims 1 to 7, wherein the electrocatalyst is used for the electrocatalytic decomposition of urea to produce hydrogen.

Description

Preparation method of carbon-point-doped Fe-Ni 3S2 @NF electrocatalyst and application thereof in urea decomposition hydrogen production Technical Field The invention belongs to the technical field of nano composite materials, relates to an electrocatalyst, and in particular relates to a preparation method of a carbon-point-doped Fe-Ni 3S2 @NF electrocatalyst and application of the carbon-point-doped Fe-Ni 3S2 @NF electrocatalyst in hydrogen production by means of electrocatalytic decomposition of urea. Background The hydrogen energy is used as clean renewable energy, has the advantages of green and pollution-free in solving the energy environment, and is widely focused. The electrolysis of water to produce hydrogen is considered a simple, convenient and promising new energy technology. However, oxygen Evolution Reaction (OER) is a half-reaction of the anode in a water electrolysis system, which greatly limits the energy efficiency of hydrogen production due to the rather high overpotential of the 4e - transfer process. In theory, the generation efficiency of H 2 can be remarkably improved by replacing the retarded oxygen evolution reaction with other thermodynamically favorable small molecular electrooxidation reactions. Currently, the electrooxidation of urea is considered to be a promising anodic reaction for the production of H 2, with a theoretical voltage of 0.37V (relative to the reversible hydrogen electrode (vs. rhe)) better than the traditional oxygen evolution reaction (1.23V vs. rhe). Meanwhile, the potential required for generating H 2 can be reduced by urea electrolysis, and the purification of wastewater rich in urea can be realized. Meanwhile, the urea oxidation reaction is also an important reaction in the urea fuel cell, and the efficiency of the urea fuel cell can be greatly improved by reducing the overpotential in the reaction. However, urea anodic oxidation (UOR) (CO (NH 2)2+6OH-＝N2+5H2O+CO2+6e-)) is a complex six electron transfer process, slow kinetics limit its catalytic performance, therefore, in order to improve the catalytic performance of the catalyst urea oxidation, efforts are continually being made to design different kinds of nanocomposite materials to achieve the purpose, mainly including the introduction of vacancies, atomic doping, the construction of heterostructures, where Fe atomic doping can change the coordination environment of Ni in Ni 3S2, optimize the binding strength of the urea oxidation intermediate on Ni 3S2 active sites, however, few documents emphasize the regulation of the morphology of an atom doped Ni 3S2 electrocatalyst by nanocarbon materials, and the advantages of Carbon Dots (CDs) having abundant surface functional groups, unique electron storage capacity, efficient and stable reactive centers, etc. become a very attractive new material in the field of catalysis. Based on the above considerations, the inventors have compounded carbon sites in 2D Fe-Ni 3S2 nanoplatelets supported on nickel foam to enhance electrocatalytic total decomposition urea hydrogen production. The unique 0D-2D nano sheet structure design not only provides larger specific surface area and rich reaction sites in the electrocatalytic reaction, but also ensures the full contact between Fe-Ni 3S2 and carbon points, and effectively promotes the adsorption decomposition of urea and the charge transfer in the reaction. Disclosure of Invention The invention aims to provide a preparation method of a carbon-point-doped Fe-Ni 3S2@NF(Fe-Ni3S2/CDs@NF) electrocatalyst. The preparation method of the carbon dot doped Fe-Ni 3S2@NF(Fe-Ni3S2/CDs@NF) electrocatalyst comprises the steps of weighing sodium sulfide, dissolving in deionized water, adding the carbon dots, stirring uniformly, putting Fe-Ni (OH) 2(Fe-Ni(OH)2 @NF) growing on foam nickel into the solution, transferring the solution into a reaction kettle, carrying out hydrothermal reaction at 110-180 ℃ for 4-10 hours, preferably 120 ℃ for 6 hours, cooling to room temperature, washing with ethanol and water three times successively, and drying to obtain the catalyst, wherein the solid-to-liquid ratio of the sodium sulfide, the carbon dots and the deionized water is 480 mg:0.5-4 mg:30mL, preferably 480mg:2mg:30ml. In the preferred disclosed example, the Fe-Ni (OH) 2(Fe-Ni(OH)2 @NF growing on the foam nickel is prepared by weighing nickel nitrate, ferric nitrate, urea and ammonium fluoride, dissolving in water, ultrasonically stirring, placing in a reaction kettle, adding the treated foam nickel, carrying out hydrothermal reaction for 4-10 hours, preferably 120 ℃ hydrothermal reaction for 8 hours in the high-pressure kettle with the temperature of 110-180 ℃, cooling to room temperature, washing with ethanol and water three times successively, and drying to obtain Fe-Ni (OH) 2, wherein the solid-to-liquid ratio of the nickel nitrate, the ferric nitrate, the urea and the ammonium fluoride to deionized water is 0.5815 g:0.0897-0.808 g:0.36g:0.15g