Preparation method of FeNi3N oxygen evolution electrocatalyst
Using FeNi3N@CC nanoarrays as OER electrocatalysts solves the problems of slow reaction kinetics and high cost of existing OER electrocatalysts, achieving efficient electrocatalytic decomposition capabilities and being suitable for large-scale production.
Patent Information
- Application Number
- CN202411365583.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2025-01-24
AI Technical Summary
The reaction kinetics of existing OER electrocatalysts are slow, inefficient, and the high cost and insufficient storage of precious metal oxides limit their large-scale use.
The FENI3N is used as an oxygen catalyst, and through specific preparation methods, including carbon ultrasound cleaning, water heat treatment and real air conversion, FENI3N@CC nano array is prepared.
The uniform distribution and high purity of the FENI3N nano arrays has a good electrocatalyst and decomposition ability as an oxygen catalyst. It is simple to operate and is suitable for large -scale industrial production.
Smart Images
Figure CN119352069A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of new materials, and in particular relates to a FeNi3N oxygen evolution electrocatalyst and a preparation method thereof. Technical Background
[0002] The rapid development of social productivity has improved the quality of human life, but it has also accelerated the overall depletion of resources and the deterioration of the natural environment. Therefore, people have made great efforts to explore green and clean energy.
[0003] Green, efficient and sustainable electrocatalytic water splitting to produce oxygen and hydrogen is an effective solution to convert renewable energy into chemical energy, thus helping to alleviate global environmental problems and energy crisis. Water electrolysis includes cathode hydrogen evolution reaction (HER) and anode oxygen evolution reaction (OER). OER has attracted extensive attention as one of the fundamental processes for renewable energy conversion and storage. Unfortunately, OER is a multi-step proton-coupled electron transfer process with slow reaction kinetics, which largely limits the overall catalytic reaction efficiency. Although noble metal oxides (such as RuO2 or IrO2) are currently considered promising OER electrocatalysts, insufficient storage and high cost severely limit their practical large-scale use.
[0004] Currently, a lot of research efforts are devoted to designing economical and efficient transition metal-based (Ni, Co, Fe, Cu, Mn, etc.) OER catalysts to replace precious metal-based catalysts, including transition metal oxides / hydroxides, sulfides, selenides, nitrides, phosphides, carbides, etc.
[0005] Transition metal nitrides (TMNs) are formed by introducing nitrogen atoms into the interstitial positions of the parent metal and belong to the interstitial alloy family. The introduction of nitrogen into transition metals causes the metal d-band to shrink, which leads to a larger density of states near the Fermi level. At the same time, the introduction of nitrogen causes the lattice parameters to change, increasing the d-band electron density of the transition metal, resulting in an electronic structure and density of states similar to that of the precious metal Pt. Due to their low cost, excellent corrosion resistance, good conductivity and metallic properties, TMNs have been developed as HER or OER catalysts. Compared with single metal nitrides (Ni3N, W2N), bimetallic nitrides (Ni3MoN, Co3FeN) show better performance due to the synergistic effect of the two metals. Among them, FeNi3N has received increasing attention due to its good catalytic activity. Summary of the invention
[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide a method for preparing a FeNi3N oxygen evolution electrocatalyst.
[0007] To achieve the above object, the present invention provides the following technical solutions:
[0008] A method for preparing an electrocatalyst comprises the following steps:
[0009] (1) The carbon cloth is ultrasonically cleaned with acetone, deionized water, and ethanol in turn for 5 to 20 minutes; nickel salt and iron salt are taken in a certain proportion, wherein the nickel salt can be nickel chloride hexahydrate or nickel nitrate hexahydrate, and the iron salt can be ferric nitrate nonahydrate or ferric chloride hexahydrate, urea and ammonium fluoride are 20 mmol and 10 mmol respectively, and dissolved in a certain amount of deionized water to form a transparent solution, and the solution is poured into a 100 ml polytetrafluoroethylene liner, and then the treated carbon cloth is placed in the solution, and then placed in a hydrothermal autoclave;
[0010] (2) The hydrothermal autoclave was placed in a hydrothermal oven at 120±20°C for 8±1h, and taken out after natural cooling. The autoclave was washed with deionized water and ethanol three times in sequence, and then placed in an oven at 60°C for overnight drying to obtain a precursor.
[0011] (3) A piece of precursor was placed in a quartz boat, which was placed downstream of the quartz tube of the tube furnace. A certain amount of dicyandiamide was weighed and placed in another quartz boat, which was placed upstream of the tube furnace. The tube furnace was sealed and evacuated to a vacuum state with a vacuum pump. The temperature was raised to a certain temperature at 5°C / min. After being kept warm for a period of time, the temperature was naturally cooled to room temperature. The sample was rinsed with pure water and alcohol several times and then dried in a 60°C forced air drying oven for 8 h to obtain a FeNi3N@CC nanoarray.
[0012] Preferably, the molar ratio of the nickel salt to the iron salt is 3:1.
[0013] Preferably, the deionized water is 70 ml.
[0014] Preferably, the precursor is Ni3Fe-LDH, denoted as Ni3Fe-LDH / CC.
[0015] Preferably, the amount of dicyandiamide is 600 mg.
[0016] Preferably, the vacuum state is -0.1 MPa.
[0017] Preferably, the temperature is 450°C.
[0018] Preferably, the insulation time is 60 minutes.
[0019] Preferably, the room temperature is 15-35°C.
[0020] Beneficial effects of the present invention:
[0021] The method of the present invention is simple, and the synthesized FeNi3N nanoarray is evenly distributed and has high purity; and as an oxygen evolution electrocatalyst, it has good electrocatalytic decomposition ability. The temperature rise program set in the present invention can ensure that the reaction is carried out safely and orderly, and will not cause safety problems and the nanoarray will not fall off due to drastic temperature rise. The whole reaction operation is simple and can achieve large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the features, technical means and specific purposes and functions achieved by the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:
[0023] Figure 1 Flowchart for conducting the experiment.
[0024] Figure 2 The XRD diagram shows the effect of reaction temperature of 450°C on the generated products.
[0025] Figure 3 This is the LSV diagram showing the effect of reaction temperature of 450°C on the generated products. DETAILED DESCRIPTION
[0026] Implementation
[0027] (1) The carbon cloth was ultrasonically cleaned with acetone, deionized water, and ethanol for 15 min in sequence; 3 mmol nickel nitrate hexahydrate, 1 mmol iron nitrate nonahydrate, 20 mmol urea, and 10 mmol ammonium fluoride were dissolved in 70 ml deionized water to form a transparent solution, the solution was poured into a 100 ml polytetrafluoroethylene liner, and the treated carbon cloth was placed in the solution, and then placed in a hydrothermal autoclave;
[0028] (2) The hydrothermal autoclave was placed in a hydrothermal box at 120°C for 8 h, taken out after natural cooling, washed with deionized water and ethanol three times in sequence, and then placed in an oven at 60°C for overnight drying to obtain Ni3Fe-LDH / CC.
[0029] (3) Place a 2×2cm 2 The Ni3Fe-LDH / CC was put into a quartz boat, and then placed downstream of the quartz tube of the tubular furnace. 600 mg of dicyandiamide was weighed and put into another quartz boat, and then placed upstream of the tubular furnace. The tubular furnace was sealed and evacuated to -0.1 MPa with a vacuum pump. The temperature was increased to 450°C at 5°C / min, and after keeping warm for 60 minutes, the temperature was naturally cooled to room temperature. The sample was rinsed with deionized water and alcohol several times and then dried in a 60°C forced air drying oven for 8 hours to obtain the FeNi3N@CC nanoarray.
[0030] Finally, it should be noted that the above embodiments are only used for the technical solutions of the present invention, rather than limiting the present invention. Although the present invention has been described in detail with reference to the above examples, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for the technical features therein, and these modifications or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for preparing a FeNi3N electrocatalyst, characterized in that: The following steps are involved: (1) The carbon cloth was ultrasonically cleaned with acetone, deionized water, and ethanol for 15 min in sequence; 3 mmol nickel nitrate hexahydrate, 1 mmol iron nitrate nonahydrate, 20 mmol urea, and 10 mmol ammonium fluoride were dissolved in 70 ml deionized water to form a transparent solution, the solution was poured into a 100 ml polytetrafluoroethylene liner, and the treated carbon cloth was placed in the solution, and then placed in a hydrothermal autoclave; (2) The hydrothermal autoclave was placed in a hydrothermal box at 120°C for 8 h, taken out after natural cooling, washed with deionized water and ethanol three times in sequence, and then placed in an oven at 60°C for overnight drying to obtain Ni3Fe-LDH / CC. (3) Place a 2×2cm 2 The Ni3Fe-LDH / CC was put into a quartz boat, and then placed downstream of the quartz tube of the tubular furnace. 600 mg of dicyandiamide was weighed and put into another quartz boat, and then placed upstream of the tubular furnace. The tubular furnace was sealed and evacuated to -0.1 MPa with a vacuum pump. The temperature was increased to 450°C at 5°C / min, and after keeping warm for 60 minutes, the temperature was naturally cooled to room temperature. The sample was rinsed with deionized water and alcohol several times and then dried in a 60°C forced air drying oven for 8 hours to obtain the FeNi3N@CC nanoarray.
2. The method for preparing a FeNi3N oxygen evolution electrocatalyst according to claim 1, characterized in that: The FeNi3N precursor was used to prepare nickel-iron hydrotalcite nanoarrays on the surface of carbon cloth by a hydrothermal method. The specific operation steps were as follows: 3mmol nickel nitrate hexahydrate, 1mmol iron nitrate nonahydrate, 20mmol urea, and 10mmol ammonium fluoride were dissolved in 70ml deionized water to form a transparent solution, the solution was poured into a 100ml polytetrafluoroethylene liner, and then the treated carbon cloth was placed in the solution and then placed in a hydrothermal autoclave; the hydrothermal autoclave was placed in a hydrothermal box at 120°C for 8h, taken out after natural cooling, washed with deionized water and ethanol three times in sequence, and then placed in an oven at 60°C for overnight drying to obtain Ni3Fe-LDH / CC.
3. The method for preparing a FeNi3N oxygen evolution electrocatalyst according to claim 1, characterized in that: Using dicyandiamide as the nitrogen source, FeNi3N nanoarrays were obtained.
4. The method for preparing a FeNi3N oxygen evolution electrocatalyst according to claim 1, characterized in that: The holding temperature is 450°C to obtain FeNi3N nanoarrays.
5. The method for preparing a FeNi3N oxygen evolution electrocatalyst according to claim 1, characterized in that: The heat preservation time is 60 minutes, and the FeNi3N nanoarray is obtained.