Iron oxide / nickel ferrite composite nanorods and a method for synthesizing the same

Abstract

The application discloses a kind of iron oxide / nickel ferrite composite nanorods and synthesis method thereof, belong to nanometer material technical field.The obtained composite nanorod is polycrystalline structure, and is composed of rhombohedral Fe2O3 and cubic NiFe2O4 crystal phase.The diameter of the composite nanorod is 10-100nm, and the length is greater than 500nm.The synthesis method is that iron acetate and nickel acetate are dissolved in deionized water, heated to temperature 80-100 DEG C, and kept for 1-5h, and iron oxide / nickel ferrite precursor is obtained after cooling and drying;iron oxide / nickel ferrite precursor is mixed with calcium chloride and sodium chloride, then the mixture is loaded into corundum crucible, the crucible is placed in reaction furnace, at temperature 800-1000 DEG C, and kept for 5-10h.The synthesis process of the application is simple, does not need complex equipment, and is easy to control.Iron oxide / nickel ferrite composite nanorod has a large number of catalytic active sites, and is expected to have good interface performance, catalytic activity, electrical and magnetic properties, and has good application prospect in catalysts, electrical devices and magnetic devices.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterials technology, specifically relating to an iron oxide / nickel ferrite composite nanorod and its synthesis method. Background Technology

[0002] Iron oxide possesses characteristics such as a low band gap (2.2 eV), excellent optical, electrical, and magnetic properties, good chemical stability, low cost, and no pollution, making it well-suited for applications in optical devices, electronic devices, magnetic devices, and catalysis. The national invention patent "A Method for Preparing Mica Iron Oxide Using Molten Salt Method" (National Invention Patent Application No.: 201010136709.6) reports the use of ferrous ammonium sulfate or ferrous sulfate, or a mixture thereof, as the iron source, and sulfate or chloride, or a mixture thereof, as the flux. The mixture is then melted to obtain mica iron oxide.

[0003] Nickel ferrite has a low band gap (1.5 eV) and excellent physical and chemical properties, showing broad application prospects in magnetism, electronics, and catalysis. The national invention patent "A Nickel Ferrite Composite Photocatalytic Material and Its Preparation Method" (National Invention Patent Application No.: 201610038117.8) discloses a nickel ferrite composite photocatalytic material. The preparation process involves mixing ferric nitrate solution and nickel nitrate solution, adding boron nitride nanosheets, and holding at a hydrothermal temperature of 150–220℃ for 5–30 hours to obtain the nickel ferrite composite photocatalytic material. The national invention patent "A Nano-Nickel Ferrite / Zinc Titanate Modified Microporous Silica, Its Preparation Method, and Its Application" (National Invention Patent No.: ZL202111059323.4) discloses a nano-nickel ferrite / zinc titanate modified microporous silica. This composite material utilizes the p–n type heterojunction formed by the combination of nano-nickel ferrite and nano-zinc titanate, which can effectively improve photocatalytic efficiency and catalytic stability, and expand the spectral absorption range. Combining iron oxide with nickel ferrite to form iron oxide / nickel ferrite composite nanomaterials can increase the catalytic active sites in the composite material, and is expected to have good interfacial properties, catalytic activity, electrical and magnetic properties, showing good application prospects in catalysts, electrical devices and magnetic devices. The national invention patent "A preparation method of iron oxide / ferrite composite membrane and its application" (National Invention Patent Application No.: 202110377242.2) discloses a method for preparing an iron oxide / ferrite composite membrane. The method involves first growing a composite membrane containing iron and transition metal salts in situ on a conductive glass substrate using a hydrothermal method, and then subjecting the conductive glass with the composite membrane attached to it to solid-state high-temperature calcination to obtain the iron oxide / ferrite composite membrane. This iron oxide / ferrite composite membrane can be used as a photoelectrode for photoelectrochemical catalytic water splitting. Summary of the Invention

[0004] To overcome the shortcomings of the existing technology, the purpose of this invention is to provide an iron oxide / nickel ferrite composite nanomaterial, and at the same time provide a method for preparing the above material, so that the preparation process is simple, requires no complicated equipment, and is easy to control.

[0005] The present invention is achieved through the following technical solutions.

[0006] This invention provides an iron oxide / nickel ferrite composite nanorod. The resulting composite nanorod has a polycrystalline structure and is composed of rhombohedral Fe2O3 and cubic NiFe2O4 crystal phases.

[0007] Furthermore, the composite nanorods have a diameter of 10–100 nm and a length greater than 500 nm.

[0008] This invention also provides a method for synthesizing the above-mentioned iron oxide / nickel ferrite composite nanorods, specifically including the following steps:

[0009] (1) Dissolve ferric acetate and nickel acetate in deionized water, heat to 80-100℃, keep warm for 1-5 hours, cool and dry to obtain ferric oxide / nickel ferrite precursor;

[0010] The molar ratio of ferric acetate to nickel acetate is 2:1; the total weight of ferric acetate and nickel acetate accounts for 5-10% of the weight of water.

[0011] (2) The iron oxide / nickel ferrite precursor obtained in step (1) is thoroughly mixed with calcium chloride and sodium chloride. Then the mixture is loaded into a corundum crucible, and the crucible is placed in a reaction furnace and kept at 800-1000℃ for 5-10 hours.

[0012] The molar ratio of calcium chloride to sodium chloride is 1:1; the total weight of ferric acetate and nickel acetate accounts for 5-10% of the weight of calcium chloride and sodium chloride.

[0013] (3) After the reactor is naturally cooled to room temperature, deionized water is added to the sample to dissolve calcium chloride and sodium chloride, remove calcium chloride and sodium chloride from the iron oxide / nickel ferrite sample, filter and wash with deionized water until the water is clear to remove residual ions, and dry the filtered sample to obtain iron oxide / nickel ferrite composite nanorods.

[0014] Further, in step (1), the temperature is heated to 100°C and kept at that temperature for 5 hours; the total weight of the iron acetate and nickel acetate accounts for 10% of the weight of the water; in step (2), the temperature is kept at 1000°C for 10 hours; the total weight of the iron acetate and nickel acetate accounts for 10% of the weight of the calcium chloride and sodium chloride; in step (3), the drying temperature is 100°C.

[0015] The scientific principles underlying this invention are speculated as follows:

[0016] This invention employs the aforementioned two-step synthesis process. First, heat treatment is performed at 80–100°C for 1–5 hours to obtain a uniform iron oxide / nickel ferrite precursor. This iron oxide / nickel ferrite precursor is then reacted in molten salt at 800–1000°C for 5–10 hours. Iron acetate and nickel acetate decompose to form iron oxide and nickel oxide, and some iron oxide reacts with nickel oxide to form nickel ferrite. Under the influence of iron oxide and nickel oxide, an oxide-assisted growth process is used to form iron oxide / nickel ferrite composite nanorods composed of rhombohedral Fe2O3 and cubic NiFe2O4 crystal phases.

[0017] Compared with the prior art, the present invention has the following technical effects:

[0018] 1. This invention employs a two-step synthesis process, which is easy to control and has good reproducibility, thus providing conditions for the practical application of iron oxide / nickel ferrite composite nanorods;

[0019] 2. The raw materials used in this invention are ferric acetate, nickel acetate, calcium chloride, sodium chloride and water, which do not produce any toxic or harmful gases and do not pollute the environment;

[0020] 3. The iron oxide / nickel ferrite composite nanorods of the present invention have a large number of catalytic active sites and are expected to have good interfacial properties, catalytic activity, electrical and magnetic properties, and have good application prospects in catalysts, electrical devices and magnetic devices. Attached Figure Description

[0021] Figure 1 The X-ray diffraction (XRD) pattern of the iron oxide / nickel ferrite composite nanorods synthesized in Example 1 is shown below.

[0022] According to the JCPDS PDF card, the obtained iron oxide / nickel ferrite composite nanorods can be identified as being composed of rhombohedral Fe2O3 (JCPDS card, card number: 33-0664) and cubic NiFe2O4 (JCPDS card, card number: 54-0964) crystal phases.

[0023] Figure 2 The image shows a scanning electron microscope (SEM) image of the iron oxide / nickel ferrite composite nanorods synthesized in Example 1.

[0024] As can be seen from the figure, the product is composed of nanorods with a diameter of 10-100 nm and a length of more than 500 nm.

[0025] Figure 3 The image shows a transmission electron microscope (TEM) image of the iron oxide / nickel ferrite composite nanorods synthesized in Example 1. Figure 3 (a) and high-resolution TEM (HRTEM) images ( Figure 3 (b));

[0026] As can be seen from the figure, the product is composed of iron oxide / nickel ferrite composite nanorods. The nanorods have a polycrystalline structure with interplanar spacing of 0.37 nm and 0.48 nm, which correspond to the interplanar spacing of the (012) crystal plane of the rhombohedral Fe2O3 crystal phase and the (111) crystal plane of the cubic NiFe2O4 crystal phase, respectively. Detailed Implementation

[0027] The present invention will be described in detail below with reference to specific embodiments, but the present invention is not limited to the following embodiments.

[0028] Example 1

[0029] (1) Dissolve ferric acetate and nickel acetate in deionized water, wherein the molar ratio of ferric acetate to nickel acetate is 2:1, and the total weight of ferric acetate and nickel acetate accounts for 10% of the weight of water. Heat to 100°C, keep warm for 5 hours, and then cool and dry to obtain ferric oxide / nickel ferrite precursor.

[0030] (2) The iron oxide / nickel ferrite precursor obtained in step (1) is thoroughly mixed with calcium chloride and sodium chloride, wherein the molar ratio of calcium chloride to sodium chloride is 1:1, and the total weight of iron acetate and nickel acetate accounts for 10% of the weight of calcium chloride and sodium chloride. Then the mixture is loaded into a corundum crucible, and the crucible is placed in a reaction furnace and kept at 1000℃ for 10h.

[0031] (3) After the reactor is naturally cooled to room temperature, deionized water is added to the sample to dissolve calcium chloride and sodium chloride, remove calcium chloride and sodium chloride from the iron oxide / nickel ferrite sample, filter and wash with deionized water until the water is clear to remove residual ions, and dry the filtered sample in a drying oven at 100°C to obtain iron oxide / nickel ferrite composite nanorods.

[0032] Example 2

[0033] (1) Dissolve ferric acetate and nickel acetate in deionized water, wherein the molar ratio of ferric acetate to nickel acetate is 2:1, and the total weight of ferric acetate and nickel acetate accounts for 5% of the weight of water. Heat to 80°C, keep warm for 1 hour, cool and dry to obtain ferric oxide / nickel ferrite precursor.

[0034] (2) The iron oxide / nickel ferrite precursor obtained in step (1) is thoroughly mixed with calcium chloride and sodium chloride, wherein the molar ratio of calcium chloride to sodium chloride is 1:1, and the total weight of iron acetate and nickel acetate accounts for 5% of the weight of calcium chloride and sodium chloride. Then the mixture is loaded into a corundum crucible, and the crucible is placed in a reaction furnace and kept at 800℃ for 5 hours.

[0035] (3) After the reactor is naturally cooled to room temperature, deionized water is added to the sample to dissolve calcium chloride and sodium chloride, remove calcium chloride and sodium chloride from the iron oxide / nickel ferrite sample, filter and wash with deionized water until the water is clear to remove residual ions, and dry the filtered sample in a drying oven at 100°C to obtain iron oxide / nickel ferrite composite nanorods.

[0036] Example 3

[0037] (1) Dissolve ferric acetate and nickel acetate in deionized water, wherein the molar ratio of ferric acetate to nickel acetate is 2:1, and the total weight of ferric acetate and nickel acetate accounts for 6% of the weight of water. Heat to 85°C, keep warm for 4 hours, and then cool and dry to obtain ferric oxide / nickel ferrite precursor.

[0038] (2) The iron oxide / nickel ferrite precursor obtained in step (1) is thoroughly mixed with calcium chloride and sodium chloride, wherein the molar ratio of calcium chloride to sodium chloride is 1:1, and the total weight of iron acetate and nickel acetate accounts for 6% of the weight of calcium chloride and sodium chloride. Then the mixture is loaded into a corundum crucible, and the crucible is placed in a reaction furnace and kept at 950°C for 9 hours.

[0039] (3) After the reactor is naturally cooled to room temperature, deionized water is added to the sample to dissolve calcium chloride and sodium chloride, remove calcium chloride and sodium chloride from the iron oxide / nickel ferrite sample, filter and wash with deionized water until the water is clear to remove residual ions, and dry the filtered sample in a drying oven at 100°C to obtain iron oxide / nickel ferrite composite nanorods.

[0040] Example 4

[0041] (1) Dissolve ferric acetate and nickel acetate in deionized water, wherein the molar ratio of ferric acetate to nickel acetate is 2:1, and the total weight of ferric acetate and nickel acetate accounts for 7% of the weight of water. Heat to 90°C, keep warm for 3 hours, and then cool and dry to obtain ferric oxide / nickel ferrite precursor.

[0042] (2) The iron oxide / nickel ferrite precursor obtained in step (1) is thoroughly mixed with calcium chloride and sodium chloride, wherein the molar ratio of calcium chloride to sodium chloride is 1:1, and the total weight of iron acetate and nickel acetate accounts for 7% of the weight of calcium chloride and sodium chloride. Then the mixture is loaded into a corundum crucible, and the crucible is placed in a reaction furnace and kept at 900℃ for 8 hours.

[0043] (3) After the reactor is naturally cooled to room temperature, deionized water is added to the sample to dissolve calcium chloride and sodium chloride, remove calcium chloride and sodium chloride from the iron oxide / nickel ferrite sample, filter and wash with deionized water until the water is clear to remove residual ions, and dry the filtered sample in a drying oven at 100°C to obtain iron oxide / nickel ferrite composite nanorods.

[0044] Example 5

[0045] (1) Dissolve ferric acetate and nickel acetate in deionized water, wherein the molar ratio of ferric acetate to nickel acetate is 2:1, and the total weight of ferric acetate and nickel acetate accounts for 8% of the weight of water. Heat to 95°C, keep warm for 2 hours, and then cool and dry to obtain ferric oxide / nickel ferrite precursor.

[0046] (2) The iron oxide / nickel ferrite precursor obtained in step (1) is thoroughly mixed with calcium chloride and sodium chloride, wherein the molar ratio of calcium chloride to sodium chloride is 1:1, and the total weight of iron acetate and nickel acetate accounts for 8% of the weight of calcium chloride and sodium chloride. Then the mixture is loaded into a corundum crucible, and the crucible is placed in a reaction furnace and kept at 850°C for 7 hours.

[0047] (3) After the reactor is naturally cooled to room temperature, deionized water is added to the sample to dissolve calcium chloride and sodium chloride, remove calcium chloride and sodium chloride from the iron oxide / nickel ferrite sample, filter and wash with deionized water until the water is clear to remove residual ions, and dry the filtered sample in a drying oven at 100°C to obtain iron oxide / nickel ferrite composite nanorods.

[0048] Example 6

[0049] (1) Dissolve ferric acetate and nickel acetate in deionized water, wherein the molar ratio of ferric acetate to nickel acetate is 2:1, and the total weight of ferric acetate and nickel acetate accounts for 9% of the weight of water. Heat to 100°C, keep warm for 1.5h, cool and dry to obtain ferric oxide / nickel ferrite precursor.

[0050] (2) The iron oxide / nickel ferrite precursor obtained in step (1) is thoroughly mixed with calcium chloride and sodium chloride, wherein the molar ratio of calcium chloride to sodium chloride is 1:1, and the total weight of iron acetate and nickel acetate accounts for 9% of the weight of calcium chloride and sodium chloride. Then the mixture is loaded into a corundum crucible, and the crucible is placed in a reaction furnace and kept at 800℃ for 6 hours.

[0051] (3) After the reactor is naturally cooled to room temperature, deionized water is added to the sample to dissolve calcium chloride and sodium chloride, remove calcium chloride and sodium chloride from the iron oxide / nickel ferrite sample, filter and wash with deionized water until the water is clear to remove residual ions, and dry the filtered sample in a drying oven at 100°C to obtain iron oxide / nickel ferrite composite nanorods.

[0052] Example 7

[0053] (1) Dissolve ferric acetate and nickel acetate in deionized water, wherein the molar ratio of ferric acetate to nickel acetate is 2:1, and the total weight of ferric acetate and nickel acetate accounts for 7% of the weight of water. Heat to 90°C, keep warm for 2.5 h, and then cool and dry to obtain ferric oxide / nickel ferrite precursor.

[0054] (2) The iron oxide / nickel ferrite precursor obtained in step (1) is thoroughly mixed with calcium chloride and sodium chloride, wherein the molar ratio of calcium chloride to sodium chloride is 1:1, and the total weight of iron acetate and nickel acetate accounts for 8% of the weight of calcium chloride and sodium chloride. Then the mixture is loaded into a corundum crucible, and the crucible is placed in a reaction furnace and kept at 900℃ for 5.5h.

[0055] (3) After the reactor is naturally cooled to room temperature, deionized water is added to the sample to dissolve calcium chloride and sodium chloride, remove calcium chloride and sodium chloride from the iron oxide / nickel ferrite sample, filter and wash with deionized water until the water is clear to remove residual ions, and dry the filtered sample in a drying oven at 100°C to obtain iron oxide / nickel ferrite composite nanorods.

[0056] Example 8

[0057] (1) Dissolve ferric acetate and nickel acetate in deionized water, wherein the molar ratio of ferric acetate to nickel acetate is 2:1, and the total weight of ferric acetate and nickel acetate accounts for 8% of the weight of water. Heat to 80°C, keep warm for 3.5 h, and then cool and dry to obtain ferric oxide / nickel ferrite precursor.

[0058] (2) The iron oxide / nickel ferrite precursor obtained in step (1) is thoroughly mixed with calcium chloride and sodium chloride, wherein the molar ratio of calcium chloride to sodium chloride is 1:1, and the total weight of iron acetate and nickel acetate accounts for 7% of the weight of calcium chloride and sodium chloride. Then the mixture is loaded into a corundum crucible, and the crucible is placed in a reaction furnace and kept at 950°C for 7.5 hours.

[0059] (3) After the reactor is naturally cooled to room temperature, deionized water is added to the sample to dissolve calcium chloride and sodium chloride, remove calcium chloride and sodium chloride from the iron oxide / nickel ferrite sample, filter and wash with deionized water until the water is clear to remove residual ions, and dry the filtered sample in a drying oven at 100°C to obtain iron oxide / nickel ferrite composite nanorods.

Claims

1. An iron oxide / nickel ferrite composite nanorod, characterized in that, The resulting composite nanorods have a polycrystalline structure, consisting of rhombohedral Fe2O3 and cubic NiFe2O4 crystal phases; the diameter of the composite nanorods is 10–100 nm and the length is greater than 500 nm. The method for synthesizing the composite nanorods includes the following steps: (1) Dissolve ferric acetate and nickel acetate in deionized water, heat to 80-100℃, keep warm for 1-5 hours, cool and dry to obtain ferric oxide / nickel ferrite precursor; The molar ratio of ferric acetate to nickel acetate is 2:1; the total weight of ferric acetate and nickel acetate accounts for 5-10% of the weight of water. The iron oxide / nickel ferrite precursor obtained in step (1) is thoroughly mixed with calcium chloride and sodium chloride. The mixture is then loaded into a corundum crucible, and the crucible is placed in a reaction furnace and kept at 800-1000℃ for 5-10 hours. The molar ratio of calcium chloride to sodium chloride is 1:1; the total weight of ferric acetate and nickel acetate accounts for 5-10% of the weight of calcium chloride and sodium chloride. (3) After the reactor is naturally cooled to room temperature, deionized water is added to the sample to dissolve calcium chloride and sodium chloride, remove calcium chloride and sodium chloride from the iron oxide / nickel ferrite sample, filter and wash with deionized water until the water is clear to remove residual ions, and dry the filtered sample to obtain iron oxide / nickel ferrite composite nanorods.

2. The method for synthesizing iron oxide / nickel ferrite composite nanorods as described in claim 1, characterized in that, In step (1), the temperature is raised to 100°C and held for 5 hours; the total weight of the iron acetate and nickel acetate accounts for 10% of the weight of the water. In step (2), the temperature is maintained at 1000℃ for 10 hours; the total weight of the iron acetate and nickel acetate accounts for 10% of the weight of the calcium chloride and sodium chloride. In step (3), the drying temperature is 100°C.

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