GRAPHENE/POROUS IRON OXIDE NANOROD COMPOSITE AND MANUFACTURING METHOD THEREOF

Abstract

The present invention discloses a graphene/porous iron oxide nanorod composite and a method for preparing the same. The composite includes graphene and Fe.sub.2O.sub.3 nanoparticles loaded on the graphene. The Fe.sub.2O.sub.3 nanoparticles have a honeycomb porous structure. The synthesis method of the composite is simple and the raw materials are inexpensive.

Claims

1. A graphene/porous iron oxide nanorod composite, comprising graphene and Fe.sub.2O.sub.3 nanoparticles loaded on the graphene, the Fe.sub.2O.sub.3 nanoparticles having a honeycomb porous structure.

2. The graphene/porous iron oxide nanorod composite as claimed in claim 1, wherein the Fe.sub.2O.sub.3 nanoparticles have a rod-shaped morphology.

3. A method for preparing the graphene/porous iron oxide nanorod composite as claimed in claim 1, comprising steps of: (1) mixing graphene oxide with a fibroin solution, and adding hydrazine hydrate for reduction after pH is adjusted to alkaline, to obtain a graphene/fibroin composite; (2) adding an iron source to the graphene/fibroin composite, and further stirring until complete dissolution to get a mixture; (3) pouring the mixture into a reactor and performing a reaction at 120-200° C. for 8-36 h; (4) naturally cooling to room temperature after the end of the reaction, centrifuging and drying the product, to obtain a solid powder; and (5) calcinating the solid powder in an inert atmosphere at 320-450° C. for 3-8 h, and naturally cooling to room temperature, to get the nanorod composite.

4. The method for preparing the graphene/porous iron oxide nanorod composite as claimed in claim 3, wherein the weight ratio of the graphene oxide to fibroin is less than or equal to 1:4.

5. The method for preparing the graphene/porous iron oxide nanorod composite as claimed in claim 3, wherein the weight ratio of the graphene oxide to hydrazine hydrate is 1:(0.0004-20).

6. The method for preparing the graphene/porous iron oxide nanorod composite as claimed in claim 3, wherein the iron source is FeCl.sub.3.6H.sub.2O, and the weight ratio of the graphene oxide to FeCl.sub.3.6H.sub.2O being 1:(20-60).

7. The method for preparing the graphene/porous iron oxide nanorod composite as claimed in claim 3, wherein in the step (1) the pH is 8-11.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are intended for further understanding of the invention as a part of the present application. The exemplary embodiments and description thereof of the invention are used for illustrating the present invention and are not intended to limit the invention in any way. In the drawings:

[0021] FIG. 1 is an SEM image of a sample in an embodiment 1 according to the present invention;

[0022] FIG. 2 is a TEM image of the sample in the embodiment 1 according to the present invention;

[0023] FIG. 3 is an XRD spectrum of the sample in the embodiment 1 according to the present invention;

[0024] FIG. 4 is a Raman spectrum of the sample in the embodiment 1 according to the present invention;

[0025] FIG. 5 is an SEM image of a sample in an embodiment 2 according to the present invention;

[0026] FIG. 6 is an SEM image of a sample in an embodiment 3 according to the present invention;

[0027] FIG. 7 is an SEM image of a sample in an embodiment 4 according to the present invention; and

[0028] FIG. 8 is an XRD spectrum of the sample in the embodiment 4 according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The present invention will be explained in more detail below with reference to the drawings and in connection with embodiments.

Embodiment 1

[0030] A method for preparing a graphene/porous iron oxide nanorod composite, comprises the following steps:

[0031] (1) 0.05 g graphene oxide was mixed with 16 mL of fibroin solution of 5.06 wt %, pH was adjusted to 10, and 0.2 mL hydrazine hydrate was added to induce reduction, and a graphene-fibroin nanofiber composite was obtained;

[0032] (2) 2.15 g FeCl.sub.3.6H.sub.2O was added into the graphene-fibroin nanofiber composite, and stirring was continuously until complete dissolution to get a mixture;

[0033] (3) the mixture was poured into a reactor and reaction was carried out at 160° C. for 20 h;

[0034] (4) after completion of the reaction, the resulting mixture was naturally cooled to room temperature, and the product was centrifuged, washed, and finally dried in vacuum to obtain a solid powder; and

[0035] (5) the resultant solid powder was calcinated in a vacuum tubular furnace in an argon atmosphere at 400° C. for 5 h, and then was naturally cooled to room temperature to get the nanorod composite.

[0036] FIG. 1 to FIG. 4 are an SEM image, TEM image, XRD spectrum, and Raman spectrum of a sample in embodiment 1 of the present invention, respectively. It can be seen from FIG. 1 and FIG. 2 that, the sample prepared by the method appears a one dimensional rod-shaped structure. It can be seen from FIG. 2 that, the rod-shaped iron oxide nanoparticles have honeycomb holes thereon. FIG. 3 shows that the sample is iron oxide. FIG. 4 further shows that the product is a composite of iron oxide with graphene.

Embodiment 2

[0037] A method for preparing a graphene/porous iron oxide nanorod composite, comprises the following steps:

[0038] (1) 0.05 g graphene oxide was mixed with 0.19 mL of fibroin solution of 5.06 wt %, pH was adjusted to 10, and 1 mL hydrazine hydrate was added to induce reduction, and a graphene-fibroin nanofiber composite was obtained;

[0039] (2) 1 g FeCl.sub.3.6H.sub.2O was added into the graphene-fibroin nanofiber composite, and stirring was continuously until complete dissolution to get a mixture;

[0040] (3) the mixture was poured into a reactor and reaction was carried out at 120° C. for 36 h;

[0041] (4) after completion of the reaction, the resulting mixture was naturally cooled to room temperature, and the product was centrifuged, washed, and finally dried in vacuum to obtain a solid powder; and

[0042] (5) the resultant solid powder was calcinated in a vacuum tubular furnace in an argon atmosphere at 320° C. for 8 h, and then was naturally cooled to room temperature to get the nanorod composite.

[0043] FIG. 5 is an SEM image, and it can be seen from the FIG. 5 that, parts of the composite are rod-shaped, and parts of are irregular-shaped.

Embodiment 3

[0044] A method for preparing a graphene/porous iron oxide nanorod composite, comprises the following steps:

[0045] (1) 0.05 g graphene oxide was mixed with 10 mL of fibroin solution of 5.06 wt %, pH was adjusted to 10, and 20 uμL hydrazine hydrate was added to induce reduction, and a graphene-fibroin nanofiber composite was obtained;

[0046] (2) 3 g FeCl.sub.3.6H.sub.2O was added into the graphene-fibroin nanofiber composite, and stirring was continuously until complete dissolution to get a mixture;

[0047] (3) the mixture was poured into a reactor and reaction was carried out at 200° C. for 8 h;

[0048] (4) after completion of the reaction, the resulting mixture was naturally cooled to room temperature, and the product was centrifuged, washed, and finally dried in vacuum to obtain a solid powder; and

[0049] (5) the resultant solid powder was calcinated in a vacuum tubular furnace in an argon atmosphere at 450° C. for 3 h, and then was naturally cooled to room temperature to get the nanorod composite.

[0050] FIG. 6 is an SEM image of the sample, and it can be seen from the FIG. 6 that, the composite are rod-shaped.

Embodiment 4

[0051] A method for preparing a graphene/porous iron oxide nanorod composite, comprises the following steps:

[0052] The synthesis method in this embodiment 4 was similar to that in the embodiment 1, except that the step (5) was omitted.

[0053] FIG. 7 is an SEM image of a sample, and it can be seen from the FIG. 7 that, the composite also shows a rod-shaped structure before calcinating. FIG. 8 is an XRD spectrum of the sample, showing that the product before the composite is calcinated is FeOOH.

[0054] In conclusion, the present invention provides a method for preparing a graphene/porous iron oxide nanorod composite. The raw materials of the method are widely available, inexpensive, and the synthesis process is simple. In the present invention, iron oxide nanoparticles are compounded with graphene, graphene has a large specific surface area and a good conductivity, and enhances the discharge capacity of the iron oxide material. The pore structure of iron oxide increases the specific surface area of iron oxide nanoparticles, such that they have more lithium storage sites and larger contact area. In the invention, fibroin induces iron oxide nanoparticles to form a rod-shaped structure and a honeycomb structure, raw materials of the invention are inexpensive and readily available, has good biocompatibility and no contamination to the environment, and can be easily removed.

[0055] The above description is only preferred embodiments of the present invention and not intended to limit the present invention, it should be noted that those of ordinary skill in the art can further make various modifications and variations without departing from the technical principles of the present invention, and these modifications and variations also should be considered to be within the scope of protection of the present invention.