CN105016315A - Preparation method of graphene oxide composite material - Google Patents

Abstract

The invention discloses a preparation method of a graphene oxide composite material, relating to the composite material. Add MA powder into GO aqueous solution, and the mixed solution is ultrasonically obtained to obtain a dispersion containing MA/GO, M is a transition metal or bismuth, A is an oxygen group element, MA is a sulfide of M or a selenide of M; GO stands for graphite oxide ene; MA/GO represents the composite material of MA and GO; the upper layer of the obtained dispersion is centrifuged at low speed, the supernatant is centrifuged at high speed, and the precipitate is washed and dispersed in water to obtain an MA/GO aqueous solution; or the upper layer of the obtained dispersion is centrifuged The solution was centrifuged step by step at 2000-13000rpm to obtain MA/GO with different sizes. The structure of the obtained graphene oxide composite material is adjustable, the dispersion liquid has good stability in aqueous solution, and can be applied in a solution system. Composite materials with different sizes, thicknesses and structures can be prepared, and the composite materials have good dispersibility at pH3-9.

Description

A kind of preparation method of graphene oxide composite material

technical field

The invention relates to composite materials, in particular to a preparation method of graphene oxide composite materials.

Background technique

Due to the excellent physical and chemical properties of graphene oxide composite materials, they have shown more excellent performance than individual two-dimensional materials in the fields of biosensors, photothermal therapy, catalysts, photoelectric detection, lithium-ion batteries, etc. ^[1-5] At present, the preparation method of graphene oxide composite material is mainly chemical vapor deposition (referred to as CVD). ^[6-8] Although the performance of composite materials prepared by CVD method is very superior, the preparation process is very complicated, and the cost is high, and the yield is relatively low. At the same time, the prepared composite material is a solid phase and cannot be dissolved in water, so it is not suitable for application in a solution system. Therefore, it is challenging to find a simple and efficient method for large-scale preparation of water-soluble GO composites in aqueous solution.

Contents of the invention

The object of the present invention is to overcome the above-mentioned shortcomings existing in the prior art, and to provide the obtained graphene oxide composite material, which not only has an adjustable structure, but also has good stability in aqueous solution, and can be used in a graphene oxide composite material for solution systems. The method of preparation of the material.

The present invention comprises the following steps:

1) Add MA powder into the GO aqueous solution to obtain a mixed solution. After the mixed solution is ultrasonicated, a dispersion solution containing MA/GO is obtained, wherein M represents a transition metal or bismuth, A represents an oxygen group element, and MA represents a sulfide of M Or the selenide of M; GO stands for graphene oxide; MA/GO stands for the composite material of MA and GO;

2) centrifuging the supernatant of the dispersion obtained in step 1) at a low speed, then centrifuging the supernatant after low speed centrifugation at a high speed, washing the obtained precipitate and dispersing it in water to obtain an MA/GO aqueous solution; or

The supernatant of the dispersion liquid obtained in step 1) is centrifuged step by step at 2000-13000 rpm to obtain MA/GO of different sizes.

In step 1), the transition metal can be selected from tungsten or molybdenum, etc., the oxygen group element can be selected from selenium or sulfur, etc., and the MA can be selected from WS ₂ , Bi ₂ Se ₃ , MoSe ₂ , etc. One; the mass ratio of MA and GO can be 1: (0.1～2), preferably 1: (0.5～1.7), preferably 1:0.25; the pH of the mixed solution can be 3～9, preferably 6-8; the ultrasonic time can be 2-60h;

In step 1), the preparation method of the GO aqueous solution can be: use natural graphite powder as a raw material, add sodium nitrate and concentrated sulfuric acid to obtain a mixed solution, add potassium permanganate to the mixed solution, and then heat Carry out the reaction, then add water to the reaction mixture, and continue the reaction at 90-100°C, and finally add water to terminate the reaction, then add hydrogen peroxide solution with a mass fraction of 30%, wash, centrifuge, and dry to obtain graphite oxide Solid, graphite oxide solid in water is ultrasonically dispersed to obtain a uniformly dispersed GO aqueous solution;

The concentrated sulfuric _acid refers to an aqueous solution of _H2SO4 with a concentration (concentration refers to the mass percentage of _H2SO4 in the aqueous solution of _H2SO4 ) greater _than or equal to 70% _;

The mass ratio of the natural graphite powder, sodium nitrate and potassium permanganate can be 2:1:6, and the mass volume ratio of the natural graphite powder and concentrated sulfuric acid can be 1g:23mL.

In step 2), the speed of the low-speed centrifugation can be 400-3000rpm, and the speed of high-speed centrifugation can be 5000-20000rpm; the step-by-step centrifugation includes: collecting the precipitate 1 and the supernatant 1 respectively by centrifuging at a low speed of 2000rpm, supernatant 1 was then centrifuged at 6000rpm to collect the precipitate 2 and supernatant 2 respectively, and the supernatant 2 was centrifuged at 10000rpm to collect the precipitate 3 and supernatant 3 respectively, and the supernatant 3 was centrifuged at 13000rpm to collect the precipitate 4 and supernatant 4 respectively, wherein Precipitation 1, Precipitation 2, Precipitation 3 and Precipitation 4 are MA/GO of different sizes.

The structure of the graphene oxide composite material obtained by the invention is adjustable, and the obtained graphene oxide composite material dispersion liquid has good stability in aqueous solution, and can be applied in a solution system. Through ultraviolet, Raman, atomic force microscope (AFM), transmission electron microscope (TEM), XRD, dynamic light scattering (DLS), Zeta potential and other analytical methods, the structure and dispersion performance of the composite material are characterized and proved, and can be prepared by the present invention Composite materials with different sizes, thicknesses and structures, and the composite materials have good dispersion in the pH range of 3 to 9. At the same time, the preparation process is green and environmentally friendly, easy to operate, and low in cost, which is conducive to the development of graphene oxide composite materials. industrialized production.

Description of drawings

Fig. 1 is an atomic force microscope image of GO precipitated by centrifugation at 2000 rpm in Example 1 of the present invention.

FIG. 2 is a graph of height versus distance corresponding to FIG. 1 .

Fig. 3 is an atomic force microscope image of GO precipitate prepared in Example 1 of the present invention after centrifugation at 6000 rpm.

FIG. 4 is a graph of height versus distance corresponding to FIG. 3 .

Fig. 5 is an atomic force microscope image of GO precipitate prepared in Example 1 of the present invention after centrifugation at 10,000 rpm.

FIG. 6 is a graph of height versus distance corresponding to FIG. 5 .

Fig. 7 is an atomic force microscope image of GO precipitate prepared in Example 1 of the present invention after centrifugation at 13000 rpm.

FIG. 8 is a graph of height versus distance corresponding to FIG. 7 .

Fig. 9 is an atomic force microscope image of the GO supernatant after centrifugation at 13000 rpm prepared in Example 1 of the present invention.

FIG. 10 is a graph of height versus distance corresponding to FIG. 9 .

Fig. 11 is the UV-vis spectrum of the MoS ₂ /GO composite material prepared in Example 2 of the present invention and GO and MoS ₂ alone.

Fig. 12 is the XRD pattern of the MoS ₂ /GO composite material prepared in Example 2 of the present invention and the separate GO and MoS ₂ bulk materials.

Fig. 13 is a Raman spectrum of the MoS ₂ /GO composite material and the MoS ₂ bulk material prepared in Example 2 of the present invention.

Fig. 14 shows the zeta potentials of the MoS ₂ /GO composite material prepared in Example 2 of the present invention and GO and MoS ₂ alone under different pH conditions.

Fig. 15 is the TEM (a) and high-resolution radio microscope (HRTEM, b) images of MoS ₂ /GO when the graphene oxide sheet prepared in Example 2 of the present invention is relatively large.

Fig. 16 is the TEM (a) and HRTEM (b) images of MoS ₂ /GO with the same size when the graphene oxide sheets prepared in Example 2 of the present invention are relatively moderate.

Fig. 17 is the TEM (a) and HRTEM (b) images of the GO/MoS ₂ /GO sandwich structure with a comparable size when the graphene oxide sheets prepared in Example 2 of the present invention are relatively moderate.

Fig. 18 is the TEM (a) and HRTEM (b) images of MoS ₂ /GO with relatively small graphene oxide sheets prepared in Example 2 of the present invention.

Fig. 19 is the UV-vis spectrum of MoS ₂ /GO of different sizes and separate GO and MoS ₂ bulk materials prepared in Example 2 of the present invention.

Fig. 20 is a DLS diagram of MoS ₂ /GO with different sizes prepared in Example 2 of the present invention.

Fig. 21 is the SEM and TEM images of the MoS ₂ /GO precipitate after centrifugation at 2000 rpm prepared in Example 2 of the present invention.

Fig. 22 is an AFM image of the MoS ₂ /GO precipitate after centrifugation at 2000 rpm prepared in Example 2 of the present invention.

FIG. 23 is a graph of height versus distance corresponding to FIG. 22 .

Fig. 24 is the SEM and TEM images of the MoS ₂ /GO precipitate after centrifugation at 6000 rpm prepared in Example 2 of the present invention.

Fig. 25 is an AFM image of the MoS ₂ /GO precipitate after centrifugation at 6000 rpm prepared in Example 2 of the present invention.

FIG. 26 is a graph of height versus distance corresponding to FIG. 25 .

Fig. 27 is the SEM and TEM images of the MoS ₂ /GO precipitate after centrifugation at 10,000 rpm prepared in Example 2 of the present invention.

Fig. 28 is an AFM image of the MoS ₂ /GO precipitate after centrifugation at 10,000 rpm prepared in Example 2 of the present invention.

FIG. 29 is a graph of height versus distance corresponding to FIG. 28 .

Fig. 30 is the SEM and TEM images of the MoS ₂ /GO precipitate after centrifugation at 10,000 rpm prepared in Example 2 of the present invention.

Fig. 31 is an AFM image of the MoS ₂ /GO precipitate after centrifugation at 10,000 rpm prepared in Example 2 of the present invention, further confirming that the MoS ₂ /GO of 100-200 nm was successfully prepared.

FIG. 32 is a graph of height versus distance corresponding to FIG. 31 .

Fig. 33 is the TEM (a) and HRTEM (b) images of Bi ₂ Se ₃ /GO prepared in Example 3 of the present invention.

Fig. 34 is an AFM image of Bi ₂ Se ₃ /GO prepared in Example 3 of the present invention.

FIG. 35 is a graph of height versus distance corresponding to FIG. 34 .

Fig. 36 is the TEM (a) and HRTEM (b) images of MoSe ₂ /GO prepared in Example 3 of the present invention.

Fig. 37 is an AFM image of MoSe ₂ /GO prepared in Example 3 of the present invention.

FIG. 38 is a graph of height versus distance corresponding to FIG. 37 .

Fig. 39 is the TEM (a) and HRTEM (b) images of WS ₂ /GO prepared in Example 3 of the present invention.

Fig. 40 is an AFM image of WS ₂ /GO prepared in Example 3 of the present invention.

FIG. 41 is a graph of height versus distance corresponding to FIG. 40 .

Detailed ways

The present invention will be further described below by means of embodiments in conjunction with the accompanying drawings.

Embodiment 1 The preparation of graphene oxide (GO)

Accurately weigh 2g of natural graphite powder and 1g of sodium nitrate into a round-bottomed flask, and mix evenly with 46mL of concentrated sulfuric acid in an ice bath; then slowly add 6g of potassium permanganate to the mixture to keep the mixture at a low temperature Stir the reaction at 20°C for 2h, then transfer the mixed solution to an oil bath at 35°C and continue to react for 30min. At this time, the reaction system is a tan viscous liquid; then slowly add 92mL deionized water to the mixed solution one by one, and Raise the temperature to 95°C and continue the reaction for 3 hours. The mixed solution turns from brown to bright yellow. Finally, add 400 mL of pure water to terminate the reaction. At the same time, add 6 mL of H ₂ O ₂ solution with a mass fraction of 30% to neutralize unreacted permanganate potassium. After the above solution was cooled to room temperature, suction filtration was performed, and the filter cake was repeatedly washed with 100 mL aqueous hydrochloric acid (1:10) and a large amount of pure water to remove residual metal ions and hydrochloric acid. Then the filter cake was redispersed in pure water, ultrasonicated for 5h to disperse, and then centrifuged at 2000rpm at low speed for 20min to collect the precipitate and supernatant respectively. Collect the precipitate and supernatant; centrifuge at 10000rpm and 13000rpm respectively according to this method, and collect the precipitate and supernatant respectively.

Refer to FIG. 1 for the atomic force microscope image of GO precipitated by centrifugation at 2000 rpm in Example 1 of the present invention. The atomic force microscopy images show that GO nanosheets with a size of 1-2 μm were successfully prepared. FIG. 2 gives a graph of height versus distance corresponding to FIG. 1 . It shows that the thickness of the prepared GO nanosheets is about 1nm. Fig. 3 shows the atomic force microscope image of the GO precipitate after centrifugation at 6000 rpm prepared in Example 1 of the present invention. The atomic force microscopy images show that GO nanosheets with a size of 700-900 nm were successfully prepared. FIG. 4 gives a graph of height versus distance corresponding to FIG. 3 . It shows that the thickness of the prepared GO nanosheets is about 1nm. Fig. 5 shows the atomic force microscope image of GO precipitate prepared in Example 1 of the present invention after centrifugation at 10,000 rpm. The atomic force microscopy images indicate that GO nanosheets with a size of 300-600 nm were successfully prepared. FIG. 6 gives a graph of height versus distance corresponding to FIG. 5 . It shows that the thickness of the prepared GO nanosheets is about 1nm. Fig. 7 shows an atomic force microscope image of GO precipitate prepared in Example 1 of the present invention after centrifugation at 13000 rpm. The atomic force microscopy images show that GO nanosheets with a size of 200-300 nm were successfully prepared. FIG. 8 gives a graph of height versus distance corresponding to FIG. 7 . It shows that the thickness of the prepared GO nanosheets is about 1nm. Fig. 9 shows the atomic force microscope image of the GO supernatant after centrifugation at 13000 rpm prepared in Example 1 of the present invention. The atomic force microscopy images show that GO nanosheets with a size of 100-200 nm were successfully prepared. FIG. 10 gives a graph of height versus distance corresponding to FIG. 9 . It shows that the thickness of the prepared GO nanosheets is about 1nm.

Preparation of Example 2 MoS ₂ /GO Composite Material

Accurately weigh 500mg and 325 mesh fineness of MoS ₂ body material powder and add it to 500mL GO solution with a concentration of 0.25mg/mL, adjust the pH of the mixed solution to 7, and then put the mixed system in an ultrasonic instrument with an electric power of 250W Ultrasound 40h. The resulting dispersion was allowed to stand for 48 hours, and two-thirds of the upper dispersion was obtained. Part of it was placed in a centrifuge and centrifuged at a low speed of 2000rpm for 20min, and the supernatant obtained by centrifugation was collected. Then the obtained supernatant was placed in a centrifuge and centrifuged at a high speed of 12000rpm for 20min, and the supernatant was removed. The resulting lower layer was washed with deionized water in a high-speed centrifuge at 12,000 rpm for 20 minutes repeatedly, and the finally collected material was dispersed in pure water to obtain MoS ₂ /GO. In another part, in order to prepare composite materials of different sizes, the precipitate and supernatant were collected by centrifugation at 2000rpm at a low speed for 20min. The precipitate obtained by centrifugation at 2000rpm was large-sized GO, and the supernatant was centrifuged at 6000rpm for 20min to collect the precipitate and supernatant respectively; Methods Centrifuge at 10000rpm and 13000rpm respectively, and collect the precipitate and supernatant respectively.

Figure 11 shows the UV-vis spectra of the MoS ₂ /GO composite material prepared in Example 2 of the present invention and separate GO and MoS ₂ , as can be seen from the figure, compared with separate MoS ₂ and GO, MoS ₂ / Both characteristic peaks of GO appeared at the same time, the characteristic peaks of GO appeared at 224nm, and the characteristic peaks of MoS ₂ appeared at 612nm and 672nm, which preliminarily proved that MoS ₂ /GO was successfully prepared. Fig. 12 shows the XRD patterns of the MoS ₂ /GO composite material prepared in Example 2 of the present invention and the separate GO and MoS ₂ bulk materials. The XRD pattern shows that compared with the MoS ₂ bulk material, many XRD peaks of MoS ₂ /GO disappear, but the peaks in the (002) crystal plane are enhanced, indicating that the MoS ₂ bulk material has been successfully exfoliated. Fig. 13 shows the Raman spectra of the MoS ₂ /GO composite material and the MoS ₂ bulk material prepared in Example 2 of the present invention. The XRD pattern shows that the E ¹ _2g of the MoS ₂ /GO composite is blue-shifted compared with the MoS ₂ bulk material, indicating that the number of few-layer MoS ₂ in the prepared MoS ₂ /GO composite is 1-3 layers. Fig. 14 shows the zeta potentials of the MoS ₂ /GO composite material prepared in Example 2 of the present invention and GO and MoS ₂ alone under different pH conditions. It can be seen from the figure that the as-prepared MoS ₂ /GO solution has excellent stability at pH 3 to 9 compared with GO and MoS ₂ alone. Fig. 15 shows the TEM (a) and high-resolution radio microscope (HRTEM, b) images of MoS ₂ /GO when the graphene oxide sheet prepared in Example 2 of the present invention is relatively large. It can be seen from the figure that the large wrinkled sheets are GO, and when the GO is relatively large, it mainly forms a structure in which smaller molybdenum disulfide sheets are adsorbed on the surface of GO. The interplanar spacing of 0.27nm in Figure b is attributed to the (100) crystal plane of MoS ₂ , further confirming that the sheets adsorbed on the wrinkled graphene surface are MoS ₂ . Fig. 16 shows the TEM (a) and HRTEM (b) images of MoS ₂ /GO with a size comparable to that of MoS 2 /GO when the graphene oxide sheets prepared in Example 2 of the present invention are relatively moderate. It can be seen from the figure that when GO is relatively moderate, a structure in which MoS ₂ sheets of comparable size are adsorbed on the surface of GO is formed. The interplanar spacing of 0.62nm in Figure b is attributed to the (002) crystal plane of MoS ₂ , further confirming that the sheets adsorbed on the wrinkled graphene surface are MoS ₂ . Fig. 17 shows the TEM (a) and HRTEM (b) images of the GO/MoS ₂ /GO sandwich structure of comparable size when the graphene oxide sheets prepared in Example 2 of the present invention are relatively moderate. It can be seen from the figure that when GO is relatively moderate, a GO/MoS ₂ /GO sandwich structure can also be formed. The interplanar spacings of 0.62nm and 0.27nm in Figure b are attributed to the (002) and (100) crystal planes of MoS ₂ respectively. GO has no obvious interplanar spacing, which further confirms the formation of a GO/MoS ₂ /GO sandwich structure. Fig. 18 shows the TEM (a) and HRTEM (b) images of MoS ₂ /GO with relatively small graphene oxide sheets prepared in Example 2 of the present invention. It can be seen from the figure that when GO is relatively small, it mainly forms a structure in which smaller GO is adsorbed on the surface of MoS ₂ . The lattice fringes of MoS ₂ cannot be seen because the small GO covers MoS ₂ in excess. Figure 19 shows the UV-vis spectra of MoS ₂ /GO of different sizes and separate GO and MoS ₂ bulk materials prepared in Example 2 of the present invention. It can be seen from the figure that as the centrifugal speed increases from 2000rpm to 13000rpm , MoS ₂ /GO blue-shifted the characteristic peak of few-layer MoS ₂ at 672nm, indicating that MoS ₂ /GO with different sizes and thicknesses was successfully prepared. Fig. 20 shows the DLS diagrams of MoS ₂ /GO with different sizes prepared in Example 2 of the present invention. DLS further confirmed the successful preparation of MoS ₂ /GO with different sizes in solution. Fig. 21 shows the SEM and TEM images of the MoS ₂ /GO precipitate after centrifugation at 2000 rpm prepared in Example 2 of the present invention. SEM and TEM images confirmed the successful preparation of MoS ₂ /GO with a thickness of 700nm-1μm. Fig. 22 shows the AFM image of the MoS ₂ /GO precipitate after centrifugation at 2000 rpm prepared in Example 2 of the present invention, further confirming that MoS ₂ /GO with a thickness of 700nm-1μm was successfully prepared. FIG. 23 presents a plot of height versus distance corresponding to FIG. 22 . It shows that the thickness of MoS ₂ /GO prepared after centrifugation at 2000rpm is 30-50nm. Fig. 24 shows the SEM and TEM images of the MoS ₂ /GO precipitate after centrifugation at 6000 rpm prepared in Example 2 of the present invention. SEM and TEM images confirmed the successful preparation of 300-600nm MoS ₂ /GO. Fig. 25 shows the AFM image of the MoS ₂ /GO precipitate after centrifugation at 6000 rpm prepared in Example 2 of the present invention, further confirming that MoS ₂ /GO of 400-600 nm was successfully prepared. FIG. 26 gives a graph of height versus distance corresponding to FIG. 25 . It shows that the thickness of MoS ₂ /GO prepared after centrifugation at 6000rpm is 10-20nm. Fig. 27 shows the SEM and TEM images of the MoS ₂ /GO precipitate after centrifugation at 10,000 rpm prepared in Example 2 of the present invention. SEM and TEM images confirmed the successful preparation of 200-400nm MoS ₂ /GO. Fig. 28 shows the AFM image of the MoS ₂ /GO precipitate after centrifugation at 10,000 rpm prepared in Example 2 of the present invention, further confirming that the MoS ₂ /GO of 200-400 nm was successfully prepared. FIG. 29 gives a graph of height versus distance corresponding to FIG. 28 . It shows that the thickness of MoS ₂ /GO prepared after centrifugation at 10000rpm is 4-8nm. Fig. 30 shows the SEM and TEM images of the MoS ₂ /GO precipitate after centrifugation at 10,000 rpm prepared in Example 2 of the present invention. SEM and TEM images confirmed the successful preparation of 100-200nm MoS ₂ /GO. Fig. 31 shows the AFM image of the MoS ₂ /GO precipitate after centrifugation at 10,000 rpm prepared in Example 2 of the present invention, further confirming that MoS ₂ /GO of 100-200 nm was successfully prepared. FIG. 32 gives a graph of height versus distance corresponding to FIG. 31 . It shows that the thickness of MoS ₂ /GO prepared after centrifugation at 10000rpm is 1-4nm.

Example 3 Preparation of WS ₂ /GO, Bi ₂ Se ₃ /GO, MoSe ₂ /GO composite materials

Accurately weigh tungsten disulfide (WS ₂ ), bismuth selenide (Bi ₂ Se ₃ ), and molybdenum selenide (MoSe ₂ ) bulk material powders with a fineness of 500 mg and 325 mesh, respectively, and add them to 500 mL of 0.25 mg/mL In the GO solution, the pH of the mixed solution was adjusted to 7, and then the mixed system was sonicated for 40 h in an ultrasonic instrument with an electric power of 250 W. The resulting dispersion was left to stand for 48 hours to obtain the upper dispersion. Put it in a centrifuge and centrifuge at a low speed of 2000rpm for 20min, and collect the supernatant obtained by centrifugation. Then the obtained supernatant was placed in a centrifuge and centrifuged at a high speed of 12000rpm for 20min, and the supernatant was removed. The obtained lower layer substance was washed several times by repeated centrifugation at 12000rpm in a high-speed centrifuge for 20min with deionized water, and the finally collected substance was dispersed in pure water to obtain a GO-based few-layer tungsten disulfide (WS ₂ /GO), bismuth selenide (Bi ₂ Se ₃ /GO), molybdenum selenide (MoSe ₂ /GO) and other two-dimensional composite materials.

Fig. 33 shows the TEM (a) and HRTEM (b) images of Bi ₂ Se ₃ /GO prepared in Example 3 of the present invention. It can be seen from figure a that the prepared Bi ₂ Se ₃ /GO sheet size is 200-600 nm. It can be seen from Figure b that the interplanar spacing of 0.21 nm is attributed to the (110) crystal plane of Bi ₂ Se ₃ . Fig. 34 shows the AFM image of Bi ₂ Se ₃ /GO prepared in Example 3 of the present invention. It can be clearly seen that there are few layers of Bi ₂ Se ₃ adsorbed on the surface of GO with low contrast, and the size is about 200-600nm. FIG. 35 gives a plot of height versus distance corresponding to FIG. 34 . It shows that there are about 2-4 layers of Bi ₂ Se ₃ in the prepared Bi ₂ Se ₃ /GO. Fig. 36 shows the TEM (a) and HRTEM (b) images of MoSe ₂ /GO prepared in Example 3 of the present invention. It can be seen from Figure a that the prepared MoSe ₂ /GO sheet size is 200-400nm. It can be seen from Figure b that the interplanar spacing of 0.28nm is due to the (10-10) crystal plane of Bi ₂ Se ₃ . Fig. 37 shows the AFM image of MoSe ₂ /GO prepared in Example 3 of the present invention. It can be clearly seen that there are few layers of Bi ₂ Se ₃ adsorbed on the surface of GO with low contrast, and the size is about 200-400nm. FIG. 38 gives a graph of height versus distance corresponding to FIG. 37 . It shows that the prepared MoSe ₂ /GO has 1-2 layers of MoSe ₂ . Fig. 39 shows the TEM (a) and HRTEM (b) images of WS ₂ /GO prepared in Example 3 of the present invention. It can be seen from figure a that the size of the prepared WS ₂ /GO sheet is 100-300nm. It can be seen from Figure b that the interplanar spacing of 0.27nm is attributed to the (100) crystal plane of WS ₂ . Fig. 40 shows the AFM image of WS ₂ /GO prepared in Example 3 of the present invention. It can be clearly seen that few layers of WS ₂ adsorbed on the surface of GO with low contrast, the size is about 100-300nm. FIG. 41 gives a plot of height versus distance corresponding to FIG. 40 . It shows that WS ₂ in the prepared WS ₂ /GO has 1-2 layers.

Example 4, Detection of GO with different sizes and its two-dimensional composite material

GO of different sizes in Example 1 was detected by atomic force microscope (AFM). Carry out ultraviolet-visible (UV-vis) spectrum to MoS in embodiment ₂ and 3/GO composite material, scanning electron microscope (SEM), transmission electron microscope (TEM), AFM, X-ray diffraction (XRD), Raman (Raman ) spectroscopy, dynamic light scattering (DLS), zeta potential measurements. Conduct TEM, AFM and other characterizations for WS ₂ /GO, Bi ₂ Se ₃ /GO and MoSe ₂ /GO and other two-dimensional composite materials.

Claims (10)

1. a preparation method for graphene oxide composite material, is characterized in that comprising the following steps:

1) MA powder is joined in the GO aqueous solution, obtains mixed solution, after mixed solution is ultrasonic, obtain the dispersion liquid containing MA/GO,

Wherein, M represents transition metal or bismuth, and A represents oxygen family element, and MA represents the sulfide of M or the selenide of M; GO represents graphene oxide; MA/GO represents the matrix material of MA and GO;

2) by step 1) the upper liquid low-speed centrifugal of gained dispersion liquid, then by the supernatant liquor high speed centrifugation after low-speed centrifugal, be dispersed in water after the sediment undergoes washing of gained, obtain the MA/GO aqueous solution; Or

By step 1) to carry out substep with 2000 ~ 13000rpm centrifugal for the upper liquid of gained dispersion liquid, obtains the MA/GO of different size.

2. the preparation method of a kind of graphene oxide composite material as claimed in claim 1, is characterized in that in step 1) in, described transition metal is selected from tungsten or molybdenum, and described oxygen family element are selected from selenium or sulphur.

3. the preparation method of a kind of graphene oxide composite material as claimed in claim 1, is characterized in that in step 1) in, described MA is selected from WS ₂, Bi ₂se ₃, MoSe ₂in one.

4. the preparation method of a kind of graphene oxide composite material as claimed in claim 1, is characterized in that in step 1) in, the mass ratio of described MA and GO is 1: (0.1 ~ 2), preferably 1: (0.5 ~ 1.7), is preferably 1: 0.25.

5. the preparation method of a kind of graphene oxide composite material as claimed in claim 1, is characterized in that in step 1) in, the pH of described mixed solution is 3 ~ 9, preferably 6 ~ 8; The described ultrasonic time can be 2 ~ 60h.

6. the preparation method of a kind of graphene oxide composite material as claimed in claim 1, it is characterized in that in step 1) in, the preparation method of the described GO aqueous solution is: be raw material with natural graphite powder, add SODIUMNITRATE, the vitriol oil obtains mixed solution, potassium permanganate is added in mixed solution, then react at 30 ~ 40 DEG C, water is added again in reaction mixture, and reaction is continued at 90 ~ 100 DEG C, finally add water termination reaction again, add the superoxol that massfraction is 30% again, through washing, centrifugal, drying obtains oxidation graphite solid, oxidation graphite solid obtains the finely dispersed GO aqueous solution through ultrasonic in water.

7. the preparation method of a kind of graphene oxide composite material as claimed in claim 6, is characterized in that the described vitriol oil is the H that mass percentage concentration is more than or equal to 70% ₂sO ₄the aqueous solution.

8. the preparation method of a kind of graphene oxide composite material as claimed in claim 6, it is characterized in that the mass ratio of described natural graphite powder, SODIUMNITRATE and potassium permanganate is 2: 1: 6, the mass volume ratio of described natural graphite powder and the vitriol oil is 1g: 23mL.

9. the preparation method of a kind of graphene oxide composite material as claimed in claim 1, is characterized in that in step 2) in, the speed of described low-speed centrifugal is 400 ~ 3000rpm, and ultracentrifugal speed is 5000 ~ 20000rpm.

10. the preparation method of a kind of graphene oxide composite material as claimed in claim 1, it is characterized in that in step 2) in, described substep is centrifugal to be comprised: with 2000rpm low-speed centrifugal collecting precipitation 1 and supernatant 1 respectively, supernatant 1 is centrifugal with 6000rpm again, collecting precipitation 2 and supernatant 2 respectively, supernatant 2 is again with 10000rpm centrifugal collecting precipitation 3 and supernatant 3 respectively, supernatant 3 is again with 13000rpm centrifugal collecting precipitation 4 and supernatant 4 respectively, and wherein said precipitation 1, precipitation 2, precipitation 3 and precipitation 4 are the MA/GO of different size.