CN102965105A

CN102965105A - Graphene-CuInS2 quantum dot compound and preparation method thereof

Info

Publication number: CN102965105A
Application number: CN2012104723532A
Authority: CN
Inventors: 高锋; 王命泰; 岳文瑾
Original assignee: Institute of Plasma Physics of CAS
Current assignee: Institute of Plasma Physics of CAS
Priority date: 2012-11-21
Filing date: 2012-11-21
Publication date: 2013-03-13
Anticipated expiration: 2032-11-21
Also published as: CN102965105B

Abstract

The invention discloses a graphene-CuInS2 quantum dot compound and a preparation method of the compound, wherein environment-friendly ethanol is taken as solvent, and the compound formed by reduced-state graphene oxide and chalcopyrite CuInS2 quantum dots is synthesized by solvothermal reaction, wherein the CuInS2 quantum dots have the size of 2-5nm; and the CuInS2 quantum dots exist in two forms including being dispersed on a graphene sheet layer in a single layer and being gathered on the surface of the graphene sheet layer to form a three-dimensional aggregation. The graphene-CuInS2 quantum dot compound has good dispersing performance in organic solvent, the preparation method is simple and environment-friendly, and massive preparation can be easily realized, so that the compound and the method have important application value in the fields such as photoelectric material, photovoltaic material and organic-inorganic complex materials.

Description

A kind of Graphene-CuInS 2Quantum dot mixture and preparation method thereof

Technical field

The present invention relates to field of nanometer material technology, exactly is a kind of Graphene-CuInS ₂Quantum dot mixture and preparation method thereof.

Background technology

Graphene is a kind of Two-dimensional Carbon material, and it has unique character, for example high heat conductance (~ 5000 Wm ^-1K ^-1), high carrier mobility (~ 200000 cm ²V ^-1S ^-1), high-specific surface area (~ 2630 m ²g ^-1), high stability and good optical transmittance etc., have in fields such as catalysis, sensing, storage, biological medicine and photovoltaics important application prospect (Prog. Mater. Sci. 2011,56,1178-1271).In recent years, the mixture that is formed by Graphene and inorganic nano structure has caused people's concern, shows potential application prospect in fields such as energy transformation, energy storage and catalysis.For example, (the Angew. Chem. Int. Ed. 2010 such as Guo, 49,3014-3017) form superlattice film at conductive glass by alternating deposit graphene oxide and CdSe quantum dot nano film, as the complex light electrode of quantum dot sensitized solar cell (QDSSC); (Nanotechnology 2011 for Wang etc., 22,405401) take the reduction-state graphene oxide sheet as the lining base carries out etching with the hydrothermal method growing ZnO nanorod and to nanometer rod, synthesized Graphene-ZnO nano pipe array mixture, with its optoelectronic pole as the polymer-based carbon solar cell; (Nanoscale 2012,4,441-443) by the method at functionalization graphene oxide lamella absorption quantum dot, synthesized graphene oxide-CdSe quantum dot mixture, as the wide range response light electrode of QDSSC battery for Chen etc.; (J. Power Sources 2012,217 85-91) has synthesized graphene oxide-Fe with hydrothermal method to Sathish etc. ₃O ₄The nano particle magnetic composite, it can be used as high performance lithium ion battery anode material; (J. Power Sources 2012,217 184-192) has synthesized reduction-state graphene oxide-Mn with the microwave-assisted hydrothermal synthesis method to Liu etc. ₃O ₄Nano-complex obtains a kind of good super capacitor material; Chen etc. (ACS Nano, 2010,4,6425-6432) use in-situ hydrolysis TiCl ₄Method prepared the graphene oxide-TiO with visible light catalytic performance ₂Nano-complex.

CuInS ₂Have narrower band gap (1.5 eV) (Chem. Mater. 2003,15,3142-3147) and larger uptake factor large (α 10 ⁵Cm ^-1) (Cryst. Growth Des. 2007,7,1547-1552), be a kind of desirable solar cell material (J. Mater. Chem. 2006,16,1597-1602, Nano Lett. 2006,6,1218-1223).Among the present invention, we obtain a kind of Graphene and CuInS with graphene oxide lamella growth in situ quantum dot and in conjunction with follow-up reduction process ₂The mixture that quantum dot forms.

Summary of the invention

The purpose of this invention is to provide a kind of Graphene-CuInS ₂Quantum dot mixture and preparation method thereof.

The present invention is achieved by the following technical solutions:

A kind of Graphene-CuInS ₂Quantum dot mixture: described Graphene-CuInS ₂The quantum dot mixture is synthetic in autoclave by solvent-thermal method, by reduction-state graphene oxide and chalcopyrite CuInS ₂Quantum dot forms, CuInS ₂Quantum point grain diameter is 2-5 nm, CuInS ₂Quantum dot with Monolayer Dispersion on graphene sheet layer and form two kinds of forms of three-dimensional aggregate at the graphene sheet layer surface aggregation and have CuInS ₂The atomic ratio of Cu:In:S is 1:1.3:1.8 in the quantum dot.

A kind of Graphene-CuInS ₂The preparation method of quantum dot mixture: first graphene oxide is scattered in the ethanol, then with Cu (Ac) ₂H ₂O, In (Ac) ₃, octadecylamine and thiocarbamide join in the alcohol dispersion liquid of graphene oxide successively, in autoclave in 150-170 ℃ of lower reaction 4-8 hour, then 75-85 ℃ by hydrazine hydrate reduction, obtain Graphene-CuInS through centrifugation, washing and drying ₂The quantum dot mixture; Described graphene oxide and Cu (Ac) ₂H ₂The mass ratio of O is 1:1-4, Cu (Ac) ₂H ₂O, In (Ac) ₃, octadecylamine tensio-active agent and thiocarbamide mol ratio be 1:1:12:4.

Advantage of the present invention is: utilize the method for solvent thermal process growth in situ quantum dot to prepare Graphene-CuInS ₂The quantum dot mixture, CuInS ₂The quantum point grain diameter homogeneous; The preparation solvent for use is ethanolic soln, and environmental friendliness is pollution-free; The used equipment of the inventive method simple (mainly being autoclave and whizzer), easy and simple to handle realizes that easily the magnanimity of mixture is synthetic; The mixture that obtains has good dispersing property in organic solvent, will have important using value in fields such as photoelectric material, photovoltaic material, composite organic-inorganic materials.

Description of drawings

Fig. 1 is the characterization result of graphene oxide of the present invention (GO) and reduction-state graphene oxide (rGO); Wherein, (a) optical photograph of the TEM photo of GO, (b) aqueous dispersion (left side yellow is GO, and the right black is rGO), (c) XRD, (d) Raman spectrum.

Fig. 2 is Graphene-CuInS of the present invention ₂The XRD of quantum dot mixture and Raman Characterization; Wherein, (a) XRD, (b) Raman spectrum.

Fig. 3 is Graphene-CuInS of the present invention ₂The TEM(a of quantum dot mixture) and HRTEM(b, c) characterize; Wherein (b) and (c) correspond respectively to interval 2 and interval 1 in (a).

Fig. 4 is Graphene-CuInS of the present invention ₂The XPS of quantum dot mixture characterizes; Wherein, (a) full spectrum, (b) Cu2p spectrum, (c) In3d spectrum, (d) S2p compose.

Fig. 5 is Graphene-CuInS of the present invention ₂The dispersiveness (leave standstill 6 hour after take a picture) of quantum dot mixture in different organic solvents.

Embodiment

Embodiment 1: the preparation of graphene oxide and reduction-state graphene oxide.

With 0.5 gram graphite and 0.5 gram NaNO ₃Join in 250 milliliters the beaker, and place 0 ℃ frozen water to mix in beaker to bathe, then to the vitriol oil (95-98%) that wherein adds 23 milliliters, fully stirred 15 minutes, obtain the suspension of black; In this suspension, add 4 gram KMnO ₄, then under 35 ℃, stir and reacted 2 hours, obtain green suspension, then add 40 ml deionized water, under 90 ℃, stir and reacted 1 hour, obtain brown color suspension; At last, in brown color suspension, add 5 milliliters of H ₂O ₂After question response liquid is cooled to room temperature, carry out centrifugation (12000 rpm, 10 minutes) and deionized water wash, product obtains graphene oxide (GO) in 60 ℃ of lower vacuum-dryings 24 hours.

5 milligrams of graphene oxides are scattered in 60 ml deionized water, obtain yellow suspension, be warming up to 80 ^oAdd 5 mL hydrazine hydrates behind the C and left standstill 2 hours, obtain black suspension, carry out centrifugation (9000 rpm, 10 minutes) and deionized water wash, product obtains reduction-state graphene oxide (rGO) in 60 ℃ of lower vacuum-dryings 24 hours.

Sign before and after the graphene oxide reduction is seen accompanying drawing 1.Transmission electron microscope (TEM) has shown the laminated structure of graphene oxide; Optical photograph has shown be yellow after graphene oxide disperses in water, but its aqueous dispersions is black after the reduction; X-ray diffraction (XRD) has shown the generation of graphene oxide, and has different diffraction peaks before and after the reduction; Raman spectrum has shown the generation of graphene oxide, and has different D(1343 cm before and after the reduction ^-1) and G(1590 cm ^-1) p-ratio.

Embodiment 2: Graphene-CuInS ₂The preparation of quantum dot mixture

(2-1) preparation of graphene oxide: see embodiment 1.

(2-2) Graphene-CuInS ₂The preparation of quantum dot mixture:

Add 5 milligrams of graphene oxides in 50 milliliters of dehydrated alcohols, ultra-sonic dispersion 30 minutes obtains the brown color dispersion liquid, adds 10 milligrams of Cu (Ac) again ₂H ₂O, ultra-sonic dispersion 5 min, dispersion liquid becomes brown-green; In brown-green solution, add 14.6 milligrams of In (Ac) ₃And ultra-sonic dispersion 10 minutes, adding 161.7 milligrams of octadecylamines and ultra-sonic dispersion 20 minutes, it is blue that dispersion liquid becomes palm fibre, adds 15.2 milligrams of thiocarbamides again, and dispersion liquid becomes brownish black immediately, stirs 20 minutes.The black dispersion liquid is transferred to 80 milliliters to be contained in the teflon-lined autoclave, in 160 ^oReaction is 6 hours under the C condition; After the question response still naturally cools to room temperature, change reaction solution over to beaker, in water-bath, be heated to 80 ^oC adds 5 mL hydrazine hydrates and leaves standstill 2 hours with further redox graphene; After being cooled to room temperature, carry out centrifugation (9000 rpm, 10 minutes) and washing with alcohol, product obtains Graphene-CuInS in 60 ℃ of lower vacuum-dryings 24 hours ₂The quantum dot mixture.

(2-3) sign of product:

Mixture characterizes sees accompanying drawing 2-5.Powder X-ray RD test has shown that product is by reduction-state graphene oxide and chalcopyrite CuInS ₂(JCPDS #85-1575) forms; Raman spectrum has shown that D and the G p-ratio of Graphene reduces greatly in the mixture, and CuInS has been described ₂The graphene sheet layer surface imperfection there is good repair; TEM and high resolution TEM(HRTEM) show CuInS ₂The quantum dot size is 2-5 nm, CuInS ₂Quantum dot with Monolayer Dispersion on graphene sheet layer and form two kinds of forms of three-dimensional aggregate at the graphene sheet layer surface aggregation and exist; Photoelectron spectrum (XPS) the analysis showed that CuInS ₂The atomic ratio of Cu:In:S is 1:1.3:1.8 in the quantum dot; Optical photograph shows, Graphene-CuInS ₂The quantum dot mixture has preferably dispersion stabilization in organic solvent (such as ethanol, chloroform and chlorobenzene).

Claims

1. Graphene-CuInS ₂The quantum dot mixture is characterized in that: described Graphene-CuInS ₂The quantum dot mixture is synthetic in autoclave by solvent-thermal method, by reduction-state graphene oxide and chalcopyrite CuInS ₂Quantum dot forms, CuInS ₂Quantum point grain diameter is 2-5 nm, CuInS ₂Quantum dot with Monolayer Dispersion on graphene sheet layer and form two kinds of forms of three-dimensional aggregate at the graphene sheet layer surface aggregation and have CuInS ₂The atomic ratio of Cu:In:S is 1:1.3:1.8 in the quantum dot.

2. Graphene-CuInS ₂The preparation method of quantum dot mixture is characterized in that: first graphene oxide is scattered in the ethanol, then with Cu (Ac) ₂H ₂O, In (Ac) ₃, octadecylamine and thiocarbamide join in the alcohol dispersion liquid of graphene oxide successively, in autoclave in 150-170 ℃ of lower reaction 4-8 hour, then 75-85 ℃ by hydrazine hydrate reduction, obtain Graphene-CuInS through centrifugation, washing and drying ₂The quantum dot mixture; Described graphene oxide and Cu (Ac) ₂H ₂The mass ratio of O is 1:1-4, Cu (Ac) ₂H ₂O, In (Ac) ₃, octadecylamine tensio-active agent and thiocarbamide mol ratio be 1:1:12:4.