CN103305185A - Method for preparing reduced-oxidized graphene/Fe3O4/Ag nano composite wave-absorbing material - Google Patents

Abstract

The invention relates to a method for preparing a reduced-oxidized graphene/Fe3O4/Ag nano composite wave-absorbing material. The method comprises the following steps: preparing GO/Fe3O4 by using a simplified coprecipitation method, and preparing the RGO/Fe3O4/Ag ternary composite material by employing a wet chemical reducing method. The preparation method is simple and rapid, large-scale production can be realized, the prepared composite material is good in wave-absorbing performance, and different wave bands can be effectively absorbed by adjusting the ratio of RGO to Fe3O4 to Ag, the amount of the reducing agent and the thickness of the composite material.

Description

Redox graphene/Fe 3O 4The preparation method of the nano combined absorbing material of/Ag

Technical field

The invention belongs to the preparation method of tri compound microwave absorbing material, be specifically related to a kind of redox graphene/Fe ₃O ₄The preparation method of the nano combined absorbing material of/Ag.

Background technology

Ferrite has advantages of that wave absorbing efficiency is high, bandwidth, cost are low, is practical and the most frequently used the earliest radio-radar absorber, but because there are the shortcomings such as density is excessive, high-temperature behavior is poor in it, has limited its widespread use.In recent years, many domestic and international investigators attempt obtaining by ferrite and carbon-based material are compound that density is little, the absorbing material of excellent performance.Graphene is the carbonaceous material with single layer structure of the tightly packed formation of carbon atom, excellent performance, and its two-dimensional sheet structure is conducive to electromagnetic absorption, adopts Fe ₃O ₄With the common grapheme modified matrix of Ag, can obtain the composite wave-suction material that quality is light, inhale the ripple bandwidth.

Document " " Materials Letters " 91 (2013) pp.209 – 212, " discloses a kind of employing high temperature reduction and has prepared RGO-Fe ₃O ₄The method of matrix material.Concrete grammar is with Fe ³⁺And redox graphene (RGO) ultrasonic dissolution adds two kinds of Surfactant SDSs (SDS) and sodium dodecyl benzenylsulfonate (SDBS) in ethylene glycol, and mixture is at 60 ℃ of lower 1h that stir; In mixing solutions, add the NaOH aqueous solution, continue to stir 2h; It is 7 that the mixture that obtains is washed till pH with deionized water, puts into 60 ℃ of dry 12h of loft drier; The powder that obtains is put in the tube furnace, slowly is heated to 450 ℃ under argon shield, keeps cooling the temperature to 350 ℃ behind the 2h, passes into hydrogen and argon gas gas mixture, keeps 30min, and the powder that obtains is RGO-Fe ₃O ₄Matrix material.The test of process electromagnetic performance when this thickness of composite material is 2mm, is lower than-10dB at the 14.3-18GHz reflection loss, reaches maximum absorption and be-22.2dB when 17.3GHz.

The described composite manufacture method of document mainly has the following disadvantages: need to add surfactant SDS and SDBS; need to use nitrogen to protect; need to use hydrogen and argon gas mixed gas to reduce; need hot environment, preparation time long (only recombination process just reaches 26h), preparation process is complicated; be difficult to realize scale production; the matrix material of preparation is inhaled ripple and is mainly appeared at high frequency, and less to absorption of electromagnetic wave, poor performance.

Summary of the invention

The technical problem that solves

For fear of the deficiencies in the prior art part, the present invention proposes a kind of redox graphene/Fe ₃O ₄The preparation method of the nano combined absorbing material of/Ag overcomes the standby RGO-Fe of high temperature reduction legal system ₃O ₄The deficiency that the matrix material preparation condition is harsh, process is complicated, the time is long, be difficult to scale operation, poor performance.

Technical scheme

A kind of redox graphene/Fe ₃O ₄The preparation method of the nano combined absorbing material of/Ag is characterized in that step is as follows:

Step 1: compound concentration is the GO graphite oxide aqueous solution of 0.2-2mg/ml, the NaOH aqueous solution of preparation 0.5-5mol/L;

Step 2: according to mass ratio GO: FeCl ₂4H ₂O: FeCl ₃6H ₂O=1: x: (0.8-1.8) x, wherein x=(0.1-10) takes by weighing FeCl ₂4H ₂O and FeCl ₃6H ₂Then O joins in the GO graphite oxide aqueous solution, and after heating in water bath kept 10min to 30-50 ℃, dripping NaOH aqueous solution adjusting pH of mixed was 9-12, and above-mentioned mixed solution forms black precipitate at 60-80 ℃ of lower heating 2-3h;

Step 3: adopt the centrifuge washing mode after deionized water wash 3-5 time, to be dissolved in the 100-400ml deionized water black precipitate that obtains, according to mass ratio GO: AgNO ₃=1:(0.1-5), then with AgNO ₃Stir 20min after mixing and obtain mixed solution; Again according to mass ratio GO: NaBH ₄=1: (5-30), take by weighing NaBH ₄Be dissolved in the 50-200ml water, and splash in the mixed solution, at 20-100 ℃ of lower heating 0.5-2h;

Step 4: the product that step 3 is obtained uses deionized water and dehydrated alcohol alternately to wash to pH=7, utilizes magnetic resolution, the black precipitate that centrifugal or suction filtration obtains, and the black powder that adopts again 40-80 ℃ of vacuum-drying to obtain is redox graphene/Fe ₃O ₄The nano combined absorbing material of/Ag.

Beneficial effect

A kind of redox graphene/Fe that the present invention proposes ₃O ₄The preparation method of the nano combined absorbing material of/Ag adopts the coprecipitation method of simplifying to make GO/Fe ₃O ₄, then adopt the wet-chemical reduction method to make RGO/Fe ₃O ₄/ Ag trielement composite material, the preparation method is simple, quick, can realize scale production, and the Radar Absorbing Properties of Composites that makes is good, can be by regulating RGO, Fe ₃O ₄Realize effective absorption of different-waveband with the thickness of the consumption of the ratio of Ag, reductive agent and matrix material.

The present invention has following beneficial effect:

1, the present invention has synthesized RGO/Fe by coprecipitation method and the wet chemical method of simplifying ₃O ₄/ Ag trielement composite material need not to add any tensio-active agent, need not to adopt the protection of inert gas such as nitrogen, need not heat, and preparation condition is easily realized;

2, preparation process of the present invention is simple, and is consuming time shorter, and recombination process only needs 6-12h, conveniently accomplishes scale production;

3, the RGO/Fe of the present invention's preparation ₃O ₄/ Ag trielement composite material wave absorbing efficiency is high, suction ripple bandwidth, the maximum Bo Keda-58dB that inhales, effectively absorb (less than-10dB) can reach more than the 4GHz, and can pass through to regulate RGO, Fe ₃O ₄Realizing effective absorption of different-waveband with the thickness of the ratio of Ag and matrix material, is a kind of absorbing material of excellent performance.

Description of drawings

Fig. 1 is the XRD spectra of three kinds of products preparing among the embodiment of the invention 1-3;

Fig. 2 is the product RGO/Fe of preparation among the embodiment 2 ₃O ₄The TEM figure of/Ag matrix material;

Fig. 3 is the product RGO/Fe of preparation among the embodiment 2 ₃O ₄The HRTEM figure of/Ag matrix material;

Fig. 4 is the product RGO/Fe of preparation among the embodiment 1 ₃O ₄The absorbing property figure of/Ag matrix material;

Fig. 5 is the product RGO/Fe of preparation among the embodiment 2 ₃O ₄The absorbing property figure of/Ag matrix material;

Fig. 6 is the product RGO/Fe of preparation among the embodiment 3 ₃O ₄The absorbing property figure of/Ag matrix material.

Embodiment

Now in conjunction with the embodiments, the invention will be further described for accompanying drawing:

Embodiment 1

1, compound concentration is the GO aqueous solution of 0.5mg/ml, and the NaOH aqueous solution of preparation 1mol/L is for subsequent use;

2, according to mass ratio GO:FeCl ₂4H ₂O:FeCl ₃6H ₂O=1:2.58:3.52 takes by weighing 258mg FeCl ₂4H ₂O and 352mg FeCl ₃6H ₂O joins in the 200ml GO aqueous solution, heating in water bath to 50 ℃ maintenance 10min, and dripping NaOH solution adjusting pH of mixed is 11, mixed solution is at 70 ℃ of lower heating 3h;

3, adopt the centrifuge washing mode after deionized water wash 3-5 time, to be dissolved in the 200ml deionized water black precipitate that obtains, according to mass ratio GO: AgNO ₃=1:0.79 takes by weighing 79mg AgNO ₃Be dissolved in above-mentioned mixed solution, stir 20min, according to mass ratio GO: NaBH ₄Take by weighing 1g NaBH at=1: 10 ₄Be dissolved in the 50ml water, splash in the mixed solution, 80 ℃ of lower heating 2h;

4, use deionized water and dehydrated alcohol alternately to wash to pH=7, utilize magnetic resolution to obtain black precipitate, adopt 60 ℃ of vacuum-dryings, the black powder that obtains is RGO/Fe ₃O ₄/ Ag trielement composite material.

The XRD spectra of embodiment 1 product is seen Fig. 1.Be that 1:1 evenly mix with solid paraffin according to mass ratio with the powdered product among the embodiment 1, in particular manufacturing craft, be pressed into the approximately coaxial sample of 3mm of external diameter 7.00mm, internal diameter 3.04mm, thickness, be that the HP8720ES vector network analyzer is tested its absorbing property with model, test frequency is 2-18GHz.Its absorbing property as shown in Figure 4, the matching thickness of this sample is 1.6mm, reaches maximum absorption and be-47.1dB when 16.7GHz, inhales ripple at 14.5-18GHz to reach-below the 10dB, effectively absorbing width is 3.5GHz.

Embodiment 2

1, compound concentration is the GO aqueous solution of 0.5mg/ml, and the NaOH aqueous solution of preparation 1mol/L is for subsequent use;

2, according to mass ratio GO:FeCl ₂4H ₂O:FeCl ₃6H ₂O=1:2.58:3.52 takes by weighing 258mg FeCl ₂4H ₂O and 352mg FeCl ₃6H ₂O joins in the 200ml GO aqueous solution, heating in water bath to 50 ℃ maintenance 10min, and dripping NaOH solution adjusting pH of mixed is 11, mixed solution is at 70 ℃ of lower heating 3h;

3, adopt the centrifuge washing mode after deionized water wash 3-5 time, to be dissolved in the 200ml deionized water black precipitate that obtains, according to mass ratio GO: AgNO ₃=1:1.58 takes by weighing 158mg AgNO ₃Be dissolved in above-mentioned mixed solution, stir 20min, according to mass ratio GO: NaBH ₄Take by weighing 1g NaBH at=1: 10 ₄Be dissolved in the 50ml water, splash in the mixed solution, 80 ℃ of lower heating 2h;

4, use deionized water and dehydrated alcohol alternately to wash to pH=7, utilize magnetic resolution to obtain black precipitate, adopt 60 ℃ of vacuum-dryings, the black powder that obtains is RGO/Fe ₃O ₄/ Ag trielement composite material.

The XRD spectra of embodiment 2 products is seen Fig. 1.Be that 1:1 evenly mix with solid paraffin according to mass ratio with the powdered product among the embodiment 2, in particular manufacturing craft, be pressed into the approximately coaxial sample of 3mm of external diameter 7.00mm, internal diameter 3.04mm, thickness, be that the HP8720ES vector network analyzer is tested its absorbing property with model, test frequency is 2-18GHz.Its absorbing property as shown in Figure 5, the matching thickness of this sample is 2.6mm, reaches maximum absorption and be-58.1dB when 9.0GHz, inhales ripple at 7.8-10.6GHz to reach-below the 10dB, effectively absorbing width is 2.8GHz; Thickness effectively absorbs width and reaches maximum when 2.0mm, absorb at 10.7-14.7GHz to reach-below the 10dB, effectively absorbing width is 4.0GHz.

The TEM figure of embodiment 2 products and HRTEM figure are as shown in Figures 2 and 3.As shown in Figure 2, Fe ₃O ₄Load on equably the surface of RGO with Ag, particle diameter is all less than 30nm; The Fe that can clearly be found out by Fig. 3 ₃O ₄Nano particle, Ag nano particle load on the graphene nanometer sheet, have illustrated that the present invention has obtained stable RGO/Fe ₃O ₄/ Ag trielement composite material.

Embodiment 3

1, compound concentration is the GO aqueous solution of 0.5mg/ml, and the NaOH aqueous solution of preparation 1mol/L is for subsequent use;

2, according to mass ratio GO:FeCl ₂4H ₂O:FeCl ₃6H ₂O=1:2.58:3.52 takes by weighing 258mg FeCl ₂4H ₂O and 352mg FeCl ₃6H ₂O joins in the 200ml GO aqueous solution, heating in water bath to 50 ℃ maintenance 10min, and dripping NaOH solution adjusting pH of mixed is 11, mixed solution is at 70 ℃ of lower heating 3h;

3, adopt the centrifuge washing mode after deionized water wash 3-5 time, to be dissolved in the 200ml deionized water black precipitate that obtains, according to mass ratio GO: AgNO ₃=1:3.15 takes by weighing 315mg AgNO ₃Be dissolved in above-mentioned mixed solution, stir 20min, according to mass ratio GO: NaBH ₄Take by weighing 1g NaBH at=1: 10 ₄Be dissolved in the 50ml water, splash in the mixed solution, 80 ℃ of lower heating 2h;

4, use deionized water and dehydrated alcohol alternately to wash to pH=7, utilize magnetic resolution to obtain black precipitate, adopt 60 ℃ of vacuum-dryings, the black powder that obtains is RGO/Fe ₃O ₄/ Ag trielement composite material.

The XRD spectra of embodiment 3 products is seen Fig. 1.Be that 1:1 evenly mix with solid paraffin according to mass ratio with the powdered product among the embodiment 6, in particular manufacturing craft, be pressed into the approximately coaxial sample of 3mm of external diameter 7.00mm, internal diameter 3.04mm, thickness, be that the HP8720ES vector network analyzer is tested its absorbing property with model, test frequency is 2-18GHz.Its absorbing property as shown in Figure 6, the matching thickness of this sample is 4.1mm, reaches maximum absorption and be-39.0dB when 6.6GHz, inhales ripple at 5.7-7.2GHz to reach-below the 10dB, effectively absorbing width is 1.5GHz; Thickness effectively absorbs width and reaches maximum when 2.0mm, absorb at 12.4-14.6GHz to reach-below the 10dB, effectively absorbing width is 2.4GHz.

Claims (1)

1. redox graphene/Fe ₃O ₄The preparation method of the nano combined absorbing material of/Ag is characterized in that step is as follows:

Step 1: compound concentration is the GO graphite oxide aqueous solution of 0.2-2mg/ml, the NaOH aqueous solution of preparation 0.5-5mol/L;

Step 2: according to mass ratio GO: FeCl ₂4H ₂O: FeCl ₃6H ₂O=1: x: (0.8-1.8) x, wherein x=(0.1-10) takes by weighing FeCl ₂4H ₂O and FeCl ₃6H ₂Then O joins in the GO graphite oxide aqueous solution, and after heating in water bath kept 10min to 30-50 ℃, dripping NaOH aqueous solution adjusting pH of mixed was 9-12, and above-mentioned mixed solution forms black precipitate at 60-80 ℃ of lower heating 2-3h;

Step 3: adopt the centrifuge washing mode after deionized water wash 3-5 time, to be dissolved in the 100-400ml deionized water black precipitate that obtains, according to mass ratio GO: AgNO ₃=1:(0.1-5), then with AgNO ₃Stir 20min after mixing and obtain mixed solution; Again according to mass ratio GO: NaBH ₄=1: (5-30), take by weighing NaBH ₄Be dissolved in the 50-200ml water, and splash in the mixed solution, at 20-100 ℃ of lower heating 0.5-2h;

Step 4: the product that step 3 is obtained uses deionized water and dehydrated alcohol alternately to wash to pH=7, utilizes magnetic resolution, the black precipitate that centrifugal or suction filtration obtains, and the black powder that adopts again 40-80 ℃ of vacuum-drying to obtain is redox graphene/Fe ₃O ₄The nano combined absorbing material of/Ag.

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