Graphene oxide / metal composite material and preparation method thereof

Abstract

The application belongs to the technical field of graphene oxide and provides a graphene oxide / metal composite material and a preparation method thereof, which comprises the following steps: S1, preparing graphene oxide by a pre-oxidation method; S2, synthesizing tetraamino metal porphyrin; and S3, doping tetraamino metal porphyrin and nano metal oxide into graphene oxide to prepare a composite material.The graphene oxide / metal composite material and the preparation method thereof can form an n-type semiconductor by doping tetraamino zinc porphyrin and nano zinc oxide into graphene oxide in a specific proportion, and the porous structure after nitrogen doping can provide more lithium storage sites, so that the conductivity of graphene oxide is greatly improved, and the structural damage caused by volume change of metal oxide during charging and discharging can be relieved, and the cycle stability is higher.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of graphene oxide, in particular to a graphene oxide / metal composite material and a preparation method thereof. BACKGROUND

[0002] Graphene oxide is an oxide of graphene, which is brownish yellow in color. Common products on the market are powdery, flaky and solution-like. After oxidation, the number of oxygen-containing functional groups on graphene oxide increases, making it more active than graphene. The properties of graphene oxide can be improved through various reactions with oxygen-containing functional groups.

[0003] Graphene oxide is widely used in the lithium battery industry due to its high specific surface area, excellent electrical conductivity and high chemical stability. Existing graphene oxide modified materials are mostly single composites of graphene oxide and metal to improve the performance of graphene oxide. However, this single composite improvement method has limited performance improvement and cannot meet the needs of technological development. Therefore, there is an urgent need to find a new graphene oxide composite material. SUMMARY

[0004] The present application aims to provide a graphene oxide / metal composite material and a preparation method thereof to solve the problem that existing graphene oxide modified materials are mostly single composites of graphene oxide and metal to improve the performance of graphene oxide, but this single composite improvement method has limited performance improvement and cannot meet the needs of technological development.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solution: a graphene oxide / metal composite material and a preparation method thereof, comprising the following steps:

[0006] S1, preparing graphene oxide by pre-oxidation method:

[0007] Dissolve potassium persulfate and phosphorus pentoxide in concentrated sulfuric acid, add graphite powder to prepare pre-oxidized graphite; add the pre-oxidized graphite to concentrated sulfuric acid, then add potassium permanganate and stir for a period of time, add hydrogen peroxide and stand overnight, then perform post-treatment to obtain graphene oxide; ultrasonically treat the graphene oxide to obtain graphene oxide;

[0008] S2, synthesizing tetraamino metal porphyrin:

[0009] Synthesize tetranitro porphyrin from p-nitrobenzaldehyde and pyrrole, then reduce it with tin dichloride to obtain tetraamino porphyrin, and then react with metal acetate to obtain tetraamino metal porphyrin, the structure formula is as follows:

[0010] S3, graphene oxide doped tetraamino metalloporphyrin and nano metal oxide, to prepare a composite material:

[0011] The graphene oxide is added into an ultrasonic device, and deionized water is added for dispersion and ultrasonic treatment. Then, an appropriate amount of tetraamino metalloporphyrin and nano metal oxide are added, and a small amount of deionized water is added for continuous ultrasonic stirring. The liquid is freeze-dried, and then placed in a tube furnace for calcination under nitrogen protection and constant temperature, to obtain a graphene oxide / metal composite material.

[0012] Preferably, the specific steps for preparing graphene oxide by the pre-oxidation method are as follows:

[0013] S11, a certain amount of potassium persulfate and diphosphorus pentoxide are dissolved in an appropriate amount of concentrated sulfuric acid, and then a certain amount of graphite powder is added. The mixture is stirred at a temperature of 80-90°C for 5-6 hours, cooled to room temperature, and then water is added. After standing overnight, the mixture is suction filtered, washed with warm deionized water, and dried to obtain pre-oxidized graphite;

[0014] S12, the pre-oxidized graphite powder is added to an appropriate amount of concentrated sulfuric acid under ice water bath conditions, and then an appropriate amount of potassium permanganate is added. The mixture is stirred and reacted at a temperature of 35-45°C for 2-3 hours, and then diluted with water. The mixture is continuously stirred for 1-2 hours, and then an appropriate amount of 20-30% hydrogen peroxide solution is added. After standing overnight, the mixture is suction filtered, washed with a 10-20% hydrochloric acid solution, dissolved in deionized water, and prepared into a 0.5-1% suspension. The mixture is left to stand at room temperature for one week, filtered, washed with warm deionized water, dried, and ground to obtain oxidized graphite;

[0015] S13, the oxidized graphite is dispersed in deionized water, and ultrasonic oscillation is performed for 1-2 hours. Then, high-speed centrifugation is performed, and the upper clear liquid is collected and dried to obtain graphene oxide.

[0016] Preferably, the synthesis steps of the tetraamino metalloporphyrin are as follows:

[0017] S21, para-nitrobenzaldehyde and pyrrole are weighed according to a molar ratio of 1:4, and a small amount of propionic acid and glacial acetic acid are added as catalysts. The mixture is refluxed at a temperature of 135-140°C for 1-2 hours to obtain tetranitro porphyrin. After the reaction is completed, the mixture is left to stand overnight, suction filtered, washed with deionized water, dried, and then refluxed in pyridine for 1-1.5 hours. The mixture is left to stand overnight, suction filtered, washed with acetone, dried, and then recrystallized with chloroform to obtain tetranitro porphyrin;

[0018] S22, stirring the reaction of the four nitro porphyrin with concentrated hydrochloric acid as solvent, stannous chloride as reducing agent, room temperature for 2.5-3h, heating to 70-80℃, continue to react for 0.5-1h, stand overnight, filter, dissolve the filter cake in deionized water, adjust the pH to neutral, filter, use chloroform as eluent, perform soxhlet extraction, then rotary evaporation, recrystallize with diethyl ether, to obtain tetraamino porphyrin;

[0019] S23, refluxing the reaction of tetraamino porphyrin and metal acetate in a mixture of methanol and DMF for 18-24h, then washing with deionized water, collecting the organic phase, concentrating, then recrystallizing with methanol to obtain tetraamino metal porphyrin.

[0020] Preferably, the mass ratio of graphene oxide, tetraamino metal porphyrin and nano metal oxide in S3 is (300-360):(1-10):(100-180).

[0021] Preferably, the tetraamino metal porphyrin is one of tetraamino zinc porphyrin, tetraamino cobalt porphyrin or tetraamino copper porphyrin; and the nano metal oxide is one of nano zinc oxide, nano ferroferric oxide or nano cobalt oxide.

[0022] Preferably, the ultrasonic device in S3 comprises a support, the support is provided in a door type, a container is arranged at the middle part of the support, a cover plate is arranged at the top of the container, supports are symmetrically arranged between the bottom of the container and the side walls of the support, an ultrasonic generator is arranged in the supports, a motor is arranged at the top of the support, a rotating shaft is arranged at the output end of the motor, the rotating shaft penetrates through the cover plate and extends into the container, a stirring rod is arranged at the side wall of the rotating shaft in the container, and a discharge pipe is arranged at the bottom of the container.

[0023] Preferably, a clamping groove is arranged at the top of the container, and a clamping block is arranged at the bottom surface of the cover plate, the clamping block and the clamping groove are connected in a matched mode.

[0024] The present application has at least the following advantages:

[0025] The present application provides a kind of graphene oxide / metal composite material and preparation method thereof, by doping tetraamino zinc porphyrin and nano zinc oxide in graphene oxide in specific proportion, the composite material prepared, form n-type semiconductor, porous structure after nitrogen doping can provide more lithium storage sites, so as to greatly improve the conductivity of graphene oxide, and, can relieve the structural damage caused by volume change of metal oxide in charge and discharge process, with higher cycle stability. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is the synthesis route map of tetraamino metal porphyrin in the present application;

[0027] Figure 2 Figure 1 is a schematic diagram of the structure of the ultrasonic device in the present application.

[0028] In the figure: 1, support; 2, container; 3, support; 4, ultrasonic generator; 5, cover plate; 6, motor; 7, rotating shaft; 8, stirring rod. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0030] Embodiment 1

[0031] A kind of graphene oxide / metal composite material and its preparation method, comprising the following steps:

[0032] S1, graphene oxide is prepared by pre-oxidation method:

[0033] Dissolve potassium persulfate and diphosphorus pentoxide in concentrated sulfuric acid, dissolve in concentrated sulfuric acid, add graphite powder, prepare pre-oxidized graphite; add the pre-oxidized graphite to concentrated sulfuric acid, then add potassium permanganate and stir for a period of time, then add hydrogen peroxide and stand overnight, after post-processing, obtain the graphene oxide; ultrasonic treatment is carried out on the graphene oxide to obtain graphene oxide;

[0034] The specific steps are as follows:

[0035] S11, a certain amount of potassium persulfate and diphosphorus pentoxide are dissolved in an appropriate amount of concentrated sulfuric acid, then a certain amount of graphite powder is added, stirred at 80℃ for 5h, cooled to room temperature, then water is added, and the mixture is left to stand overnight, then filtered, washed with warm deionized water, and dried to obtain pre-oxidized graphite;

[0036] S12, under ice water bath condition, the pre-oxidized graphite powder is added to an appropriate amount of concentrated sulfuric acid, then an appropriate amount of potassium permanganate is added, stirred at 35℃ for 2h, then diluted with water, continue to stir for 1h, then add an appropriate amount of hydrogen peroxide with a mass fraction of 20%, stand overnight, filter, wash with a hydrochloric acid solution with a mass fraction of 10%, then dissolve in deionized water, configure a suspension with a mass fraction of 0.5%, stand at room temperature for a week, filter, wash with warm deionized water, dry, grind, and obtain the graphene oxide;

[0037] S13, the graphene oxide is dispersed in deionized water, ultrasonic oscillation is carried out for 1h, then high-speed centrifugation is carried out, the upper clear liquid is collected, and dried to obtain graphene oxide.

[0038] S2, synthesis of tetraamino zinc porphyrin:

[0039] Tetranitro porphyrin is prepared by using p-nitrobenzaldehyde and pyrrole as raw materials, then reduced by tin dichloride to obtain tetraamino porphyrin, and then reacted with metal acetate to obtain tetraamino zinc porphyrin, and the structural formula is as follows:

[0040]

[0041] The synthesis steps of tetraamino zinc porphyrin are as follows:

[0042] S21, p-nitrobenzaldehyde and pyrrole are weighed according to a molar ratio of 1:4, nitrobenzene is used as a solvent, a small amount of propionic acid and glacial acetic acid are added as catalysts, and tetranitro porphyrin is prepared by refluxing at 135℃ for 1h. After the reaction is completed, it is left overnight, filtered, washed with deionized water, dried, and then refluxed in pyridine for 1h, left overnight, filtered, washed with acetone, and dried. Then, tetranitro porphyrin is obtained by recrystallization with chloroform;

[0043] S22, tetranitro porphyrin is dissolved in concentrated hydrochloric acid as a solvent, and stannous chloride is used as a reducing agent. After stirring at room temperature for 2.5h, the temperature is increased to 70℃, and the reaction is continued for 0.5h. After standing overnight, the filter cake is dissolved in deionized water, the pH is adjusted to neutral, and then Soxhlet extraction is performed with chloroform as the eluent. Then, tetraamino porphyrin is obtained by rotary evaporation, recrystallization with ether, and drying.

[0044] S23, tetraamino porphyrin is reacted with zinc acetate in a mixture of methanol and DMF to obtain tetraamino zinc porphyrin by refluxing for 18h, washing with deionized water, collecting the organic phase, concentrating, and recrystallizing with methanol.

[0045] S3, graphene oxide doped with tetraamino zinc porphyrin and nano zinc oxide to prepare a composite material:

[0046] Graphene oxide is added to an ultrasonic device and dispersed in deionized water for 0.5h. Then, a proper amount of tetraamino zinc porphyrin and nano zinc oxide are added, and the mass ratio of graphene oxide, tetraamino zinc porphyrin and nano zinc oxide is 300:1:100. A small amount of deionized water is added, and the stirring is continued for 2h. Then, the liquid is freeze-dried and placed in a tube furnace for calcination at 600℃ for 2h under nitrogen protection to obtain a graphene oxide / metal composite material.

[0047] Example 2

[0048] A graphene oxide / metal composite material and a preparation method thereof, comprising the following steps:

[0049] S1, preparation of graphene oxide by pre-oxidation method:

[0050] Dissolve potassium persulfate and phosphorus pentoxide in concentrated sulfuric acid, dissolve in concentrated sulfuric acid, add graphite powder, prepare pre-oxidized graphite; add the pre-oxidized graphite to concentrated sulfuric acid, then add potassium permanganate and stir for a period of time, then add hydrogen peroxide and stand overnight, and after post-processing, obtain the oxidized graphite; ultrasonic treatment of the oxidized graphite to obtain graphene oxide;

[0051] The specific steps are as follows:

[0052] S11, a certain amount of potassium persulfate and phosphorus pentoxide are dissolved in an appropriate amount of concentrated sulfuric acid, then a certain amount of graphite powder is added, stirred at 85℃ for 5.5h, cooled to room temperature, then water is added and left to stand overnight, filtered, washed with warm deionized water, and dried to obtain pre-oxidized graphite;

[0053] S12, under ice water bath conditions, the pre-oxidized graphite powder is added to an appropriate amount of concentrated sulfuric acid, then an appropriate amount of potassium permanganate is added, stirred at 40℃ for 2.5h, then diluted with water, continue to stir for 1.5h, then add an appropriate amount of hydrogen peroxide with a mass fraction of 25%, stand overnight, filter, wash with a hydrochloric acid solution with a mass fraction of 15%, then dissolve in deionized water, configure a suspension with a mass fraction of 0.8%, stand at room temperature for a week, filter, wash with warm deionized water, dry, grind, and obtain the oxidized graphite;

[0054] S13, the oxidized graphite is dispersed in deionized water, ultrasonic oscillation for 1.75h, then high-speed centrifugation is performed, the upper clear liquid is collected, and dried to obtain graphene oxide.

[0055] S2, synthesis of tetraamino iron porphyrin:

[0056] Tetranitro porphyrin is prepared from p-nitrobenzaldehyde and pyrrole, then reduced by tin dichloride to obtain tetraamino porphyrin, and then reacted with metal acetate to obtain tetraamino iron porphyrin, and the structural formula is as follows:

[0057]

[0058] The synthesis steps of tetraamino iron porphyrin are as follows:

[0059] S21, according to the molar ratio of 1:4, weigh p-nitrobenzaldehyde and pyrrole, take nitrobenzene as the solvent, add a small amount of propionic acid and glacial acetic acid as catalyst, reflux at 138℃ for 1.5h to obtain tetranitro porphyrin, after the reaction is completed, stand overnight, filter, wash with deionized water, dry, then reflux in pyridine for 1.2h, stand overnight, filter, wash with acetone, dry, then recrystallize with chloroform to obtain tetranitro porphyrin;

[0060] S22, four nitro porphyrin is dissolved in concentrated hydrochloric acid as a solvent, stannous chloride as a reducing agent, stirring at room temperature for 2.7h, then heated to 75℃, continue to react for 0.75h, stand overnight, filter, dissolve the filter cake in deionized water, adjust the pH to neutral, filter, use chloroform as eluent, Soxhlet extraction, then rotary evaporation, recrystallized with diethyl ether, to obtain tetraamino porphyrin;

[0061] S23, tetraamino porphyrin and iron acetate in methanol and DMF mixture, reflux for 20h, then washed with deionized water, collect the organic phase, concentrated, then recrystallized with methanol to obtain tetraamino iron porphyrin.

[0062] S3, graphene oxide doped tetraamino iron porphyrin and nano four iron oxide, to prepare composite material:

[0063] Take graphene oxide into the ultrasonic device, add deionized water, disperse, ultrasonic 0.75h, then add appropriate amount of tetraamino iron porphyrin and nano four iron oxide, the mass ratio of graphene oxide, tetraamino iron porphyrin and nano four iron oxide is 320:5:160, add a small amount of deionized water, continue to ultrasonic stirring for 2.5h, freeze drying the liquid, then put it in the tube furnace, under nitrogen protection, keep 750℃ calcination for 2.5h, get graphene oxide / metal iron composite material.

[0064] Example 3

[0065] A kind of graphene oxide / metal composite material and its preparation method, comprising the following steps:

[0066] S1, preparation of graphene oxide by pre-oxidation method:

[0067] Dissolve potassium persulfate and phosphorus pentoxide in concentrated sulfuric acid, dissolve in concentrated sulfuric acid, add graphite powder, prepare pre-oxidized graphite; add the pre-oxidized graphite to concentrated sulfuric acid, then add potassium permanganate after stirring for a period of time, add hydrogen peroxide and stand overnight, after treatment, get the graphite oxide; ultrasonic treatment of graphite oxide to obtain graphene oxide;

[0068] The specific steps are as follows:

[0069] S11, a certain amount of potassium persulfate and phosphorus pentoxide are dissolved in a certain amount of concentrated sulfuric acid, then a certain amount of graphite powder is added, stirring at 90℃ for 6h, cooling to room temperature, then adding water, standing overnight, filter, washing with warm deionized water, drying, to obtain pre-oxidized graphite;

[0070] S12, under the condition of ice water bath, the pre-oxidized graphite powder is added into appropriate amount of concentrated sulfuric acid, and then appropriate amount of potassium permanganate is added, and the reaction is stirred at 45 DEG C for 3h, and then water is added for dilution, and the stirring is continued for 2h, and then appropriate amount of 30% mass fraction hydrogen peroxide is added, and it is left overnight, and then it is filtered, and washed with 20% mass fraction hydrochloric acid solution, and then it is dissolved in deionized water, and a 1% mass fraction suspension is configured, and it is left at room temperature for one week, and then it is filtered, and washed with warm deionized water, and dried, and ground, and then the oxidized graphite is prepared;

[0071] S13, the oxidized graphite is dispersed in deionized water, and ultrasonic oscillation is carried out for 2h, and then high-speed centrifugation is carried out, and the supernatant is collected, and dried, and then the oxidized graphene is obtained.

[0072] S2, synthesis of tetraamino cobalt porphyrin:

[0073] Tetranitro porphyrin is prepared by using p-nitrobenzaldehyde and pyrrole as raw materials, and then reduced by using tin dichloride to prepare tetraamino porphyrin, and then reacted with metal acetate to prepare tetraamino cobalt porphyrin, and the structural formula is as follows:

[0074] The synthesis steps of tetraamino cobalt porphyrin are as follows:

[0075] S21, p-nitrobenzaldehyde and pyrrole are weighed according to the molar ratio of 1:4, and then nitrobenzene is used as a solvent, and a small amount of propionic acid and glacial acetic acid are added as catalysts, and then refluxed at 140 DEG C for 2h to prepare tetranitro porphyrin, and after the reaction is completed, it is left overnight, and then filtered, and washed with deionized water, and dried, and then pyridine is used as a solvent, and refluxed for 1.5h, and then left overnight, and then filtered, and washed with acetone, and dried, and then recrystallized with chloroform to obtain tetranitro porphyrin;

[0076] S22, tetranitro porphyrin is dissolved in concentrated hydrochloric acid as a solvent, and stannous chloride is used as a reducing agent, and then stirred at room temperature for 3h, and then heated to 80 DEG C for 1h, and then left overnight, and then filtered, and then the filter cake is dissolved in deionized water, and the pH is adjusted to neutral, and then filtered, and then Soxhlet extraction is carried out with chloroform as an eluent, and then concentrated by rotary evaporation, and then recrystallized with diethyl ether to obtain tetraamino porphyrin;

[0077] S23, tetraamino porphyrin and cobalt acetate are refluxed in a mixture of methanol and DMF for 24h, and then washed with deionized water, and then the organic phase is collected and concentrated, and then recrystallized with methanol to obtain tetraamino cobalt porphyrin.

[0078] S3, graphene oxide doped with tetraamino cobalt porphyrin and nano cobalt oxide is prepared to prepare a composite material:

[0079] The graphene oxide is taken into an ultrasonic device, and deionized water is added for dispersion, ultrasonic treatment for 1h, and then a proper amount of tetraamino cobalt porphyrin and nano cobalt oxide is added, the mass ratio of graphene oxide, tetraamino cobalt porphyrin and nano cobalt oxide is 360:10:180, a small amount of deionized water is added, and ultrasonic stirring is continued for 3h, the liquid is freeze-dried, and then is placed in a tube furnace, calcined at 800 DEG C for 3h under nitrogen protection, to obtain a graphene oxide / metallic cobalt composite material.

[0080] The ultrasonic device involved in the above embodiments 1-3 comprises a support 1, the support 1 is provided in a door type, a container 2 is arranged at the middle part of the support 1, a cover plate 5 is arranged at the top of the container 2, a support 3 is symmetrically arranged between the bottom of the container 2 and the side wall of the support 1, specifically, the side wall of the support 3 is fixedly connected with the side wall of the support 1, the top surface of the support 3 is fixedly connected with the bottom surface of the container 2, an ultrasonic generator 4 is arranged in the inside of the support 3, an electric motor 6 is arranged at the top of the support 1, specifically, the electric motor 6 is fixedly connected with the top of the support 1, an output end of the electric motor 6 is provided with a rotating shaft 7, specifically, the rotating shaft 7 is fixedly connected with the electric motor 6, the rotating shaft 7 penetrates through the cover plate 5 and extends into the inside of the container 2, specifically, the cover plate 5 is provided with a through hole, the side wall of the rotating shaft 7 is not in contact with the inner wall of the through hole of the cover plate 5, the cover plate 5 can move upward or downward along the rotating shaft 7 through the through hole, the side wall of the rotating shaft 7 arranged in the inside of the container 2 is provided with a stirring rod 8, specifically, the stirring rod 8 is fixedly connected with the rotating shaft 7, the top of the container 2 is provided with a clamping groove, the bottom surface of the cover plate 5 is provided with a clamping block, the clamping block is connected with the clamping groove in a matched mode, specifically, the clamping block can be inserted into the clamping groove, the bottom of the container 2 is provided with a discharging pipe, specifically, the discharging pipe is connected with a valve.

[0081] The working principle and use process of the ultrasonic device in the application are as follows: raw materials and deionized water are placed into the container 2, the cover plate 5 is matched with the clamping groove through the clamping block and is covered on the container 2, the ultrasonic generator 4 is started to perform ultrasonic oscillation, the electric motor 6 can be started to drive the rotating shaft 7 to rotate, the stirring rod 8 is driven to rotate, and the solution is stirred, when the reaction is completed, the discharging pipe can be used for discharging.

[0082] The ultrasonic device in the application efficiently combines ultrasonic oscillation and mechanical stirring together, can perform ultrasonic treatment and stirring on raw materials under sealed conditions, and replaces the traditional laboratory which needs to build complex experimental instrument equipment through an experimental instrument support, thereby greatly facilitating use.

[0083] The composite material prepared in the above embodiments 1-3 has better electric conductivity and cycle stability compared with a single composite metal oxide product.

[0084] The graphene oxide is doped with the tetraamino metal porphyrin, nitrogen is doped in the graphene oxide, an n-type semiconductor is formed, and the porous structure after the nitrogen doping can provide more lithium storage sites, so that the conductivity of the graphene oxide is greatly improved, in addition, the metal oxide can further improve the conductivity of the graphene oxide, the composite material prepared by the application can relieve the structure damage caused by the volume change of the metal oxide in the charging and discharging process, and therefore has higher cycle stability.

[0085] The products obtained in Examples 1-3 are uniformly coated on the surface of an aluminum foil, then appropriate amounts of an adhesive and a conductive agent are added to prepare electrode sheets, lithium sheets are used as counter electrodes to assemble button cells, and the cycle charging and discharging curves are measured at different current densities to test the capacity performance, and the test results are shown in the following table:

[0086] In the experiment, the capacity retention rate = (initial discharge capacity-500 cycle discharge capacity) / initial discharge capacity

[0087]

[0088] As shown in the above table, the graphene oxide / metal composite material and the preparation method thereof provided by the application have high capacity retention rate and stable charging and discharging performance.

[0089] The above shows and describes the basic principles and main features of the application and the advantages of the application, and it is obvious for those skilled in the art that the application is not limited to the details of the above exemplary embodiments, and the application can be realized in other specific forms without departing from the spirit or basic characteristics of the application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the application.

[0090] Although the embodiments of the application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirit of the application, and the scope of the application is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a graphene oxide / metal composite material, characterized by, Comprise the following steps: S1, preparation of graphene oxide by pre-oxidation method: Dissolve potassium persulfate and phosphorus pentoxide in concentrated sulfuric acid, add graphite powder to prepare pre-oxidized graphite; add pre-oxidized graphite to concentrated sulfuric acid, then add potassium permanganate and stir for a period of time, then add hydrogen peroxide and stand overnight, after post-processing, obtain the graphene oxide; ultrasonic treatment of graphene oxide to obtain graphene oxide; S2, synthesis of tetraamino metal porphyrin: Take p-nitrobenzaldehyde and pyrrole as raw materials to prepare tetranitro porphyrin, then reduce it with tin dichloride to prepare tetraamino porphyrin, and then react with metal acetate to prepare tetraamino metal porphyrin, the structure is as follows: ； S3, graphene oxide doped with tetraamino metal porphyrin and nano metal oxide to prepare composite material: Take graphene oxide and add deionized water to the ultrasonic device for dispersion, ultrasonic, then add appropriate amount of tetraamino metal porphyrin and nano metal oxide, continue to ultrasonic stirring, freeze-dry the liquid, then place it in a tube furnace, keep constant temperature under nitrogen protection, calcine to obtain graphene oxide / metal composite material; The mass ratio of graphene oxide, tetraamino metal porphyrin and nano metal oxide in S3 is (300-360):(1-10):(100-180); The tetraamino metal porphyrin is one of tetraamino zinc porphyrin, tetraamino cobalt porphyrin or tetraamino copper porphyrin; the nano metal oxide is one of nano zinc oxide, nano ferric oxide or nano cobalt oxide.

2. The method for preparing a graphene oxide / metal composite material according to claim 1, wherein: The specific steps of the pre-oxidation method for preparing graphene oxide are as follows: S11, dissolve a certain amount of potassium persulfate and phosphorus pentoxide in a proper amount of concentrated sulfuric acid, then add a certain amount of graphite powder, stir at 80-90℃ for 5-6h, cool to room temperature, add water, stand overnight, filter, wash with warm deionized water, dry to obtain pre-oxidized graphite; S12, under ice water bath condition, add pre-oxidized graphite powder to a proper amount of concentrated sulfuric acid, then add a proper amount of potassium permanganate, stir at 35-45℃ for 2-3h, then dilute with water, continue to stir for 1-2h, then add a proper amount of hydrogen peroxide with mass fraction of 20-30%, stand overnight, filter, wash with hydrochloric acid solution with mass fraction of 10-20%, then dissolve in deionized water, configure suspension with mass fraction of 0.5-1%, stand at room temperature for a week, filter, wash with warm deionized water, dry, grind to obtain graphene oxide; S13, disperse graphene oxide in deionized water, ultrasonic oscillation for 1-2h, then high-speed centrifugation, collect the upper clear liquid, dry to obtain graphene oxide.

3. The method for preparing a graphene oxide / metal composite material according to claim 1, wherein: The synthesis steps of tetraamino metal porphyrin are as follows: S21, the p-nitrobenzaldehyde and pyrrole are weighed according to the molar ratio of 1:4, the nitrobenzene is used as a solvent, a trace of propionic acid and glacial acetic acid are added as catalysts, the four-nitro porphyrin is prepared by refluxing at 135-140 DEG C for 1-2 hours, after the reaction, the product is left overnight, filtered, washed with deionized water, dried, then refluxed in pyridine for 1-1.5 hours, left overnight, filtered, washed with acetone, dried, then recrystallized with chloroform to obtain the four-nitro porphyrin; S22, the four-nitro porphyrin is dissolved in concentrated hydrochloric acid as a solvent, stannous chloride is used as a reducing agent, the mixture is stirred at room temperature for 2.5-3 hours, then heated to 70-80 DEG C and continuously reacted for 0.5-1 hour, left overnight, filtered, the filter cake is dissolved in deionized water, the pH is adjusted to neutral, filtered, Soxhlet extracted with chloroform as eluent, then concentrated by rotary evaporation, recrystallized with diethyl ether to obtain the four-amino porphyrin; S23, the four-amino porphyrin is refluxed with metal acetate in a mixture of methanol and DMF for 18-24 hours, then washed with deionized water, the organic phase is collected and concentrated, then recrystallized with methanol to obtain the four-amino metal porphyrin.

4. The method for preparing a graphene oxide / metal composite material according to claim 1, wherein: The ultrasonic device in S3 comprises a support (1), the support (1) is provided in a door type, a container (2) is arranged at the middle of the support (1), a cover plate (5) is arranged at the top of the container (2), supports (3) are symmetrically arranged between the bottom of the container (2) and the side walls of the support (1), an ultrasonic generator (4) is arranged in the supports (3), a motor (6) is arranged at the top of the support (1), a rotating shaft (7) is arranged at the output end of the motor (6), the rotating shaft (7) penetrates through the cover plate (5) and extends into the container (2), a stirring rod (8) is arranged on the side wall of the rotating shaft (7) in the container (2), and a discharge pipe is arranged at the bottom of the container (2).

5. The method for preparing a graphene oxide / metal composite material according to claim 4, wherein: A clamping groove is formed in the top of the container (2), and a clamping block is arranged on the bottom surface of the cover plate (5) and connected with the clamping groove.

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