Electrolytic preparation device for universal covalent functionalized graphene and use method of electrolytic preparation device

Abstract

The invention belongs to the technical field of graphene material preparation, and particularly relates to a universal covalent functionalized graphene electrolysis preparation device and a use method thereof. A reactant graphite paper electrode of the device is mounted in an electrode mounting hole in an electrolytic tank cover of a four-channel electrolytic reaction tank mechanism through a conductive clamp mechanism, the graphite paper conductive clamp mechanism is clamped at the upper end of the graphite paper electrode, and the graphite paper electrode extends into an inner cavity of an electrolytic tank main body; four groups of liquid conveying systems of the working liquid conveying mechanism are communicated with four liquid injection and drainage ports of the four-channel electrolytic reaction tank mechanism through working liquid pipelines, and the four-channel electrolytic reaction tank mechanism, the graphite paper electrode conductive clamp mechanism, the working liquid conveying mechanism and the electric control mechanism are integrally mounted on the shell and the mounting integration mechanism. According to the invention, automatic control parts are effectively combined, so that the covalent functionalized graphene electrochemical preparation method is automatically realized through program control.

Description

Technical Field

[0001] The present invention belongs to the technical field of graphene material preparation, and specifically relates to a general-purpose covalently functionalized graphene (CFG) electrolytic preparation device and a method for using the device and the working process, and the efficient preparation of CFG materials with different functionalized characteristics can be achieved by regulating the chemical composition of the electrolyte and the parameters of the electrochemical reaction process. Background Art

[0002] CFG refers to a graphene-like two-dimensional material that has a large amount of non-carbon atoms or organic functional group structures grafted onto or within the graphene carbon plane by forming covalent bonds. The presence of these functional groups or doping atoms can give graphene materials more diverse functions and improve their dispersibility in solvents so that they can be assembled into macroscopic application materials and effectively perform their functions. Therefore, CFG is a key material form for graphene applications, and its efficient controlled preparation has important application value.

[0003] The Chinese invention patent application with application number CN202311072987.3, "A universal electrochemical preparation method for covalently functionalized graphene", proposes a technology for efficiently preparing different types of covalently functionalized graphene using two-step micro-liquid membrane electrolysis technology. The core technology lies in the stable existence of the first-order intercalated graphite electrode through oil sealing technology and the construction and manipulation of the micro-liquid membrane structure for electrolysis. The realization of this preparation technology requires multiple working liquids to be injected or discharged into the electrolytic cell according to a specific procedure, and has strict requirements on the synergy of the injection speed, which is difficult to achieve effective control through artificial methods. Summary of the invention

[0004] The purpose of the present invention is to provide a universal covalently functionalized graphene electrolytic preparation device and a method of using the same. Through the design of the structure and operation process of the preparation device and the effective combination of automated control components, the covalently functionalized graphene electrochemical preparation method can be automatically realized through program control.

[0005] The technical solution of the present invention is:

[0006] A general-purpose covalently functionalized graphene electrolytic preparation device includes: a four-channel electrolytic reaction tank mechanism, a graphite paper electrode conductive fixture mechanism, a working liquid transport mechanism, an electrical control mechanism, a housing and an installation integrated mechanism. The specific structure is as follows:

[0007] The graphite paper electrode conductive clamp mechanism is installed in the electrode mounting hole on the electrolytic cell cover of the four-channel electrolytic reaction cell mechanism. The graphite paper electrode conductive clamp mechanism clamps the upper end of the graphite paper electrode, and the graphite paper electrode extends into the inner cavity of the electrolytic cell body. The four groups of infusion systems of the working liquid transport mechanism are connected with the four injection and discharge ports of the four-channel electrolytic reaction cell mechanism through the working liquid pipeline. The four-channel electrolytic reaction cell mechanism, the anode graphite paper conductive clamp mechanism, the working liquid transport mechanism, and the electrical control mechanism are integrated and installed in the shell and the installation integrated mechanism.

[0008] The four-channel electrolytic reaction tank mechanism of the universal covalently functionalized graphene electrolysis preparation device comprises an integrated four-channel electrolytic tank body and a multifunctional electrolytic tank cover, wherein: the integrated four-channel electrolytic tank body is barrel-shaped, the upper opening is open for installing the electrolytic tank cover, and the side wall and the bottom have four liquid path openings: 1# injection and discharge port, 2# injection and discharge port, 3# injection and discharge port, 4# injection and discharge port, a hole is opened on the side wall close to the upper edge of the electrolytic tank body, and a single-hole liquid inlet and discharge pipe is connected, the outer end of the single-hole liquid inlet and discharge pipe is the 1# injection and discharge port, the lower bottom of the electrolytic tank body adopts a hemispherical head, the bottom of the electrolytic tank body is opened and connected with a pipe joint, and the The pipe joint includes a vertical liquid inlet and discharge pipe and two horizontal liquid inlet and discharge pipes. The horizontal liquid inlet and discharge pipes are arranged in parallel up and down and are vertically connected with the vertical liquid inlet and discharge pipes. The outer ports of the upper and lower horizontal liquid inlet and discharge pipes are 2# liquid injection and discharge ports and 3# liquid injection and discharge ports respectively. The lower port of the vertical liquid inlet and discharge pipe is 4# liquid injection and discharge port. The uppermost opening of the pipe joint is connected to the electrolytic cell body; the cathode rod and the insulating partition are installed on the multifunctional electrolytic cell cover, and the anode graphite paper conductive clamp mechanism is carried. The top of the electrolytic cell cover is provided with two cathode rod mounting holes, two partition mounting holes, more than two slot cover exhaust holes, and an anode mounting hole matching the shape of the anode graphite paper conductive clamp mechanism.

[0009] The universal covalently functionalized graphene electrolysis preparation device is provided with a lower liquid level gauge for sensing the starting position of the micro-liquid membrane operation and an upper liquid level gauge for sensing the ending position on the side wall of the electrolytic cell body. The lower liquid level gauge and the upper liquid level gauge adopt resistive liquid level sensors or capacitive liquid level sensors, and the electrolytic cell body is made of glass, quartz, ceramic, metal or plastic.

[0010] In the universal covalently functionalized graphene electrolysis preparation device, the cathode rod is made of inert conductive material, the length of the cathode rod ensures that it can contact the bottom of the inner cavity of the electrolytic cell body, and a certain wiring length is retained above the electrolytic cell cover for connecting with the power supply electrode.

[0011] The described general-purpose covalently functionalized graphene electrolysis preparation device, the anode graphite paper conductive clamp mechanism includes two conductive clamps with threaded holes, the anode graphite paper is clamped between the two conductive clamps, and the clamp fastening screws are inserted into the threaded holes so that the conductive clamps tightly clamp the anode graphite paper; the upper parts of the two conductive clamps are penetrated with wiring terminals for connecting with the positive pole of the power supply through wires; the connection between the upper part of the anode graphite paper and the conductive clamp corresponds to the oil sealing area of ​​the electrolytic cell, and the remaining anode graphite paper corresponds to the reaction area of ​​the electrolytic cell.

[0012] The universal covalently functionalized graphene electrolysis preparation device described herein has a working liquid transport mechanism including four groups of infusion systems consisting of a working liquid storage tank, a peristaltic pump, a bidirectional solenoid valve and a working liquid pipeline. Each group of infusion systems is connected to the corresponding injection and discharge ports of the integrated four-channel electrolytic cell body through a working liquid pipeline, and is used for bidirectional transport of four working liquids between the electrolytic cell and the working liquid storage tank. Among them, the first group of infusion systems is a working liquid pipeline having a 1# working liquid storage tank, a 1# peristaltic pump and a 1# solenoid valve in sequence, and one end of the working liquid pipeline is connected to the 1# working liquid storage tank. The injection and discharge ports are connected; the second group of infusion system is that the working liquid pipeline is equipped with a 2# working liquid storage tank, a 2# peristaltic pump, and a 2# solenoid valve in sequence, and one end of the working liquid pipeline is connected to the 2# injection and discharge port; the third group of infusion system is that the working liquid pipeline is equipped with a 3# working liquid storage tank, a 3# peristaltic pump, and a 3# solenoid valve in sequence, and one end of the working liquid pipeline is connected to the 3# injection and discharge port; the fourth group of infusion system is that the working liquid pipeline is equipped with a 4# working liquid storage tank, a 4# peristaltic pump, and a 4# solenoid valve in sequence, and one end of the working liquid pipeline is connected to the 4# injection and discharge port.

[0013] The described general-purpose covalently functionalized graphene electrolysis preparation device adopts a shell and an integrated installation mechanism as a whole. The shell is surrounded by a front panel, a back panel, a top panel, a bottom panel, an electrical component and a control area side panel on the left, and a transparent side panel of a working liquid transport mechanism installation area on the right to form a compartment structure. The electrolytic cell body is fixed to the upper part of the front panel by a bracket, and a transparent protective cover of the reaction area is placed on the front panel around the electrolytic cell body to form a reaction area. The upper part of the front panel is provided with a wiring terminal, and the lower part of the front panel is provided with a heat dissipation hole; the shell of the electrolytic preparation device adopts a two-compartment layout inside, the right side is the working liquid transport mechanism installation area, the left side is the electrical component and control area, the left and right areas are separated by an installation mainboard, and the installation mainboard is used as a system mainboard for installing various electrical and piping devices. The PLC-HMI controller as the device working control core and the human-machine interaction interface is embedded and installed on the inner surface of the electrical component and control area side panel on the left.

[0014] The universal covalently functionalized graphene electrolytic preparation device has electrical components and a control area side panel on the left side of the electrolytic preparation device shell, and a transparent side panel of the working liquid transport mechanism installation area on the right side, all of which are made of transparent plastic material. The back panel of the shell of the electrolytic preparation device is integrated with a power interface, a data communication interface and a cooling fan, and a handle is provided on the upper surface of the top plate of the shell of the electrolytic preparation device.

[0015] A method for using a general-purpose covalently functionalized graphene electrolytic preparation device, wherein the preparation of CFG using the device requires two operation processes, namely, electrolytic intercalation treatment and electrolytic oxidation treatment:

[0016] Process 1: Electrolytic intercalation is divided into the following 5 steps:

[0017] Step 1: Add 1# working liquid light sealing oil, 2# working liquid concentrated sulfuric acid intercalation agent, 3# working liquid aqueous electrolyte and 4# working liquid heavy sealing oil into 1# working liquid storage tank, 2# working liquid storage tank, 3# working liquid storage tank and 4# working liquid storage tank respectively, and turn on the power supply;

[0018] Step 2: When the electrolytic cell body is empty, open the 4# solenoid valve 28, and suck the high-density 4# working liquid heavy sealing oil from the 4# working liquid storage tank by the 4# peristaltic pump, and push it into the electrolytic cell body from the 4# injection and discharge port at the bottom of the electrolytic cell body. The amount of sealing oil added is controlled so that the sealing oil just covers the 3# injection and discharge port and remains stable, and then close the 4# solenoid valve and the 4# peristaltic pump;

[0019] Step 3: Open the 2# solenoid valve, use the 2# peristaltic pump to extract the 2# working liquid concentrated sulfuric acid intercalant and inject it into the electrolytic cell body through the 2# injection and discharge port. When the liquid level reaches the position of the lower liquid level gauge, open the 1# solenoid valve, and use the 1# peristaltic pump to suck the 1# working liquid light sealing oil from the 1# working liquid storage tank and push it into the electrolytic cell body through the 1# injection and discharge port on the upper part of the electrolytic cell body. The amount of addition is initially set to form a sealing oil film with a height of 5 mm, and then close the 1# solenoid valve and the 1# peristaltic pump;

[0020] Step 4: When the liquid level of the 2# working liquid concentrated sulfuric acid intercalation agent reaches the upper liquid level gauge position, close the 2# solenoid valve and the 2# peristaltic pump; at this point, the pre-treatment process of the electrolytic intercalation is completed, and the electrolytic power supply is turned on for static electrolytic intercalation;

[0021] Step 5: Open the 1# solenoid valve and the 2# solenoid valve, and connect the 1# peristaltic pump in the forward direction and the 2# peristaltic pump in the reverse direction, so that the 1# working liquid light sealing oil is injected while discharging the 2# working liquid concentrated sulfuric acid intercalation agent at the same speed, and ensure that the liquid level of the sealing oil remains basically unchanged; when the interface position of the 1# working liquid light sealing oil and the 2# working liquid concentrated sulfuric acid intercalation agent is lowered to the bottom of the 2# injection and discharge port, stop the 1# peristaltic pump and the 2# peristaltic pump and close the 2# solenoid valve, at which time the 2# working liquid concentrated sulfuric acid intercalation agent is discharged;

[0022] Process 2, electrolytic oxidation is divided into the following three steps:

[0023] Step 1: Open the 3# solenoid valve, use the 3# peristaltic pump to extract the 2# working liquid concentrated sulfuric acid intercalation agent and inject it into the electrolytic cell body through the 3# injection and discharge port. When the injection volume forms a liquid film with a thickness of 1mm, stop the injection and close the 3# solenoid valve and the 3# peristaltic pump;

[0024] Step 2: Open the 4# solenoid valve and the 1# solenoid valve, the 4# peristaltic pump rotates forward and the 1# peristaltic pump rotates reversely, and the high-density 4# working liquid heavy sealing oil is injected into the electrolytic cell body from the 4# injection and discharge port at the bottom of the electrolytic cell body, pushing the reaction 3# working liquid aqueous electrolyte film to gradually rise; and the 1# working liquid light sealing oil discharged due to the rise in liquid level is pumped back into the 1# working liquid storage tank by the 1# peristaltic pump; when the position of the 3# working liquid aqueous electrolyte film rises to the position of the lower liquid level gauge, adjust Adjust the power supply voltage to the voltage value required for electrolytic oxidation, and gradually approach the GIC electrode to start oxidation; when the liquid level of the 3# working liquid aqueous electrolyte rises to the position of the upper liquid level gauge, the oxidation of this GIC electrode is completed and CFG is obtained; at this time, stop the power supply, close the 1# solenoid valve and the 4# solenoid valve and the peristaltic pump, and the electrolytic oxidation reaction process ends; at this time, all the 1# working liquid light sealing oil will be completely discharged from the electrolytic cell body, and the reaction product CFG will be immersed in the 4# working liquid heavy sealing oil;

[0025] Step 3: Open the 4# solenoid valve, and the 4# peristaltic pump reverses to discharge all the working liquid in the electrolytic cell body into the 4# working liquid storage tank.

[0026] The method for using the general-purpose covalently functionalized graphene electrolytic preparation device is as follows: in step 4 of process one, after the electrolytic intercalation is completed, the 2# working liquid concentrated sulfuric acid intercalation agent is released from the electrolytic cell body, and the 1# working liquid light sealing oil is simultaneously injected to ensure that the graphite intercalation compound obtained by the intercalation is always not in contact with the air; in step 3 of process one, after the electrochemical reaction treatment is completed, the product CFG sample strip is taken out from the electrolytic cell body, the graphite paper that does not participate in the reaction is cut off, and then put into water for ultrasonic or shear exfoliation to obtain an aqueous dispersion of CFG.

[0027] The advantages and beneficial effects of the present invention are as follows:

[0028] 1. The device can be used to efficiently prepare different types of CFG with high product purity and few by-products.

[0029] 2. The device can realize automatic control of the reaction process for preparing CFG. The operator only needs to add appropriate working liquid into the corresponding working liquid storage tank and start the device, and the device can automatically perform subsequent operations. The reaction process is disorderly and human intervention is unnecessary. It is simple and easy to use, and the properties of different batches of products are highly consistent.

[0030] 3. The reaction device prepared by the invention is small and easy to use, and the time required for a single preparation is short. It is very suitable for the preparation of a small amount of CFG samples at the laboratory level, and is also convenient for the research of related material preparation technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1-Figure 4 .Structural model diagram of the four-channel electrolytic reaction tank of the CFG electrolytic preparation device. Figure 1 For the main view, Figure 2 is a side view, Figure 3 For a stereogram, Figure 4 For the electrolytic cell cover.

[0032] Figure 5 .Model diagram of the conductive fixture mechanism of the anode graphite paper of the CFG electrolysis preparation device. (a) is the main view and (b) is the stereogram.

[0033] Figure 6 .Model diagram of the working liquid transport mechanism of the CFG electrolytic preparation device.

[0034] Figure 7-10 .The overall structural model diagram of the CFG electrolytic preparation device. Figure 7 For the back of the device (interface area), Figure 8 For the side of the device (electrical components and control area), Fig. 9 is the front side of the device (reaction area), Fig.10 It is the side of the device (the area where the working liquid transport mechanism is installed).

[0035] Attached Figure 1-10The names of the parts or devices indicated by the numbers are as follows: 1-electrolytic cell body, 2-1# injection and discharge port, 3-2# ​​injection and discharge port, 4-3# injection and discharge port, 5-4# injection and discharge port, 6-upper liquid level gauge, 7-lower liquid level gauge, 8-electrolytic cell cover, 9-cathode rod, 10-insulating partition, 11-tank cover exhaust hole, 12-anode mounting hole, 13-conductive clamp, 14-clamp fastening screw, 15-anode graphite paper, 16-terminal, 17-1# working liquid storage tank, 18-1# peristaltic pump, 19-1# solenoid valve, 20-2# working liquid storage tank, 21-2# peristaltic pump, 22-2# solenoid valve, 23-3# working liquid storage tank, 24-3# peristaltic peristaltic pump, 25-3# solenoid valve, 26-4# working liquid storage tank, 27-4# peristaltic pump, 28-4# solenoid valve, 29-working liquid pipeline, 30-bottom plate, 31-working liquid transport mechanism installation area, 32-electrical components and control area, 33-reaction area, 34-back panel, 35-installation main board, 36-top plate, 37-transparent side panel of working liquid transport mechanism installation area, 38-front panel, 39-transparent protective cover of reaction area, 40-terminal block, 41-heat dissipation hole, 42-electrical components and control area side panel, 43-PLC-HMI controller, 44-cooling fan, 45-data communication interface, 46-power interface, 47-handle. DETAILED DESCRIPTION

[0036] In the specific implementation process, the present invention proposes a universal covalent functionalized graphene electrolysis preparation device, the core components of which include: a four-channel electrolysis reaction tank mechanism, an anode graphite paper conductive clamp mechanism, a working liquid transport mechanism, an electrical control mechanism, a housing and an installation integrated mechanism, and the specific structure is as follows:

[0037] like Figure 1-Figure 4 As shown, the four-channel electrolytic reaction tank mechanism includes an integrated four-channel electrolytic tank body 1 and a multifunctional electrolytic tank cover 8, wherein:

[0038] The integrated four-channel electrolytic cell body 1 is barrel-shaped, with an open top for installing the electrolytic cell cover 8, and four liquid path openings on the side wall and the bottom: 1# injection and discharge port 2, 2# injection and discharge port 3, 3# injection and discharge port 4, and 4# injection and discharge port 5, which are respectively used for injecting and discharging 1#, 2#, 3#, and 4# working liquids into and out of the electrolytic cell. Among them, a hole is opened on the side wall close to the upper edge of the electrolytic cell body 1, and a single-hole inlet and drain pipe is connected, the outer end of the single-hole inlet and drain pipe is a 1# injection and drain port 2, which is used for the injection and discharge of the 1# working liquid; the lower bottom of the electrolytic cell body 1 adopts a hemispherical head, the bottom of the electrolytic cell body 1 is opened and connected with a pipe joint, the pipe joint includes a vertical inlet and drain pipe and two horizontal inlet and drain pipes, the horizontal inlet and drain pipes are arranged in parallel up and down and are vertically connected with the vertical inlet and drain pipes, the outer ports of the upper and lower horizontal inlet and drain pipes are 2# injection and drain port 3 and 3# injection and drain port 4 respectively, the lower port of the vertical inlet and drain pipe is 4# injection and drain port 5, the uppermost opening of the pipe joint is connected to the electrolytic cell body 1, and the 2# injection and drain port 3, 3# injection and drain port 4, and 4# injection and drain port 5 on the pipe joint are used for the injection and discharge of 2# (top of the bottom), 3# (middle of the bottom), and 4# (bottom of the bottom) working liquids respectively. Two groups of liquid level sensing components are arranged on the side wall of the electrolytic cell body 1, which are mainly used to sense the starting (lower liquid level gauge 7) and ending (upper liquid level gauge 6) positions of the micro-liquid membrane operation, and can adopt a resistive liquid level sensor or a capacitive liquid level sensor. The electrolytic cell body 1 can be made of glass, quartz, ceramic, metal or plastic material, and its basic requirement is that the material used can maintain stable physical or chemical properties for a long time after contacting the four types of working liquids.

[0039] The multifunctional electrolytic cell cover 8 is mainly used to install the cathode rod 9 and the insulating partition 10, and to carry the anode graphite paper conductive clamp mechanism. The top of the electrolytic cell cover 8 is provided with two cathode rod mounting holes, two partition mounting holes, more than two slot cover exhaust holes 11, and an anode mounting hole 12 that matches the shape of the anode graphite paper conductive clamp mechanism. The cathode rod 9 is made of inert conductive materials, including but not limited to metal materials such as stainless steel, platinum, rhodium, gold, or non-metallic materials such as graphite; the length of the cathode rod must ensure that it can contact the bottom of the inner cavity of the electrolytic cell body 1, and a certain wiring length is retained above the electrolytic cell cover 8 for connection with the power supply electrode. The insulating partition 10 is used to prevent the anode graphite paper 15 immersed in the electrolytic cell body 1 from accidentally contacting the cathode rod 9 during the electrochemical reaction, causing a short circuit. The slot cover exhaust hole 11 is used to discharge gas byproducts that may be produced on the electrode surface during the electrochemical reaction, such as hydrogen, oxygen, etc.

[0040] like Figure 5As shown, the anode graphite paper conductive clamp mechanism includes two conductive clamps 13 with threaded holes. When in use, the anode graphite paper 15 is clamped between the two conductive clamps 13, and the clamp fastening screws 14 are inserted into the threaded holes to fix the conductive clamps 13 tightly clamp the anode graphite paper 15, so that the current can be effectively conducted to the anode graphite paper 15. The upper part of the two conductive clamps 13 is penetrated with a terminal 16 for connecting with the positive pole of the power supply through a wire. The upper part of the anode graphite paper 15 and the conductive clamp 13 are connected to the oil sealing area of ​​the electrolytic cell, and the rest of the anode graphite paper 15 corresponds to the reaction area of ​​the electrolytic cell.

[0041] like Figure 6 As shown, the working liquid transport mechanism includes four groups of infusion systems consisting of working liquid storage tanks, peristaltic pumps, two-way solenoid valves and working liquid pipelines. Each group of infusion systems is connected to the corresponding injection and discharge ports of the integrated four-channel electrolytic cell body 1 through working liquid pipelines, and is used for two-way transportation of four working liquids between the electrolytic cell and the working liquid storage tanks. Among them, the first group of infusion systems is that the working liquid pipeline 29 is provided with a 1# working liquid storage tank 17, a 1# peristaltic pump 18, and a 1# solenoid valve 19 in sequence, and one end of the working liquid pipeline 29 is connected to the 1# injection and discharge port 2; the second group of infusion systems is that the working liquid pipeline is provided with a 2# working liquid storage tank 20, a 2# peristaltic pump 21, and a 2# solenoid valve 22 in sequence, and one end of the working liquid pipeline is connected to the 2# injection and discharge port 3; the third group of infusion systems is that the working liquid pipeline is provided with a 3# working liquid storage tank 23, a 3# peristaltic pump 24, and a 3# solenoid valve 25 in sequence, and one end of the working liquid pipeline is connected to the 3# injection and discharge port 4; the fourth group of infusion systems is that the working liquid pipeline is provided with a 4# working liquid storage tank 26, a 4# peristaltic pump 27, and a 4# solenoid valve 28 in sequence, and one end of the working liquid pipeline is connected to the 4# injection and discharge port 5. The 1# working liquid storage tank 17 , the 2# working liquid storage tank 20 , the 3# working liquid storage tank 23 , and the 4# working liquid storage tank 26 are all disposed on the bottom plate 30 .

[0042] The electrical control mechanism mainly includes: power supply for electrical components of the device (220V AC to 12V / 24V DC power supply), electrolytic power supply (high-precision DC CNC constant voltage / constant current power supply), peristaltic pump stepper motor and controller, solenoid valve control relay, liquid level sensor, programmable controller (PLC), touch screen human-machine interface (HMI) and circuit connection system between various electrical components.

[0043] The shell and installation integrated mechanism mainly includes the device shell, the installation space of each component inside the shell, and the controller, circuit / gas / liquid interface and key component protection device installed on the shell surface. The mechanism can be used to integrate the above-mentioned four-channel electrolytic reaction tank mechanism, anode graphite paper conductive fixture mechanism, working liquid transportation mechanism, and electrical control mechanism into an independent device, and realize the effective preparation of CFG.

[0044] Below, the present invention is further described in detail by examples.

[0045] Example 1

[0046] like Figure 1-Figure 4 As shown, the design of the multi-channel electrolytic cell is made of quartz glass. Four injection and discharge ports (1# injection and discharge port 2, 2# injection and discharge port 3, 3# injection and discharge port 4, 4# injection and discharge port 5) and two groups of liquid level sensor probes (upper liquid level gauge 6, lower liquid level gauge 7) are arranged on the bottom and wall of the electrolytic cell body 1. The basic functions are as follows:

[0047] 1# injection and discharge port 2: used for the inlet and outlet of the upper sealing oil (working liquid 1).

[0048] 2# injection and discharge port 3: used for the inlet and outlet of the intercalation agent (working liquid 2).

[0049] 3# injection and discharge port 4: used for the inlet and outlet of aqueous reaction electrolyte (working liquid 3).

[0050] 4# liquid injection and discharge port 5: used for the inlet and outlet of the lower sealing oil (working liquid 4), and for draining the working liquid in the electrolytic cell body 1 after the reaction is completed.

[0051] Upper liquid level probe: used to determine the highest position of the intercalation agent and reaction electrolyte level rise, and to collect the solution conductivity change signal for automatic control. Its specific position is preset to be about 2 mm below the bottom of No. 1 injection and discharge port 2.

[0052] Lower liquid level probe: used to determine the starting liquid level of the oxidation reaction, and to collect the solution conductivity change signal for automatic control. Its specific position is preset to be about 2 mm below the bottom edge of the fixed anode graphite paper 15.

[0053] The electrolytic cell cover 8 is used to fix the movable parts of the electrolytic reaction, including: a cathode rod 9, an insulating partition 10, and an anode graphite paper conductive clamp mechanism. The cathode rod 9 is made of a stainless steel rod, and the insulating partition 10 is made of quartz glass; the insulating partition 10 and the electrolytic cell cover 8 are vertically positioned by a tight fit. The electrolytic cell cover 8 is provided with four cell cover exhaust holes 11 for discharging gaseous by-products in the electrolytic reaction; the cell cover exhaust holes 11 can also be used as temporary filling holes for liquid materials. A square anode mounting hole 12 is opened in the center of the electrolytic cell cover 8 for inserting the anode graphite paper conductive clamp mechanism and the anode graphite paper 15.

[0054] like Figure 5As shown, the conductive clamp mechanism of the anode graphite paper is made of two conductive clamps 13 (thick copper plates), and the two conductive clamps 13 fasten the anode graphite paper 15 (narrow strip of graphite paper) in the middle through the clamp fastening screws 14 to ensure good electrical contact and clamping strength, while ensuring the simplicity of operation. After the clamped anode graphite paper 15 is inserted into the electrolytic cell body 1 through the middle anode mounting hole 12 of the electrolytic cell cover 8, the conductive clamp 13 is fixed on the surface of the electrolytic cell cover 8 as a bracket, and is positioned to ensure the consistency of the relative position of the reaction electrodes each time.

[0055] like Figure 6 As shown, the working liquid transport mechanism of the integrated electrolytic preparation device, the transport process of the working liquid of each group of infusion systems to the electrolytic cell body 1 is realized by a group of passages consisting of "working liquid storage tank-working liquid pipeline-peristaltic pump-solenoid valve-electrolytic cell body 1". Four different working liquids are stored in four different working liquid storage tanks, and the flow direction of the working liquid is controlled by the forward and reverse rotation of the peristaltic pump; the solenoid valve is used to control the on-off of the liquid passage, and the flow of the working liquid can only be controlled by the peristaltic pump when the solenoid valve is open; the working liquid pipeline is used to connect various components to form a channel for liquid transport. Both the peristaltic pump and the solenoid valve can be automatically controlled by PLC.

[0056] like Figure 1-Figure 10 As shown, the present invention has a universal covalent functionalized graphene electrolytic preparation device, and the preparation of CFG using the device requires two operation processes of electrolytic intercalation treatment and electrolytic oxidation treatment in sequence. Each process is divided into multiple steps for operation. The basic process flow and control process are as follows:

[0057] Process 1: Electrolytic intercalation is divided into the following 5 steps:

[0058] Step 1: Add 1# working liquid (light sealing oil), 2# working liquid (concentrated sulfuric acid intercalation agent), 3# working liquid (aqueous electrolyte) and 4# working liquid (heavy sealing oil) into 1# working liquid storage tank 17, 2# working liquid storage tank 20, 3# working liquid storage tank 23 and 4# working liquid storage tank 26 respectively, and then turn on the power.

[0059] Step 2: When the electrolytic cell body 1 is empty, open the 4# solenoid valve 28, suck the high-density lower layer sealing oil from the 4# working liquid storage tank 26 by the 4# peristaltic pump 27, and push it into the electrolytic cell body 1 from the 4# injection and discharge port 5 at the bottom of the electrolytic cell body 1. The added amount is controlled so that the sealing oil just covers the 3# injection and discharge port 4 and remains stable, and then close the 4# solenoid valve 28 and the 4# peristaltic pump 27.

[0060] Step 3: Open the 2# electromagnetic valve 22, use the 2# peristaltic pump 21 to extract the intercalant and inject it into the electrolytic cell body 1 through the 2# injection and discharge port 3. When the liquid level reaches the position of the lower liquid level gauge 7, open the 1# electromagnetic valve 19, and suck the upper sealing oil from the 1# working liquid storage tank 17 by the 1# peristaltic pump 18 and push it into the electrolytic cell body 1 through the 1# injection and discharge port 2 at the top of the electrolytic cell body 1. The amount of addition is initially set to form a sealing oil film with a height of about 5 mm, and then close the 1# electromagnetic valve 19 and the 1# peristaltic pump 18. The injection speed of the intercalant remains unchanged during this process.

[0061] Step 4: When the liquid level of the intercalation agent reaches the position of the upper liquid level gauge 6, close the 2# electromagnetic valve 22 and the 2# peristaltic pump 21; at this point, the pre-treatment process of electrolytic intercalation is completed, and the electrolytic power supply can be turned on for static electrolytic intercalation.

[0062] After the electrolytic intercalation is completed, the intercalation agent needs to be released from the electrolytic cell body 1 and the upper sealing oil is injected simultaneously to ensure that the graphite intercalation compound (GIC) obtained by intercalation is never in contact with the air. To achieve this goal, the following control is required:

[0063] Step 5: Open the 1# solenoid valve 19 and the 2# solenoid valve 22, and connect the 1# peristaltic pump 18 in the forward direction and the 2# peristaltic pump 21 in the reverse direction, so that the upper sealing oil is injected at the same speed while discharging the intercalation agent, and ensure that the liquid level of the sealing oil remains basically unchanged. When the interface position between the upper sealing oil and the intercalation agent drops to the bottom of the 2# injection and discharge port 3, stop the 1# peristaltic pump 18 and the 2# peristaltic pump 21 and close the 2# solenoid valve 22, and the intercalation agent is discharged. At this point, the first step of the intercalation process is completed.

[0064] Process 2, electrolytic oxidation is divided into the following three steps:

[0065] Step 1: Open the 3# electromagnetic valve 25, use the 3# peristaltic pump 24 to extract the intercalant and inject it into the electrolytic cell body 1 through the 3# injection and discharge port 4. When the injection amount can form a liquid film with a thickness of about 1 mm (the thickness of the liquid film is a key variable, and the optimal value will be sought through experimental research), stop the injection and close the 3# electromagnetic valve 25 and the 3# peristaltic pump 24.

[0066] Step 2: Open the 4# solenoid valve 28 and the 1# solenoid valve 19, the 4# peristaltic pump 27 rotates forward and the 1# peristaltic pump 18 rotates reversely, and the high-density lower sealing oil is injected into the electrolytic cell body 1 from the 4# injection and discharge port 5 at the bottom of the electrolytic cell body 1, pushing the reaction electrolyte film to gradually rise; and the upper sealing oil discharged due to the rise of the liquid level is pumped back to the 1# working liquid storage tank 17 by the 1# peristaltic pump 18. The initial lifting speed of the electrolyte film can be fast. When the electrolyte film position rises to the position of the lower liquid level gauge 7, adjust the power supply voltage to the voltage value required for electrolytic oxidation, and start to run at a controlled speed (the voltage value and the liquid film lifting speed are both key variables, and the optimal value will be sought through experimental research), and gradually approach the GIC electrode to start oxidation. When the electrolyte level rises to the position of the upper liquid level gauge 6, the oxidation of the GIC electrode is completed and CFG is obtained; at this time, stop the power supply, close the 1# solenoid valve 19 and the 4# solenoid valve 28 and the peristaltic pump, and the electrolytic oxidation reaction process ends. At this time, all the upper sealing oil will be completely discharged from the electrolytic cell body 1, and the reaction product CFG will be mainly immersed in the lower sealing oil. According to the previous experimental phenomena and the oleophobic characteristics of CFG, the CFG after the reaction will still be gathered together in the form of sample strips, rather than directly peeling off and entering the liquid phase.

[0067] Step 3: Open the 4# electromagnetic valve 28, and the 4# peristaltic pump 27 is reversed to discharge all the working liquid in the electrolytic cell body 1 into the 4# working liquid storage tank 26. At this point, the second step of the electrolytic oxidation treatment process is completed.

[0068] After the electrochemical reaction treatment is completed, the product CFG sample strip is taken out from the electrolytic cell body 1, and after cutting off the graphite paper that does not participate in the reaction, it is put into water for ultrasonic or shear peeling to obtain a CFG aqueous dispersion.

[0069] like Figure 7-10As shown, the present invention has a universal covalent functionalized graphene electrolysis preparation device, which adopts a shell and an integrated installation mechanism as a whole. The overall size of the device is expected to be 230mm (width) × 400mm (height) × 480mm (length, including the electrolytic cell body 1 area), and the shell is surrounded by a front panel 38, a back panel 34, a top panel 36, a bottom panel 30, a side panel 42 of the electrical components and control area on the left, and a transparent side panel 37 of the working liquid transport mechanism installation area on the right to form a box structure. The electrolytic cell body 1 is fixed to the upper part of the front panel 38 by a bracket. In order to facilitate experimental observation and protect the electrolytic cell body 1 made of quartz glass from impact damage, a reaction zone transparent protective cover 39 is required to be placed around the electrolytic cell body 1 and placed on the front panel 38 to form a reaction zone 33. A wiring terminal 40 is provided on the upper part of the front panel 38, and a heat dissipation hole 41 is opened at the lower part of the front panel 38. The inside of the shell of the electrolytic preparation device adopts a two-compartment layout, with the right side being the working liquid transport mechanism installation area 31, and the left side being the electrical components and control area 32. The left and right areas are separated by an installation main board 35, and the installation main board 35 also serves as a system main board for installing various electrical and piping devices.

[0070] The installation height of all electrical components is far away from the bottom plate 30 to avoid damage to the electrical components caused by accidental leakage of the working liquid. In order to facilitate real-time observation of the working liquid transportation situation inside the electrolytic preparation device and the working situation of the electrical components, the left and right side panels of the shell of the electrolytic preparation device (the electrical components and control area side panel 42 on the left, and the transparent side panel 37 of the working liquid transportation mechanism installation area on the right) are all made of transparent plastic material. The PLC-HMI controller 43, which serves as the device working control core and the human-machine interaction interface, will be embedded on the inner surface of the electrical components and control area side panel 42 on the left to facilitate control operations. The power supply interface 46, the data communication interface 45, and the cooling fan 44 are integrated on the back panel 34 of the shell of the electrolytic preparation device. The weight of the whole machine is about 15kg, and a handle 47 is set on the upper surface of the shell top plate 36 of the electrolytic preparation device to facilitate single-person carrying operations.

[0071] The implementation results show that the present invention integrates the automatic control system and the working liquid operation system into a small-scale preparation device that can be independently operated through integrated design, which can meet the needs of efficient controlled preparation of small batches of experimental functionalized graphene. This invention is a key progress in the process of transforming the electrochemical preparation of covalently functionalized graphene from a method to an applied technology, and has important application value.

Claims

1. A general-purpose electrolytic preparation device for covalently functionalized graphene, characterized in that: The device includes: a four-channel electrolytic reaction tank mechanism, a graphite paper electrode conductive fixture mechanism, a working liquid transport mechanism, an electrical control mechanism, a housing and an installation integrated mechanism. The specific structure is as follows: The graphite paper electrode conductive clamp mechanism is installed in the electrode mounting hole on the electrolytic cell cover of the four-channel electrolytic reaction cell mechanism. The graphite paper electrode conductive clamp mechanism clamps the upper end of the graphite paper electrode, and the graphite paper electrode extends into the inner cavity of the electrolytic cell body. The four groups of infusion systems of the working liquid transport mechanism are connected with the four injection and discharge ports of the four-channel electrolytic reaction cell mechanism through the working liquid pipeline. The four-channel electrolytic reaction cell mechanism, the anode graphite paper conductive clamp mechanism, the working liquid transport mechanism, and the electrical control mechanism are integrated and installed in the shell and the installation integrated mechanism.

2. The general-purpose electrolytic preparation device for covalently functionalized graphene according to claim 1, characterized in that: The four-channel electrolytic reaction tank mechanism includes an integrated four-channel electrolytic tank body and a multifunctional electrolytic tank cover, wherein: the integrated four-channel electrolytic tank body is barrel-shaped, the upper opening is open for installing the electrolytic tank cover, and the side wall and the bottom have four liquid path openings: 1# injection and discharge port, 2# injection and discharge port, 3# injection and discharge port, 4# injection and discharge port, a hole is opened on the side wall close to the upper edge of the electrolytic tank body, and a single-hole inlet and discharge pipe is connected, the outer end of the single-hole inlet and discharge pipe is the 1# injection and discharge port, the lower bottom of the electrolytic tank body adopts a hemispherical head, the bottom of the electrolytic tank body is opened and connected with a pipe joint, and the pipe joint includes a vertical inlet and discharge The multifunctional electrolytic cell cover is provided with a cathode rod and an insulating partition plate, and carries an anode graphite paper conductive clamp mechanism. The top of the electrolytic cell cover is provided with two cathode rod mounting holes, two partition plate mounting holes, more than two slot cover exhaust holes, and an anode mounting hole matching the shape of the anode graphite paper conductive clamp mechanism.

3. The general-purpose electrolytic preparation device for covalently functionalized graphene according to claim 2, characterized in that: A lower liquid level gauge for sensing the starting position of the micro-liquid membrane operation and an upper liquid level gauge for sensing the ending position are arranged on the side wall of the electrolytic cell body. The lower liquid level gauge and the upper liquid level gauge adopt resistive liquid level sensors or capacitive liquid level sensors. The electrolytic cell body is made of glass, quartz, ceramic, metal or plastic.

4. The general-purpose electrolytic preparation device for covalently functionalized graphene according to claim 2, characterized in that: The cathode rod is made of inert conductive material. The length of the cathode rod ensures that it can contact the bottom of the inner cavity of the electrolytic cell body, and a certain wiring length is retained above the electrolytic cell cover for connection with the power supply electrode.

5. The general-purpose electrolytic preparation device for covalently functionalized graphene according to claim 1, characterized in that: The conductive clamp mechanism of the anode graphite paper comprises two conductive clamping plates with threaded holes, the anode graphite paper is clamped between the two conductive clamping plates, and the clamp fastening screws are inserted into the threaded holes so that the conductive clamping plates tightly clamp the anode graphite paper; the upper parts of the two conductive clamping plates are provided with wiring terminals for connecting with the positive pole of the power supply through wires; the connection between the upper part of the anode graphite paper and the conductive clamping plates corresponds to the oil sealing area of ​​the electrolytic cell, and the rest of the anode graphite paper corresponds to the reaction area of ​​the electrolytic cell.

6. The general-purpose electrolytic preparation device for covalently functionalized graphene according to claim 1, characterized in that: The working liquid transport mechanism includes four groups of infusion systems consisting of working liquid storage tanks, peristaltic pumps, two-way solenoid valves and working liquid pipelines. Each group of infusion systems is connected to the corresponding injection and discharge ports of the integrated four-channel electrolyzer body through working liquid pipelines, and is used for two-way transport of four working liquids between the electrolyzer and the working liquid storage tanks. Among them, the first group of infusion systems is a working liquid pipeline with a 1# working liquid storage tank, a 1# peristaltic pump, and a 1# solenoid valve in sequence, and one end of the working liquid pipeline is connected to the 1# injection and discharge port; the second group of infusion systems is a working liquid pipeline with a 1# working liquid storage tank, a 1# peristaltic pump, and a 1# solenoid valve in sequence, and one end of the working liquid pipeline is connected to the 1# injection and discharge port; The liquid system is provided with a 2# working liquid storage tank, a 2# peristaltic pump, and a 2# solenoid valve in sequence on the working liquid pipeline, and one end of the working liquid pipeline is connected to the 2# injection and discharge port; the third group of infusion system is provided with a 3# working liquid storage tank, a 3# peristaltic pump, and a 3# solenoid valve in sequence on the working liquid pipeline, and one end of the working liquid pipeline is connected to the 3# injection and discharge port; the fourth group of infusion system is provided with a 4# working liquid storage tank, a 4# peristaltic pump, and a 4# solenoid valve in sequence on the working liquid pipeline, and one end of the working liquid pipeline is connected to the 4# injection and discharge port.

7. The general-purpose electrolytic preparation device for covalently functionalized graphene according to claim 1, characterized in that: The device as a whole adopts a shell and an integrated installation mechanism. The shell is surrounded by a front panel, a back panel, a top panel, a bottom panel, an electrical component and control area side panel on the left, and a transparent side panel of the working liquid transport mechanism installation area on the right to form a compartment structure. The electrolytic cell body is fixed to the upper part of the front panel by a bracket, and a transparent protective cover of the reaction area is placed on the front panel around the electrolytic cell body to form a reaction area. The upper part of the front panel is provided with wiring terminals, and the lower part of the front panel is provided with heat dissipation holes; the inside of the shell of the electrolytic preparation device adopts a two-compartment layout, the right side is the working liquid transport mechanism installation area, and the left side is the electrical component and control area. The left and right areas are separated by an installation mainboard. At the same time, the installation mainboard is used as a system mainboard for installing various electrical and piping devices. The PLC-HMI controller as the device working control core and the human-machine interaction interface is embedded and installed on the inner surface of the electrical component and control area side panel on the left.

8. The general-purpose electrolytic preparation device for covalently functionalized graphene according to claim 1, characterized in that: The electrical components and control area side panels on the left side of the electrolytic preparation device shell and the transparent side panels of the working liquid transport mechanism installation area on the right side are all made of transparent plastic material. The power interface, data communication interface and cooling fan are integrated on the back panel of the electrolytic preparation device shell, and a handle is provided on the upper surface of the top plate of the electrolytic preparation device shell.

9. A method for using the universal covalently functionalized graphene electrolytic preparation device according to any one of claims 1 to 8, characterized in that: The preparation of CFG using this device requires two operations: electrolytic intercalation treatment and electrolytic oxidation treatment: Process 1: Electrolytic intercalation is divided into the following 5 steps: Step 1: Add 1# working liquid light sealing oil, 2# working liquid concentrated sulfuric acid intercalation agent, 3# working liquid aqueous electrolyte and 4# working liquid heavy sealing oil into 1# working liquid storage tank, 2# working liquid storage tank, 3# working liquid storage tank and 4# working liquid storage tank respectively, and turn on the power supply; Step 2: When the electrolytic cell body is empty, open the 4# solenoid valve 28, and suck the high-density 4# working liquid heavy sealing oil from the 4# working liquid storage tank by the 4# peristaltic pump, and push it into the electrolytic cell body from the 4# injection and discharge port at the bottom of the electrolytic cell body. The amount of sealing oil added is controlled so that the sealing oil just covers the 3# injection and discharge port and remains stable, and then close the 4# solenoid valve and the 4# peristaltic pump; Step 3: Open the 2# solenoid valve, use the 2# peristaltic pump to extract the 2# working liquid concentrated sulfuric acid intercalant and inject it into the electrolytic cell body through the 2# injection and discharge port. When the liquid level reaches the position of the lower liquid level gauge, open the 1# solenoid valve, and use the 1# peristaltic pump to suck the 1# working liquid light sealing oil from the 1# working liquid storage tank and push it into the electrolytic cell body through the 1# injection and discharge port on the upper part of the electrolytic cell body. The amount of addition is initially set to form a sealing oil film with a height of 5 mm, and then close the 1# solenoid valve and the 1# peristaltic pump; Step 4: When the liquid level of the 2# working liquid concentrated sulfuric acid intercalation agent reaches the upper liquid level gauge position, close the 2# solenoid valve and the 2# peristaltic pump; at this point, the pre-treatment process of the electrolytic intercalation is completed, and the electrolytic power supply is turned on for static electrolytic intercalation; Step 5: Open the 1# solenoid valve and the 2# solenoid valve, and connect the 1# peristaltic pump in the forward direction and the 2# peristaltic pump in the reverse direction, so that the 1# working liquid light sealing oil is injected while discharging the 2# working liquid concentrated sulfuric acid intercalation agent at the same speed, and ensure that the liquid level of the sealing oil remains basically unchanged; when the interface position of the 1# working liquid light sealing oil and the 2# working liquid concentrated sulfuric acid intercalation agent is lowered to the bottom of the 2# injection and discharge port, stop the 1# peristaltic pump and the 2# peristaltic pump and close the 2# solenoid valve, at which time the 2# working liquid concentrated sulfuric acid intercalation agent is discharged; Process 2, electrolytic oxidation is divided into the following three steps: Step 1: Open the 3# solenoid valve, use the 3# peristaltic pump to extract the 2# working liquid concentrated sulfuric acid intercalation agent and inject it into the electrolytic cell body through the 3# injection and discharge port. When the injection volume forms a liquid film with a thickness of 1mm, stop the injection and close the 3# solenoid valve and the 3# peristaltic pump; Step 2: Open the 4# solenoid valve and the 1# solenoid valve, the 4# peristaltic pump rotates forward and the 1# peristaltic pump rotates reversely, and the high-density 4# working liquid heavy sealing oil is injected into the electrolytic cell body from the 4# injection and discharge port at the bottom of the electrolytic cell body, pushing the reaction 3# working liquid aqueous electrolyte film to gradually rise; and the 1# working liquid light sealing oil discharged due to the rise in liquid level is pumped back into the 1# working liquid storage tank by the 1# peristaltic pump; when the position of the 3# working liquid aqueous electrolyte film rises to the position of the lower liquid level gauge, adjust Adjust the power supply voltage to the voltage value required for electrolytic oxidation, and gradually approach the GIC electrode to start oxidation; when the liquid level of the 3# working liquid aqueous electrolyte rises to the position of the upper liquid level gauge, the oxidation of this GIC electrode is completed and CFG is obtained; at this time, stop the power supply, close the 1# solenoid valve and the 4# solenoid valve and the peristaltic pump, and the electrolytic oxidation reaction process ends; at this time, all the 1# working liquid light sealing oil will be completely discharged from the electrolytic cell body, and the reaction product CFG will be immersed in the 4# working liquid heavy sealing oil; Step 3: Open the 4# solenoid valve, and the 4# peristaltic pump reverses to discharge all the working liquid in the electrolytic cell body into the 4# working liquid storage tank.

10. The method for using the general-purpose electrolytic preparation device for covalently functionalized graphene according to claim 9, characterized in that: In step 4 of process one, after the electrolytic intercalation is completed, the 2# working liquid concentrated sulfuric acid intercalation agent is released from the electrolytic cell body, and the 1# working liquid light sealing oil is injected simultaneously to ensure that the graphite intercalation compound obtained by the intercalation is always not in contact with the air; in step 3 of process one, after the electrochemical reaction treatment is completed, the product CFG sample strip is taken out from the electrolytic cell body, the graphite paper that does not participate in the reaction is cut off, and then it is put into water for ultrasonic or shear exfoliation to obtain an aqueous dispersion of CFG.

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