A method for preparing phosphorus-doped graphene using phosphorus-containing sludge and biomass
Through hydrothermal carbonization and flash joule heat technology, phosphorus-containing sludge and biomass are converted into phosphorus-doped graphene, solving the problem of phosphorus resources and biomass waste utilization, and achieving efficient and low-cost graphene preparation. Have good application potential.
Patent Information
- Application Number
- CN202410555517.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-07
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2044-05-07
AI Technical Summary
The prior art is difficult to effectively utilize phosphorus resources and biomass waste, and the preparation method of graphene is complex and costly, and lacks environmentally friendly and efficient preparation processes.
Phosphorus-containing sludge and biomass are used to generate phosphorus-doped hydrothermal carbonization reaction, and phosphorus-doped graphene is prepared in combination with flash joule heat technology, and high added value is achieved using low-cost phosphorus-containing sludge and biomass. reuse.
In-situ doping of phosphorus elements is achieved, pollutants are avoided, and high-quality phosphorus-doped graphene is prepared. The process is simple and fast, the cost is low, and it is suitable for large-scale production.
Smart Images
Figure CN118289752B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of solid waste resource utilization and environmental protection, and specifically relates to a method for preparing phosphorus-doped graphene by using phosphorus-containing sludge and biomass. Background Art
[0002] Hydrothermal carbonization is an exothermic thermochemical process and a very promising thermochemical technology. It is considered to be a very promising thermochemical technology for the treatment of organic wastes with high water content. Compared with traditional hydrothermal carbonization, co-hydrothermal carbonization can not only treat multiple wastes at the same time, but also, due to the interaction between different components, the synergistic effect produced can affect the physical and chemical properties of hydrothermal carbon and the migration and transformation of the nutrients contained in it. Phosphorus is an important strategic resource, and the recycling of phosphorus resources is imminent. Phosphorus has a large atomic radius. Introducing phosphorus atoms into carbon materials will increase the interlayer spacing of carbon atoms, form new catalytic active sites, improve the utilization rate of the specific surface area of biomass carbon-based materials, and make the carbon materials have higher reactivity.
[0003] Graphene is a carbon material composed of a single layer of carbon atoms tightly arranged in a two-dimensional honeycomb structure. Graphene exhibits many excellent physical and chemical properties and has attracted widespread attention in various fields since its discovery. Graphene has a high specific surface area, great mechanical strength, strong electronic conductivity, good flexibility and easy chemical processing. Therefore, graphene has great application potential in many fields such as electricity, catalysis, optics and sensors.
[0004] The physical, chemical and electronic properties of graphene can also be significantly changed by heteroatom doping. Heteroatom doping technology refers to replacing carbon atoms in graphene with other elements, such as nitrogen, phosphorus, sulfur, etc. This technology uses various experimental means to allow heteroatoms to enter the carbon skeleton of graphene. Heteroatom doping will affect the original structure of graphene and produce new graphene-like structures to a certain extent. Therefore, how to obtain high-quality doped graphene and explore a mature and feasible preparation method is particularly important. In recent years, carbon-containing raw materials have been converted into high-quality flash graphene by flash Joule heating. Flash Joule heating technology is a fast and environmentally friendly material synthesis technology. Rapid temperature rise and fall can reduce energy consumption and can also quickly synthesize graphene. Summary of the invention
[0005] Based on the above technical background, the present invention provides a method for preparing phosphorus-doped graphene using phosphorus-containing sludge and biomass. The present invention uses phosphorus-containing sludge and biomass waste as raw materials, with low raw material cost, large output and high potential utilization value. By using phosphorus in phosphorus-containing sludge as a phosphorus source and biomass as a carbon source for hydrothermal carbonization reaction, and coupling flash Joule heat technology, high value-added recycling of low-value solid waste is achieved.
[0006] To achieve the above object, the present invention provides the following technical solutions:
[0007] A method for preparing phosphorus-doped graphene using phosphorus-containing sludge and biomass, comprising the following steps:
[0008] The phosphorus-containing sludge and biomass are subjected to a hydrothermal reaction, and the product is washed and dried to obtain phosphorus-doped hydrothermal carbon; the phosphorus-doped hydrothermal carbon is subjected to a flash Joule heat treatment to obtain phosphorus-doped graphene.
[0009] Preferably, the biomass is corn cobs.
[0010] Preferably, the mass ratio of the phosphorus-containing sludge to the biomass is 1:1-9.
[0011] Preferably, the temperature of the hydrothermal reaction is 150-300°C.
[0012] Preferably, the washing liquid for washing is water and anhydrous ethanol.
[0013] Preferably, the drying temperature is 105° C. and the drying time is 12 hours.
[0014] Preferably, the discharge voltage of the Joule heat in the flash Joule heat treatment is 150 to 300 V, the discharge time is 0.1 to 10 s, and the number of flash evaporations is 1 to 10 times.
[0015] The phosphorus-doped hydrothermal carbon prepared by the present invention needs to measure the resistance before flash Joule heat treatment, and the resistance should be controlled at ≤6Ω; the maximum temperature generated by the flash Joule heat discharge parameters provided by the present invention is 1000-3500°C.
[0016] The beneficial technical effects of the present invention are as follows:
[0017] The present invention utilizes phosphorus in phosphorus-containing sludge to achieve in-situ doping of phosphorus through hydrothermal carbonization reaction, thereby avoiding the generation of new pollutants; phosphorus-containing sludge and waste corn cobs form hydrothermal carbon through hydrothermal reaction, thereby achieving the reduction and resource utilization of phosphorus-containing sludge and corn cobs; flash Joule heat rapidly heats phosphorus-containing sludge and corn cob hydrothermal carbon to a high temperature in a very short time and then rapidly cools down, thereby avoiding the volatilization and decomposition of phosphorus-containing sludge and corn cob hydrothermal carbon, thereby forming a graphitized structure and obtaining phosphorus-doped graphene; the method for preparing phosphorus-doped graphene by Joule heat flash only uses electrical energy, and the process is simple and fast, low in cost, and less in pollution. Hydrothermal carbonization can achieve mild reaction and uniform phosphorus doping, and flash Joule heat can achieve rapid and high-quality graphene preparation. The method of preparing phosphorus-doped graphene by first hydrothermal carbonization and then Joule heat flash can prepare phosphorus-doped graphene with a high degree of graphitization.
[0018] The method for preparing phosphorus-doped graphene by Joule thermal flash evaporation provided by the present invention uses cheap and easily available phosphorus-containing sludge and corn cobs as precursors, adopts a hydrothermal carbonization method to achieve in-situ doping of phosphorus elements, and then uses a Joule thermal flash evaporation method to obtain high-quality phosphorus-doped graphene. The preparation method has controllable conditions, is rapid, has simple steps, and is highly efficient, and is conducive to large-scale production and application. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 The figure is a flow chart of preparing phosphorus-doped graphene in an embodiment of the present invention.
[0020] Figure 2 This is the Raman spectrum of the phosphorus-doped graphene prepared in Examples 1 to 3.
[0021] Figure 3 FT-IR spectra of phosphorus-doped graphene prepared in Examples 1 to 3.
[0022] Figure 4 This is the XPS graph of the phosphorus-doped graphene P2p prepared in Example 1.
[0023] Figure 5 This is the XPS graph of phosphorus-doped graphene P2p prepared in Example 2.
[0024] Figure 6 This is the XPS graph of phosphorus-doped graphene P2p prepared in Example 3. DETAILED DESCRIPTION
[0025] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.
[0026] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.
[0027] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.
[0028] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.
[0029] The flowchart of preparing phosphorus-doped graphene in the embodiment of the present invention is shown in Figure 1 .
[0030] The elemental analysis and industrial analysis results of the phosphorus-containing sludge and corn cobs used in Examples 1 to 3 of the present invention are shown in Table 1.
[0031] The XRF analysis results of the phosphorus-containing sludge used in Examples 1 to 3 of the present invention are shown in Table 2.
[0032] Table 1 Elemental analysis and industrial analysis results of the raw materials used in Examples 1 to 3
[0033]
[0034] Table 2 XRF analysis results of raw materials used in Examples 1 to 3
[0035] Compound wt% element wt% <![CDATA[P2O5]]> 63.89 P 27.88 CaO 25.47 Ca 18.21 <![CDATA[Na2O]]> 2.67 Na 1.98 <![CDATA[Al2O3]]> 1.92 Al 1.02 <![CDATA[Fe2O3]]> 0.37 Fe 0.26
[0036] Example 1
[0037] Preparation of phosphorus-doped graphene:
[0038] (1) Phosphorus-containing sludge and corn cobs are added to a hydrothermal reactor in a mass ratio of 1:1, the reaction temperature is 200°C, and the reaction time is 1 hour; after the reaction is completed, the mixture in the reactor is filtered and rinsed with anhydrous ethanol and deionized water until the upper liquid is colorless, and the solid phase product is dried in a forced air oven at 105°C for 12 hours to obtain phosphorus-doped hydrothermal carbon;
[0039] (2) 0.1 g of phosphorus-doped hydrothermal carbon was placed into a 10 mm inner diameter quartz tube covered with graphite paper, and both ends of the quartz tube were plugged with graphite electrode plugs with a diameter of 10 mm. The plugs were slowly compressed and the resistance was measured until the resistance was about 1.0 ohm. The compression was stopped; the temperature probe was installed and aligned, the vacuum box was closed, and the vacuum was evacuated to reduce the pressure in the box to 0.02 atmospheres;
[0040] (3) Set the discharge voltage to 180V and the discharge time to 1 second, repeat the discharge three times, and monitor the temperature in the quartz tube; during discharge, the mixed powder emits dazzling white light, and the highest temperature reaches 2500°C. After the three discharges are completed, cool to room temperature, take out the quartz tube, and pour out the reacted powder in the quartz tube, which is phosphorus-doped graphene (PCC-11-200-1).
[0041] Example 2
[0042] Preparation of phosphorus-doped graphene:
[0043] (1) Phosphorus-containing sludge and corn cobs are added to a hydrothermal reactor in a mass ratio of 1:1, the reaction temperature is 240°C, and the reaction time is 1 hour; after the reaction is completed, the mixture in the reactor is filtered and rinsed with anhydrous ethanol and deionized water until the upper liquid is colorless, and the solid phase product is dried in a forced air oven at 105°C for 12 hours to obtain phosphorus-doped hydrothermal carbon;
[0044] (2) 0.1 g of phosphorus-doped hydrothermal carbon was placed into a 10 mm inner diameter quartz tube covered with graphite paper, and both ends of the quartz tube were plugged with graphite electrode plugs with a diameter of 10 mm. The plugs were slowly compressed and the resistance was measured until the resistance was about 1.0 ohm. The compression was stopped; the temperature probe was installed and aligned, the vacuum box was closed, and the vacuum was evacuated to reduce the pressure in the box to 0.02 atmospheres;
[0045] (3) Set the discharge voltage to 180V and the discharge time to 1 second, repeat the discharge three times, and monitor the temperature in the quartz tube; during discharge, the mixed powder emits dazzling white light, and the highest temperature reaches 2800°C. After the three discharges are completed, cool to room temperature, take out the quartz tube, and pour out the reacted powder in the quartz tube, which is phosphorus-doped graphene (PCC-11-240-1).
[0046] Example 3
[0047] Preparation of phosphorus-doped graphene:
[0048] (1) Phosphorus-containing sludge and corn cobs are added to a hydrothermal reactor in a mass ratio of 1:1, the reaction temperature is 280°C, and the reaction time is 1 hour; after the reaction is completed, the mixture in the reactor is filtered and rinsed with anhydrous ethanol and deionized water until the upper liquid is colorless, and the solid phase product is dried in a forced air oven at 105°C for 12 hours to obtain phosphorus-doped hydrothermal carbon;
[0049] (2) 0.1 g of phosphorus-doped hydrothermal carbon was placed into a 10 mm inner diameter quartz tube covered with graphite paper, and both ends of the quartz tube were plugged with graphite electrode plugs with a diameter of 10 mm. The plugs were slowly compressed and the resistance was measured until the resistance was about 1.0 ohm. The compression was stopped; the temperature probe was installed and aligned, the vacuum box was closed, and the vacuum was evacuated to reduce the pressure in the box to 0.02 atmospheres;
[0050] (3) Set the discharge voltage to 180V and the discharge time to 1 second, repeat the discharge three times, and monitor the temperature in the quartz tube; during discharge, the mixed powder emits dazzling white light, and the highest temperature reaches 2500°C. After the three discharges are completed, cool to room temperature, take out the quartz tube, and pour out the reacted powder in the quartz tube, which is phosphorus-doped graphene (PCC-11-280-1).
[0051] The Raman spectra of phosphorus-doped graphene prepared in Examples 1 to 3 are shown in Figure 2 .from Figure 2It can be seen that the phosphorus-doped graphene prepared in Example 1 has obvious D peak and G peak. D / I G =0.75; the phosphorus-doped graphene prepared in Example 2 has obvious D peak and G peak, and its I D / I G =0.89; The phosphorus-doped graphene prepared in Example 3 has obvious D peak and G peak, and its I D / I G =0.99. Figure 2 The Raman spectra of each sample show obvious D peaks and G peaks, and ID:IG is less than 1, indicating that the sample has a graphitized structure and only has very few defects; combined with the FT-IR spectrum, it shows that CP bonds are generated in the prepared graphene, proving that phosphorus-doped graphene has been successfully prepared.
[0052] The FT-IR spectra of phosphorus-doped graphene prepared in Examples 1 to 3 are shown in Figure 3 .from Figure 3 It can be seen that the main functional groups contained in the phosphorus-doped graphene prepared in Examples 1 to 3 are -OH, CH, C=C, PO and POP.
[0053] The XPS graph of phosphorus-doped graphene P2p prepared in Example 1 is shown in Figure 4 .from Figure 4 It can be seen that there are PO and PC structures in the material, proving that phosphorus has been successfully doped into graphene.
[0054] The XPS graph of phosphorus-doped graphene P2p prepared in Example 2 is shown in Figure 5 .from Figure 5 It can be seen that there are PO and PC structures in the material, proving that phosphorus has been successfully doped into graphene.
[0055] The XPS graph of phosphorus-doped graphene P2p prepared in Example 3 is shown in Figure 6 .from Figure 6 It can be seen that there are PO and PC structures in the material, proving that phosphorus has been successfully doped into graphene.
[0056] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.
Claims
1. A method for preparing phosphorus-doped graphene using phosphorus-containing sludge and biomass, characterized in that: The following steps are involved: The phosphorus-containing sludge and biomass are subjected to a hydrothermal reaction, and the product is washed and dried to obtain phosphorus-doped hydrothermal carbon; the phosphorus-doped hydrothermal carbon is subjected to a flash Joule heat treatment to obtain phosphorus-doped graphene; The biomass is corn cobs; The mass ratio of the phosphorus-containing sludge to the biomass is 1:1-9; The temperature of the hydrothermal reaction is 150-300°C; The Joule heat discharge voltage in the flash Joule heat treatment is 150 to 300 V, the discharge time is 0.1 to 10 seconds, and the number of flash evaporations is 1 to 10 times.
2. The method for preparing phosphorus-doped graphene using phosphorus-containing sludge and biomass according to claim 1, characterized in that: The washing liquid for washing is water and anhydrous ethanol.
3. The method for preparing phosphorus-doped graphene using phosphorus-containing sludge and biomass according to claim 1, characterized in that: The drying temperature is 105° C. and the drying time is 12 h.