A method for rapid preparation of biomass-derived MXene materials induced by joule heat

Abstract

The application provides a method for promoting millisecond-level rapid conversion of biomass material to MXene material by using flash joule heating technology. Biomass material and metal powder are used as precursors, a uniform mixture is formed after mixing and grinding, and then a transient high voltage is applied between two electrodes to trigger millisecond-level ultrafast heating to a reaction temperature. Under the extreme transient thermal field, the biomass is instantaneously pyrolyzed and reconstructed into high-activity amorphous carbon, and the metal component is simultaneously activated; the ultra-high heating rate and non-equilibrium environment significantly strengthen the atomic interdiffusion of the carbon / metal interface, driving the in-situ generation of MXene. This method breaks through the limitations of traditional multi-step processes, realizes the direct conversion of biomass to MXene, has the advantages of high efficiency and low cost, provides a new paradigm for the high-value utilization of biomass, and has a wide application prospect in the fields of energy storage, catalysis and adsorption.

Description

Technical Field

[0001] This invention relates to a high-value utilization technology for biomass materials. Specifically, it uses biomass materials as precursors and, based on flash Joule heating technology, simultaneously achieves rapid carbonization of biomass and its millisecond-level conversion into high-performance MXene materials in an instantaneous high-temperature field, thus endowing it with ultra-high added value. Biomass-based MXene materials prepared by this method can be widely used in fields such as supercapacitors, electrochemical adsorption, and catalyst supports. Background Technology

[0002] Biomass, as one of the most widely available renewable resources in nature, boasts significant advantages such as vast reserves, carbon neutrality, and environmental friendliness, making it the most abundant carbon-containing organic macromolecule functional body on Earth. Currently, biomass resources are widely used in energy, chemical engineering, and materials fields, primarily through conversion into gaseous and liquid fuels such as biogas, biomethanol, and bioethanol, as well as the preparation of solid carbon materials like activated carbon and graphite. These technological pathways have alleviated dependence on fossil resources to some extent and are of positive significance for promoting energy structure transformation and reducing carbon emissions. However, from the perspective of resource utilization efficiency and product added value, existing biomass conversion models are still mainly focused on low-end fuels and general-purpose carbon materials, with limited economic value and functional levels, making it difficult to fully unleash the potential of biomass in replacing high-carbon-emission fossil raw materials. Especially under the "dual carbon" goal, simply using biomass for low-value-added energy or conventional carbon materials is no longer sufficient to meet the demands of high-quality and sustainable development. Therefore, promoting the transformation of biomass from "energy-type utilization" to "material-type, functional, and high-value-added utilization" has become an inevitable trend in biomass resource development. Against this backdrop, exploring new pathways for the transformation of biomass into high-end functional materials is of great scientific significance and strategic value for realizing its truly high-value utilization.

[0003] MXene is a new class of two-dimensional transition metal carbide / nitride materials (such as Ti3C2T). x Mo2CT x V2CT xMXenes (e.g., graphene, MAX phase precursors) have garnered significant attention since their inception due to their excellent electrical conductivity, tunable surface chemistry, layered structure, and outstanding electrochemical and electromagnetic response characteristics. They exhibit remarkable application potential in energy storage devices, electromagnetic shielding, catalysis, electrochemical sensing, flexible electronics, and environmental remediation, and are considered one of the most promising two-dimensional functional materials after graphene. Compared to traditional carbon materials, MXenes not only possess high specific surface area and excellent electron transport properties but also incorporate multi-electronic states and strong interactions conferred by transition metal elements, giving them significant advantages in both functionality and added value. Therefore, the synthesis and large-scale preparation of MXenes have become a core focus of current research. However, existing MXene preparation routes heavily rely on high-temperature MAX phase precursors and fluorine-containing etching systems, resulting in complex processes, high energy consumption, and significant environmental risks. This reality objectively limits the deep integration of MXenes with sustainable raw material systems. To date, there are no reports of direct synthesis of MXenes using biomass as a precursor; this gap is determined by the synthesis mechanism of MXene materials. From a synthetic science perspective, MXenes essentially originate from the formation and structural regulation of transition metal carbides. Traditionally, precursors used in the synthesis of metal carbides typically require highly ordered graphite structures to ensure controllable diffusion and reaction of carbon within the metal. In contrast, biomass-derived carbon is usually amorphous or poorly graphitized, with complex structures and diverse compositions, and has long been considered unsuitable as an ideal precursor for finely controlling carbide structures. Furthermore, in metal-carbon reaction systems, although the diffusion rate of carbon atoms is generally higher than that of metal atoms, achieving uniform and rapid carbonization often requires the introduction of additional metal diffusion promoters or prolonged high-temperature treatment. These factors collectively present significant challenges to the application of biomass in MXene synthesis systems.

[0004] Against this backdrop, Flash Joule Heating (FJH) technology offers a new physicochemical pathway to overcome the aforementioned limitations. FJH is an ultrafast bulk heating technology based on the Joule effect, capable of achieving rapid temperature jumps (up to several thousand degrees Celsius) in materials within milliseconds to seconds, accompanied by extremely high heating and cooling rates. This transient, high-temperature, and strongly non-equilibrium heat treatment method not only significantly reduces overall energy consumption but also introduces kinetic conditions for solid-solid reactions that are difficult to achieve with traditional heat treatments. When FJH is applied to biomass-metal systems, its unique advantages are particularly prominent. On the one hand, ultrafast thermal shock can drive biomass to complete pyrolysis in an extremely short time, generating highly dispersed and highly reactive amorphous carbon; on the other hand, instantaneous high temperatures can induce crystal structure transformations in transition metals, significantly enhancing their atomic diffusion capabilities and reactivity. In this non-equilibrium thermal field, the mutual diffusion and reaction between carbon and metal atoms are greatly accelerated, thus creating the possibility for the formation of complex carbides and even MXene structures without the need for prolonged high-temperature treatment and additional dispersants.

[0005] This study proposes a novel strategy for the millisecond-level rapid synthesis of MXene using biomass as a reaction precursor and flash evaporation with Joule heating. This method overcomes the dependence of traditional MXene synthesis on high-purity graphite carbon sources, high-temperature MAX phases, and highly corrosive etchants, organically combining the high-value utilization of biomass with the green synthesis of MXene. This not only expands the application boundaries of biomass resources but also provides a new scientific paradigm for the sustainable preparation of two-dimensional high-value-added materials. Summary of the Invention

[0006] The main objective of this invention is to provide an innovative method for the rapid conversion of biomass into MXene materials using flash Joule heating. This method first involves thoroughly mixing and grinding biomass powder and metal powder to achieve close contact between the two phases. Subsequently, the temperature of the mixed powder is rapidly increased to the high-temperature range required for the synthesis reaction using FJH technology. As the temperature rises, the biomass material rapidly pyrolyzes, transforming into amorphous carbon materials. When the temperature reaches the temperature required for the transformation to a highly reactive phase, the metal powder rapidly transforms from a low-reactivity phase to a highly reactive phase, thereby triggering the interdiffusion and infiltration of carbon and metal, achieving the synthesis of MXene materials.

[0007] The technical solution of the present invention specifically includes the following steps:

[0008] I. Preparation of Biomass / Metal Hybrid Powder

[0009] Biomass materials (poplar, bamboo, sugarcane bagasse, etc.) are mixed with metal powders (titanium powder, molybdenum powder, vanadium powder, etc.) to obtain biomass / metal mixed powder. The specific preparation steps are as follows: First, the natural biomass materials are pretreated (e.g., dried, washed) to remove surface impurities. Then, the biomass materials are pulverized in a pulverizer. The pulverized biomass powder is sieved through a 400-mesh sieve to collect powders that meet the fineness requirements. The sieved biomass powder is then mixed with metal powder in a certain proportion and thoroughly ground in a mortar until uniformly mixed, finally obtaining the biomass / metal mixed powder.

[0010] II. FJH Heat Treatment

[0011] The prepared biomass / metal hybrid powder was placed in the electrode clamping device of the FJH system, and instantaneous high voltage was applied to achieve a millisecond-level temperature surge to the preset reaction temperature. As the temperature increased, the biomass material rapidly transformed into amorphous carbon, while the metal powder also changed from a low-activity phase to a highly reactive phase. Under high temperature, the amorphous carbon and metal powder interdiffused and reacted, thereby synthesizing MXene materials.

[0012] Compared with existing methods for high-value utilization of biomass materials, this invention has the following significant advantages: (1) Wide adaptability of raw materials: Natural biomass powder can be used directly, with low requirements for raw material purity and crystallinity; (2) Millisecond-level high-efficiency activation: Millisecond-level ultra-fast heating is achieved with the help of FJH technology, the reaction time is extremely short, the energy utilization efficiency is high, and the preparation efficiency is greatly improved; (3) Simplified process: Biomass carbonization, titanium powder phase change activation and synthesis reaction are integrated into an instantaneous step, without the need for pre-preparation of biochar or subsequent lengthy mixing and heat treatment, the equipment requirements are low, and the process conditions are simple; (4) Unique product structure: Instantaneous ultra-high temperature and rapid quenching are conducive to the formation of a porous amorphous carbon network with high defect density, and can achieve atomic-level tight composite with active metals, providing an ideal precursor structure for the synthesis of high-performance MXene materials; (5) Low cost and strong environmental friendliness: Avoid the use of highly corrosive chemical reagents (such as hydrofluoric acid involved in the traditional MXene preparation), no need for subsequent complex waste liquid treatment, less environmental burden, greener, safer and lower cost. Detailed Implementation

[0013] Example 1

[0014] (1) First, natural poplar wood is cut into 2*2*2cm blocks and pre-treated (e.g., dried, washed) to remove surface impurities. Then, the poplar blocks are put into a pulverizer for crushing. The resulting wood powder is sieved through a 400-mesh sieve to collect poplar wood powder that meets the fineness requirements. 1g of the sieved wood powder is mixed with 2g of titanium powder and ground thoroughly in a mortar until uniformly mixed, finally obtaining a poplar wood powder / titanium powder mixed powder.

[0015] (2) The prepared poplar wood powder / titanium powder mixture was placed in the electrode clamping device of the FJH system, and instantaneous high pressure was applied to achieve a millisecond-level temperature surge to 950℃. As the temperature increased, the poplar wood powder rapidly pyrolyzed to generate amorphous carbon, while the titanium powder rapidly transformed into a highly active state. Under high temperature, the amorphous carbon and titanium diffused and reacted with each other, thus achieving the synthesis of MXene material. The X-ray diffraction pattern of the obtained sample is shown below. Figure 1 As shown in the figure, the synthesized product of Example 1 exhibits a distinct diffraction peak at around 10°, corresponding to the 002 crystal plane of MXene. Simultaneously, in the mid-to-high angle region (30-80°), the sample shows characteristic peaks at approximately 36°, 41°, 60°, and 72°. These diffraction peaks can be attributed to the (111), (200), (220), and (311) crystal planes of MXene, respectively. This indicates that under flash Joule heating conditions, a rapid and complete carbothermic reaction occurred between the metal and the biomass material, successfully generating TiC with high crystallinity. x The phases demonstrate the successful synthesis of MXene. Furthermore, Example 1 exhibits the highest diffraction peak intensity and the sharpest peak shape, indicating that its product possesses higher crystallinity and a more complete crystal structure.

[0016] Example 2

[0017] (1) First, take a certain amount of bamboo and pre-treat it (such as drying and washing) to remove surface impurities. Then, put the bamboo into a pulverizer for pulverization. The pulverized bamboo powder is sieved through a 400-mesh sieve to collect powder that meets the fineness requirements. Take 1g of pure bamboo powder and mix it with 2g of titanium powder, and grind it thoroughly in a mortar until it is evenly mixed to finally obtain bamboo / titanium powder mixture powder.

[0018] (2) The prepared bamboo / titanium powder mixture was placed in the electrode clamping device of the FJH system, and instantaneous high voltage was applied to achieve a millisecond-level temperature surge to 950℃. As the temperature increased, the bamboo powder rapidly pyrolyzed to generate amorphous carbon, while the titanium powder rapidly transformed into a highly active state. Under high temperature, the amorphous carbon and titanium diffused and reacted with each other, thus achieving the synthesis of MXene material. The X-ray diffraction pattern of the obtained sample is shown below. Figure 1As shown in the figure, the synthesized product exhibits a weak diffraction peak at around 10°, corresponding to the 002 crystal plane of MXene. Simultaneously, in the mid-to-high angle region (30-80°), the sample shows characteristic peaks at approximately 36°, 41°, 60°, and 72°. These diffraction peaks can be attributed to the (111), (200), (220), and (311) crystal planes of MXene, respectively. This indicates that under flash Joule heating conditions, a rapid and complete carbothermic reaction occurred between the metal and the carbon source, successfully generating TiC with high crystallinity. x This further proves the successful synthesis of MXene.

[0019] Example 3

[0020] (1) First, take a certain amount of waste sugarcane bagasse and pre-treat it (such as drying and washing) to remove surface impurities. Then, put the sugarcane bagasse into a pulverizer for thorough pulverization. The pulverized sugarcane bagasse powder is sieved through a 400-mesh sieve to collect powder that meets the fineness requirements. Take 1g of powder and mix it with 2g of titanium powder, and grind it thoroughly in a mortar until the mixture is uniform, finally obtaining sugarcane bagasse / titanium powder mixed powder.

[0021] (2) The prepared bagasse / titanium powder mixture was placed in the electrode clamping device of the FJH system, and instantaneous high pressure was applied to achieve a millisecond-level temperature surge to 950℃. As the temperature increased, the bagasse powder rapidly pyrolyzed to generate amorphous carbon, while the titanium powder rapidly transformed into a highly active state. Under high temperature, the amorphous carbon and titanium diffused and reacted with each other, thus achieving the synthesis of MXene material. The X-ray diffraction pattern of the obtained sample is shown below. Figure 1 As shown in the figure, the synthesized product exhibits a weak diffraction peak at around 10°, corresponding to the 002 crystal plane of MXene. Simultaneously, in the mid-to-high angle region (30-80°), the sample shows characteristic peaks at approximately 36°, 41°, 60°, and 72°. These diffraction peaks can be attributed to the (111), (200), (220), and (311) crystal planes of MXene, respectively. This indicates that under flash Joule heating conditions, a rapid and complete carbothermic reaction occurred between the metal and the biomass material, successfully generating TiC with high crystallinity. x This further proves the successful synthesis of MXene.

[0022] Comparative Example 1

[0023] Take 0.3g of graphite powder and 2g of titanium powder, mix them, and grind them thoroughly in a mortar until they are evenly mixed to obtain a graphite powder / titanium powder mixture.

[0024] The prepared graphite / titanium powder mixture was placed in the electrode clamping device of the FJH system, and a 200W instantaneous high voltage was applied to achieve a millisecond-level temperature surge to 950℃. As the temperature increased, the titanium powder rapidly transformed into a highly active state and reacted with the graphite. The X-ray diffraction pattern of the obtained sample is shown below. Figure 1 As shown, the sample in Comparative Example 1 exhibits strong and sharp titanium characteristic diffraction peaks at approximately 40°, indicating that the reaction between biomass materials and titanium is relatively low under these reaction temperature conditions, and titanium powder still exists primarily in elemental form in the reaction system. This result further illustrates that graphite is difficult to fully react with metallic titanium in this synthesis system, thus significantly limiting the formation of MXene.

[0025] Comparative Example 2

[0026] First, natural poplar wood is cut into 2*2*2cm blocks, and then pre-treated (e.g., dried, washed) to remove surface impurities. Next, the poplar blocks are fed into a pulverizer for grinding. The resulting wood powder is sieved through a 400-mesh sieve to collect the fineness required. 1g of the sieved poplar powder is mixed with 2g of titanium powder and thoroughly ground in a mortar until homogeneous, ultimately yielding a poplar / titanium powder mixture.

[0027] The prepared poplar wood powder / titanium powder mixture was placed in a tube furnace, heated to 950℃ and held for two hours to obtain the reaction product. The X-ray diffraction pattern of the obtained sample is shown below. Figure 1 As shown, the sample in Comparative Example 2 also exhibits a strong and sharp titanium characteristic diffraction peak at approximately 40°, indicating that the degree of reaction between biomass and titanium is low under these reaction temperature conditions, and the titanium powder still exists mainly in elemental form in the system. This result shows that the traditional slow heating method of tube furnaces is insufficient to meet the requirements of rapid carbothermic reaction between biomass carbon source and metal source, thus significantly limiting the formation efficiency and crystal quality of the target carbide phase.

Claims

1. This invention relates to a method for preparing Joule-induced biomass-derived MXene materials, characterized in that: First, biomass powder and metal powder are thoroughly mixed and ground uniformly in a specific ratio to ensure close contact between the two phases. Then, using FJH technology, the temperature of the mixed powder is rapidly increased to the high-temperature range required for the synthesis reaction within a very short time, simultaneously achieving the pyrolysis of the biomass material and its conversion into MXene. By triggering the interdiffusion and reaction between carbon and metal powder at high temperature, the synthesis of MXene material is achieved in one step.

2. The method for preparing a Joule-induced biomass-derived MXene material according to claim 1, characterized in that: The MXene mentioned includes Ti3C2T x Mo2CT x V2CT x And all other two-dimensional metal carbides.

3. The method for preparing a Joule-inducible biomass-derived MXene material according to claim 1, characterized in that: The mass ratio of biomass powder to titanium powder is 3:1 to 1:

1.

4. The method for preparing a Joule-induced biomass-derived MXene material according to claim 1, characterized in that: The biomass materials mentioned include balsa wood, poplar wood, bamboo, straw, bagasse, and all other carbon-containing biomass materials.

5. The method for preparing a Joule-induced biomass-derived MXene material according to claim 1, characterized in that: The reaction requires a temperature of 850-1000℃.

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