Graphene based on lignin in-situ generation and preparation method thereof

Abstract

The invention discloses graphene based on lignin in-situ generation and a preparation method thereof, and belongs to the technical field of nano material preparation. The method comprises the following steps: by adopting a high-temperature sintering technology and taking lignin as a carbon source, carrying out high-temperature pyrolysis process treatment on the lignin, and then carrying out cooling process treatment, so as to prepare the graphene based on lignin in-situ generation. Therefore, the method disclosed by the invention is simple to operate and good in repeatability, avoids using an organic solvent, a dispersing agent, a chemical reducing agent and a stabilizing agent, and has the advantages of being green, environment-friendly, low in cost, economical and energy-saving. The lignin-based in-situ generated graphene prepared by the preparation method forms a crystal lamellar structure, and is single-layer graphene, multi-layer graphene or a mixture of the single-layer graphene and the multi-layer graphene, so that the lignin-based in-situ generated graphene has good dispersity and stability and has industrial production prospects and application value.

Description

technical field

[0001] The invention belongs to the technical field of nanomaterial preparation, and relates to graphene generated in situ based on lignin and a preparation method thereof. Background technique

[0002] In 2004, graphene material was successfully prepared, which triggered a new wave of research on carbon materials. Graphene is a planar carbon nanomaterial composed of a layer of carbon atoms. It is the thinnest two-dimensional material known so far, with a thickness of only 0.335nm. It is composed of hexagonal lattices. The carbon atoms in graphene are connected by σ bonds, endowing graphene with extremely excellent mechanical properties and structural rigidity. Moreover, in graphene, each carbon atom has an unbonded p-electron. These p-electrons can move freely in the crystal, and the movement speed is as high as 1 / 300 of the speed of light, which endows graphene with good conductivity. Optically, graphene is almost completely transparent, absorbing only 2....

Examples

preparation example Construction

[0038] The invention discloses a preparation method of graphene based on lignin in-situ generation, which comprises the following steps: using lignin as a carbon source, in a vacuum hot-pressing sintering furnace, first performing a high-temperature pyrolysis process, and then performing a cooling process treatment to produce graphene based on lignin in-situ generation; wherein, the high-temperature pyrolysis process includes the first-stage heat treatment and the second-stage heat treatment, specifically including: heating from room temperature to 800 °C at a heating rate of 2-10 °C / min ~1000°C, heat preservation for 30-60min, and gasification and pyrolysis after the first stage of heat treatment to obtain the lignin carbon sphere precursor. Subsequently, the temperature was raised to 1200-1600°C at 2-10°C / min, and held for 5-60min, and the obtained graphene precursor was subjected to a second-stage heat treatment so that the temperature between the lignin carbon spheres was h...

Embodiment 1

[0047] Put 0.5g of nano-lignin directly in a vacuum hot-pressing sintering furnace for high-temperature pyrolysis: heat up to 800°C at 5°C / min for the first stage of heat treatment, and keep warm for 30 minutes, then continue to heat up to 1200°C at 5°C / min for 30 minutes Carry out the second stage of heat treatment, and then cool down to 400°C at 5°C / min for the cooling process, then cool to room temperature with the furnace and take out graphene powder based on graphene generated in situ from lignin, with a yield of 78% . Adopt scanning electron microscope (SEM) to obtain the sheet thickness of the graphene based on lignin in situ generation of gained is about 12nm, transmission electron microscope (TEM) get the lattice size of the described graphene based on lignin in situ generation is 0.338nm, The sheet thickness is about 13nm. The BET specific surface area test method shows that the obtained graphene based on lignin in situ has a specific surface area of ​​1050m 2 / g, ...

Embodiment 2

[0049] Put 0.8g of industrial alkali lignin directly in a hot-pressed sintering furnace for high-temperature pyrolysis (at a pressure of 30MPa). After filling nitrogen, heat up to 900°C at 8°C / min for the first-stage heat treatment. After holding for 50min, continue to Raise the temperature to 1300°C at 8°C / min, hold for 30 minutes for the second stage of heat treatment, then cool down to 500°C at 8°C / min for the cooling process, then cool to room temperature with the furnace and take out to obtain graphene based on lignin in situ graphene powder with a yield of 80%. Adopt scanning electron microscope (SEM) to obtain the sheet thickness of the graphene based on the in situ generation of lignin of gained is about 14nm, transmission electron microscope (TEM) obtain the lattice size of the graphene based on the in situ generation of lignin to be 0.401nm, The sheet thickness is about 15nm. The BET specific surface area test method shows that the obtained graphene based on lignin ...

technical field

[0001] The invention belongs to the technical field of nanomaterial preparation, and relates to graphene generated in situ based on lignin and a preparation method thereof. Background technique

[0002] In 2004, graphene material was successfully prepared, which triggered a new wave of research on carbon materials. Graphene is a planar carbon nanomaterial composed of a layer of carbon atoms. It is the thinnest two-dimensional material known so far, with a thickness of only 0.335nm. It is composed of hexagonal lattices. The carbon atoms in graphene are connected by σ bonds, endowing graphene with extremely excellent mechanical properties and structural rigidity. Moreover, in graphene, each carbon atom has an unbonded p-electron. These p-electrons can move freely in the crystal, and the movement speed is as high as 1 / 300 of the speed of light, which endows graphene with good conductivity. Optically, graphene is almost completely transparent, absorbing only 2....

Examples

preparation example Construction

[0038] The invention discloses a preparation method of graphene based on lignin in-situ generation, which comprises the following steps: using lignin as a carbon source, in a vacuum hot-pressing sintering furnace, first performing a high-temperature pyrolysis process, and then performing a cooling process treatment to produce graphene based on lignin in-situ generation; wherein, the high-temperature pyrolysis process includes the first-stage heat treatment and the second-stage heat treatment, specifically including: heating from room temperature to 800 °C at a heating rate of 2-10 °C / min ~1000°C, heat preservation for 30-60min, and gasification and pyrolysis after the first stage of heat treatment to obtain the lignin carbon sphere precursor. Subsequently, the temperature was raised to 1200-1600°C at 2-10°C / min, and held for 5-60min, and the obtained graphene precursor was subjected to a second-stage heat treatment so that the temperature between the lignin carbon spheres was h...

Embodiment 1

[0047] Put 0.5g of nano-lignin directly in a vacuum hot-pressing sintering furnace for high-temperature pyrolysis: heat up to 800°C at 5°C / min for the first stage of heat treatment, and keep warm for 30 minutes, then continue to heat up to 1200°C at 5°C / min for 30 minutes Carry out the second stage of heat treatment, and then cool down to 400°C at 5°C / min for the cooling process, then cool to room temperature with the furnace and take out graphene powder based on graphene generated in situ from lignin, with a yield of 78% . Adopt scanning electron microscope (SEM) to obtain the sheet thickness of the graphene based on lignin in situ generation of gained is about 12nm, transmission electron microscope (TEM) get the lattice size of the described graphene based on lignin in situ generation is 0.338nm, The sheet thickness is about 13nm. The BET specific surface area test method shows that the obtained graphene based on lignin in situ has a specific surface area of ​​1050m 2 / g, ...

Embodiment 2

[0049] Put 0.8g of industrial alkali lignin directly in a hot-pressed sintering furnace for high-temperature pyrolysis (at a pressure of 30MPa). After filling nitrogen, heat up to 900°C at 8°C / min for the first-stage heat treatment. After holding for 50min, continue to Raise the temperature to 1300°C at 8°C / min, hold for 30 minutes for the second stage of heat treatment, then cool down to 500°C at 8°C / min for the cooling process, then cool to room temperature with the furnace and take out to obtain graphene based on lignin in situ graphene powder with a yield of 80%. Adopt scanning electron microscope (SEM) to obtain the sheet thickness of the graphene based on the in situ generation of lignin of gained is about 14nm, transmission electron microscope (TEM) obtain the lattice size of the graphene based on the in situ generation of lignin to be 0.401nm, The sheet thickness is about 15nm. The BET specific surface area test method shows that the obtained graphene based on lignin ...

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