Method for non-invasive efficient purification of single-wall carbon nano tube

Abstract

The invention belongs to the field of material synthesis, in particular relates to a method for non-invasive efficient purification of a single-wall carbon nano tube. The method comprises the following steps: laying original single-wall carbon nano tube samples in a quartz boat, and placing the quartz boat in a quartz tube; raising the temperature of a furnace to 400-500 DEG C at the speed rate of 10 DEG C. min<-1> and insulating for 1-3 hours; after an air oxidation reaction is finished, closing two ends of the quartz tube and introducing protective gas argon so as to exhaust the air in the quartz tube; then raising the temperature of the furnace to 750-1000 DEG C at the speed rate of 10 DEG C. min<-1> and insulating for 1-3 hours; after a high-temperature reduction reaction thermal treatment process is finished, introducing the protective gas, taking out the samples after the temperature of the furnace is reduced to room temperature, and removing catalyst particles and unreacted metal oxides, wherein the metals on the catalyst particles are reduced out; and filtering, washing and drying again, so as to obtain the purified single-wall carbon nano tube samples. In the method, the purification process is simple, the tube wall structure of the single-wall carbon nano tube is not destroyed in the whole purification process, the purification cost is low, environment is not polluted, and continuous operation can be realized, thus the method is suitable for large-scale purification of the single-wall carbon nano tube.

Description

technical field [0001] The invention belongs to the field of material synthesis, and in particular relates to a method for efficiently purifying single-walled carbon nanotubes without damage. Background technique [0002] With its unique electrical, mechanical and chemical properties and unique quasi-one-dimensional tubular molecular structure, carbon nanotubes have become a research hotspot in many fields such as physics, chemistry and material science, and have shown their potential in the fields of energy materials and electronic devices. Broad application prospects. No matter the original samples of SWNTs prepared by arc method, laser method, or catalytic pyrolysis method contain a large amount of impurities, including metal catalyst particles, non-SWCNT carbon tissues mainly include fullerenes, amorphous Carbon, multi-wall carbon nanotubes, etc. The existence of these impurities hinders the further research and application of single-wall carbon nanotubes. The purificat...

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Problems solved by technology

Mainly use HNO 3 , HClO 4 , KMnO 4 / H 2 SO 4 As a strong oxidant, but during the purification process, the strong oxidant also destroys the wall structure of carbon nanotubes while removing impurities, and even breaks and breaks

lead to more sample loss, Wu (Wu C. X., Li J. X., Dong G. F., et al., Removal of Ferromagnetic Metals for the Large-Scale Purification of Single-Walled Carbon Nanotubes, J. Phys. Chem. C, 2009, 113, 3612-3616) and others reported a multi-step purification method for single-walled carbon nanotubes. The original sample of single-walled carbon nanotubes was subjected to air oxidation, high temperature treatment, HCl and HNO 3 The purified single-walled carbon nanotube samples were obtained after multiple processes. The original sample volume before treatment was 2.7g, and the sample obtained after multiple purification processes was only ~200mg. Most of the single-walled carbon nanotubes were in consumed during purification

[0004] The current problem of the above purification method is that the metal particles that act as catalysts after the growth of carbon nanotubes are tightly wrapped by graphitic carbon layers. These graphitized carbon layers exhibit very strong oxidation resistance. A large number of catalyst particles may not be removed after removal, or more hollow carbon layer structures remain after removal, which still remain in the sample as impurities

In order to obtain a better purification effect, a strong oxidizing environment is adopted, but in this case the destruction of the wall structure of carbon nanotubes and the loss of a large amount of samples cannot be avoided

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