Preparation method of carbon nanotube field emission cathode

Abstract

The invention relates to a preparation method of a carbon nanotube field emission cathode and belongs to the field of nanomaterial preparation and application. The method comprises the following steps of: preparing a porous anodized aluminum template by secondary anodic oxidation process, soaking the template in a nickel chloride or cobalt chloride solution, taking out and air-drying to obtain a template (2); preparing carbon nanotubes in the pores of the template (2) by chemical vapor deposition process to obtain a template (3); adding dropwise a phosphoric acid solution to the surface on which the carbon nanotubes are not deposited to obtain a template (4); forming a silver coating on a stainless steel substrate by evaporation and then sticking the carbon nanotube-grown surface of the template (4) onto the silver coating, to produce the carbon nanotube field emission cathode. The pressure reduction method is adopted in the late stage of the preparation of the porous anodized aluminum template, so as to reduce the diameters of the pores at the bottom of the porous anodized aluminum template and thus to increase the length-diameter ratio of the carbon nanotubes and improve the field emission characteristics of the carbon nanotube field emission cathode.

Description

technical field [0001] The invention relates to a method for preparing a carbon nanotube field emission cathode, which belongs to the field of nanomaterial preparation and application. Background technique [0002] Since the Japanese scientist Iijima discovered carbon nanotubes in 1991, scientists have conducted a lot of research on the preparation and mechanism of carbon nanotubes, and gradually shifted their attention to their applications. In the preparation process of carbon nanotube field emission cathodes used in vacuum ionization gauges, most carbon nanotube field emission cathodes are prepared by screen printing and thermochemical vapor deposition. [0003] The document "Huarong Liu, Hitoshi Nakahara, Sashiro Uemura, et al.Ionization vacuum gauge with a carbon nanotube field electron emitter combined with a shield electrode.Vacuum 84, 2010" introduced the porous anodized aluminum template obtained by electrochemical anodic oxidation Finally, in the holes of the alum...

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Problems solved by technology

[0004] In view of the problems in the prior art that carbon nanotubes are grown on the surface of anodized aluminum templates as field emission cathodes, the carbon nanotubes are easy to lodging, and it is difficult to control the length and density of the carbon nanotubes. The purpose of the present invention is to provide a carbon nanotube The preparation method of nanotube field emission cathode can effectively control the length and shape of carbon nanotubes

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