Field emission from multiwall carbon nanotubes prepared by electrodeposition without the use of a dispersant

Preparation and field emission properties of multiwall carbon nanotube (MWNT):nickel (Ni) composite are presented. MWNT:Ni composite is deposited without the use of a dispersant by placing the plating solution in a sonic bath for 15 minutes before electrodeposition. Electrochemical measurements are conducted using a μAutolab computer controlled potentiostat with a three-electrode configuration and typical cell volume of 10 cm³. Scanning electron microscopy is used to image the resulting electrodeposits. Strong adhesion is observed between nickel coated nanotubes and the substrate surface. The substrates are subjected to field emission characterisation, where emission current is recorded as a function of macroscopic electric field at a vacuum of around 10^-6 mbar. Threshold fields of the order 20 V/μm are observed. It is expected that by altering the deposition conditions, much lower threshold fields would be observed.