Electrospun MgO-loaded carbon nanofibers: Enhanced field electron emission from the fibers in vacuum

► Magnesium acetate-polyacrylonitrile composite nanofibers (NFs) have been produced via electrospinning technique. ► As-spun precursor NFs have been stabilized in air (280 °C) and then carbonized in nitrogen (800 °C) atmospheres. ► Magnesium oxide-carbon nanofibers (MgO/CNFs) have been obtained after the heat treatment processes. ► Field emission characteristics of the carbonized NFs made in a ultra high vacuum chamber. ► Enhancement in field electron emission of MgO/CNFs (195.5% enhancement) occurs compared that of pure CNFs.