A novel method for the development of porous, flexible carbon nanofibers from a bead-free, electrospun Polyacrylonitrile (PAN)/sodium bicarbonate (NaHCO3) nanocomposite fibers using thermally induced selective removal mechanism is reported. Uniform size distribution of ball-milled NaHCO3 nanoparticles in PAN nanofibers provided an effective pathway for the creation of homogenous mesopores in carbon nanofibers with reduced fiber diameter. Structural and morphological characterization using Fourier Transform Infrared spectroscopy (FTIR), Atomic Force Microscopy (AFM), High Resolution Transmission Electron Microscopy (HRTEM), Field Emission Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD) and Raman Spectroscopy revealed the evolution of porous carbon nanofibers from electrospun PAN/NaHCO3 nanocomposite fibers during the controlled thermal treatment process and the formation of graphitic crystallites in the networks of nanofibers. The micro/mesopores having uniform size distribution was created on the surface of the nanofibers as well as inside the fibers creating a porous fiber assembly. The mesoporous carbon nanofibers exhibited high specific surface area of 724 m(2) g(-1) and excellent electrical conductivity of 294 S/m which suggests their promising application as a highperformance catalyst support material in fuel cells. (C) 2016 Elsevier Inc. All rights reserved.