Synthesis of superhydrophobic carbon sphere by pyrolysis of heavy oil fraction of coal tar/ferrocene mixture and their magnetic nanostructure

Abstract

This present work describes the ferrocene-catalyzed conversion of heavy oil fraction of coal tar to carbon sphere aggregate films in the form of necklace-like carbon spheres, carbon sphere‑carbon nanotube composite, and pomegranate-like carbon spheres by chemical vapor deposition (CVD). Necklace-like carbon spheres exhibit hydrophobic surfaces, whereas pomegranate-like carbon spheres-CNT composites and pomegranate-like carbon spheres display superhydrophobic surfaces. The as-prepared hydrophobic and superhydrophobic surfaces were carefully characterized by Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HRTEM), Atomic Force Microscopy (AFM), and Magnetic Force Microscopy (MFM) to confirm the effect of geometric carbon aggregates with thermally decomposed ferrocene (FeCp2) catalysts on their magnetic nanostructure. The surface chemistry as well as oxidation resistance was studied by Fourier Transform Infrared spectroscopy (FTIR), Raman spectroscopy, and Thermal Gravimetric Analysis (TGA). FeCp2 catalyst concentration in the heavy oil fraction of coal tar was observed to have a direct correlation with morphology, disordered level of graphitic structure, magnetic domain pattern arrangement, and thermal oxidation resistance of as-produced carbon sphere aggregate.