Direct and one-stage conversion of coal into carbon nanostructures with spherical, rod, tube and plate geometry by chemical solid synthesis method

Abstract

In this Study, various carbon nanostructures (nanospheres, nanorods, nanotubes and Graphene quantum dots) were synthesized by carbonization of bituminous coal (less than 44 micron) in solid phase. Since synthesis has taken place in the solid phase, this method has been named the catalytic chemical solid synthesis. Carbon nanospheres (50-60 nm in diameter) and Carbon nanotubes (outer diameter: 20-30nm) were synthesized in the presence of Ferrocene as catalyst, carbonization time of one hour and at carbonization temperature of 650°C and 800°C respectively. The change in the type of catalyst from ferrocene to magnetite nanoparticles (Fe3O4, 50-70 nm in diameter) at 800°C ;as the growth temperature of carbon nanostructures;, resulted in the synthesis of carbon nanorods (60-80 nm in diameter). Without catalysts, the growing nanostructures were not observed at carboniztion temperatures of 650°C, 800°C and 950°C. However, with acid preparation, an increase in carbonization temperature from 800°C to 950°C and an increase in carbonization time from 1 hour to 5 hours, the graphene quantum dots were observed. Samples were analyzed by scanning and transmission electron microscopy, X-ray diffraction, Energy-dispersive X-ray and ultraviolet spectroscopy. The results show that the maximum peak UV-visible spectrum of carbon nanospheres, grown nanostructures and graphene quantum dots are 214, 266 and above 300 nm, respectively.The diameters of carbon nanotubes and nanorods are in the range of iron nanoparticles (20-50 nm in diameter); due to the ferrocene decomposition; and magnetite nanoparticles(60-80 nm in diameter) respectively.

Keywords

• carbon nanostructure
• coal
• ferrosene
• graphene quantum dots