Graphene nanosheets from the controlled explosion of aromatic hydrocarbons

Abstract

Explosions of benzene, toluene and xylenes were carried out in a 16.7 L chamber in the presence of O₂ at different fuel-rich molar ratios such that an aerosol of elemental carbon was produced. The product was a powder at higher precursor oxygen content and an aerosol gel at lower oxygen where the carbon yield was larger. The explosion temperature was measured by a spectrometer that detected black body, Planck radiation from the incandescent carbon, the analysis of which indicated temperatures in the range 2000–2500 K. The product collected was characterized by Raman, X-ray diffraction, Brunauer, Emmett and Teller (BET) specific surface area, high-resolution transmission electron microscopy (HRTEM), etc. HRTEM and Raman showed two product types: amorphous soot at a lower explosion temperature and few-layer graphene at a higher explosion temperature. BET showed that the graphene sample is highly porous and has a specific surface area of 388 m²/g. We conclude that chamber explosion of aromatic hydrocarbons can produce graphene, and the high explosion temperature during the reaction is the primary reason graphene is formed rather than soot.