While few-layered graphene (FG) has been synthesized by several different arc-discharge methods, its growing mechanism has hardly been studied by experiment. Here, we have investigated systematically its growth mechanism using the arc-discharge method under different environments including helium, oxygen-helium and hydrogen-helium. The results indicate that FG can only be produced in the presence of reactive gases, implying that the growing mechanism of few-layered graphene involves graphite evaporation and reactive-gas-confining crystallization of the evaporated carbon clusters. The key factor inducing the discrepancies in FG synthesis under different buffer gases can be assigned to the reactivity of corresponding gases.

It is a great challenge to find a reusable solid fuel material with both high absorption capability for organic liquids and clean use. In this work, a highly reusable and environmentally friendly solid fuel material based on three-dimensional graphene foam (3D-GF) was prepared, with high absorption capability for organic liquid fuels up to over 900 times its own weight and outstanding fire resistance. This 3D-GF shows high combustion efficiency, exceeding 99%. A rather clean burning was observed without toxic gases and soot particles released, as in the case of the conventional solid fuel materials. More importantly, the reusability and mechanical stability of the material are kept almost unchanged after 10 cycles of adsorption–combustion with organic liquid fuels.