Directional assembly of flowerlike maghemite on graphene and its catalytic activity for the thermal decomposition of CL-20

Metal oxides/graphene composites are potential solid propellant combustion catalysts owing to their complementary property between two components. Herein, an in-situ growth method was used for preparing gamma-Fe2O3/graphene composites (gamma-Fe2O3/G) with intimately coupled graphene sheets and flowerlike gamma-Fe2O3 nanoparticles (NPs). The in-situ growth strategy can not only inhibit the aggregation of gamma-Fe2O3 NPs, but also reduce the particle size of gamma-Fe2O3. As an efficient catalyst for the thermal decomposition of hexanitrohexaazaisowurtzitane (CL-20), gamma-Fe2O3/G2 (2 represents the graphene concentration is 2 mg/mL) decreases the thermal decomposition temperature of CL-20 from 252.13 degrees C to 245.20 degrees C and the apparent activation energy from 183.02 kJ/mol to 150.68 kJ/mol, respectively. The improved catalytic activity may be attributed to the synergistic effect between gamma-Fe2O3 and graphene, which can efficiently construct the three-dimensional framework structure for exposing more active sites.