Unusual Cu-Co/GO Composite with Special High Organic Content Synthesized by an in Situ Self-Assembly Approach: Pyrolysis and Catalytic Decomposition on Energetic Materials

An interesting Cu-Co/GO composite with special high organic content was accidentally fabricated for the first time via a one-pot solvothermal method in the mixed solvent of isopropanol and glycerol. The Cu-Co/GO composite was calcined separately in three different atmospheres (air, nitrogen, and argon) and further investigated by a series of characterization techniques. The results indicate that the spinel phase nano-CuCo2O4 composite, nanometal oxides (CuO and CoO), and nanometal mixture of Cu and Co were unexpectedly formed after calcination in air, N2, and Ar atmospheres, respectively, and the possible reaction mechanism was discussed. The specific mass losses of the Cu-Co/GO composite calcined in air, N2, and Ar atmospheres were 28.14 %, 21.68 %, and 23.76 %, respectively. The catalytic decomposition performances of the as-prepared samples for cyclotrimethylenetrinitramine (RDX) and the mixture of nitrocellulose (NC) and RDX (NC + RDX) were investigated and compared via DSC method, and the results demonstrate that Cu-Co/GO composites obviously decrease the thermal decomposition temperature of RDX from 242.3 to 236.5 (before calcination), 238.6 (air), 235.8 (N2), and 228.6 °C (Ar), respectively. Cu-Co/GO(Ar) composite exhibits the best catalytic decomposition performance among all samples, which makes the decomposition temperature of RDX and NC + RDX decrease by 13.7 and 4.9 °C and the apparent activation energy of decomposition for RDX decrease by 110.1 kJ/mol. The enhanced catalytic performance of Cu-Co/GO(Ar) composite could be attributed to the smaller particle size, better crystallinity, and specific well-dispersed metal atoms, whereas the Cu-Co/GO(air) composite after air calcination presents a bad catalytic performance due to the removal of GO.