Graphene oxide induced nanoscale energetic coordination polymer with self-sustaining combustion ability

The self-sustaining combustion of energetic materials, especially for propellants and pyrotechnics, is highly expected because it is related to various issues, such as combustion efficiency, ignition energy, and environmental protection. In this work, we present a method to solve the discontinuous and quenching combustion issues of energetic coordination polymer (ECP) by introducing graphene oxide (GO) into the growth of ECP. An ECP [(NiC₂H₄N₈O₄)_n, Ni-BTO] constructed from Ni²⁺ and H₂BTO [1H,1′H-(5,5′-bitetrazole)-1,1′-bis(olate)] ligand is in situ grown on GO layers. The abundant active sites of GO derived from its oxygen groups make it participate in the coordination and polymerization of Ni-BTO, thereby inducing a new kind of ECP (GO-Ni-BTO). The induction effect of GO reduces the size of Ni-BTO particles to the nanoscale and allows them to chemically bond to GO layers. The effects of different GO contents on the exothermic, combustion, and pressure-generation properties of GO-Ni-BTO are systematically investigated. Results indicate that GO-Ni-BTO ECP with 7.5 ​wt% GO content can solve the quenching and discontinuous combustion issues presented by micro-size Ni-BTO with a higher heat output (3265.58 J·g⁻¹) because of the reduced size of GO-Ni-BTO, oxygen-release ability of GO, and strong thermal conductivity of reduced GO. Correspondingly, the peak pressure and pressurization rate of GO-Ni-BTO ECP with 7.5 ​wt% GO content are also greatly enhanced. This interesting GO-Ni-BTO ECP can be used as a heat source for the initiation of secondary explosives and as a gas generator for the propulsion system.