Preparation and capacitance performance of CNTs/3D graphene composites based on ternary catalysts

The ternary metallic Ni-Mg-Al oxide (TMO) was synthesized by a homogeneous precipitation method. The carbon nanotubes/3D graphene composites (CNTs/3DGR) were synthesized on the TMO by chemical vapor deposition(CVD) method using CH₄ as carbon source and Ar as protective gas. Herein, CNTs were grown on the in-situ reduced Ni nanoparticles, and the 3DGR was grown over the metallic composite oxides of Mg and Al. After etching the metal oxides, the CNTs/3DGR composite was obtained. The structure and performance of CNTs/3DGR were optimized by controlling the parameters during the precipitation of TMO and the CVD reaction of CNTs/3DGR, such as the metal ion molar ratio, growth temperature and growth time. TEM, SEM, EDS, Raman and XRD were employed to demonstrate the structure, morphology and composition of CNTs/3DGR composite. The results support that the synergistic roles of CNTs and GR contribute to give more paves for the electron transport, which promotes the electronic conductivity to improve the capacitance performance significantly with a specific capacitance of 20 F/g.