Multi-functional graphene/carbon nanotube aerogels for its applications in supercapacitor and direct methanol fuel cell

Three-dimensional graphene/carbon nanotube (GR-CNTs) aerogels was fabricated by the freeze-drying process, in which polyvinyl alcohol (PVA) was empolyed as an organic binder. The electrochemical energy storage properties of aerogels were investigated using cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy tests, which indicated that GR-CNTs aerogels electrode possessed high specific capacitances of 375 F/g in 6 M KOH solution with a capacity retention of about 88% and 94.8% after 5000 cycles, respectively. Moreover, The GR-CNTs aerogels was also identified to be a support matrix for the decoration of ultrafine Pt nanoparticles. Noticeably, exceptional electrocatalytic properties including high activity, good antipoisoning capacity, and outstanding durability were achieved for the Pt/GR-CNTs catalyst due to its unique three-dimensional interconnected porous structure and high specific surface area.