Abstract
Graphene is widely used in supercapacitors due to its large specific surface area and excellent electrical conductivity. However, a large scale efficient and sustainable production of high–quality graphene is still an urgent challenge. We report a controllable self-propagating high–temperature synthesis (SHS) process to convert CO2 with a mixed powder of magnesium and zinc into porous graphene (PG). The prepared PG contains 3–6 layers, with a plenty of uniform 2–4 nm mesopores, and has a specific surface area as high as 1458 m2 g?1. The obtained PG was used as an electrode material for the supercapacitor and exhibited a superior capacitance performance. At a current density of 1 A g?1, the specific capacitance can reach 177 F g?1. Capacitance retention rate is as high as 91% after 10,000 cycles at a current density of 5 A g?1. In addition, the charge–discharge curve remains approximately triangular at a current density of 20 A g?1, which shows satisfactory capacitance properties. We expect that our results will contribute to the development of the large-scale graphene synthesis technology based on a use of the SHS method aimed for the application as high–performance supercapacitor materials.
NSTL
Elsevier