Self-propagating high–temperature synthesis of porous graphene by magnesiothermic reaction as high–performance electrochemical electrode material

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.