N, S Codoped Hierarchical Porous Graphene Nanosheets Derived from Petroleum Asphalt via in Situ Texturing Strategy for High-Performance Supercapacitors

A facile yet rational strategy is highly desired for the synthesis of high-value-added carbon materials from cheap petroleum asphalt. Here, we develop an in situ texturing strategy for the synthesis of nitrogen and sulfur codoped hierarchical porous graphene nanosheets (N,S-hPGNs) by using dual-functional graphitic carbon nitride templates. The synthetic strategy avoids using additional sulfur sources and a cumbersome acid washing process. The well-developed pores and abundant heteroatoms endow the N,S-hPGNs with a high capacity of 302 F g–1 at 1 A g–1 and an excellent cycling stability. Moreover, the as-fabricated supercapacitors display a high energy density of 10.42 Wh kg–1 at the power density of 250 W kg–1, outperforming other previous carbon materials from petroleum asphalt. This work not only demonstrates the great potential of N,S-hPGNs for supercapacitors, but also provides a new avenue for the high-value-added utilization of petroleum asphalt.