▎ 摘　　要

A novel single-step technique is introduced for preparation of three-dimensional highly porous graphene (3D-HPG) without the need for a backbone substrate. Using bagasse as a solid source of carbon (instead of a hydrocarbon-based gas) and a copper salt, gram-scale 3D graphene nanostructures with admirable quality could be achieved in a cost-efficient manner. The products were characterized by SEM, TEM, Raman, XPS, XRD, and ASAP. Specific surface area (SSA) of almost 3000 m(2)/g was resulted via a simultaneous activation treatment that generated nanopores in the graphene-based samples. The as-prepared 3D-HPG exhibited favorable methane adsorption capability (0.115 mg/mg at 5 bar and almost 0.2 mg/mg at 35 bar) at ambient temperatures. This new synthesis method can be of great significance as it provides an economical approach for mass production of graphene, desired in adsorbed natural gas (ANG) storage technology, high-capacity lithium ion batteries (LIB), supercapacitors, and enhanced oil recovery (EOR) applications. (C) 2016 Elsevier B.V. All rights reserved.