▎ 摘　　要

We report a versatile and eco-friendly approach for the reduction of graphene oxide into high-quality graphene nanoplatelets by simple solid-state mechanochemical ball-milling in the presence of hydrogen. After the ball-milling process, the resultant graphene nanoplatelets show the efficient restoration of the graphitic structure completely free from any heteroatom doping (e.g., nitrogen, sulfur) and enhanced electrical conductivities up to 120 and 3400 S/m before and after an appropriate heat treatment (e.g., 900 degrees C for 2 h under nitrogen). (C) 2014 Elsevier Ltd. All rights reserved.