▎ 摘　　要

Graphene sheets have a vast number of potential applications due to their excellent properties. However, poor quality and harsh preparation conditions restrict their application. Here, few-layer graphene (FLG) sheet powder with high quality has been synthesized from waste expanded polystyrene (EPS) at low temperature by dense Fe cluster catalysis. The micron-sized FLG sheets comprising about three layers show high crystallinity and good electrical conductivity that are comparable to those of the shear-exfoliated graphene nanoplatelets. More than 70% carbon yield of FLG sheets from cheap EPS and their safe, controllable synthesis conditions make it easy to expand production. The catalytic formation mechanism of FLG sheets is studied.