High-quality reduced graphene, termed PG, has been synthesized by a simple, low-cost, and green plasma approach, and applied as adsorbent to remove 4,4′-dichloribiphenyl (4,4′-DCB) from aqueous solutions. As a comparison, the adsorption of 4,4′-DCB on graphene oxide (GO) and multiwalled carbon nanotubes (MWCNTs) was also studied under the same experimental conditions. PG performs significantly better with regard to 4,4′-DCB adsorption than GO and MWCNTs, or any reported nanomaterials, with a maximum adsorption capacity (qmax) of 1552 mg g−1 at pH 7.0. The high affinity of 4,4′-DCB to PG is mainly a result of strong π–π interactions, as also confirmed by DFT calculations. The results reveal that PG sheets hold promise for the removal of persistent organic pollutants. We expect possible applications of this fast and mild plasma technique in the fabrication of nanomaterials and envisage their use in a variety of advanced chemical processes.