Graphene and graphene oxide as effective adsorbents toward anionic and cationic dyes

► Exfoliated graphene and graphene oxide are shown to be very good adsorbents for various charged dye molecules. ► Depending on the charge on the dye, either graphene oxide or reduced graphene oxide can be used for effective adsorption. ► Molecular level interactions between the adsorbents and dyes have been probed using spectroscopic techniques. ► Adsorption isotherms are studied in detail. ► High surface area of graphene - based materials are used for environmental decontamination.