Highly efficient and recyclable spongy nanoporous graphene for remediation of organic pollutants

Spongy carbon nanostructures are prepared by using nanoporous graphene (NPG), single-wall carbon nanotubes (SWCNTs) and multi-wall carbon nanotubes (MWCNTs). For absorbing oil spills from the surface of water the sponges were made. The characterization of the sponges and their related substratum materials are performed by XRD, BET, FT-IR, TGA and DTA; the results were then evaluated by SEM and TEM; and the adsorption capacities were measured. Having changed the powder form to sponge, a 5.01 (g. g(-1)) enhancement of adsorption was seen for SWCNT and there was also a 14.07 (g. g(-1)) increase in MWCNT. The 176.33 (g. g(-1)) adsorption capacity of the nanoporous graphene sponge towards chloroform was a big surprise which was partly related to the powder's own high adsorption, 155.46 (g. g(-1)). In other word, an increase of 11-14% was observed in adsorption capacity of nanoporous graphene in sponge in comparison to powdery form. In addition, nanoporous graphene sponge (NPGS) is demonstrated to be perfectly recyclable and versatile, having been recycled through heat treatment, solvent extraction and mild-suction filtration with proper recovery ratios. The obtained recovery capacities of the three methods were 99.01, 98.50, and 98.05 %, respectively. Surprisingly, the adsorption capacity of the NPGS reached up to 98 % even after it was used 10 times. Based on a proper performance of NPGS, it can be a great candidate for oil spill cleanup. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.