Nanoporous graphene and graphene oxide-coated polyurethane sponge as a highly efficient, superhydrophobic, and reusable oil spill absorbent.

In the present study, the application of graphene-coated polyurethane (PU) sponge for the selective absorption of oil spills from water was carefully investigated. Nanoporous graphene (NPG), prepared by the chemical vapor deposition (CVD) method, and graphene oxide (GO) flakes produced by a modified Hummer’s method, were individually integrated with the porous texture of PU, leading to NPG/PU and GO/PU preparation respectively. The structure and surface properties of the modified sponges were characterized using Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), and optical contact angle measuring device. The NPG/PU sponges depict a high capacity to remove crude oil and organic liquid stains. The obtained absorption capacity for NPG/PU sponge was much higher than that of GO/PU sponge, and was recorded at 70 g/g for crude oil removal. In other word, the modified sponges indicated up to 230% increase in the uptake of crude oil. Absorbent recyclability was also evaluated, and after 10 times of reuse, just a negligible decrease in absorption capacity was observed. Consequently, in oil spill absorption, graphene-coated polyurethane (PU) sponge can be considered a relatively more cost-effective method compared to other methods, such as graphene sponges, and can be applied on a large scale. [ABSTRACT FROM AUTHOR]