Graphene-based melamine sponges with reverse wettability for oil/water separation through absorption and filtration. Issue 3 (June 2022)

• Record Type: Journal Article
• Authors: Yang, Shaolin; Li, Jinze; Zhen, Cheng; Li, Fangfang; Sha, Simiao; Hou, Chunping; Lu, Hui; Wu, Jiandong; Sheng, Zhilin; Ma, Jinfu
• Is Part Of: Journal of environmental chemical engineering. Volume 10:Issue 3(2022)
• Publication Date: 2022-06
• Subjects: Reverse wettability -- Graphene -- Absorption -- Filtration -- Oil/water separation; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.107543
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: To achieve oil/water separation using both absorption and filtration regardless of the oil/water density relationship, the super-hydrophilic/underwater super-oleophobic graphene oxide coated melamine sponge (GO@MS) and super-hydrophobic/super-oleophilic reduced graphene oxide coated melamine sponge (rGO@MS) were prepared via dip-coating of graphene oxide (GO) sheets onto melamine sponge (MS) and subsequent chemical reduction, respectively. The structures of the GO@MS and rGO@MS were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectra, and X-ray diffraction (XRD). Both GO@MS and rGO@MS can preserve their original wettability in harsh environments containing acidic, alkaline, saline, and hot waters. The GO@MS and rGO@MS show excellent capability for selective absorption of water and oil respectively, with high capacities of 72.3–136.5 g g −1 and excellent recyclability. The compressed GO@MS and rGO@MS also exhibit high separation efficiency of about 99% and ultra-high permeation flux above 1.62 × 10 5 L m −2 h −1 for separating different oil/water mixtures containing light and heavy oils through filtration driven by gravity, respectively. Furthermore, a bidirectional separation setup assembled with the compressed GO@MS and rGO@MS was constructed, which demonstrates high efficiency for continuously separating different oil/water mixtures of any oil density. Graphical Abstract: ga1 Highlights: We report a simple way to fabricate graphene-based sponges with reverse wettability. The GO@MS and rGO@MS show high capacity and recyclability for selective absorption. Both sponges exhibit superior performance for oil/water separation through filtration. A bidirectional separation setup was assembled for continuous oil/water separation.