Large-Scale Nanofiber Manufacturing| Lightweight, compressible and superhydrophobic coal-based nanofibrous/graphene oxide composite aerogel towards efficient oil and organicsolvents adsorption

Xinjiang University’s Prof. Wu Xueyan, Prof. Guo Jixi & Prof. Jia Dianzeng: Lightweight, Compressible, Superhydrophobic Composite Aerogel for Efficient Oil/Organic Solvent Adsorption

With rapid industrial development, frequent oil spills and massive organic solvent discharges have severely damaged ecosystems and threatened human health. Developing high-performance oil-absorbing materials is crucial for effective water purification. However, commercial oil-absorbing felts suffer from low absorption capacity, poor selectivity, and difficult recovery. Thus, creating reusable materials with high absorption capacity is imperative.

Recently, Prof. Wu Xueyan, Prof. Guo Jixi, and Prof. Jia Dianzeng from Xinjiang University published their findings in Desalination: "Lightweight, compressible and superhydrophobic coal-based nanofibrous/graphene oxide composite aerogel towards efficient oil and organic solvents adsorption." The team developed a high-performance coal-based nanofiber/graphene oxide composite aerogel (MGCF) via hydrothermal and freeze-drying methods (Figure 1).MGCF exhibits high adsorption capacity (70–190 g/g) for various organic solvents/oils. The flexible coal-based nanofiber membrane maintains the aerogel’s 3D structure, preventing deformation during freeze-drying/adsorption and enhancing reusability.

Figure 1: Schematic diagram of the preparation of coal-based nanofiber/graphene oxide composite aerogel.

Conventional carbon aerogels lack mechanical robustness, showing poor elasticity and fatigue resistance under stress (Figure 2a). Incorporating coal-based carbon nanofibers (CCNFs) improves MGCF’s mechanical properties by:
(1) Increasing fiber-matrix contact area for stress distribution (Figure 2b);
(2) Enhancing flexibility to resist brittle fracture.

MGCF demonstrates stability in air and organic solvents (Figures 2c–e).

Figure 2: Mechanical properties of the coal-based nanofiber/graphene oxide composite aerogel.

Figure 3: Evaluation of oil absorption performance for the coal-based nanofiber/graphene oxide composite aerogel.

 Adsorption tests (Figure 3) reveal that a 3:1 GO/CCNF ratio achieves 240 g/g dichloromethane uptake, as CCNFs prevent GO self-aggregation, creating more adsorption sites.Adsorption kinetics/isotherms (Figure 4) indicate MGCF’s oil-adsorption mechanism involves pore capture, hydrogen bonding, electrostatic interactions, and π-π stacking, synergistically enabling exceptional performance.

Figure 4: Investigation of the adsorption mechanism for the coal-based nanofiber/graphene oxide composite aerogel.