Multifunctional superhydrophobic adsorbents by mixed-dimensional particles assembly for polymorphic and highly efficient oil-water separation

Supra-wetting materials, especially superhydrophobic absorption materials, as an emerging advanced oil-water separation material have attracted extensive concern in the treatment of oil spillage and industrial oily wastewater. However, it is still a challenge to fabricate robust and multifunctional superhydrophobic materials for the multitasking oil-water separation and fast clean-up of the viscous crude oil by an environment-friendly and scalable method. Herein, a solid-solid phase ball-milling strategy without chemical reagent-free modification was proposed to construct heterogeneous superhydrophobic composites by using waste soot as the solid-phase superhydrophobic modifier. A series of covalent bond restricted soot-graphene (S-GN) or soot-Fe3O4 (S-Fe3O4) composite materials with a peculiar micro-nano structure are prepared. Through "glue+superhydrophobic particles" method, the prepared soot-based composite particles are facilely loaded on the porous skeleton of the sponge to obtain multifunctional superhydrophobic adsorbents. The reported superhydrophobic adsorbents exhibited robust chemical and mechanical stability, convenient magnetic collection, the high oil absorption capacity of 60–142 g g−1, durable recyclability (>250 cycles), efficient separation efficiency (>99.5%) and outstanding self-heated performance, which enable them to be competent for oil-water separation in multitasking and complex environment (floating oils, continuous oil collection, oil-in-water emulsion, and viscous oil-spills). [Display omitted] Scheme. Preparation and application of multifunctional superhydrophobic adsorbent by mixed-dimensional particles assembly strategy. •A mixed-dimensional particle assembly strategy for constructing soot-based superhydrophobic composites was proposed.•The assembly and wettability transition mechanism of soot combined with graphene/Fe3O4 were revealed.•Superhydrophobic adsorbents can be obtained by bonding soot-based composite particles with commercial glue.•Superhydrophobic adsorbents exhibit robust chemical and mechanical stability, oil absorption capacity and durability.•MS@S-Fe3O4 and MS@S-GN significantly reduce the viscosity of crude oil by photothermal effect for oil spills remediation.