Flexible reduced graphene oxide/carbon nanotubes/EPDM composite aerogel with superior photothermal conversion for selective oil recovery and emulsion separation

• Reduced graphene aerogel was prepared via CCNTs supporting and eEPDM crosslinking. • Excellent mechanical resilience was achieved by π-π stacking/elastomeric network. • Tunable hydrophobicity enabled good oil adsorption and demulsification effect. • rGCA/eEPDM showed excellent oil/water separation with good cyclic capacity. • High photothermal efficiency enabled viscous oil recovery under solar irradiation. The development of robust, multifunctional aerogels for efficient oil/water separation remains challenging due to the inherent fragility of conventional graphene-based architectures. Herein, we presented a hierarchical reduced graphene oxide/carboxylated carbon nanotube/epoxidized EPDM (rGCA/eEPDM) composite aerogel engineered through chemical reduction-assisted self-assembly and freeze-casting. By synergistically integrating π-π stacked framework and hydrogen bonding with crosslinked elastomeric networks, endowing rGCA/eEPDM with exceptional mechanical resilience and tunable hydrophobicity (water contact angle up to 128.4°), which enabled rapid oil/water separation with good adsorption capacity and demulsification effect. High permeation flux of 859 L /m 2 ·h for water-in-oil emulsions along with a high separation efficiency of 98.8 % was achieved under the gravity. Moreover, rGCA/eEPDM showed good structural stability and cyclic adsorption capacity over 20 cycles. Crucially, carboxylated carbon nanotube incorporation conferred outstanding photothermal conversion, reducing viscosity of high-viscosity oil under sun irradiation to achieve rapid viscous oil recovery. This work establishes a paradigm for designing mechanically robust, photothermal responsive composite aerogels through porous structure optimization and molecular-scale crosslink engineering, offering a sustainable solution for oil/solvent recovery and emulsion separation.