Bioinspired carbon micro/nanofiber sponge featuring curly and hollow channels for high-efficiency oil recovery.

Oil spill accidents cause severe damage to the ecological environment and social resources, highlighting an urgent need for high-performance oil adsorption materials. However, existing materials typically suffer from limited adsorption capacity and unsatisfactory oil retention, hindering their effectiveness in oil remediation. Here, inspired by lotus stems, a curly carbon micro/nanofiber sponge with hollow channels is created based on phase-driven shrinkage electrospinning for high-efficiency oil remediation. By regulating the asymmetric shrinkage degree and compatibility of polymer precursors, curly fibers are induced to form and then entangle to assemble into a fluffy sponge during the rapid phase separation and solidification process of the jet; the carbon micro/nanofiber sponge with hollow channels is subsequently constructed through high-temperature template removal. Benefiting from the entangled network formed by curly fibers, the carbon sponge exhibits remarkable elasticity (almost no plastic deformation after 500 compression cycles) while maintaining high porosity. Furthermore, the sponge demonstrates outstanding oil adsorption performance (up to 37 g/g) and good recyclability, as well as the capability for all-weather oil cleanup enabled by the synergistic effect of its photothermal and electrothermal properties. This work offers a new perspective for developing advanced carbon sponges for applications in the energy and environmental fields.