Tailoring surface features and pore structure by carbon spiral fibers to construct the high-strength carbon foams for the fast and cyclic photo-thermal oil absorption

Two key limitations affecting the commercial application of carbon foams for fast clean-up of varied oils are the complex synthesis process and poor mechanical stability. In this work, an effective method is reported to fabricate the efficient oil-absorbing materials (CSF@MCF) of carbon spiral fibers (CSFs) anchored on melamine carbon foam (MCF) with superior mechanical properties and excellent photothermal conversion. The interwoven CSFs can not only provide extra rigidity but also reduce the stress concentration of the carbon skeleton, which greatly improves the mechanical properties with 6.3 times maximum compression stress and 4.5 times ultimate tensile strength than MCF. In addition, the pure carbon component can reduce the interface resistance and excite the free electrons more easily, thus realizing high-efficiency photothermal conversion in a wide range of wavelengths. Under light irradiation, the CSF@MCF can be quickly heated up to 70 °C and achieve ultra-high absorption of crude oil, up to 62 g g−1, due to its low density and large absorption volume. Meanwhile, the CSF@MCF exhibits impressive absorption stability with persistent superhydrophobicity and a high recovery efficiency of over 85%. Superadding its simple preparation process, low production cost, and excellent acid-alkali resistance, the CSF@MCF shows great commercial potential for effectively absorbing varied oils.