Thermal oxidation etched carbon fiber aerogels with hierarchical pore structure as high-performance oil adsorbent

A novel thermal oxidation etching (TOE) strategy was employed here to increase the voids of aerogels. The etched carbon fiber aerogels (ECFAs) have exhibited a network structure constituted by fibers, in which macropores ranging from 0.4 to 5 μm could be observed. Moreover, ECFAs also showed wide distributions in meso/micropores, which further proved that the ECFAs owned a hierarchical pore structure. Meanwhile, porosity was used to measure the space for oil storage inside the ECFAs. Among them, the ECFA-25 (ECFA that was etched for 25 min) had the highest porosity of 99.63%. It also showed the best oil adsorption performance (64.75 g/g), more than twice that of the unetched carbon fiber aerogels. This promising TOE strategy exhibits significant potential as a guidance to obtain efficient sorbents in oil adsorption. Graphical abstract