Self-Powered Aligned Porous Superhydrophobic Sponge for Selective and Efficient Absorption of Highly Viscous Oil Spills

The cleanup of viscous crude oil spills is a global challenge. Although a variety of liquid absorption materials have been developed, manual operations such as pumping and electric heating are still required. Efficient and autonomous crude oil spill cleanup methods are urgently needed today. Here, we report a sponge (SPC-Sponge), which combines superhydrophobic property and aligned porous structures, prepared from a ternary suspension (hydrophobic silica nanoparticles, polyurethane, and cellulose nanofibers) by single-step directional freeze casting. Compared with common porous materials, SPC-Sponge has excellent oil-water selection function, liquid absorption speed, and absorption capacity. Moreover, the sponge can self-absorb highly viscous crude oil over 80,000 mPa‧s on seawater without external energy and human intervention. By adding carbon nanotubes, the sponge can implement in-situ solar heating of crude oil, and the absorption speed is further improved. Given its unique structural design and superwetting property, this SPC-Sponge provides an efficient remediation approach for viscous oil spills