Flexible carbon nanofiber sponges for highly efficient and recyclable oil absorption

Carbon nanofiber (CNF) sponges have been prepared though a facile chemical vapor deposition method using C2H4 as carbon source and Ni-Cu alloy as catalyst. The as-prepared CNF sponges are composed of three-dimensional (3D) networks with thick CNFs as the reinforcing rods and thin CNFs as the binding wires that hold CNFs entangled together. Such CNF sponges exhibit controllable bulk density (0.02-0.14 g cm(-3)) and high porosity (92%-98%) through changing catalyst amount. The CNF sponges display admirable mechanical flexibility with large compressive strain (>90%). The CNF sponges also exhibit super hydrophobicity (contact angle > 153 degrees) and super oleophilicity. The absorption capacities of the CNF sponges for oils can achieve 22-75 times their own weight and can even be controlled by altering their density or porosity. Furthermore, the CNF sponges demonstrate outstanding recyclability by mechanically squeezing. The present work suggests the CNF sponges a widespread potential for applications in the topics regarding environment protection.