Oily wastewater and
oil spills pose a threat to the environment
and human health, and porous sponge materials are highly desired for
oil/water separation. Herein, we design a new superhydrophobic/superoleophilic
TiO
2
-decorated polyvinyl alcohol (PVA) sponge material
for efficient oil/water separation. The TiO
2
–PVA
sponge is obtained by firmly anchoring TiO
2
nanoparticles
onto the skeleton surface of pristine PVA sponge via the cross-linking
reactions between TiO
2
nanoparticles and H
3
BO
3
and KH550, followed by the chemical modification of 1
H
,1
H
,2
H
,2
H
-perfluorodecyltrichlorosilane. The as-prepared TiO
2
–PVA
sponge shows a high water contact angle of 157° (a sliding angle
of 5.5°) and an oil contact angle of ∼0°, showing
excellent superhydrophobicity and superoleophilicity. The TiO
2
–PVA sponge exhibits excellent chemical stability,
thermal stability, and mechanical durability in terms of immersing
it in the corrosive solutions and solvents, boiling it in water, and
the sandpaper abrasion test. Moreover, the as-prepared TiO
2
–PVA sponge possesses excellent absorption capacity of oils
or organic solvents ranging from 4.3 to 13.6 times its own weight.
More importantly, the as-prepared TiO
2
–PVA sponge
can separate carbon tetrachloride from the oil–water mixture
with a separation efficiency of 97.8% with the aid of gravity and
maintains a separation efficiency of 96.5% even after 15 cyclic oil/water
separation processes. Therefore, the rationally designed superhydrophobic/superoleophilic
TiO
2
–PVA sponge shows great potential in practical
applications of dealing with oily wastewater and oil spills.