Joule-heated carbonized melamine sponge for high-speed absorption of viscous oil spills

Introducing heating function to oil sorbents opens up a new pathway to the fast cleanup of viscous crude oil spills in situ. The oil sorption speed increases with the rise of the temperature, thus oil sorbents with high heating temperature are desirable. Besides, the oil sorbents also need to be produced environment-friendly. Here we present carbonized melamine-formaldehyde sponges (CMSs) that exhibited superior heating performance and the CMSs could be massively fabricated through a non-polluting pyrolysis process. The conductive CMSs could be heated over 300 °C with a low applied voltage of 6.9 V and keep above 250 °C for 30 min in the air without obvious damage. Such high heating performance enabled heating up the oil spills with a high rate of 2.65 °C·s^-1 and 14% improvement of oil sorption coefficient compared with the state-of-the-art value. We demonstrated that one joule-heated CMS could continuously and selectively collect viscous oil spills (9,010 mPa·s) 690 times its own weight in one hour. The CMSs will be a highly competitive sorbent material for the fast remediation of future crude oil spills.