Oil/water separation based on natural materials with super-wettability: recent advances

The frequency of oil spills and the increasing amount of oily sewage not only cause serious water pollution as well as a lot of ecological problems but also result in huge economic losses. To address such problems, developing advanced technologies and materials for achieving efficient oil/water separation is a critical way and emerging as a hot research topic nowadays. Herein, we have reviewed the recent developments in oil/water separation by using superwetting porous materials, mainly focusing on natural materials. By using natural materials as examples, we show how to use superwetting porous materials to separate different mixtures of water and oil, including the inherent superwettability of the natural materials, separating method/process, and separation mechanism. Natural superwetting materials are usually low-cost and eco-friendly, and can be easily obtained, so oil/water separation based on natural materials has great promise to address the above-mentioned globally recognized oil contamination challenge. In addition, these natural examples seem more attractive to the general researcher who is new to this field as well as the expert and even the public, since natural materials look more interesting than artificial complex materials. We believe our review will help beginners better understand the significance, application value, mechanism and principle of oil/water separation by superwetting porous materials.