Hydrophobic Carbon Nitride Nanolayer Enables High-Flux Oil/Water Separation with Photocatalytic Antifouling Ability.

He, Mao; Wu, Suqin; Xiong, Shubin; Zhang, Lei; Lai, Chen; Peng, Xiaoying; Zhong, Shengliang; Lu, Zhang-Hui et al. · Nano Lett · 2023

basic_science · Level V

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Abstract

Efficient oil/water separation tackles various issues in occasions of oil leakage and oil discharge, such as environmental pollution, recollection of the oil, and saving the water. Herein, a compact superhydrophobic/superoleophilic graphitic carbon nitride nanolayer coated on carbon fiber networks (CNBA/CF) is designed and synthesized for efficient gravity-driven oil/water separation. The CNBA/CF shows excellent oil absorption and an impressive oil/water filtration separation performance. The flux reaches the state-of-art value of 4.29 × 10<sup>5</sup> L/m<sup>2</sup>/h for dichloromethane with separation efficiency up to 99%. Successive oil absorption tests, long-term filtration separation, and harsh conditions experiments confirm the remarkable separation and chemical structure stability of the CNBA/CF filter. Besides, the CNBA/CF demonstrates good photocatalytic antifouling ability thanks to the extended visible light absorption and improved charge separation. This work combines the material surface wettability modulation with a photocatalytic self-cleaning property in the fabrication of efficient oil/water separation materials while overcoming the filter fouling issue.