Reusable graphitic carbon nitride nanosheet-based aerogels as sorbents for oils and organic solvents

Increasing oily wastewater and frequent oil leakage accidents have become a serious global environmental problem. To improve the adsorption capacity and simplify the recovery process of crude oil, it is a great significance to develop various advanced oil adsorbents and oil-collecting devices. In this work, a lightweight and compressible three-dimensional (3D) g-C3N4/poly(vinyl alcohol) (PVA) nanosheet-based aerogel was successfully fabricated. The resulting 3D g-C3N4/PVA nanosheet-based aerogel has the advantages of high porosity and good hydrophobicity, making it a suitable material for use as an adsorbent. The 3D g-C3N4/PVA nanosheet-based aerogel can absorb various oils and organic solvents as high as 228-695 times its weight. Moreover, aerogel regeneration and recovery of oil can be achieved by cyclic distillation, squeezing, or combustion. After 40 cycles, the structure of 3D g-C3N4/PVA nanosheet-based aerogels are well kept and the adsorption capacity still retained 95, 93, and 95% by distillation, squeezing, and combustion, respectively. 3D g-C3N4/PVA nanosheet-based aerogel as an adsorbent has great potential in the application of oil/water separation for the removal of pollutants.This work was supported by the National Natural Science Foundation of China (51902222) and the National Natural Science Foundation of China (21606113)