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.