A Robust Nacre-like Graphene Oxide-Calcium Carbonate Hybrid Mesh with Underwater Superoleophobic Property for Highly Efficient Oil/Water Separation.

Inspired by the mastoid structure of lotus leaf and robust layered structure of nacre, a novel nacre-like graphene oxide-calcium carbonate (GO-CaCO₃) hybrid mesh with superhydrophilic and underwater superoleophobic property was prepared for the first time, via a facile, economical and environmentally friendly layer-by-layer (LBL) self-assembly method using commercially available stainless steel mesh (SSM) as a ready-made mask. Interestingly, GO nanosheet played a 3-fold role, regulating the growth of CaCO₃ nanocrystalline between the GO interlamination for constructing "brick-and-mortar" structure, improving the interface stability via coordination assembly onto SSM, and creating the strong hydration derived from the rich oxygen-containing functional groups. The surface hydrophilicity and hierarchically micro/nanoscale structure of GO-CaCO₃ artificial pearls imbed on SSM contributed to outstanding superhydrophilicity and underwater superoleophobicity. The biomimetic hybrid mesh exhibited a strong mechanical property with the Young's modulus of 25.4±2.6 GPa. The optimized hybrid mesh showed the high separation efficiency more than 99% towards a series of oil/water mixtures with high flux. The low oil-adhesion force, high fatigue-resistant, chemical stability (acid/alkali/salt resistance), and excellent recycle performance enlighten the great prospects of GO-based nacre-like material for application in oily wastewater treatment.