Nanolayered Graphene/Black Phosphorus Films for Fire-Retardant Coatings

As one of typical bottom-up self-assembly natural materials, the abalone nacre with a special layered "brick-andmortar" structure exhibited unique physical and chemical properties. Inspired by this structure, we developed a biomimetic material by combining linear polyvinyl alcohol (PVA) with hydroxylfunctionalized black phosphorus (BP-OH) nanosheets and graphene oxide (GO) nanosheets in an evaporation-induced selfassembly method. Owing to the strong interfacial hydrogen bond between linear PVA and two-dimensional BP-OH-GO, the PVA/ BP-OH-GO 25 composite film exhibited outstanding mechanical properties, with tensile fracture strain up to 86.6% and tensile strength up to 74.3 MPa (1.63 and 2.14 times that of pure PVA, respectively). In addition, the toughness of the PVA/BP-OH-GO 25 film reached 2-3 times that of pure PVA, achieving the purpose of increasing strength and toughness simultaneously. In addition, the composite film also achieved admirable fire resistance, thermal stability, smoke suppression, and toxicity reduction performance. Therefore, a type of bionic PVA/BP/GO film was designed and prepared, which provided a direction for designing synthetic biomimetic composite materials with high fire safety and mechanical properties.