Bio-inspired and lanthanide-induced hierarchical sodium alginate/graphene oxide composite paper with enhanced physicochemical properties

This paper reports an artificial nacre-like composite paper based on sodium alginate (SA) and graphene oxide (GO) by lanthanide ions cross-linking. SA-coated GO were used as building “bricks and mortar” and self-assembled into aligned GO/SA composite hydrogel by the coordination of lanthanide ions. Subsequently, the hierarchical GO/SA composite paper was formed under evaporation. Four types of lanthanide ions (Nd3+, Ce3+, Gd3+, and Yb3+) were used to fabricate hierarchical GO/SA composite papers. The lanthanides enhanced the mechanical properties of the GO/SA composite papers (strength of 255.8 ± 8.52 MPa and toughness of 4.83 ± 0.28 MJ m−3) and endowed the papers with high stability. Due to the anisotropic nature along parallel and perpendicular directions, the hierarchical GO/SA composite papers exhibited a specific thermal conductivity. These features greatly expand the application of the composite papers, which are believed to show competitive advantages in aerospace, electronic devices, and thermal interface materials.