Mechanical enhancement of a nanoconfined-electrodeposited nacre-like Cu2O layered crystal/graphene oxide nanosheet composite thin film

Abstract

Graphene oxide (GO) based two dimensional (2D) nanosheets show great advantages for constructing nacre-like composites. Among the existing nacre structures, GO sheets were mostly used as hard inorganic components as those in nacre to improve the mechanical properties. Here, a novel nanoconfined electrodeposition process was explored to fabricate nacre-like Cu₂O/graphene oxide (GO) thin films, where GO nanosheets functioned as the soft organic components in nacre. The inter-layer spaces between the GO nanosheets were used as templates for the growth of single crystalline Cu₂O nanolayers, with thicknesses of several to tens of nanometers, though Cu₂O belongs to the cubic phase. Due to the small lattice mismatch between the (10) plane of Cu₂O and the (001) plane of GO, the Cu₂O nanolayers most likely grew on the (001) plane of GO. The resulting nacre-like thin film demonstrates a 6 times greater hardness and a 3 times greater Young’s modulus, than those of pure GO thin films. This technique provides a promising route for the synthesis of nacre-like metal (metal-oxide)/GO composites.