Synthesis of Diphenylalanine/Cobalt Oxide Hybrid Nanowires and Their Application to Energy Storage

We report the synthesis of novel diphenylalanine/cobalt(II,III) oxide (Co3O4) composite nanowires by peptide self-assembly. Peptide nanowires were prepared by treating amorphous diphenylalanine film with aniline vapor at an elevated temperature. They were hybridized with Co3O4 nanocrystals through the reduction of cobalt ions in an aqueous solution using sodium borohydride (NaBH4) without any complex processes such as heat treatment. The formation of peptide/Co3O4 composite nanowires was characterized using multiple tools, such as electron microscoples and elemental analysis, and their potential application as a negative electrode for Li-ion batteries was explored by constructing Swagelok-type cells with hybrid nanowires as a working electrode and examining their charge/discharge behavior. The present study provides a useful approach for the synthesis of functional metal oxide nanomaterials by demonstrating the feasibility of peptide/Co3O4 hybrid nanowires as an energy storage material.