Stable CoO2 Nanoscrolls with Outstanding Electrical Properties

Abstract

Abstract Layered CoO2 is of great interest for its promising properties but is meta‐stable in its bulk form. CoO2 is synthesized by converting the quasi‐1D crystal structure of bulk Ca3Co2O6 via a hydrothermal treatment. The resulting nanostructures are predominantly nanoscrolls with very thin walls, which exhibit long‐term stability. A detailed structural investigation reveals that the CoO2 is found to crystallize in monoclinic form, similar to the related CaCoO2‐CoO2 misfit structure. Individual nanoscrolls are characterized electrically and show a p‐type semiconducting nature with a high current‐carrying capacity of 4·105 A cm−2 and an extremely high breakdown voltage of up to 270 kV cm−1. The results demonstrate the possibility to stabilize meta‐stable materials in low‐dimensional forms and a promising application of the nanoscrolls as interconnect in high‐voltage electronic circuitry.

Keywords

• cobalt dioxide
• crystal conversion
• electrical properties
• nanoscroll