Synthesis and electrochemical performance of CuO/Cu_<i>x</i>S_<i>y</i> octahedral core-shell structure

Abstract

A copper oxide/copper sulphide (CuO/CuxSy)composite was simply synthesized through an ion-exchange process just at room temperature, owning a unique octahedral core-shell structure. By adjusting reaction time of sulfuration, the morphology and composition of CuO/CuxSy octahedral core-shell material were changed, which has an important influence on the electrochemical performance. XRD, SEM, TEM and XPS were conducted to analysize the morphology and structure of CuO/CuxSy composite. It shows the hollow composite possesses a shell layer with the interconnected CuxSy nanosheets and a CuO core-layer in the octahedron.The unique core-shell octahedral structure and the synergy between CuO and CuxSy are beneficial for the electrochemical process. When the reaction time is 6 h, as-obtained CuO/CuxSy core-shell octahedral material has a high specific capacity of 413.6 F·g-1 at a current density of 1 A·g-1, and better rate performance and stability even at a higher current density of 20 A·g-1.

Keywords

• supercapacitor
• copper oxide
• copper sulfide
• core-shell structure