Room-Temperature Chemical Transformation Route to CuO Nanowires toward High-Performance Electrode Materials

Abstract

We demonstrated an efficient room-temperature chemical transformation route to CuO nanowires (NWs), from irregular particles to NWs coupled with a series of phase changes from CuCl, through Cu2(OH)3Cl, to Cu­(OH)2, and finally to CuO. The room-temperature chemical transformation of Cu­(OH)2 NW can reserve the initial NW morphology and made the synthesized CuO NW more active in electrochemical reactions. As the anode materials for lithium ion battery, these CuO NWs can exhibit a reversible capacity of 696.1 mAh g–1 after 40 cycles at the rate of 100 mA g–1. The high lithium-storage capacity can be ascribed to the unique structure of these CuO NWs with size of ∼10 nm and grain boundaries on the NWs surfaces, which show more active for the initial electrochemical reaction. CuO NWs and intermediate Cu­(OH)2 NWs can also be fabricated as pseudocapacitor electrodes; in KOH electrolyte, their specific capacitances are 118 and 114 F g–1 at the current density of 1 A g–1. The present results indicate that the current room-temperature chemical transformation route is promising to produce advanced electrode materials for both lithium ion batteries and supercapacitors