Copper oxides nanosheets and nanowires were directly grown on a copper sheet by a single step voltammetry process in an alkaline solution. The transition from the out-of-plane nanosheets to high aspect ratio nanowires is triggered by the change in the voltage sweep rate. The scan rate changes the growth mechanism from nucleation and coarsening at the slow scan rate for nanosheets to an oriented oxide nanowire growth at high scan rates. Polycrystalline copper oxide nanostructures contain both Cu(I) and Cu(II) oxide phases, which were characterized by the FEG-SEM, XRD, XPS, Raman, and TEM analysis. The copper oxides nanosheets and nanowires electrodes delivered the maximum specific areal capacitance 320 mF cm⁻², energy density 3.36 µWh cm⁻² and, power density 1.7 mW cm⁻² with capacitance retention of 115% up to 5000 cycles. The process presents a simple, low cost and scalable option for the preparation of binder-free copper oxides nanowires and nanosheets electrodes for supercapacitor application.

通过单步伏安法在碱性溶液中将氧化铜纳米片和纳米线直接生长在铜片上。从平面外纳米片到高深宽比纳米线的转变是由电压扫描速率的变化触发的。扫描速率将生长机制从纳米片的慢扫描速率下的成核和粗化转变为高扫描速率下的定向氧化物纳米线生长。多晶氧化铜纳米结构同时包含Cu（I）和Cu（II）氧化物相，并通过FEG-SEM，XRD，XPS，Raman和TEM分析进行了表征。氧化铜纳米片和纳米线电极的最大比表面积电容为320 mF cm ^-2，能量密度为3.36 µWh cm ^-2，功率密度为1.7 mW cm ^-2电容保持率高达115％（最多5000次）。该方法为制备用于超级电容器应用的无粘合剂氧化铜纳米线和纳米片电极提供了一种简单，低成本和可扩展的选择。