Abstract The successful synthesis of a self-supported 3D hetero-structured Co3O4 array on Ni foam under hydrothermal conditions is described herein. In this unique nanoarray structure, the Co3O4 nanowires are anchored onto the surface of Co3O4 nanoflakes, which effectively enlarge the surface area, provide rich active states for the Faraday redox reaction and promote the diffusion rate of the electrolyte ions. The super-capacitive performance of the hetero-structured Co3O4 array is shown to be easily optimized by altering the hydrothermal reaction time to control the integration of the Co3O4 nanowires onto the surface of the nanoflakes. As expected, the hetero-structured Co3O4 array synthesized using a hydrothermal time of 8 h exhibits remarkable super-capacitive performance, such as a high specific capacitance of 2053.1 F g−1 and a high rate capability. Further, the hybrid supercapacitor device assembled using the hetero-structured Co3O4 array and graphene has an energy density of 22.2 Wh kg−1 and outstanding cycle stability. The capacitance retention is up to 93.3% after 10,000 cycles, demonstrating the great potential of the Co3O4 array for supercapacitor application. This work also provides a better strategy for enhancing the charge storage capacity of the metal oxides.

中文翻译：

---

锚定在纳米薄片上的 Co3O4 纳米线的异质结构纳米阵列结构作为超级电容器的高性能电极

摘要 本文描述了在水热条件下在泡沫镍上成功合成自支撑 3D 异质结构 Co3O4 阵列。在这种独特的纳米阵列结构中，Co3O4 纳米线锚定在 Co3O4 纳米薄片的表面，有效地扩大了表面积，为法拉第氧化还原反应提供了丰富的活性状态，并促进了电解质离子的扩散速率。通过改变水热反应时间来控制 Co3O4 纳米线在纳米薄片表面上的集成，异质结构 Co3O4 阵列的超电容性能很容易优化。正如预期的那样，使用 8 小时的水热时间合成的异质结构 Co3O4 阵列表现出卓越的超电容性能，例如 2053 的高比电容。1 F g-1 和高倍率能力。此外，使用异质结构 Co3O4 阵列和石墨烯组装的混合超级电容器装置具有 22.2 Wh kg-1 的能量密度和出色的循环稳定性。10,000 次循环后电容保持率高达 93.3%，证明了 Co3O4 阵列在超级电容器应用中的巨大潜力。这项工作还为提高金属氧化物的电荷存储能力提供了更好的策略。