Insufficient exposure and utilization of active sites often induces an inferior reactivity for transition-metal-based two-dimensional (2D) materials. In response, we for the first time propose a universal "nano-tailoring" strategy to incorporate abundant defects and active sites into low-crystallinity nanosheets by electrochemically leaching of Al species. With MnAl layered double hydroxides (LDHs) as a representative example, potassium-birnessite MnO₂ (AK-MnO₂) with oxygen vacancies and abundant edge sites is successfully produced. The oxygen vacancies are shown to help optimize the electron-transfer and ion-adsorption capability. These integrated advantages endow the AK-MnO₂ with a high capacitance value of 239 F g⁻¹ at 100 A g⁻¹. By further combining with soft X-ray absorption spectroscopy techniques, we unravel that the reducibility of M²⁺ in M²⁺Al-LDH serves as the key descriptor for the reconstruction rate. This "nano-tailoring" strategy can provide some important implications and clues to manipulating 2D materials for efficient energy storage and conversion.

活性位点的暴露和利用不足通常会导致基于过渡金属的二维 (2D) 材料的反应性较差。作为回应，我们首次提出了一种通用的“纳米定制”策略，通过电化学浸出 Al 物质将丰富的缺陷和活性位点整合到低结晶度纳米片中。以MnAl层状双氢氧化物（LDHs）为例，成功制备了具有氧空位和丰富边缘位点的钾水钠锰矿MnO ₂（AK-MnO ₂）。氧空位有助于优化电子转移和离子吸附能力。这些综合优势使 AK-MnO ₂在 100 A g 下具有 239 F g ^-1的高电容值^-1。通过进一步与软X射线吸收光谱技术相结合，我们解开的M的还原²⁺以M ²⁺的Al-LDH作为用于重建率的关键描述符。这种“纳米定制”策略可以为操纵二维材料以实现高效的能量存储和转换提供一些重要的启示和线索。