Porous metals with a cellular architecture have attracted considerable attention for a diverse range of applications. Extensive efforts have been devoted to exploring cost-effective ways to create porous metals. Here we propose a novel approach for the fabrication of micron porous Ni metals through a redox process in a CH₄–O₂ gas mixture at 750 °C. The multiple redox cycles at high temperatures facilitate a rapid reconstruction of Ni atoms, producing a cellular architecture. This process is simple and clean, avoiding the use of precious metals and templates. The redox process is applicable to the creation of porous architectures (from surface texturing to 3D cellular structures) on a Ni sheet and a unique hierarchical porous architecture on Ni foam. Furthermore, nanocrystalline MnO₂ is successfully coated on a micron porous Ni foam (MPNF) to form a supercapacitor electrode. The micron porous architectures of the MPNF–MnO₂ electrode enhance not only the electrochemical performance but also the mechanical integrity and robustness, leading to ultrahigh capacitance and excellent cycling stability. More importantly, the strategy of micron-sculpturing of metals using a redox process is readily applicable to other metal systems for the fabrication of cellular metals and alloys for a variety of applications, including catalysis, energy storage and conversion, and chemical sensing.

中文翻译：

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通过简单的氧化还原工艺雕刻的3D分层多孔镍及其在高性能超级电容器中的应用

具有多孔结构的多孔金属已经引起了广泛的关注，用于各种应用。已经进行了广泛的努力来探索成本有效的方式来制造多孔金属。在这里，我们提出了一种新方法，该方法是在750°C的CH ₄ -O ₂气体混合物中通过氧化还原工艺制造微米级多孔镍金属的。高温下的多个氧化还原循环有助于快速重建Ni原子，从而产生细胞结构。此过程简单而干净，避免了使用贵金属和模板。氧化还原工艺适用于在镍片上创建多孔结构（从表面纹理到3D蜂窝结构），以及在镍泡沫上创建独特的分层多孔结构。此外，纳米晶MnO_将2成功地涂覆在微米多孔镍泡沫（MPNF）上以形成超级电容器电极。MPNF-MnO ₂电极的微米级多孔结构不仅增强了电化学性能，而且还增强了机械完整性和鲁棒性，从而实现了超高电容和出色的循环稳定性。更重要的是，使用氧化还原工艺对金属进行微米级雕刻的策略很容易适用于其他金属系统，用于制造蜂窝金属和合金，从而可用于各种应用，包括催化，能量存储和转化以及化学传感。