A newly designed water‐stable NH₂‐MIL‐88B(Fe₂Ni)‐metal–organic framework (MOF), in situ grown on the surface of a highly conducting 3D macroporous nickel foam (NF), termed NFN‐MOF/NF, is demonstrated to be a highly efficient bifunctional electrocatalyst for overall water splitting with ultrastability at high current densities. The NFN‐MOF/NF achieves ultralow overpotentials of 240 and 87 mV at current density of 10 mA cm⁻² for the oxygen evolution reaction and hydrogen evolution reaction, respectively, in 1 m KOH. For the overall water splitting, it requires only an ultralow cell voltage of 1.56 V to reach the current density of 10 mA cm⁻², outperforming the pairing of Pt/C on NF as the cathode and IrO₂ on NF as the anode at the same catalyst loading. The stability of the NFN‐MOF/NF catalyst is also outstanding, exhibiting only a minor chronopotentiometric decay of 7.8% at 500 mA cm⁻² after 30 h. The success of the present NFN‐MOF/NF catalyst is attributed to the abundant active centers, the bimetallic clusters {Fe₂Ni(µ₃‐O)(COO)₆(H₂O)₃}, in the MOF, the positive coupling effect between Ni and Fe metal ions in the MOF, and synergistic effect between the MOF and NF.

中文翻译：

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原位生长的基于双金属MOF的复合材料作为高效双功能电催化剂，可在高电流密度下实现超稳定的总水分解

一种新设计的水稳定型NH ₂ -MIL-88B（Fe ₂ Ni）-金属-有机骨架（MOF）原位生长在高导电3D大孔镍泡沫（NF）的表面上，称为NFN-MOF / NF被证明是一种高效的双功能电催化剂，用于在高电流密度下具有超稳定性的整体水分解。NFN-MOF / NF在1 m KOH中分别在10 mA cm ^-2的电流密度下实现了240和87 mV的超低超电势，分别用于氧气析出反应和氢气析出反应。对于整个水分解，仅需要1.56 V的超低电池电压即可达到10 mA cm ^-2的电流密度，胜过NF上作为阴极和IrO的Pt / C配对在相同的催化剂负载下，在NF上的₂作为阳极。NFN-MOF / NF催化剂的稳定性也很出色，30小时后在500 mA cm ^-2时仅表现出较小的计时电位衰减7.8％。目前的NFN‐MOF / NF催化剂的成功归因于丰富的活性中心，即双金属簇{Fe ₂ Ni（µ ₃ -O）（COO）₆（H ₂ O）₃ }，MOF中的正极MOF中的Ni和Fe金属离子之间的偶联效应，以及MOF和NF之间的协同效应。