For overall water electrolysis, the hydrogen evolution reaction (HER) is severely limited by the sluggish kinetics of the anodic oxygen evolution reaction (OER). Therefore, replacing the OER with a more favorable anodic oxidation reaction with remarkable kinetics is of paramount significance, especially the one that can produce value-added chemicals. Moreover, time-saving and cost-effective strategies for the fabrication of electrodes are helpful for the wide application of electrolysis. Herein, thermodynamically more favorable iodide electrooxidation over Ni doped Co(OH)₂ nanosheet arrays (NSAs) in alkaline solution is presented as the alternative to the OER to boost the HER. And the active species are determined to be the reverse redox of the Co(IV)/Co(III) couple. Remarkably, a negative shift of voltage of 320 mV is observed at a current density of 10 mA cm⁻² after using iodide electrolysis to replace ordinary water splitting. The synthetic strategy and iodide oxidation in this work expand the application of Co-based materials in the field of energy-saving hydrogen production.

中文翻译：

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通过 Ni-Co(OH)2 纳米片阵列上碘化物的阳极氧化促进氢气产生

对于整个水电解来说，析氢反应（HER）受到阳极析氧反应（OER）缓慢动力学的严重限制。因此，用一种更有利且具有显着动力学性能的阳极氧化反应取代OER具有重要意义，尤其是能够生产高附加值化学品的阳极氧化反应。此外，节省时间和成本效益的电极制造策略有助于电解的广泛应用。在此，提出了在碱性溶液中热力学上比 Ni 掺杂 Co(OH) ₂纳米片阵列 (NSA) 更有利的碘化物电氧化作为 OER 的替代方案，以提高 HER 的性能。确定活性物质为Co( IV )/Co( III )对的逆氧化还原。值得注意的是，在使用碘化物电解代替普通水分解后，在10 mA cm ^-2的电流密度下观察到320 mV的电压负移。该工作的合成策略和碘化物氧化拓展了钴基材料在节能制氢领域的应用。