Hollow nanostructures with higher surface area offer great advantages for electrocatalytic water splitting. Here, we demonstrate the fabrication of amorphous hollow M(OH)_x (M = Fe, Co, Ni) nanocubes through a template-assisted route inspired by Pearson's hard and soft acid–base (HSAB) principle with Cu₂O nanocubes with different sizes (50 nm, 500 nm) as the sacrificial templates. A comparative study of the electrocatalytic oxygen evolution reaction (OER) of the hollow M(OH)_x nanocubes with a similar size indicates that Ni(OH)₂ has better OER catalytic activity. It has been revealed that the metal oxyhydroxides formed at the surface are actually the real active species for the OER electrocatalysis. In particular, Ni(OH)₂ nanocubes obtained by the Cu₂O (50 nm) template provide the best OER activity, with a low overpotential of 349 mV vs. RHE to achieve a current density of 10 mA cm⁻² and a low Tafel slope of 63 mV dec⁻¹. The hollow metal hydroxide nanostructures through the Pearson's principle-inspired strategy can be highly efficient electrocatalysts for OER applications.

中文翻译：

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皮尔森（Pearson）原理启发的策略，用于合成无定形过渡金属氢氧化物空心纳米立方体，用于电催化氧气的释放†

具有较高表面积的中空纳米结构为电催化水分解提供了很大的优势。在这里，我们展示了通过皮尔逊的硬酸和软酸碱（HSAB）原理以及不同Cu ₂ O纳米立方体的模板辅助途径，通过模板辅助途径制备了无定形空心M（OH）_x（M = Fe，Co，Ni）纳米立方体。尺寸（50 nm，500 nm）作为牺牲模板。对具有类似尺寸的中空M（OH）_x纳米立方体的电催化氧释放反应（OER）的比较研究表明，Ni（OH）₂具有更好的OER催化活性。已经发现，在表面形成的金属羟基氧化物实际上是OER电催化的真正活性物质。特别是Ni（OH）₂通过Cu ₂ O（50 nm）模板获得的纳米立方体具有最佳的OER活性，相对于RHE具有349 mV的低过电势，可实现10 mA cm ^-2的电流密度和63 mV dec ^-1的低Tafel斜率。通过Pearson原理启发的策略，中空的金属氢氧化物纳米结构可以成为用于OER应用的高效电催化剂。