Efficient Water Oxidation Using Nanostructured α-Nickel-Hydroxide as an Electrocatalyst
Efficient Water Oxidation Using Nanostructured α-Nickel-Hydroxide as an Electrocatalyst
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DOI：
10.1021/ja502128j
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发表时间：
2014-05-14
影响因子：
15
通讯作者：
Yan, Yushan
中科院分区：
文献类型：
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作者：
Gao, Minrui;Sheng, Wenchao;Yan, Yushan
电化学水分解是一种将间歇性可再生的风能和太阳能储存在氢燃料中的清洁技术。然而，在水电解槽的阳极处的缓慢的析氧反应（OER）动力学极大地阻碍了大规模的H-2生产。虽然已经开发了许多OER电催化剂来解决这个困难的反应，但仍然需要在设计廉价，耐用和有效的催化剂方面取得实质性进展，并且被认为是一个巨大的挑战。在此，我们报告了简单的合成和使用的α-Ni（OH）（2）纳米晶体作为一个显着的活性和稳定的OER催化剂在碱性介质中。我们发现高度纳米结构的α-Ni（OH）（2）催化剂在仅为0.331 V的小过电位和类似于42 mV/decade的小塔菲尔斜率下提供10 mA cm（-2）的电流密度，与最先进的RuO 2催化剂相比是有利的。这种α-Ni（OH）（2）催化剂在苛刻的OER循环条件下也具有出色的耐久性，其稳定性远远优于RuO 2。此外，通过比较α-Ni（OH）（2）与两种均在同一体系中合成的β-Ni（OH）（2）的性能，我们实验证明α-Ni（OH）（2）具有更有效的OER催化作用。这些结果表明，通过使用廉价且易于制备的α-Ni（OH）（2）来替代昂贵的商业催化剂如RuO 2或IrO 2，开发有效且稳健的OER电催化剂的可能性。
Electrochemical water splitting is a clean technology that can store the intermittent renewable wind and solar energy in H-2 fuels. However, large-scale H-2 production is greatly hindered by the sluggish oxygen evolution reaction (OER) kinetics at the anode of a water electrolyzer. Although many OER electrocatalysts have been developed to negotiate this difficult reaction, substantial progresses in the design of cheap, robust, and efficient catalysts are still required and have been considered a huge challenge. Herein, we report the simple synthesis and use of alpha-Ni(OH)(2) nanocrystals as a remarkably active and stable OER catalyst in alkaline media. We found the highly nanostructured alpha-Ni(OH)(2) catalyst afforded a current density of 10 mA cm(-2) at a small overpotential of a mere 0.331 V and a small Tafel slope of similar to 42 mV/decade, comparing favorably with the state-of-the-art RuO2 catalyst. This alpha-Ni(OH)(2) catalyst also presents outstanding durability under harsh OER cycling conditions, and its stability is much better than that of RuO2. Additionally, by comparing the performance of alpha-Ni(OH)(2) with two kinds of beta-Ni(OH)(2), all synthesized in the same system, we experimentally demonstrate that alpha-Ni(OH)(2) effects more efficient OER catalysis. These results suggest the possibility for the development of effective and robust OER electrocatalysts by using cheap and easily prepared alpha-Ni(OH)(2) to replace the expensive commercial catalysts such as RuO2 or IrO2.