Effect of Graphene Encapsulation of NiMo Alloys on Oxygen Evolution Reaction
Effect of Graphene Encapsulation of NiMo Alloys on Oxygen Evolution Reaction
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DOI：
10.1021/acscatal.9b04134
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发表时间：
2020-01-03
期刊：
影响因子：
12.9
通讯作者：
Ito, Yoshikazu
中科院分区：
文献类型：
--
作者：
Jeong, Samuel;Hu, Kailong;Ito, Yoshikazu
电化学水裂解是一种从水中制取氢气和氧气的环保技术。电极是控制水裂解效率的关键部件。虽然贵金属如Pt、Ru和Ir可以实现高能量效率，但它们在水分解中的应用受到其高成本的限制。因此，开发高效的无贵金属电极对于实现可持续的氢社会是必要的。在这里，我们报告了一种石墨烯封装NiMo合金的技术，用于在不含过渡金属杂质的KOH水溶液电解质中的非贵金属阳极中实现高催化活性和高化学稳定性。电化学分析表明，石墨烯封装显着提高了析氧反应（OER）的NiMo阳极的活动，并提供了长的电极寿命和性能的商业可获得的阳极。密度泛函理论计算表明，石墨烯包覆显著降低了中间体在NiMo表面的吸附能，从而显著提高了OER活性。石墨烯封装方法提供了一种有前景的电极设计，以改善水裂解电解槽的性能。
Electrochemical water splitting is an ecofriendly technology for generating oxygen and hydrogen from water. The electrode is a key component that controls the efficiency of water splitting. Although noble metals such as Pt, Ru and Ir can achieve high energy efficiencies, their application in water splitting is limited by their high cost. Thus, developing efficient noble-metal-free electrodes is necessary to achieve sustainable hydrogen societies. Here, we report a technique of graphene encapsulation of NiMo alloys for realizing both high catalytic activity and high chemical stability in non-noble metal anodes in transition metal impurities-free aqueous KOH electrolyte. Electrochemical analysis showed that graphene encapsulation significantly enhanced the oxygen evolution reaction (OER) activities of the NiMo anodes and provided long electrode lifetimes and performances comparable to those of commercially available anodes. Density functional theory calculation revealed that graphene encapsulation significantly reduced the adsorption energy of intermediates onto the NiMo surface, thereby remarkably enhancing the OER activity. The graphene encapsulation method provides a promising electrode design to improve the performance in water splitting electrolyzers.