Hybrid Co@Ni12P5/PPy microspheres with dual synergies for high performance oxygen evolution
Hybrid Co@Ni12P5/PPy microspheres with dual synergies for high performance oxygen evolution
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DOI：
10.1016/j.jcat.2020.08.035
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发表时间：
2020-11-01
影响因子：
7.3
通讯作者：
Kuhn, John N.
中科院分区：
文献类型：
--
作者：
Ramani, Swetha;Cogal, Sadik;Kuhn, John N.
电化学水分解是清洁和可再生能源储存的有效替代途径。然而，该技术的广泛应用受到缓慢的阳极析氧反应（OER）所需的高过电位的阻碍。在这篇文章中，我们报道了新型的N基导电聚合物在富土过渡金属中表现出优异的电荷转移特性。通过XPS鉴定了聚吡咯（PPy）中的Ni和N之间的强相互作用，导致界面上有大量的Ni δ ++位点。来自PPy壳层的电负性N覆盖在Ni12P5微球上，与内缘的Ni和外缘的电沉积Co相互作用，形成双重协同效应。这种杂化催化剂具有Co-N和Ni-N活性界面，由于对羟基离子的亲电性改善，表现出更快的OER动力学。Co@Ni12P5/PPy具有双M-N位点，具有40 mV/dec的低Tafel斜率和长达7 h的电化学循环稳定性。这项工作使人们能够发现一类基于金属- ppy类似物的碱性OER阳极材料。(C) 2020爱思唯尔公司版权所有。
Electrochemical water splitting could be an efficient alternative route for clean and renewable energy storage. However, widespread application of this technique is hindered by the high overpotential required for the sluggish anodic oxygen evolution reaction (OER). In this contribution, we report that novel N based conducting polymers exhibit excellent charge transfer properties with earth abundant transition metals. A strong interaction between Ni and N from polypyrrole (PPy) was identified via XPS, resulting in higher amounts of Ni delta++ sites at the interface. Electronegative N from PPy shell, covering Ni12P5 microspheres, interacts with Ni on the inner edge and electrodeposited Co on the outer edge, establishing a dual synergic effect. This hybrid catalyst, with Co-N and Ni-N active interfaces, demonstrates faster OER kinetics owing to improved electrophilicity towards hydroxyl ions. With dual M-N sites, Co@Ni12P5/PPy displays a low Tafel slope of 40 mV/dec and stability up to 7 h of electrochemical cycling. This work enables discovery of a new class of anode materials based on metal-PPy analogs for alkaline OER. (C) 2020 Elsevier Inc. All rights reserved.