Electronic coupling strategy to boost water oxidation efficiency based on the modelling of trimetallic hydroxides Ni1-x-yFexCry(OH)2: From theory to experiment
Electronic coupling strategy to boost water oxidation efficiency based on the modelling of trimetallic hydroxides Ni1-x-yFexCry(OH)2: From theory to experiment
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DOI：
10.1016/j.cej.2020.126144
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发表时间：
2020-12
影响因子：
15.1
通讯作者：
Jun Ma;Pengsong Li;Xiao Lin;Yijun Huang;Y. Zhong;Lipeng Zhang;Xiaoming Sun;Daojin Zhou
中科院分区：
文献类型：
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作者：
Jun Ma;Pengsong Li;Xiao Lin;Yijun Huang;Y. Zhong;Lipeng Zhang;Xiaoming Sun;Daojin Zhou
开发低成本、高效率的地球资源丰富的析氧反应电催化剂对于工业规模的水裂解制氢以及可充电金属-空气电池具有重要意义。在寻找新型催化剂的过程中，从根本上理解催化剂的作用机理，并能够合理地设计和操纵催化中心同样重要。从密度泛函理论（DFT）计算作为指导，我们的理论模型表明，在Ni 1-xFex（OH）2中铬取代不仅加速了电荷转移，而且调节了OER中间体的吸附能，以达到最佳结合强度。在实验中，Cr掺杂到Ni 1-xFex（OH）2的叠层中，提高了其析氧反应的催化性能，证实了理论预测的结果。多孔超薄三元Ni 1-x-yFexCry（OH）2电催化剂直接生长在泡沫镍（NF）基底上，确定了最佳组成Ni0.66Fe0.27Cr0.07（OH）2/NF，其表现出上级OER性能，即，在231 mV的低过电位下实现10 mA cm-2的显著电流密度、小的塔菲尔斜率（31 mV dec-1）和在碱性电解质中相对于RHE的1.68 V的高氧化电位下的优异稳定性。综合研究涉及的理论和实验结果在这项工作中提供了一个有见地的指导，在设计有效的OER催化剂的化学和电能转换和存储。
Developing low-cost yet highly efficient earth-abundant electrocatalysts for oxygen evolution reaction (OER) is of great significance for industrial scale water splitting for clean hydrogen production, as well as for rechargeable metal-air batteries. In searching for advanced catalysts, it is equally important to fundamentally understand working mechanism and be able to rationally design and manipulate catalytic sites. Starting from the density functional theory (DFT) calculations as a guidance, our theoretical model revealed that chromium substitution in nickel–iron hydroxides (Ni1-xFex(OH)2) not only accelerated the charge transfer but also regulated the adsorption energy of OER intermediates to achieve optimal binding strength. Experimentally, chromium was doped into the laminate of Ni1-xFex(OH)2, resulting in the enhanced catalytic performance for oxygen evolution reaction, which confirmed the predictions from the theoretical data. The porous and ultra-thin ternary Ni1-x-yFexCry(OH)2electrocatalysts were grown directly on a nickel foam (NF) substrate, with an optimum composition Ni0.66Fe0.27Cr0.07(OH)2/NF identified, which exhibited a superior OER performance, i.e., achieving a significant current density of 10 mA cm−2at a low overpotential of 231 mV, a small Tafel slope (31 mV dec−1) and an excellent stability at a highly oxidative potential of 1.68 V vs RHE in alkaline electrolyte. The comprehensive study involving both theoretical and experimental results in this work provides an insightful guidance in designing efficient OER catalysts for chemical and electrical energy conversion and storage.