Nickel diselenide nanoflakes give superior urea electrocatalytic conversion
Nickel diselenide nanoflakes give superior urea electrocatalytic conversion
复制标题
二硒化镍纳米片具有优异的尿素电催化转化能力
DOI：
10.1016/j.electacta.2018.12.043
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发表时间：
2019-02-20
影响因子：
6.6
通讯作者：
Wang, Chundong
中科院分区：
文献类型：
--
作者：
Xiong, Pei;Ao, Xiang;Wang, Chundong
尿素电氧化反应（UOR）是一种有前途但具有挑战性的可再生能源生产技术，它通常需要较低的电化学电位，并且显示出从废水中去除潜在有害物质和/或将人类废物转化为财富的能力。然而，由于6e（-）转移过程的参与，目前最先进的UOR存在动力学迟缓的问题。在此，作为一项概念验证研究，我们通过简单的水热反应合成了富含Ni-III的二硒化镍纳米片。与对应的氢氧镍相比，镍的硒化处理成功地产生了更多暴露的活性位点和有效电子传递的协同效应。特别是，由于合成的二硒化镍富含Ni-III的性质，大大加速了Ni-II和Ni-III之间的还原/氧化反应，从而有效地降低了所需的过电位，延长了催化寿命，从而显著提高了UOR性能。深入的机理分析表明，二硒化镍（相对于氧化镍）的重构可能是在硒化物物种消失过程中同时发生从Ni-II氧化到Ni-III的主要原因，这一结果可能推广到其他硒基体系。(C) 2018 Elsevier Ltd.版权所有。
Urea electro-oxidation reaction (UOR) is a promising but challenging renewable energy production technology, which generally requires lower electrochemical potential, and shows the capabilities in eliminating a potentially harmful substance from wastewater and/or converting human waste into treasure. However, the state-of-the art UOR suffers from the sluggish kinetics because of the 6 e(-) transfer process involvement. Herein, as a proof-of-concept study, we synthesized the Ni-III -rich nickel diselenide nanoflake through a facile hydrothermal reaction. Compared to the counterpart nickel (oxy) hydroxide, the selenylation processing of nickel successfully produces synergetic effects of more exposed active sites and effective electron transports. Particularly, due to the Ni-III -rich nature of the as-synthesized nickel diselenide, the reduction/oxidation reactions between Ni-II and Ni-III is greatly accelerated, which in turn effectively decreases the required overpotentials, prolongate the catalytic lifetime, giving rise to the significantly enhanced UOR performances. In-depth mechanistic analysis evidences that the restructure of nickel diselenide (vs. nickel oxide hydroxide) could be the main reason for affording the decent UOR activity as the oxidation from Ni-II to Ni-III was simultaneous occurred during the selenide species disappear process, a result that may be extended to other selenide-based systems. (C) 2018 Elsevier Ltd. All rights reserved.