Ni-foam supported Co(OH)F and Co-P nanoarrays for energy-efficient hydrogen production via urea electrolysis
Ni-foam supported Co(OH)F and Co-P nanoarrays for energy-efficient hydrogen production via urea electrolysis
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DOI：
10.1039/c8ta10985k
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发表时间：
2019-02-28
影响因子：
11.9
通讯作者：
Liu, Xien
中科院分区：
文献类型：
--
作者：
Song, Min;Zhang, Zijin;Liu, Xien
开发具有优良电催化活性和稳定性的非贵金属基催化剂是促进节能制氢发展的迫切需求。本文中，开发了一种简单且可扩展的策略来合成负载在Ni-泡沫上的棒状Co（OH）F和Co-P纳米阵列，分别表示为Co（OH）F/NF和Co-P/NF。电化学测试结果表明，Co-P/NF具有优异的电催化性能，在碱性和酸性介质中，在10 mA cm（-2）时，其过电位分别为70 mV和43 mV。此外，所制备的Co（OH）F/NF有助于优异的析氧反应（OER）性能，在10 mA cm（-2）下具有约1.5 V的低氧化电位。此外，Co（OH）F/NF还可以实现高效的尿素氧化反应（UOR）电催化，其可以用来替代OER以降低过电位，从而减少在H2-产生期间的电能消耗。作为概念的证明，在具有0.7M尿素的IM KOH中分别用Co-P/NF和Co（OH）F/NF作为阴极和阳极进行完全水裂解测量。Co-P/NFkCo（OH）F/NF电极能够在仅1.42 V的电池电势下产生20 mA cm（-2）的电流密度，这比无尿素的对应物低230 mV，表明其在节能制氢的实际应用中的潜在可行性。
It is an urgent requirement to develop non-precious metal-based catalysts with excellent electrocatalytic activity and stability to accelerate the development of hydrogen generation via energy-efficient routes. Herein, a facile and scalable strategy was developed to synthesize both rod-like Co(OH) F and Co-P nanoarrays supported on Ni-foam, denoted as Co(OH) F/NF and Co-P/NF, respectively. Electrochemical measurements demonstrate that Co-P/NF exhibits excellent electrocatalytic performance for the hydrogen evolution reaction (HER), delivering a low overpotential of 70 mV and 43 mV at 10 mA cm(-2) in alkaline and acid media, respectively. Furthermore, the as-prepared Co(OH) F/NF contributes to an outstanding oxygen evolution reaction (OER) performance with a low oxidation potential of about 1.5 V at 10 mA cm(-2). In addition, the Co(OH) F/NF also can enable highly efficient urea oxidation reaction (UOR) electrocatalysis, which can be utilized to substitute OER to lower the overpotential and thus reduce electrical energy consumption during H2-production. As a proof of concept, full water-splitting measurements were performed with Co-P/NF and Co(OH) F/NF as cathode and anode, respectively, in 1 M KOH with 0.7 M urea. The Co-P/NFkCo(OH) F/NF electrode is capable of producing a current density of 20 mA cm(-2) at a cell potential of only 1.42 V, which is 230 mV less than that for the urea-free counterpart, demonstrating its potential feasibility in practical applications of energy-efficient hydrogen production.