催化学报 ›› 2022, Vol. 43 ›› Issue (5): 1267-1276.DOI: 10.1016/S1872-2067(21)63962-1

• 论文 • 上一篇    下一篇

海胆状NiMoO4纳米棒阵列作为高效双功能催化剂用于电催化及光伏驱动尿素电解

陈晨欣a, 何苏祺a, Kamran Dastafkanb, 邹泽华a, 汪庆祥a(), 赵川b()   

  1. a闽南师范大学化学与环境科学系, 现代分析科学与分离技术福建省重点实验室, 福建漳州363000, 中国
    b新南威尔士大学化学与材料学院制造未来研究所, 悉尼, 澳大利亚
  • 收稿日期:2021-09-15 接受日期:2021-10-22 出版日期:2022-05-18 发布日期:2022-03-23
  • 通讯作者: 汪庆祥,赵川
  • 基金资助:
    澳大利亚研究委员会未来研究基金(FT170100224);国家自然科学基金(21275127);福建省自然科学基金(2018J01435)

Sea urchin-like NiMoO4 nanorod arrays as highly efficient bifunctional catalysts for electrocatalytic/photovoltage-driven urea electrolysis

Chenxin Chena, Suqi Hea, Kamran Dastafkanb, Zehua Zoua, Qingxiang Wanga(), Chuan Zhaob()   

  1. aDepartment of Chemistry and Environment Science, Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, Fujian, China
    bSchool of Chemistry and Materials & Manufacturing Futures Institute, The University of New South Wales, Sydney 2052, Australia
  • Received:2021-09-15 Accepted:2021-10-22 Online:2022-05-18 Published:2022-03-23
  • Contact: Qingxiang Wang, Chuan Zhao
  • Supported by:
    Future Fellow from Australian Research Council(FT170100224);National Natural Science Foundation of China(21275127);Natural Science Foundation of Fujian Province(2018J01435)

摘要:

氢能因具有储量丰富、零排放和可再生等优点, 受到各国在能源布局过程中的广泛关注. 制氢是氢能源开发和利用的重要环节, 其中电解水制氢技术可通过低能耗水分解获得氢气, 具有很高的社会效益和经济效益. 在电解水过程中, 由于受析氧反应(OER)的缓慢动力学过程限制, 电解水制氢体系在碱性介质中的理论工作电压高达1.23 V, 增加了制氢能耗. 在使用电化学催化剂的同时采用具有低热力学电势(0.37 V)的尿素氧化反应(UOR)代替OER, 可降低制氢过程的能耗.

本文采用水热反应结合煅烧反应在泡沫镍上生长了海胆状NiMoO4纳米棒阵列, 并将其作为双功能电催化剂, 用于阴极析氢和阳极尿素氧化反应. 结果表明, 200 °C煅烧产物(NiMoO4-200/NF)表现出高效的析氢反应(HER)性能, 在1.0 mol/L KOH中电流密度为10 mA cm-2时的过电位仅为68 mV. 而300 °C煅烧产物(NiMoO4-300/NF)表现出优异的析氧反应和尿素氧化反应活性.

为了探究NiMoO4纳米棒阵列在不同反应中催化性能差异的原因, 通过各种表征手段对催化剂进行了结构及组成的表征. X射线衍射与高分辨透射电镜结果表明, 200和300 °C下的煅烧产物由NiMoO4与NiMoO4·xH2O组成, 而煅烧温度变化引起的电催化活性和选择性的差异则归因于产物不同的晶格氧含量. X射线光电子能谱结果表明, NiMoO4-300/NF比NiMoO4-200/NF含有更多的晶格氧; 而对于高价态金属氧化物而言, 催化剂中的晶格氧在电氧化过程中可以被激活并直接参与到阳极氧化反应过程, 从而有利于析氧反应和尿素氧化反应的进行. 另外, 以NiMoO4-300/NF和NiMoO4-200/NF作为阳极和阴极组装尿素电解槽, 可在1.38 V的电池电压下提供10 mA cm-2的电流密度. 将电极与商品太阳能板连接, NiMoO4纳米棒阵列双电极可成功实现光电压驱动的尿素电解和制氢, 表明其在太阳能驱动的能量转换方面具有巨大潜力.

关键词: NiMoO4纳米棒, 双功能电催化剂, 尿素氧化, 光驱动, 晶格氧, 海胆状

Abstract:

Developing multifunctional electrocatalysts with high catalytic activity, long-term stability, and low cost is essential for electrocatalytic energy conversion. Herein, sea urchin-like NiMoO4 nanorod arrays grown on nickel foam has been developed as a bifunctional electrocatalyst for urea oxidation and hydrogen evolution. The NiMoO4-200/NF catalyst exhibits efficient activity toward hydrogen evolution reaction with a low overpotential of only 68 mV in 1.0 mol/L KOH to gain a current density of 10 mA cm-2. The NiMoO4-300/NF catalyst exhibits a prominent oxygen evolution reaction (OER) catalytic activity with an overpotential of 288 mV at 50 mA cm-2, as well as for urea oxidation reaction with an ultra-low potential of 1.36 V at 10 mA cm-2. The observed difference in electrocatalytic activity and selectivity, derived by temperature variation, is ascribed to different lattice oxygen contents. The lattice oxygen of NiMoO4-300/NF is more than that of NiMoO4-200/NF, and the lattice oxygen is conducive to the progress of OER. A urea electrolyzer was assembled with NiMoO4-200/NF and NiMoO4-300/NF as cathode and anode respectively, delivering a current density of 10 mA cm-2 at a cell voltage of merely 1.38 V. The NiMoO4 nanorod arrays has also been successfully applied for photovoltage-driven urea electrolysis and hydrogen production, revealing its great potential for solar-driven energy conversion.

Key words: NiMoO4 nanorod, Bifunctional electrocatalyst, Urea electrolysis, Photovoltage-driven, Lattice oxygen, Sea urchin-like