Li Guang-Lan, Qiao Xiang-Yue, Miao Ying-Ying, Wang Tian-Yu, Deng Fei
State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116023, P. R. China.
School of Chemical Engineering, Dalian University of Technology, Panjin, 124221, P. R. China.
Small. 2023 Jul;19(28):e2207196. doi: 10.1002/smll.202207196. Epub 2023 Apr 7.
The exploring of economical, high-efficiency, and stable bifunctional catalysts for hydrogen evolution and oxygen evolution reactions (HER/OER) is highly imperative for the development of electrolytic water. Herein, a 3D cross-linked carbon nanotube supported oxygen vacancy (V )-rich N-NiMoO /Ni heterostructure bifunctional water splitting catalyst (N-NiMoO /Ni/CNTs) is synthesized by hydrothermal-H calcination method. Physical characterization confirms that V -rich N-NiMoO /Ni nanoparticles with an average size of ≈19 nm are secondary aggregated on CNTs that form a hierarchical porous structure. The formation of Ni and NiMoO heterojunctions modify the electronic structure of N-NiMoO /Ni/CNTs. Benefiting from these properties, N-NiMoO /Ni/CNTs drives an impressive HER overpotential of only 46 mV and OER overpotential of 330 mV at 10 mA cm , which also shows exceptional cycling stability, respectively. Furthermore, the as-assembled N-NiMoO /Ni/CNTs||N-NiMoO /Ni/CNTs electrolyzer reaches a cell voltage of 1.64 V at 10 mA cm in alkaline solution. Operando Raman analysis reveals that surface reconstruction is essential for the improved catalytic activity. Density functional theory (DFT) calculations further demonstrate that the enhanced HER/OER performance should be attributed to the synergistic effect of V and heteostructure that improve the conductivity of N-NiMoO /Ni/CNTs and facilitatethe desorption of reaction intermediates.
开发用于析氢反应和析氧反应（HER/OER）的经济、高效且稳定的双功能催化剂对于电解水的发展至关重要。在此，通过水热 - H煅烧法合成了一种三维交联碳纳米管负载的富含氧空位（V ）的N - NiMoO /Ni异质结构双功能水分解催化剂（N - NiMoO /Ni/CNTs）。物理表征证实，平均尺寸约为19 nm的富含V 的N - NiMoO /Ni纳米颗粒二次聚集在形成分级多孔结构的碳纳米管上。Ni和NiMoO异质结的形成改变了N - NiMoO /Ni/CNTs的电子结构。受益于这些特性，N - NiMoO /Ni/CNTs在10 mA cm 时驱动的令人印象深刻的HER过电位仅为46 mV，OER过电位为330 mV，其循环稳定性也分别表现出色。此外，组装好的N - NiMoO /Ni/CNTs||N - NiMoO /Ni/CNTs电解槽在碱性溶液中10 mA cm 时的电池电压达到1.64 V。原位拉曼分析表明表面重构对于提高催化活性至关重要。密度泛函理论（DFT）计算进一步证明，增强的HER/OER性能应归因于V和异质结构的协同效应，该效应提高了N - NiMoO /Ni/CNTs的导电性并促进了反应中间体的解吸。
