Huang Tan, Chen Yu, Lee Jong-Min
Energy Research Institute@NTU, Interdisciplinary Graduate School, Nanyang Technological University, 50 Nanyang Drive, Singapore, 637553, Singapore.
School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.
Small. 2017 Dec;13(48). doi: 10.1002/smll.201702753. Epub 2017 Nov 9.
Developing highly efficient electrocatalysts for oxygen evolution is vital for renewable and sustainable energy production and storage. Herein, nitrogen-doped carbon encapsulated CoOx-MoC heterostructures are reported for the first time as high performance oxygen evolution electrocatalysts. The composition can be tuned by the addition of a Mo source to form a nanowire-assembled hierarchically porous microstructure, which can enlarge the specific surface area, thus exposing more active sites, facilitating mass transport and charge transfer. Moreover, it is demonstrated that the formation of CoOx-MoC heterostructures and the resulting synergistic effect between MoC and Co facilitate the reaction kinetics, leading to significantly improved oxygen evolution reaction (OER) activity with an onset overpotential of merely 290 mV, and a low overpotential of 330 mV to afford a current density of 10 mA cm . The well-constructed microarchitecture contributes to superior long term stability electrochemical behaviors. This work provides a facile strategy via composition tuning and structure optimization for the development of next-generation nonprecious metal-based OER electrocatalysts.
开发高效的析氧电催化剂对于可再生和可持续能源的生产与存储至关重要。在此，首次报道了氮掺杂碳包覆的CoOx-MoC异质结构作为高性能析氧电催化剂。通过添加钼源可以调节其组成，形成纳米线组装的分级多孔微结构，这可以扩大比表面积，从而暴露出更多的活性位点，促进传质和电荷转移。此外，结果表明，CoOx-MoC异质结构的形成以及由此产生的MoC和Co之间的协同效应促进了反应动力学，导致析氧反应（OER）活性显著提高，起始过电位仅为290 mV，低过电位为330 mV时可提供10 mA cm的电流密度。构建良好的微结构有助于实现优异的长期稳定性电化学行为。这项工作通过组成调节和结构优化为开发下一代非贵金属基OER电催化剂提供了一种简便策略。
