Co-CoO/ZnFe2O4 encapsulated in carbon nanowires derived from MOFs as electrocatalysts for hydrogen evolution
2020
Liu, Wenqi | Zhou, Yuming | Bao, Jiehua | Wang, Jiaqi | Zhang, Yiwei | Sheng, Xiaoli | Xue, Yi | Guo, Chang | Chen, Xinchun
Transition metals are increasingly attracting interest in electrocatalysts for use in water decomposition due to their excellent catalytic activity and stability. Simultaneously, metal-organic frameworks with designable metal ion centers and organic ligands are the promising precursors for the one-step synthesis of metal encapsulated in carbon composites for alkaline hydrogen evolution reaction (HER). Herein, we report the successful construction of Co-CoO/ZnFe₂O₄ encapsulated in carbon nanowires (Co-CoO/ZnFe₂O₄@CNWs) by annealing as-synthesized nanowire Co/Zn/Fe-MOF at 400 °C in N₂. This structure provides the rich defect sites and active centers, and the synergy of Co, CoO and ZnFe₂O₄ lead to efficient hydrogen evolution when the composite is used as a catalytic electrode for HER in 1.0 M KOH. The catalyst shows a low initial overpotential (97 mV) and a small Tafel slope (138 mV dec⁻¹), and the overpotential at 10 mA cm⁻² is only 226 mV. In addition, this composite material exhibits excellent long-term durability even after 1000 cycles. It is expected that it is a potential alternative catalyst for rational utilization in the field of electrolytic water decomposition.
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