Chen Qiming, Zhang Qicheng, Liu Huibin, Liang Junmei, Peng Wenchao, Li Yang, Zhang Fengbao, Fan Xiaobin
School of Chemical Engineering and Technology, State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, P. R. China.
Small. 2021 Apr;17(13):e2007858. doi: 10.1002/smll.202007858. Epub 2021 Mar 9.
Transition metal phosphides (TMPs), especially the dual-metal TMPs, are highly active non-precious metal oxygen evolution reaction (OER) electrocatalysts. Herein, an interesting atom migration phenomenon induced by Kirkendall effect is reported for the preparation of cobalt-iron (Co-Fe) phosphides by the direct phosphorization of Co-Fe alloys. The compositions and distributions of the Co and Fe phosphides phases on the surfaces of the electrocatalysts can be readily controlled by Co Fe alloys precursors and the phosphorization process with interesting atom migration phenomenon. The optimized Co Fe phosphides exhibit a low overpotential of 225 mV at 10 mA cm in 1 m KOH alkaline media, with a small Tafel slope of 37.88 mV dec and excellent durability. It only requires a voltage of 1.56 V to drive the current density of 10 mA cm when used as both anode and cathode for overall water splitting. This work opens a new strategy to controllable preparation of dual-metal TMPs with designed phosphides active sites for enhanced OER and overall water splitting.
过渡金属磷化物（TMPs），尤其是双金属TMPs，是高活性的非贵金属析氧反应（OER）电催化剂。在此，报道了一种由柯肯达尔效应诱导的有趣的原子迁移现象，用于通过Co-Fe合金的直接磷化制备钴铁（Co-Fe）磷化物。通过Co-Fe合金前驱体和具有有趣原子迁移现象的磷化过程，可以很容易地控制电催化剂表面Co和Fe磷化物相的组成和分布。优化后的Co-Fe磷化物在1 m KOH碱性介质中，在10 mA cm时具有225 mV的低过电位，塔菲尔斜率为37.88 mV dec，耐久性优异。当用作全水解的阳极和阴极时，仅需1.56 V的电压即可驱动10 mA cm的电流密度。这项工作为可控制备具有设计磷化物活性位点的双金属TMPs开辟了一条新策略，以增强OER和全水解性能。
