Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), CAS Key Laboratory of Mechanical Behavior and Design of Materials and ‡CAS Key Laboratory of Materials for Energy Conversion and Department of Material Science and Engineering, University of Science and Technology of China , Hefei, Anhui 230026, P. R. China.
Nano Lett. 2017 Jan 11;17(1):578-583. doi: 10.1021/acs.nanolett.6b04732. Epub 2016 Dec 6.
In this study, by using dicobalt phosphide nanoparticles as precatalysts, we demonstrated that electrochemical activation of metallic precatalysts in alkaline media (comparing with directly electrochemical activation in neutral media) could significantly promote the OER catalysis in neutral media, specifically realizing a 2-fold enhanced activity and meanwhile showing a greatly decreased overpotential of about 100 mV at 10 mA cm. Compared directly with electrochemical activation in neutral media, the electrochemical activation in harsh alkaline media could easily break the strong Co-Co bond and promote active species generation on the surface of metallic CoP, thus accounting for the enhancement of neutral OER activity, which is also evidenced by HRTEM and the electrochemical double-layer capacitance measurement. The activation of electrochemical oxidation of metallic precatalysts in alkaline media enhanced neutral OER catalysis could also be observed on CoP nanoparticles and NiP nanoparticles, suggesting this is a generic strategy. Our work highlights that the activation of electrochemical oxidation of metallic precatalysts in alkaline media would pave new avenues for the design of advanced neutral OER electrocatalysts.
在这项研究中，我们使用二钴磷纳米粒子作为前催化剂，证明了在碱性介质中电化学激活金属前催化剂（与在中性介质中直接电化学激活相比）可以显著促进中性介质中的 OER 催化，特别是实现了 2 倍的活性增强，同时在 10 mA cm 时表现出约 100 mV 的大大降低的过电位。与在中性介质中直接电化学激活相比，在苛刻的碱性介质中电化学激活可以轻易地打破强 Co-Co 键，并促进表面上的活性物质的生成金属 CoP，从而解释了中性 OER 活性的增强，这也得到了 HRTEM 和电化学双层电容测量的证实。在碱性介质中电化学氧化的金属前催化剂的活化也可以在 CoP 纳米粒子和 NiP 纳米粒子上观察到增强的中性 OER 催化作用，这表明这是一种通用策略。我们的工作强调了在碱性介质中电化学氧化的金属前催化剂的活化将为设计先进的中性 OER 电催化剂开辟新途径。
