Stable Cobalt Nanoparticles and Their Monolayer Array as an Efficient Electrocatalyst for Oxygen Evolution Reaction

作者：Liheng Wu, Qing Li, Chenghao Wu, Huiyuan Zhu, Adriana Mendoza‐Garcia, Bo Shen, Jinghua Guo, Shouheng Sun · 发表于：Journal of the American Chemical Society · 年份：2015 · DOI：10.1021/jacs.5b04142 · 被引用次数：336 · 研究领域：Electrocatalysts for Energy Conversion、Advanced battery technologies research、Electrochemical Analysis and Applications

Monodisperse cobalt (Co) nanoparticles (NPs) were synthesized and stabilized against oxidation via reductive annealing at 600 °C. The stable Co NPs are active for catalyzing the oxygen evolution reaction (OER) in 0.1 M KOH, producing a current density of 10 mA/cm(2) at an overpotential of 0.39 V (1.62 V vs RHE, no iR-correction). Their catalysis is superior to the commercial Ir catalyst in both activity and stability. These Co NPs are also assembled into a monolayer array on the working electrode, allowing the detailed study of their intrinsic OER activity. The Co NPs in the monolayer array show 15 times higher turnover frequency (2.13 s(-1)) and mass activity (1949 A/g) than the NPs deposited on conventional carbon black (0.14 s(-1) and 126 A/g, respectively) at an overpotential of 0.4 V. These stable Co NPs are a promising new class of noble-metal-free catalyst for water splitting.