| 초록 |
Reported herein is elucidation of a novel Co-based oxygen evolution catalyst generated in–situ from cobalt phosphide (CoP) nanoparticles at anodic potentials. Present as-prepared CoP nanoparticles, efficient hydrogen-evolving materials at cathodic potentials, were revealed to experience dramatic metamorphosis at anodic potentials, yielding totally transformed nature which is highly effective toward oxygen evolution reaction (OER) in alkaline electrolyte. Our extensive post-catalysis characterization strongly implies that the in-situ transformed catalyst bears active Co-Pi like environments along with high oxidation states of cobalt center. Outstanding OER efficiency was achievable with the active catalyst; only 360 mV of the overpotential is required to reach 10 mA cm-2 current density, which is favorably comparable to the best reported Co-based catalysts and even a precious iridium catalyst in alkaline medium. More remarkable feature is its longterm durability, superior to iridium and cobalt oxide based materials. Moreover, 12 hr bulk electrolysis continuously operating at high current density was completely tolerable. |
