121st General Meeting of the KCS

Type Poster Presentation
Area Material Chemistry
Room No. Event Hall
Time 4월 20일 (금요일) 11:00~12:30
Code MAT.P-342
Subject High-Density Crystalline/Amorphous Phase Boundaries in Electrochemically Activated Nickel-Doped Cobalt Sulfide for Efficient Oxygen Evolution Reaction
Authors Yu-Rim Hong, Won-Sik Han1,*
Korea Institute of Industrial Technology, Korea
1Department of Chemistry, Seoul Women's University, Korea
Abstract Developing effective and earth-abundant electrocatalysts for the oxygen evolution reaction (OER) is critical for the practical realization of a water-splitting system. It has recently been proposed that the OER activity of transition metal sulfides (TMSs) can be enhanced by forming a thin amorphous layer on a pristine surface. We report here a novel strategy for enhancing OER by developing a nickel-doped cobalt sulfide (CNS) with a high density of crystalline and amorphous phase boundaries. Electrochemical activation (ECA) can partially amorphize hollow CNS nanoparticles derived from surface-selective sulfidation. ECA-treated CNS (ECA-CNS) electrocatalysts, which are comprised of CNS nanodots separated by thin amorphous layers, show high densities of crystalline and amorphous phase boundaries. This catalyst shows superior OER catalytic performance with a current density of 10 mA cm-2 at a small overpotential of 290 mV, a low Tafel slope of 46 mV dec-1, a high mass activity of 217 A g-1, a high turnover frequency of 0.21 s-1 at an overpotential of 340 mV, and excellent stability in alkaline media.
E-mail abc9523@kitech.re.kr