일시 : 2017년 11월 8일(수) 오후5시-7시
장소 : 과학관 604호
연사 : 장진호 교수님(성신여대, 화학과)
Title: Electrochemistry on ultramicroelectrode: from fundamentals to redox flow battery analyses
Abstract: In the first part of this presentation, electro-analyses of electrochemically generated quaternary ammonium polybromides (QBr2n+1) on Pt ultramicroelectrode (UME) are introduced. At first, we report the electrochemistry of Br− electro-oxidation in MEPBr2n+1 droplets during their collision on Pt UME through the current transient method, and reveal that MEPBr2n+1 also plays a vital role as an electrochemical reaction medium for Br− electro-oxidation in the Br−/Br2 redox system. Also, we present Br- electro-oxidation in QBr2n+1 strongly depends on Q+, and Br- transfer from aqueous to QBr2n+1 is the important preceding step for Br- electrolysis during the collision of QBr2n+1 droplets on Pt UME.
In the second part, we present the determination of ZnXn2-n complexes in high concentration ZnX2 solutions though steady state voltammograms on Pt UME, which is important for understanding Znpolyiodide redox flow battery system. The steady state current from I- electro-oxidation are deviated as the concentration of ZnX2 in the solutions increased, and we found it is mainly due to the ZnXn2-n complexation. From the finite element analysis of the deviated currents, we measured the stability constants of ZnXn2-n, and estimated fractional diagrams of each ZnXn2-n.