120th General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation of Young Scholars in Electrochemistry
Room No. Room 201+202
Time THU 09:45-:
Code ELEC.O-4
Subject Iridium-Iridium Oxide Nanofibers as an Improved Electrocatalyst for Hydrogen Evolution Reaction
Authors Su-jin Kim, Myung Hwa Kim1, Chongmok Lee, Youngmi Lee*
Department of Chemistry and Nano Science, Ewha Womans University, Korea
1Chemistry Department of Nano-Science, Ewha Womans University, Korea
Abstract Hydrogen evolution reaction (HER) has been actively studied for renewable electrochemical storage systems and energy conversion. HER electrocatalysts are required to have low overpotentials with generating high cathodic current densities of HER. Therefore, various materials have been developed and characterized as electrocatalysts for HER. In this research, we synthesize iridium-iridium oxide nanofibers (Ir-IrO2 nanofibers) via simple electrospinning of an iridium precursor/polymer solution and subsequent calcination at various temperatures (300, 500, 700, and 900 ℃). The structural morphologies and compositions of Ir-IrO2 nanofibers calcined at various temperatures are characterized by field emission scanning electron microscopy, transmission electron microscopy and X-ray diffraction. When the calcination temperature is increased, the portion crystallized IrO2 species is also increased, and Ir metal portion is decreased. The electrochemical HER activities of Ir-IrO2 nanofibers are studied using rotating disk electrode linear sweep voltammetry. The onset potential, Tafel slope and stability for HER on synthesized Ir-IrO2 nanofibers are compared with those on platinum. To understand the experimental results on the fundamental basis, HER catalyzed by Ir-IrO2 nanofibers is studied using density functional theory calculations based on d-band theory. This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Ministry of Education, Science and Technology (NRF-2017R1A2A2A14001137).
E-mail dj0910@hanmail.net