| 초록 |
A series of NiFe-LDH catalysts were prepared by electrodeposition of Ni and Fe with varying Ni to Fe molar ratios of 99:1, 97:3, and 79:21 on a carbon paper to examine the electrochemical redox properties and the OER performance in 1.0 M KOH. Fe doping on Ni(OH)2 and Ni was also carried out to investigate active sites of the catalysts in the OER. Structural properties of the catalysts were characterized by in situ X-ray absorption near edge structure (XANES) spectroscopy coupled with cyclic voltammetry (CV), which revealed that the degradation of NiFe-LDH was facilitated by irreversible phase change of Ni(OH)2/NiOOH. On the other hand, Fe doped Ni samples exhibited high activity and stability in the OER while maintaining the Ni phase of Ni2+. It was thus demonstrated that the Fe sites on the surface of Ni(OH)2 could play as active sites in the OER. |
