Ultrafine Core‐Shell Nanostructured Iron Cobalt Ferrocyanide with Excellent Electrocatalytic Activity toward Overall Water Splitting
Arunagiri Gayathri, Selvam Mathi, Murugan Vijayarangan, Jayaraman Jayabharathi, V. Thanikachalam
Abstract
Abstract The development and production of non‐noble metal electrocatalysts with exceptional activity and stability for water electrolysis was essential for energy conversion and storage. An optimized working electrode of core‐shell nanosphere Fe 2 Co 8 HCF on nickel foam exhibits a small overpotential of 241 mV (63 mV/dec) for OER and 158 mV (92 mV/dec) for HER at 10 mA/cm 2 (without iR correction) in 1.0 M KOH. Fe 2 Co 8 HCF shows ultra‐stability (150 h) with loss of 2.9 % and 3.1 % for OER and HER, respectively. The interaction between Fe, Co and HCF that resulted in the formation of core‐shell nanostructure was highly beneficial for reaction kinetics. The active bifunctional Fe 2 Co 8 HCF/NF electrode pair aids in the development of a water electrolyzer that provides 10 mA/cm 2 at 1.63 V. The Fe 2 Co 8 HCF/NF//Fe 2 Co 8 HCF/NF displays great durability (over 150 h) with loss of 4.2 %. The solar‐driven water electrolysis at 1.63 V demonstrates the enhanced efficiency of an optimized electrocatalyst. These results imply that Fe 2 Co 8 HCF/NF//Fe 2 Co 8 HCF/NF can be utilized to generate a huge amount of hydrogen at low cost.