Hierarchical Superaerophobic Nanoarray Electrode (FeOOH/CoFe LDH) as an Efficient Oxygen Evolution Reaction Catalyst for Alkaline Seawater Electrolysis
Dongdong Wang, Lili Liu, Yue Liu, Wenhao Luo, Yaojia Xie, Tiantao Xiao, Yinhu Wang, Zhihui Song, Heng Zhang, Xindong Wang
Abstract
The lack of highly efficient and long-term stable catalysts for the oxygen evolution reaction (OER) severely hampers the advancement of alkaline seawater electrolysis. Herein, a hierarchical superaerophobic OER catalyst electrode, FeOOH/CoFe layered double hydroxide (FeOOH/CoFe LDH), has been prepared on nickel foam through a one-step hydrothermal reaction as an efficient OER catalyst for alkaline seawater electrolysis. The hierarchical nanostructure provides abundant active sites for the catalyst; the superaerophobic property ensures sufficient contact between the catalysts and the electrolyte, and the interaction between FeOOH and CoFe LDH further enhances the OER activity. The FeOOH/CoFe LDH catalytic electrode exhibits remarkable OER performance in simulated seawater solution (1.0 M KOH + 0.5 M NaCl). Specifically, at an industrial current density of 400 mA cm –2, the overpotentials are just 320 mV at 25 °C and 257 mV at 60 °C. Meanwhile, after 300 h of stability testing at a current density of 100 mA cm –2, the overpotential of the electrode increases by a mere 19 mV. This work will afford a simple approach for designing effective electrodes for alkaline seawater electrolysis.