Author(s)

Toshihiro Takashima^1*, Koki Ishikawa², Hiroshi Irie¹

¹Clean Energy Research Center, University of Yamanashi, Yamanashi, Japan.
²Special Doctoral Program for Green Energy Conversion Science and Technology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi, Japan.

Development of active iron based water oxidation for designing an ideal artificial photosynthesis devices operating under benign neutral pH is highly demanded. We investigated the electrocatalytic activity of Ruddlesden-Pop-per-type strontium ferrite (Sr₃Fe₂O₇) toward the oxygen evolution reaction (OER). Owing to the temperature-dependent efficiency of the charge disproportionation of Fe4⁺, the OER activity of Sr₃Fe₂O₇ varied with the temperature, and the onset potential for the OER at a neutral pH underwent a negative shift of approximately 200 mV by increasing the temperature for the stabilization of Fe4⁺. When metal substitution was made to Sr₃Fe₂O₇ for stabilizing Fe4⁺ at room temperature, the temperature dependence of the OER activity disappeared and the OER was driven at a small overpotential without increasing the temperature, indicating that the stabilization of Fe4⁺ is substantially important for achieving high OER activity.

Oxygen Evolution, Charge Disproportionation, Water-Splitting, Sr₃Fe₂O₇

Takashima, T. , Ishikawa, K. and Irie, H. (2017) Enhancement of Oxygen Evolution Activity of Ruddlesden-Popper-Type Strontium Ferrite by Stabilizing Fe4⁺. Journal of Materials Science and Chemical Engineering, 5, 45-55. doi: 10.4236/msce.2017.54005.