Easy conversion perovskite fluorides KCo 1- x Fe x F 3 for efficient oxygen evolution reaction.

Herein, we report an easily oxidized Co-Fe perovskite fluoride as an efficient catalyst for the oxygen evolution reaction (OER). In situ Raman spectroscopy showed that the presence of F promotes reconstruction to form highly active (Co 3+ Fe 3+ )OOH, and the current density of 10 mA cm -2 can be achieved at the overpotential of only 118 mV in 1 M KOH aqueous solution. This work helps to understand the role of fluoride during the OER.