Boosting the Oxygen Evolution Reaction Activity of NiFe(2)O(4) Nanosheets by Phosphate Ion Functionalization

[Image: see text] Here, we demonstrate an effective strategy to constitutionally increase the conductivity and electrocatalytic property of NiFe(2)O(4) by phosphate ion functionalization. The phosphate-ion-modified NiFe(2)O(4) (P-NiFe(2)O(4)) nanosheets are readily grown on a carbon cloth by a simple hydrothermal method and followed by a phosphating process. The introduction of phosphate ions on the NiFe(2)O(4) surface is highly beneficial for increasing the charge transport rate and electrocatalytic active sites. As a result, the as-prepared P-NiFe(2)O(4) nanosheets show outstanding electrocatalytic activity toward oxygen evolution reaction (OER), with a low overpotential (231 mV at 10 mA/cm(2)) and Tafel slope (49 mV/dec). Furthermore, the P-NiFe(2)O(4) electrode has a remarkable stability with no activity fading after 50 h. In addition, the as-fabricated water electrocatalysts exhibit excellent flexibility at the foldable state. These features make the phosphate-ion-functionalized NiFe(2)O(4) electrodes open a new way to develop OER electrocatalysts with high electrochemical property.