Activating CoFe2O4 electrocatalysts by trace Au for enhanced oxygen evolution activity

Development of effective electrocatalysts for oxygen evolution reaction (OER) is critically important, which is believed as the bottleneck process in overall water splitting and chargeable metal-air battery. In this study, we fulfill an OER improvement by introducing of trace Au on CoFe2O4 surface by electrochemical method. The loading of trace Au highly improves the OER activity, decreasing the overpotential of 374 mV at 10 mA cm(-2) to 312 mV and showing a small Tafel slope of 35 mV dec(-1) in 1 M KOH. The loaded trace Au largely increases the electrochemical active specific area. The electronic interactions between Au and the adjacent CoFe2O4 modulate the electron structure of metal sites, which further optimize the binding strength between the involved intermediates and catalysts, facilitating the transform of rate-limiting step. Importantly, such enhanced electrocatalytic performance can be largely maintained after a long-time stability test.