Rapid Fabrication of Nife(Oh)X/Fe0.2co-Se Complexes for Oxygen Evolution Reaction Electrocatalysis

Abstract

The development of inexpensive and efficient OER electrocatalysts is crucial for improving the efficiency of electrocatalytic water splitting, since the slow four-electron OER process is a rate-limiting step in electrocatalytic water splitting. Herein, we prepared the NiFe(OH)x/Fe0.2Co-Se complexes on carbon paper (CP) via a facile two-step electrochemical deposition strategy. By varying the doping amount of Fe and the deposition time of Fe0.2Co-Se, the OER activity of NiFe(OH)x/Fe0.2Co-Se/CP was optimized to the best: only requiring low overpotentials of 243 and 277 mV at the current density of 20 and 100 mA/cm2 and a small Tafel slope of 23 mV/dec, along with a terrific long-term stability. Based on the experimental results, the rich exposed active sites, improved intrinsic site activity and enhanced electrical conductivity leads to the superior OER performance. Our work will provide some inspiration for designing other metal selenide/hydroxide heterostructures for other energy conversion or storage applications.

Keywords: OER, NiFe(OH)x/Fe0.2Co-Se, Overpotentials, Tafel slope, Active sites