Effects of phosphate precursors on morphology and oxygen evolution reaction activity of NiFe (oxy)hydroxide on nickel foams

NiFe (oxy)hydroxides nanosheets were synthesized on nickel foams via co-precipitation and electrochemical activation. It is found that the phosphate precursors (Na3PO4, Na2HPO4 and NaH2PO4) have diverse effects on the morphology and thus the oxygen evolution reaction activity of the formed final catalysts. The resulting NiFe (oxy)hydroxides nanosheets prepared with Na2HPO4 demonstrate a low overpotential of 205 mV to achieve a current density of 50 mA/cm(2) with a Tafel slope down to 30 mV/dec in 1 mol/L KOH, and remain stable for 20 h during stability test.