Synthesis of FeCo2O4@Co3O4 nanocomposites and their electrochemical catalytical performaces for energy-saving H2 prodcution

In this study, FeCo2O4@Co3O4 bifunctional catalysts with a unique structure combining nanosheets and nanowires were prepared on nickel foam by a simple hydrothermal + annealing method. The catalysts exhibited excellent catalytic activity for hydrogen production during urea electrooxidation reaction (UOR) and ethanol oxidation reaction (EOR). For UOR, the potential at 10 mA/cm2 current density is 1.387 V and the tafel slope is 67 mV/dec. In the configured two-electrode electrolytic cell, the FeCo2O4@Co3O4 catalysts in the UOR and EOR processes required only 1.425 and 1.471 V, respectively, to produce a current density of 10 mA/cm2, which is much less than that of the (oxygen evolution reaction) OER (1.640 V). In addition, the current density remained stable at a fixed potential during a long time (20 h) i-t test in the urea solution.