Micelle-template synthesis of a 3D porous FeNi alloy and nitrogen-codoped carbon material as a bifunctional oxygen electrocatalyst

The sluggish kinetics of oxygen reduction reaction and oxygen evolution reaction (ORR/OER) are the key scientific issues that need to be addressed for the application of renewable energy technologies. Rational coupling transition metal with porous heteroatom-doped carbon is extensively investigated as an efficient strategy to achieve high performance ORR/OER nonprecious metal electocatalysts. In this study, a FeNi alloy coated with N-doped carbon material (namely FeNi/NC) was designed by using triblock copolymer Pluronic F127 as a surfactant co-assembly with g-C3N4. This strategy enabled FeNi/NC possessing a high BET surface area in terms of three-dimensional hierarchical porous structure together with abundant defect sites. The optimized FeNi/NC catalyst displays an excellent oxygen electrode electrocatalytic activity with a potential gap △E of 0.77 V in alkaline media which substantially outperformed benchmark Pt/C + RuO2 (△E = 0.80 V). Furthermore, it shows almost no decay after long-time cycling tests for ORR/OER. The excellent catalytic performance along with the low cost for FeNi/NC catalyst makes it possible to commercialize the renewable energy devices.