One Pot Synthesis of FeCo/N‐Doped 3D Porous Carbon Nanosheets as Bifunctional Electrocatalyst for the Oxygen Reduction and Evolution Reactions

Abstract In this work, FeCo/N‐doped porous carbon nanosheets (FeCo/NPC) were in‐situ synthesised as bifunctional oxygen catalyst following a sodium chloride (NaCl) template‐assisted strategy. The results show that this strategy assists in generating a 3D interconnected carbon nanosheets network with hierarchical pores and a larger specific surface area through a stencil effect. X‐ray photoelectron spectroscopy (XPS) results show that the Fe 2p 3/2 and Co 2p 3/2 core‐level binding energy (BE) of the FeCo/NPC catalyst exhibits a positive shift compared to monometallic catalysts, which is associated with downshifts of the d‐band position of the metal by alloying and weakening of the interaction between oxygenic species and metal surfaces, thereby improving the catalytic activity. The FeCo/NPC catalyst shows excellent electrocatalytic activity for bothoxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline solution: a high onset potential of 0.92 V (vs. RHE), only 10 mV difference of half‐wave potential comparable with commercial Pt/C (20 wt%), a high current retention of 95.7 % after stability test of 20000 s for ORR and a potential of 1.68 V (vs. RHE) for OER at 10 mA ⋅ cm −2 . The high catalytic performance of the FeCo/NPC catalyst and the simplicity of the synthesis method provide a possibility for its practical application in metal‐air batteries.