TEA driven C, N co-doped superfine FeO nanoparticles for efficient trifunctional electrode materials.

Poor conductivity is an obstacle that restricts the development of the electrochemistry performance of FeO. In this work, a novel carbon and nitrogen co-doped ultrafine FeO nanoparticles (CN-FeO) have been synthesized by triethylamine (TEA) induction and subsequent calcination. The addition of TEA could not only regulate the size of FeO nanoparticles, but also promote the formation of amorphous carbon layer. Well-designed CN-FeO heterostructures provide a highly interconnected porous conductive network, large heterogeneous interface area, large specific surface area and a large number of active sites, which greatly improve conductivity and promote electron transfer and electrolyte diffusion. The prepared CN-FeO electrode exhibits a high specific capacitance of 399.3 mF cm and good cycling stability. Meanwhile, CN-FeO catalyst exhibits excellent oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) activities, with overpotentials of 136 and 281 mV at the current density of 10 mA cm, respectively. This work provides a promising approach for the design of high-performance anode materials for supercapacitors and provides profound implications for the development of catalysts with bifunctional catalytic activity.