Electrochemical water splitting is an important process for next generation of eco-friendly energy systems. The oxygen evolution reaction (OER), which occurs at an anode during the process, requires efficient electrocatalysts to reduce activation energies. Although Ru- or Ir-containing materials show excellent electrocatalytic activities, their high cost is a critical drawback. Consequently, the development of efficient electrocatalysts composed of low-cost metal components is a great challenge. In this study, we develop a new route to produce a hybrid material (Fe–NC) containing Fe3C particles dispersed on the surface of N-doped carbon (NC) materials by heat treatment of a mixture of urea and Fe(II)Cl2(H2O)4. Microscopic analyses prove that the Fe3C particles are placed on the surfaces of thin NC materials. Additionally, various characterizations reveal that the particles contain Fe3C structure. Fe–NC shows good electrocatalytic properties with onset and overpotentials of 1.57 V and 545 mV, respectively, for OER in KOH electrolyte. This study suggests the possibility of the use of Fe3C- based composites as OER electrocatalysts.

    Abstract
    1 Introduction
    2 Experimental section
        2.1 Preparation of Fe–NC sample
        2.2 Preparation of UCN
        2.3 Electrochemical measurements
        2.4 Instruments
    3 Results and discussion
    4 Conclusion
    Acknowledgements 
    References

• Minseon Choi(Department of Chemistry and Chemical Engineering, Inha University)
• Suyeon Lee(Department of Chemistry and Chemical Engineering, Inha University)
• Dawoon Jang(Department of Chemistry and Chemical Engineering, Inha University)
• Sungjin Park(Department of Chemistry and Chemical Engineering, Inha University)