Hydrogen energy is a promising source of renewable and clean energy for various industries, such as chemical, automobile, and energy industries. Electrolysis of water is one of the basic methods for the production of hydrogen energy. However, the high overpotential of the oxygen evolution reaction (OER) in water electrolysis has hindered the effective production of hydrogen using this method. Thus, the development of high-efficiency non-precious metal-based electrocatalysts for OER is extremely significant. In this study, we adopted a one-step hydrothermal method to fabricate Ni-based catalysts with N/Sdual doped graphene oxide/carbon nanotube (GO/CNT) supports using thiourea ( CH4N2S) and urea as the S source and the N source. It was observed that the amount of thiourea utilized in the synthesis of the catalyst affected the morphology, composition, and the electrochemical properties of the catalyst. For a GO/CNT-to-thiourea mass ratio of 1:10, the catalyst exhibited the highest activity, where the OER overpotential was 320 mV at a current density of 10 mA/cm2. This was attributed to the high specific surface area, high conductivity, and fast electron transport channels of the N/S-dual doped GO/ CNT composite. Furthermore, sulfurization of the Ni particles to form nickel sulfide played a significant role in enhancing the catalytic performance.

    Abstract
    1 Introduction
    2 Experimental
        2.1 Synthesis of GO and acid-treated MWCNTs
        2.2 Synthesis of catalysts
        2.3 Characterization
        2.4 Electrochemical measurements
    3 Results and discussion
        3.1 Structural characterizations of catalysts
        3.2 Electrochemical activity of catalysts
    4 Conclusion
    Acknowledgements 
    References

• Jin‑Chi Jiang(Department of Chemistry, College of Science, Yanbian University)
• Jiamin Liu(Department of Chemical Engineering, College of Engineering, Yanbian University)
• Yingai Piao(Testing and Analysis Centers, Yanbian University)
• Mei‑Shan Zhang(Department of Chemistry, College of Science, Yanbian University)
• Long‑Yue Meng(Department of Chemistry, College of Science, Yanbian University, Department of Chemistry and Environmental Science, College of Geography and Ocean Sciences, Yanbian University)