The synthesis of advanced functional nanomaterials for electrochemical applications, such as water splitting, dye-sensitized solar cells (DSCs), and supercapacitor has been the topic of interest in recent years. This work presents the synthesis of ruthenium (Ru)/reduced graphene oxide (RGO) nanocomposite by using a facile and scalable liquid plasma-assisted method and its application as an electrode material in electrochemical applications for supercapacitor and triiodide reduction at counter electrodes (CEs) of DSCs. As the results, Ru nanoparticles have a size in the range of 4-10 nm that were homogenously distributed on the surface of the RGO layer. Electrochemical measurements demonstrated that the synthesized material is suitable for supercapacitor applications, whereas the capacitance is approximately 136.7 F.g(-1) at a scan rate of 20 mV.s(-1). The developed materials are applied in CEs of DSCs. We found that the efficiency of 6.78% for DSCs with CE fabricated by Ru/RGO which is higher than that of 6.20% for a cell assembled with Pt electrode.