Preparation and characterization of electro-spun RuO2–Ag2O composite nanowires for electrochemical capacitors

We synthesized RuO2–Ag2O composite nanowires by means of an electrospinning method and investigated the capacitance, high-rate performance, and cycle number dependence of the composite nanowire electrodes. In order to synthesize optimum RuO2–Ag2O composite nanowires, the relative mole ratio of Ag precursor to Ru precursor varied from ∼0.1 to ∼0.3. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy results show that crystalline RuO2–Ag2O composite nanowires (∼40–70 nm in diameter) are formed upon calcinations. Cyclic voltammetry results show that among the samples, the RuO2–Ag2O composite nanowires fabricated with the mole ratio of ∼0.2 give the highest capacitance, excellent high-rate performance, and excellent retention of capacity (∼97%).

Research highlights▶ Synthesis of RuO2–Ag2O composite nanowires by means of an electrospinning method. ▶ Structural properties of the RuO2–Ag2O composite nanowires using XRD, XPS, SEM, and TEM investigated. ▶ Optimum performance of electrochemical capacitors with the composite nanowires discussed.