Supercapacitive performance of hydrous ruthenium oxide (RuO₂ · nH₂O) thin films synthesized by chemical route at low temperature

Abstract

In the present investigation, we report the synthesis of ruthenium oxide (RuO₂ · nH₂O) thin films by simple chemical bath deposition (CBD) method at low temperature on the stainless steel substrate. The prepared thin films are characterized for their structural and morphological properties by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT–IR) and scanning electron microscopy (SEM). The structural study revealed that the ruthenium oxide thin films are amorphous. Scanning electron microscopy study shows compact morphology with small overgrown particles on the surface of the substrate. FT–IR study confirms the formation of RuO₂ · nH₂O material. The supercapacitor behaviour of RuO₂ · nH₂O thin film was studied using cyclic voltammetry (CV) technique in 0 · 5 M H₂SO₄electrolyte. RuO₂ · nH₂O film showed maximum specific capacitance of 192 F · g^{− 1}at a scan rate of 20 mV · s^{− 1}. The charge–discharge studies of RuO₂ · nH₂O carried out at 300 μA · cm^{− 2}current density revealed the specific power of 1 · 5 kW.kg^{− 1}and specific energy of 41 · 6 Wh.kg^{− 1}with 95% coulombic efficiency.