Synthesis of rGO/TiO₂ composite electrode material for enhanced electrochemical activity and its applications in supercapacitors

The present work illustrates the synthesis and electrochemical performance of rGO-TiO₂ composite electrodes for their potential application in energy storage devices. The rGO-TiO₂ composite was prepared via ultrasonication method, and rGO-TiO₂ electrodes were prepared by drop-cast technique. The rGO-TiO₂ composite electrodes were electrochemically analyzed using galvanostatic charge–discharge (GCD) and cyclic voltammetry (CV) methods. These tests were performed with three distinct electrolytes (H₂SO₄, Na₂SO₄, and KOH), each with a 1 molar concentration. The rGO-TiO₂ composite electrodes’ specific capacitance (C_sp) in 1 M H₂SO₄ electrolyte was estimated to be 4.89 F/g; it was estimated to be 3.35 F/g in case of 1 M Na₂SO₄ and 1.42 F/g for the 1 M KOH liquid electrolyte at a scan rate of 0.05 V/s. Using GCD, it was found that in the case of 1 M H₂SO₄, energy density and power density values were 1.78 Wh/kg and 4000 Wh/kg at a current density of 10 A/g, respectively; in 1 M Na₂SO₄, the energy density was found to be 2.58 Wh/kg, and conversely, in 1 M KOH, the energy density was measured as 2.39 Wh/kg at 1.25 A/g. AC impedance studies were conducted, and the prepared rGO-TiO₂ electrodes exhibited specific capacitance values of 14.21 F/g, 12.68 F/g, and 15.02 F/g in H₂SO₄, Na₂SO₄, and KOH electrolytes, respectively. Hence, the research work demonstrated a simple and affordable method of synthesis of rGO-TiO₂ electrodes that holds promise for supercapacitor applications, particularly when optimized for specific electrolyte conditions.