Fabrication of NiO/TiO2/rGO nanocomposites as a quasi-solid-state asymmetric supercapacitor: Paving the way for PhotoSupercapacitor application

Abstract

In this present communication, a novel ternary nanocomposite, NiO/TiO₂/rGO (NTG), was synthesised via a simple hydrothermal technique for photosupercapacitor application. The XRD pattern confirmed the crystalline nature and phase structure of the as-synthesised material. FE-SEM and HR-TEM analyses demonstrated the embellishment of NiO/TiO₂ nanoparticles on the rGO sheets, which facilitates more voids and shorter diffusion paths. The electrochemical investigation of the prepared samples was assessed using 1 M Na₂SO₄ and Na₂CO₃ aqueous electrolyte solutions. Among the synthesised samples, NTG-2 carried out under 1 M Na₂SO₄ electrolyte exhibited a maximum specific capacitance of 1285 Fg^-1 at 1 Ag^-1, maintaining a capacitance retention of 94 % after 5000 cycles. The NTG-2 electrode was additionally utilised in the construction of an asymmetric supercapacitor that has an impressive specific capacitance of 478 Fg^-1 at 1 Ag^-1. This displays an intriguing performance in terms of energy and power density of 42.2 Wh Kg⁻¹ at 0.5 kW kg⁻¹. In PSC, the as-fabricated TiO₂/N719/I⁻/I₃⁻/Pt@NTG-2//AC architecture possessed a specific capacitance of 567.5 Fg^-1 at 1 Ag^-1, with an energy density of 50.4 Wh Kg⁻¹ and a power density of 0.4 kW kg⁻¹. As a result, it has been concluded that the novel NTG-2 device opens new opportunities to develop new architectures for efficient energy storage applications.