Electrochemical Studies of SrTiO3/Reduced Graphene Oxide Composite for High-Power Energy Storage and Oxygen Evolution Reaction Applications.

Abstract

Strontium titanium perovskite oxide (SrTiO₃, STO) has emerged as a promising material for energy applications, but its insulating nature limits its performance. Herein, a hierarchical structure of STO particles (600-700 nm) anchored onto reduced graphene oxide (rGO) is developed and their dual functionality in energy storage and water-splitting applications is evaluated. The STO-rGO composites exhibit enhanced high-power electrochemical performance in aqueous electrolytes, driven by their large electrochemical surface area and nondiffusion-controlled charge storage process. Furthermore, symmetric supercapacitors and asymmetric supercapacitors fabricated with STO-rGO composites demonstrate excellent electrochemical performance, achieving stable cycling stability with 90% and 95% capacity retention after 10,000 cycles, respectively, highlighting the potential of STO-rGO composites as high-power electrodes. Additionally, STO-rGO composites demonstrate superior oxygen evolution reaction activity, with a low overpotential of 303 mV, high mass activity, and an improved turnover frequency compared to pristine STO, with better long-term cycling stability, retaining performance after a 24 h chronopotentiometry test at a current density of 10 mA cm^-2. This work demonstrates the dual functionality of strontium-based perovskite materials for energy storage and water-splitting applications, with significantly enhanced performance achieved through the incorporation of rGO.