Abstract
Microwave hybrid annealing (MHA) using a silicon wafer susceptor in a domestic oven (10–80 min) was employed to enhance the crystallinity and electrochemical performance of Strontium Titanate (SrTiO3). First-principles calculations were performed using local density approximation by density functional theory (DFT). Structural analysis confirmed that 20 min yielded optimal crystallinity and phase purity via X-ray diffraction and Rietveld refinement. Brunauer-Emmett-Teller surface area increased from 8.27 m2 g−1 (pristine) to a maximum of 13.39 m2 g−1 at 20 min of MHA treatment. X-ray photoelectron spectroscopy of the optimized sample showed sharper Ti 2p, Sr 3d, and O 1s peaks with more oxygen vacancies, enhancing reactivity and conductivity. UV–Visible spectroscopy revealed a redshift with slight band gap (Eg) reduction (3.22–3.20 eV), indicating structural rearrangement and improved absorption. DFT results confirmed that strain and oxygen vacancies influence Eg and conductivity, suggesting enhanced electronic properties for supercapacitor performance. The SrTiO3//AC device delivered a maximum capacitance of 51.15 F g−1 at 0.4 A g−1 with 9.67 Wh kg−1 at 200 W kg−1, retaining 84.53 % capacitance at 1 A g−1 after 3000 cycles, highlighting good durability. This low-cost, rapid, and scalable MHA route offers a promising strategy for fabricating high-performance supercapacitor electrodes from readily available materials.