Microwave synthesis and characterization of calcium copper titanate oxide and composites for supercapacitor applications

Abstract

Microwave synthesis and characterization of calcium copper titanate oxide (CCTO) and its composites with La 2 O and Nd 2 O 3 were carried out. Structural and morphological analyses were conducted using X-ray diffraction (XRD) and scanning electron microscopy (SEM), revealing single-phase formation of CCTO with a body-centered cubic structure and improvements in microstructure and grain morphology post-annealing. The average crystallite sizes were 48.95 nm for unannealed CCTO, 51.72 nm for annealed CCTO, 43.06 nm for CCTO/La 2 O composite, and 44.10 nm for CCTO/Nd 2 O 3 composite. Electrochemical behavior was evaluated using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). Specific capacitance values obtained from CV were 16.31 F/g for CCTO, 4.96 F/g for CCTO/La 2 O composite, and 8.31 F/g for CCTO/Nd 2 O 3 composite. GCD measurements yielded specific capacitance values of 1.3488 F/g for CCTO, 1.404 F/g for CCT/La 2 O, and 1.2717 F/g for CCTO/Nd 2 O 3 composites. Notably, after 500 cycles at 0.1 A/g, CCTO, for CCTO/La 2 O, and CCTO/Nd 2 O 3 composites retained 92 %, 94 %, and 95 % of their specific capacitance, respectively, indicating good stability. These findings highlight the potential of microwave synthesis in tailoring the properties of CCTO and its composites, paving the way for their application in various electrochemical devices. • Microwave synthesis yielded single-phase CCTO with improved structure after annealing. • La₂O₃/Nd₂O₃ composites showed smaller crystallites (≈ 43–44 nm) than CCTO, tuning microstructure. • CCTO's CV results indicate high specific capacitance (906.1 mF/cm²). • CCTO's > 92 % capacitance retention after 500 cycles shows its energy storage potential.