Emerging rare earth perovskite nanostructures for efficient electrochemical energy conversion and storage

Rare earth-based perovskite nanostructures are potential materials for electrocatalytic water splitting and energy storage applications due to their great chemical stability. DyMnO₃ nanoaggregates and DyFeO₃ nanoflakes were synthesized using the polymeric citrate precursor and ethylene glycol-assisted hydrothermal routes, respectively. A comprehensive set of characterization techniques, including X-ray diffraction, scanning and transmission electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy and Brunauer–Emmett–Teller (BET) surface area analysis were carried out. Surface area studies showed that DyMnO₃ has higher specific surface area (33 m²/g) than DyFeO₃ nanoflakes (8 m²/g). Electrochemical water splitting and supercapacitor performance revealed DyMnO₃ nanoaggregates displayed remarkable activity for oxygen evolution reaction with an overpotential of 0.22 V vs. RHE and a faster reaction kinetics. DyFeO₃ nanoflakes demonstrated superior pseudo-capacitance behavior, exhibiting a specific capacitance of 97.82 F/g and 100 % coulombic efficiency. These findings contribute to the advancement of materials design for electrochemical energy conversion and storage applications, emphasizing the potential of rare earth-based perovskite nanostructures in sustainable energy technologies.