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.