Electrochemical and DFT investigations of light rare earth chromite nanofibers

The electrospun light rare earth orthochromites RCrO₃ (R = La, Pr, Nd, Sm, Eu) nanofibers have perovskite-type orthorhombic structures. Raman spectra proved the typical vibration modes of the rotation, bending, and stretching of the CrO₆ octahedra in RCrO₃ nanofibers. The rare earth element with large ion radius, low electronegativity, and remarkable affinity for oxygen, and the rich redox reaction of Cr endow RCrO₃ a potential energy storage material for supercapacitors. It is highly significant to investigate the electrochemical properties of RCrO₃. The electrochemical properties of the RCrO₃ nanofibers as supercapacitor electrodes were elucidated. At 0.5 A/g, the LaCrO₃, PrCrO₃, NdCrO₃, SmCrO₃, and EuCrO₃ nanofibers exhibited the specific capacitance values of 267.8, 132.8, 157.6, 170.5, and 170.4 F/g, respectively. First-principles density functional theory method was used to clarify the electronic structure and total density of states of the RCrO₃ nanofibers. This study provides a rational design and fabrication method to pseudocapacitor electrodes.