A novel Dy3+doped Zn2V2O7 nanoparticles: Photoluminescence and electrochemical studies for display and supercapacitor applications

A novel series of Dy3+-doped Zn2V2O7 (ZV) nanoparticles (NPs) spanning concentrations from 1 to 9 mol% was synthesized via Menthaspicata leaves extract-mediated solution combustion method. Upon Dy3+ doping, the diffraction pattern matches well with the monoclinic crystal structure with the C 2/ c (2/ m ) space group of ZV host matrix. Morphological analysis revealed a transition from irregularly shaped NPs to hexagonal shaped NPs with varying dopant concentration. The crystallite size estimated via Scherrer's method correlated closely with transmission electron microscopy analysis. Determination of the optical band gap from Tauc's plot using UV-Visible absorption indicated a tuning from 3.045 to 2.986 eV with increasing dopant concentration. Under 266 nm excitation, the peak at 489 and 586 nm corresponds to 4 F 9/2- 6 H 15/2 (Magnetic dipole) and4F9/2- 6 H 13/2 (electric dipole) transition of Dy3+ ion. The dominance of the blue emission (MD) over the yellow emission (ED) of Dy3+ indicates the symmetric nature of the host. The sample exhibits 7 mol % as the optimal doping content. CIE coordinates distinctly falls within the blue region with increasing dopant concentration, with an average color-coordinated temperature of 19902 K, indicative of a cooler appearance. Moreover, cyclic voltammetry analysis provided valuable insights into redox reactions, electrode kinetics, and overall electrochemical behavior, while Electrochemical Impedance Spectroscopy (EIS) offered information on ion transport kinetics. Galvanostatic Charge-Discharge (GCD) analysis revealed super capacitance values ranging from 85.79 F/g to 143.92 F/g at 10 mV/s scan rate, with increasing dopant concentration, highlighting the material's potential for applications in energy storage and display technology.