The electrochemical, dielectric, and ferroelectric properties of Gd and Fe doped LaNiO with an efficient solar-light driven catalytic activity to oxidize malachite green dye.

This work investigates the effects of double ion substitution on the ferroelectric, electrochemical, dielectric and photocatalytic properties of Gd and Fe doped LaGdNiFeO nanoparticles (NPs). LaGdNiFeO was fabricated by facile micro-emulsion path and its properties were studied by thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman scattering, Fourier Transform of Infrared (FTIR), energy dispersive x-rays (EDX) techniques. It has a distorted rhombohedral shape with crystallite size within the range of 17-23 nm. The doped material has a spherical heterogeneous morphology, and its surface area increased with increased doping. The electrochemical (CV, EIS, and I-V), conductivity and dielectric (dielectric constant and low dielectric & tangent loss) properties of LaGdNiFeO were dependent on the contents of the dopants (Gd and Fe). The doped material had improved specific capacitance compared to the undoped LaNiO due to the synergistic effect of Gd and Fe on the doped materials. The conductivity of Gd and Fe doped LaNiO 5.16 × 10 Sm was enhanced compared to the undoped LaNiO 3.52 × 10 Sm. Furthermore, hysteresis loop was used to investigate the coercivity (Hc), saturation magnetization (Ms) and remanence (Mr) of the material. The Ms and Mr values were enhanced with the content of the dopants. The photocatalytic activity (PCA) of the material in degrading malachite green (MG) dye was studied. LaGdNiFeO NPs was able to degrade up to 96.4% of the dye under visible light irradiation in 50 min. LaGdNiFeO has remarkable dielectric, electrochemical, ferroelectric and photo-catalytic properties and have potential applications in microwave, electrical, electronic, energy storage devices. It is also an active photo-catalyst material for the removal/oxidation of toxic pollutants from the environment.