Exploring the comparison of optical, dielectric and photocatalytic performance of Yb3+ and Gd3+ half-doped DyCrO3 nanostructures

Abstract

The auto combustion sol-gel method was utilized to prepare Dy0.5Gd0.5CrO3 (DGCO) and Dy0.5Yb0.5CrO3 (DYCO) nanomaterials. The single-phase formation of materials was confirmed with the X-ray diffraction technique. Utilizing Kubelka-Munk function, the optical bandgap energy values were found to be 3.39 eV (DGCO) and 2.61 eV (DYCO). The dielectric properties were analyzed in frequency range from 10 kHz to 2 MHz and a temperature range from 25 °C to 225 °C. The conduction mechanism followed the universal Jonscher's power law, which revealed that conduction process was primarily governed by the small polaron hopping. The CBH, NSPT, and QMT models were applicable for the a.c. conduction in the DGCO nanomaterial whereas the CBH and NSPT models were more appropriate for the DYCO nanomaterial. The Kohlrausch, Williams and Watts function was used to correlate the imaginary electrical modulus spectrum, which confirmed that the relaxation process in the materials was non Debye-type. An impedance spectroscopic measurement revealed the influence of grain and grain boundaries and it followed negative temperature coefficient resistance behaviour at higher temperatures. Both DGCO and DYCO nanomaterials were also investigated for their photocatalytic degradation of Rhodamine B (RhB) and Methylene Blue (MB) dyes. The degradation, under direct solar irradiation, was 84 % (RhB) and 63 % (MB) for DYCO nanomaterial and 54 % (RhB) and 44 % (MB) for DGCO nanomaterial, indicating their potential in water treatment.