Optical, Photocatalytic, Electrochemical, Magnetic, Dielectric, and Ferroelectric Properties of Cd- and Er-Doped BiFeO₃ Prepared via a Facile Microemulsion Route

Abstract

A series of Cd-and Er-doped bismuth ferrites were synthesized using a simple microemulsion technique. The influence of Cd and Er doping on the structural, ferroelectric, photocatalytic, and dielectric properties of bismuth ferrite (BFO) was examined in this research. The prepared materials were examined by Xray diffraction, Raman, scanning electron microscopy, and UV−vis techniques. The XRD patterns reflected the formation of a monophasic rhombohedral structure with the space group R3 − c and an average crystallite size calculated to be in the range of 29 to 32 nm. The saturation polarization (P s ), coercivity (H c ), and retentivity (P r ) of the materials were investigated by a hysteresis loop (P-E), and it was perceived that increasing the dopant contents improved the P s and P r values, which may be due to the variation of metal cation valence states. In accordance with the photoluminescence (PL) spectra, a highly substituted material displayed lower recombination and increased charge separation rate (e − −h + ), which eventually contributed to a higher photocatalytic degradation performance of the prepared NMs. Furthermore, as the frequency and dopant concentration increased, the dielectric loss decreased, which could be due to different types of polarization. Bi 1 − x Cd x Fe 1 − y Er y O 3 showed well-saturated hysteresis loops (P-E) with enhanced saturation polarization near 9.7 × 10 −4 μC•cm −2 . The remnant polarization of the BFO and BFOCE NPs was 2.26 × 10 −4 and 8.11 × 10 −4 μC• cm −2 , respectively, under a maximum electric field, which may be due to the variation of the metal cation valence states. The improved ferroelectric and dielectric properties of Bi 1 − x Cd x Fe 1 − y Er y O 3 NPs are attributed to the reduced concentration of defects, the different domain behavior, and the valence state of Cd and Er ions. The electrochemical (crystal violet (CV) and I−V) properties of Bi 1 − x Cd x Fe 1 − y Er y O 3 were all influenced by the dopant concentrations (Cd and Er). The synergistic effects of Cd and Er on the substituted material enhanced the specific capacitance in comparison to undoped BiFeO 3 . The photocatalytic activity to degrade CV under visible irradiation increased in BFOCE as the dopant (x,y) concentration increased from 0 to 0.25 by showing 84% dye degradation in comparison to pristine BiFeO 3 (53% only) within 120 min under visible light. Moreover, the stability of these prepared nanoparticles was confirmed using recycling experiments, with the results indicating that the synthesized nanomaterials demonstrated promising stability and reusability.

Zn/Mn co‐doped NiO synthesized by sol‐gel route for the photocatalytic degradation of methylene blue dye

“…for doping Mn and Zn on NiO nanoparticles, respectively. Also, doping of other metals like Co, Fe doped NiO particles by wet method reported the decrease in bandgap values [26] . This reduced bandgap was an actual cause of high efficiency of the prepared samples and hence, proved them an active photocatalysts for dye degradation.…”

“…Also, doping of other metals like Co, Fe doped NiO particles by wet method reported the decrease in bandgap values. [26] This reduced bandgap was an actual cause of high efficiency of the prepared samples and hence, proved them an active photocatalysts for dye degradation. The doped metals (Zn and Mn) are likely to play a crucial role in the photocatalytic process as entrapped sites.…”

“…The peaks present in the range of 530–860 cm −1 were due to the lattice enlargement and defects in the crystal which occurred due to the presence of Zn and Mn metal ions in the lattice. Peak at 430 cm −1 corresponds to the Ni−O stretching vibration [26,31–33] …”

Synthesis of different types of nano-hydroxyapatites for efficient photocatalytic degradation of textile dye (Congo red): a crystallographic characterization

“…Several scavengers were used in principal component analysis to measure the function of hydroxyl radicals, holes, and electrons. 26 Using the above-mentioned ideal setting, isopropyl alcohol (IPA) as well as ethylenediaminetetraacetic acid (EDTA) were utilized to examine the function of hydroxyl radicals and electrons on all synthesized Hap. If not mentioned otherwise, 10 mL of the scavenger was chosen in 40 mL of 20 ppm Congo red dye for 90 min using 0.1 g of catalyst.…”