Investigation on Structural, Optical, and Ectrical Properties of Erbium Oxide-based Composites for Photocatalysis /

Abstract

Rare earth metals like erbium oxide exhibits exceptional properties for the photocatalysis applications. However, its high recombination rate and low surface area limit its performance. Therefore, different metal oxides were added to improve its photocatalytic and opto-electronic properties. In this study, the composite of the erbium oxide and zinc oxide was synthesized using the sol-gel combustion method to enhance its surface area. Moreover, loading of molybdenum was used to suppress the charge recombination. The detailed characterization was conducted by employing XRay Diffraction (XRD), Raman Spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Brunauer–Emmett–Teller (BET) analysis, Photoluminescence (PL) Spectroscopy, and UV-Vis spectroscopy. The composite of ZnO with the Er2O3 exhibited the reduced band gap from 3.65 eV to 3.62 eV after loading of the Molybdenum (Mo) and a porous structure studied by Tauc’s plot and SEM analysis, respectively. BET analysis revealed the enhancement of surface area by adding ZnO and Mo from SBET = 29.07 m/g which is one of the crucial factors to increase the photocatalytic activity. The loading of molybdenum enhanced the immobilization of carriers that facilitated the photooxidation process and suppressed the electron-holes recombination from 800 counts to 100 counts as confirmed by the PL spectroscopy. The photocatalytic studies were comparatively analyzed by degrading the textile dye methylene blue (MB). The degradation process was carried out under standard conditions (1 sun, 1atm). The efficiency of Er2O3 improved up to 80% by adding the ZnO and Mo. The composite of ZnO with the Er2O3 and loading of Mo, not only improves the photocatalytic properties but also improves the electrical properties of the Er2O3 (σ = 4.4×10 2/g to SBET = 45.71 m2-4-1 Sm to σ = 5.1×10-4- Sm1) that was confirmed by the Hall Effect. To conclude, this study demonstrated the significant role of ZnO and Mo in improving surface area and suppressing charge recombination. Mo@ZnO-Er2O3 has been identified as a novel photocatalyst for removing organic dyes. Additionally, the electronic properties of Mo@ZnO-Er2O3 suggest that it is a promising candidate for photoelectronic devices.