Investigation of the photo-Fenton efficiency and dielectric properties of BiVO4/α-Fe2O3 nanocomposites

Abstract

This study focuses on successfully synthesizing BiVO4 nanoparticles (NPs), α-Fe2O3 NPs, and their nanocomposites (NCs) using the facile hydrothermal method to degrade methylene blue (MB) dye molecules and fabricate flexible electronic devices. X-ray diffraction studies revealed the monoclinic and rhombohedral crystal structures of BiVO4 and α-Fe2O3 NPs, respectively. Further, it evidences the formation of BiVO4/α-Fe2O3 NCs. The X-ray photoelectron spectroscopy (XPS) and UV–visible spectroscopy observations substantiate the formation of BiVO4/α-Fe2O3 NCs. Under solar irradiation of the MB dye molecules, the 8% of α-Fe2O3 added BiVO4 (BF8) composite exhibited a 94% dye degradation efficiency within 120 min. Interestingly, the photo-Fenton process (adding 0.3 mL of H2O2 with BF8) enhanced the photodegradation performance of the BF8 NC by achieving 98% dye degradation within 60 min. This comparative analysis demonstrates that the photo-Fenton process not only accelerates the degradation rate but also reduces the time required to degrade dye molecules by half. Additionally, the BF8 composite demonstrated excellent photostability for up to five cycles, and experiments on radical trapping evidenced that hydroxyl and hole radicals played a crucial role in breaking down organic dye molecules in both processes. Impedance spectroscopy revealed that the BF8 NCs exhibit a higher dielectric constant of 30.8 and a low dielectric loss of 0.09. It also demonstrated a maximum ionic conductivity of 2.66 × 10−4 S/cm, highlighting its potential for flexible electronic device applications.