Photoelectrocatalytic degradation of 4-chlorophenol using nanostructured α-Fe₂O₃ thin films under sunlight illumination

In this work, nanostructured α-Fe₂O₃ thin films have been deposited onto the glass and fluorine doped tin oxide coated glass substrates using simple chemical bath deposition method. The influence of bath temperature on the properties of α-Fe₂O₃ thin films are studied with the help of different characterization techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy, Raman spectroscopy, Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and optical properties. XRD study reveals that films are polycrystalline in nature with rhombohedral crystal structure. Raman spectroscopy is used to study the structure and symmetry of α-Fe₂O₃ thin films. The SEM study reveals that substrate surface is well covered with small tiny grains. Specific surface area of 30.12 m² g⁻¹ is measured by BET technique. Optical study shows that the band gap energy of α-Fe₂O₃ film is varied from 2.19 to 2.35 eV. The synthesized α-Fe₂O₃ photoelectrode is used as a catalyst for the photoelectrocatalytic degradation of 4-chlorphenol in an aqueous medium. The photoelectrocatalytic degradation experiment shows that the degradation percentage of 4-chlorophenol (4-CP) has reached 50% under sunlight illumination after 240 min. The mineralization of 4-CP with reaction time is studied with the help of chemical oxygen demand (COD) measurement.