A new approach to the synthesis of CuFe₂O₄@CeO₂ direct Z‐scheme with a core‐shell structure for enhanced photo‐degradation of methyl violet under ultraviolet and visible‐light irradiation

Abstract

A direct Z-scheme photocatalyst CuFe 2 O 4 @CeO 2 core-shell was applied in the photocatalytic degradation of the methyl violet dye 2B (MV). In first, CuFe 2 O 4 and CeO 2 were synthesized via sol-gel method, and then CuFe 2 O 4 @CeO 2 nanocomposite was prepared using microwave process. The nanoparticles were characterized by thermogravimetric analysis (TG and derivative thermogravimetry [DTG]), atomic absorption spectroscopy (AAS), Brunauer-Emmett-Teller (BET) analysis, Xray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), energy dispersive-X-ray (EDX) and ultraviolet (UV)visible diffuse reflectance/absorption spectroscopy. The photocatalytic activity of CuFe 2 O 4 @CeO 2 nanocomposite was evaluated by the photo-degradation of the MV under UV and visible-light irradiation. MV does not rapidly degrade itself in UV or visible-light but the process is accelerated upon the addition of semiconductors with a wide band-gap. The CuFe 2 O 4 @CeO 2 nanocomposite shows an important MV decomposition rate under visible-light irradiation (95.35% within 1.5 h) as compared to UV-light (86.10% within 2.5 h). The excellent activity of CuFe 2 O 4 @CeO 2 under UV and visible-light was mainly attributed to direct Z-scheme which are originated from a core-shell structure which prompted the generation of ˙OH radical species responsible for the photo-degradation of the substance. However, this could also be due to the large specific surface area and/or efficient UV-vis harvesting.

Photocatalysis process to treat polluted water by azo dye Cibacron Brilliant Yellow 3G-P

“…Hence, his adsorption onto the surface of semiconductor was scarcely. In the case of methyl orange (Abbas & Trarib 2021) and Methyl Violet (Touahra et al 2022), using TiO 2 as semiconductor, higher decolorization efficiency was reported under acidic conditions. In the case of ZnO, decolorization was reached an initial maximum at pH 4, then decreases around the neutral region and picks up again to reach a maximum at pH 11.…”

“…TiO 2 and ZnO have been widely used as photocatalysts due to their high activity, desirable physical and chemical properties, low cost, high specific surface area and availability (Ghribi et al 2020;Aoudjit et al 2021;Shathy et al 2022). The mechanism that has been suggested regarding the heterogeneous photocatalytic degradation of dyes can be expressed by the fact that when a catalyst is exposed to UV radiation, electrons are promoted from the valence band to the conduction band, as a consequence, an electron-hole pair is produced (Touahra et al 2022).…”