Magnetic Photocatalyst Nanocomposite Based on MnFe<sub>2</sub>O<sub>4</sub>@ZnO for AZO Dye Degradation
Javier Alonso Lopez Medina, D. Domínguez, Pedro Pizá, Guoduan Liu, Camilo Vélez, Faustino Reyes Gómez, M.H. Farı́as, Uriel Caudillo‐Flores, G. Soto, Hugo Tiznado, J. R. Mejía-Salazar
Abstract
High Resolution Image Download MS PowerPoint Slide This work focuses on fabricating a photocatalyst nanocomposite based on MnFe 2 O 4 @ZnO for degrading Red Amaranth azo dye. Manganese ferrite (MnFe 2 O 4 ) magnetic nanoparticles were synthesized via a hydrothermal method, while a ZnO thin film, acting as the photoactive layer, was deposited on the magnetic cores using the atomic layer deposition (ALD) technique. X-ray diffraction (XRD) confirmed the spinel ferrite structure of MnFe 2 O 4 and the hexagonal wurtzite phase of ZnO. The crystallite size, determined from the (311) peak, was 36.5 nm; this value was consistent with the average size of 33.2 nm measured by transmission electron microscopy (TEM). Magnetic characterization via vibrating sample magnetometry (VSM) at room temperature revealed a superparamagnetic behavior, determined by a very small hysteresis loop. The ZnO coating, achieved with 200 ALD cycles, resulted in a degradation efficiency η eff of approximately 60% for the Red Amaranth dye. Finite-difference time-domain (FDTD) simulations provided theoretical insights into the electromagnetic interactions driving the photodegradation process, supporting the UV–vis absorbance data of the AZO dye. This nanocomposite can be considered as a soft magnetic material that offers promising applications in nanotechnology for environmentally friendly wastewater treatment and remediation.