Performance of magnetite/layered double hydroxide composite for dye removal via adsorption, Fenton and photo-Fenton processes

• Published in: Applied clay science 2019-10, Vol.179, p.105152, Article 105152
• Main Authors: Gonçalves, Rosembergue Gabriel Lima, Lopes, Paloma Aparecida, Resende, Júlia Alvarenga, Pinto, Frederico Garcia, Tronto, Jairo, Guerreiro, Mário César, de Oliveira, Luiz Carlos Alves, de Castro Nunes, Wallace, Neto, Jonas Leal
• Format: Article
• Language: English
• Subjects: Dye removal; Fenton-like reaction; Layered double hydroxide; Magnetite
• ISSN: 0169-1317; 1872-9053
• DOI: 10.1016/j.clay.2019.105152

In order to investigate the effect of the addition of magnetite in layered double hydroxide (LDH) from a structural and catalytic point of view, the synthesis of LDH containing cobalt and chromium (CoCr-LDH) was performed with or without Fe3O4. These materials were systematically characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), N2 adsorption Isotherms, Fourier transform infrared spectroscopy (FTIR), and evaluated as adsorbents and heterogeneous catalysts in Fenton-like and photo-Fenton-like reactions. The results showed that the magnetite was prepared and incorporated to the LDH with success, forming a composite providing magnetic properties and promoting alteration in the morphology, quantity and size of the LDH pores. The evaluation of the adsorption and oxidation processes utilizing the Fe3O4/LDH composite showed to be more efficient than for pure LDH. This better performance can be explained by higher surface area and larger pores for Fe3O4/LDH which allow a more effective contact with the dye solution and more proximity of large molecules like those of Reactive Black with the sites where the OH• radicals are formed. •Synthesis and characterization of CoCr-LDH and CoCr/Fe3O4-LDH catalysts.•Catalytic activity in Fenton and/or photo-Fenton reactions were evaluated.•Cr-based catalysts were applied without leaching into the liquid phase.•Facility of catalysts recovering and recycling due their magnetic properties.