Efficient removal of Malachite Green from aqueous solution by adsorption on carbon nanotubes modified with ZnFe2O4 nanoparticles

Abstract

In this study, multiwall carbon nanotubes modified with spinel zinc ferrite nanoparticle (ZnFe 2 O 4 /MWCNTs) were used as a solid phase adsorbent for the removal of Malachite Green (MG) from aqueous media. The synthesized nanocomposite was characterized by different methods, such as Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Batch adsorption experiments to determine the optimal adsorption conditions and different factors that influence the adsorption efficiency (i.e., pH, amount of adsorbent, contact time, and the initial concentration of MG) were also evaluated and optimized. The data were satisfactorily fitted to the Langmuir model and a maximum adsorption capacity of 116.2 mg g-1 was obtained at a pH of 7.5. In addition, adsorption kinetics studies were performed. The adsorption of the model dye (MG) was found to reach equilibrium after 60 min, following a pseudo-second-order kinetic model. Furthermore, an external magnetic field could easily separate the nanoparticles from water with a high separation efficiency.

Efficient cationic dye removal from water through Arachis hypogaea skin-derived carbon nanospheres: a rapid and sustainable approach

“…The adsorption of MG was enhanced at higher pH values until 7 and subsequently reduced as the pH increased. This behaviour may be explained by the presence of extra negative charges on the nanoparticles' surfaces, which might strengthen their electrostatic interaction with the cationic dye MG. 46 Due to the transformation of MG into protonated MG (MGH) under acidic pH conditions and into a carbinol base under basic pH conditions, the structural modifications of the molecule should be taken into consideration when removing the compound. 47 …”

Synthesis and Properties of Ferrite-Based Nanoparticles

“…Among the wide variety of oxide perovskites and perovskite-like structures, special attention is paid to ferrites, in which cerium is used as a rare-earth element [28,29,30], due to its crystalline structure and conductive characteristics. As a rule, such structures are obtained by solid-phase synthesis [31,32], hydrolysis [33,34], mechanochemical treatment, followed by heat treatment [35,36], the results of which are micro or macro particles with non-uniform composition. Cerium ferrite is characterized by high corrosion and structural stability, which makes it environmentally safe and suitable for use in almost all branches of solid fuel energy.…”