Investigating the adsorption of Malachite green and Methyl green onto synthesized Ni0.5Zn0.5Fe2O4 spinel ferrites

Abstract

Nano-sized Ni0.5Zn0.5Fe2O4 spinel ferrites were synthesized at the nanoscale by the co-precipitation method via a sonochemical approach. High-intensity ultrasonic radiation treated the hydroxide suspension at 90 °C for 2 hours. Both the X-ray diffraction analysis (XRD) and the Fourier transform infrared spectra (FT-IR) analysis confirm the presence of the cubic spinel phase with a grain size of 15 – 25 nm. The vapor adsorption experiments confirmed that the pore surface area was found to be 95.34 m2/g by N2 adsorption desorption isotherm, and the material was mesoporous. The saturation magnetization of ferrite powders was investigated using a vibrating sample magnetometer (VSM). This work mainly focuses on the removal of Malachite green (MaG) and Methyl green (MG) with the help of adsorption technology from water using Ni0.5Zn0.5Fe2O4 spinel ferrites. The adsorption studies examined the impact of mass and pH, revealing that both factors influence adsorption. The optimum conditions for Malachite green and Methyl green adsorption onto the spinel Ni-Zn ferrites were 0.02 g for spinel mass, pH values (6−8). At 328 K, the maximum capacity for Ni0.5Zn0.5Fe2O4 spinel adsorbents was 82 and 180 mg/g MaG and MG, respectively. The removal efficiency for MaG and MG dye was respectively 95 % in 420 and 180 minutes. According to the kinetic studies, a pseudo-second-order model is the most suitable model for the adsorption process. The adsorption mechanism was examined by fitting the adsorption data to Langmuir, Freundlich, Radushkevich, and Temkin adsorption models. The Langmuir model can adequately describe results.