Preparation and Modification of Mullite Whiskers/Cordierite Porous Ceramics for Cu2+ Adsorption and Removing

摘要

In this paper, mullite whiskers were prepared by a molten salt reaction method based on a porous cordierite ceramic substrate (MC), and the modified mullite whiskers/cordierite ceramic sample (MCK) was obtained via the silane coupling reaction with γ-aminopropyl triethoxysilane (KH550). The structural morphology and phase compositions of the MC were characterized by X-ray diffraction and scanning electron microscopy. The surface functional groups of MCK were characterized using Fourier transform infrared spectroscopy, and the result showed that the amino group (?NH_(2)) was successfully grafted onto the surface of cordierite ceramic. X-ray photoelectron spectroscopy analysis successfully showed inclusion of the amino and Cu~(2+) adsorption mechanism onto MCK. The adsorption properties of MCK were investigated using Cu~(2+) as the target pollutant by varying the experimental conditions such as pH, time, temperature, and initial Cu~(2+) concentration. The adsorption was found to be spontaneous, endothermic, and feasible, as indicated by the study of thermodynamic parameters. The adsorption kinetic analysis suggested that the pseudo-second-order kinetic model was best fitted for Cu~(2+) adsorption. The adsorption isotherm studies showed that the results of the Freundlich model are more suitable for experimental adsorption data than the Langmuir model. The adsorption–desorption cycle indicated that MCK had good reusability and stability. A novel porous ceramic-based adsorbent with high Cu~(2+) adsorption and removal efficiency was fabricated and has potential applications for the metal ion removing field.