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

Abstract

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 (-NH2) was successfully grafted onto the surface of cordierite ceramic. X-ray photoelectron spectroscopy analysis successfully showed inclusion of the amino and Cu2+ adsorption mechanism onto MCK. The adsorption properties of MCK were investigated using Cu2+ as the target pollutant by varying the experimental conditions such as pH, time, temperature, and initial Cu2+ 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 Cu2+ 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 Cu2+ adsorption and removal efficiency was fabricated and has potential applications for the metal ion removing field.