الفهرس | Only 14 pages are availabe for public view |
Abstract The incorporation of silver oxide nanoparticles in the pores of mesoporous silicas might produce materials with interesting catalytic and sensing capabilities, but the proper control of pore filling and the a voidance of nanoparticles migration to outside the pores are processes not yet completely under stood. In this work, we evaluated the role of –SH groups post grafted into MCM-41 on the production of silver oxide nanoparticles by impregnation-evaporation method. The structural characterization was investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transforms infrared (FTIR). The prepared materials were used for removal of methylene blue and brilliant green dyes from aqueous medium considering the effect of adsorbent dosage, pH, shaking time and initial dye concentration. The results showed that adsorption capacity of Ag2O/MCM-41 and Ag2O/MCM-41:SH nanoadsorbent higher than pure MCM-41. The best results were obtained with 25% Ag2O/MCM-41 and 10 wt. % Ag2O/MCM-41:SH which shows higher adsorption activity. The adsorption was found to follow the pseudo-second-order adsorption kinetic model and fitted with Langmuir adsorption isotherm. The results showed that the Ag2O/MCM-41:SH has a higher adsorption capacity for dyes and heavy metals compare with Ag2O/MCM-41 due to the presence of the thiol groups on the MCM-41. Thiol groups were capable of promoting the formation of Ag2O inside the pores, with the highest Ag2O loading. This study showed the importance on selecting an adequate surface functional group in order to obtain silver nanoparticles filling the pores of MCM-41. |