MESOPOROUS SILICA MODIFIED WITH AMINO GROUP (NH2-MCM-48) AS ADSORBENT OF Ag(I) AND Cr(III) IN WATER

The amino-modified mesoporous silica (NH2-MCM-48) was synthesized using a mixture of surfactants as a template that was re-extracted using a methanol-hydrochloride solution. The modifying agent was 3- aminopropyltrimethoxysilane (3-APTMS). The characterization was conducted using an X-ray diffractometer (XRD), Fourier Transform Infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM). We investigated the reduction of Ag(I) and Cr(III) concentrations in the solutions using the modified material under several variables, i.e., pH, contact time, and initial ion concentration. An atomic absorption spectrophotometer measured the concentrations of the ions. The XRD and FTIR results proved that the basic material was MCM-48, and the template was mostly removed after the extraction, respectively. The modified material was successfully produced showed by the FTIR peak of N-H stretching vibration. The equilibrium of the Cr(III) adsorption was achieved in a longer time than that of the Ag(I) adsorption. The adsorption kinetics of Ag(I) and Cr(III) ions obeyed a model of pseudo-second-order and followed better the Langmuir adsorption model than the Freundlich, with a capacity of 0.87 and 2.02 mmol g-1 , respectively. The amine-modified mesoporous silica, NH2-MCM-48 for this study is a very high potential as an adsorbent of metal ions used in the study.