| Abstract |
Graphene oxide (GO) was optimally produced from graphite as a starting material and was subject to functionalized with 3-mercaptopropyl-trimethoxysilane (MPTMS) to acquire thiol group (-SH) as a selective carbon-based adsorbent for the removal of mercury from aqueous solution comparing with its bare graphite (BGP). The GO-SH was characterized by Fourier transform infrared spectroscopy (FTIR) and energy dispersive X-ray spectroscopy (EDX). IR characteristic peaks appear at wave numbers of 3367(O-H), 2576 (S-H), 1719 (C=O), 1224 and 1049 (C-O), and 1160 (Si-O-C) indicating the thiol group attached. Also, EDX spectrum revealing both Si and S peaks confirms the MPTMS bound on the GO surface. For an optimal adsorption study, the effects of pH solution (pH 2-9), contact time (10-100 min) and initial concentration of Hg(II) (0.1-60 mg/L) were investigated in details in association with determination of Hg(II) by FI-HGAAS. From the results, the adsorption capacity of the functionalized GO-SH for the Hg(II) was 80.65 mg/g at pH 6.6, about 3 times higher than that of its BGP (22.94 mg/g). The adsorption isotherm of the GO-SH for Hg(II) was found only fitting well with Langmuir model, while that of BGP followed the Freundlich one. It is implied that graphene oxide modified with thiol can be used as a high potential adsorbent for such a toxic metal in pollutants. |
Publication
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