Synthesis of Chitosan/Graphene Oxide Nanocomposites for Methylene Blue Adsorption

In this paper, chitosan (CTS) with molecular weight (M-w) similar to 810 kDa and degree of deacetylation (DDA) similar to 83 % was synthesized from prawns shell. Graphene oxide (GO) was prepared by improved Hummers method. CTS/GO nanocomposites were lyophilized using aldehyde formic as a cross-linked to obtain the hydrogels. The hydrogels were freeze dried to make CTS/GO nanocomposite. Characterizations of the CTS/GO nanocomposites were performed by Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, and Brunauer-Emmett-Teller specific surface area. Additionally, the effects of pH, contact time, and initial concentration on adsorption for methylene blue (MB) were investigated. The results showed that the CTS/GO nanocomposites were found to be good adsorbent for MB with a maximum adsorption capacity of 662.25 mg/g according to the Langmuir isotherm model. The adsorption data could be well described by pseudo-second-order model. After the adsorption, CTS/GO nanocomposite was easily recovered by filtration or low speed centrifugation. Accordingly, this study demonstrates potential CTS/GO adsorbent for the removal of MB from aqueous solution.