Chromium compounds are commonly used in a variety of industries, including paint processing, leather tanning, metallurgy and wood preservation. However, Hexavalent chromium is most toxic and carcinogenic to human body among all the valence states of chromium. Moreover, it exists as chromate (CrO4-) at normal pH. So it is stable in water and pollutes soil and groundwater. For this reason, many researches has been done to effectively eliminate them. Among others, adsorption is one of promising methods due to high efficiency and operational simplicity. Adsorption, especially using amines, effectively removes hexavalent chromium through electrostatic attraction between the positive amines and the CrO4-. This study investigated the mechanisms of hexavalent chromium removal by synthesized various amino silanes-graphene oxide composites to elucidate the effects of primary and secondary amines. Through various analyses such as hexavalent chromium removal experiment, TGA, and XPS, it was confirmed that amino silanes are uniformly grafted on GO surface and hexavalent chromium removal efficiency of primary and secondary amines was calculated. In conclusion, we achieved a relatively high hexavalent chromium removal capacity of 260.74 mg/g. In addition, we found primary amines are more effective for hexavalent chromium adsorption. But the hexavalent chromium adsorption capacity order is 1N-GO &lt; 2N-GO &lt; 3N-GO, which is that total number of amines, the sum of primary and secondary amines was more important.

Which aminosilane molecules are the most suitable for surface functionalization of GO toward hexavalent chromium adsorption?

2019 Fall National Meeting

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