Preparation of Graphene Oxide-Based Hydrogels as Efficient Dye Adsorbents for Wastewater Treatment.

Haiying Guo,Qiuming Peng,Tifeng Jiao,Xuehai Yan,Wenfeng Guo,Qingrui Zhang

doi:10.1186/s11671-015-0931-2

Haiying Guo, Qiuming Peng + Show 4 more

Open Access

https://doi.org/10.1186/s11671-015-0931-2

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Abstract

Graphene oxide (GO) sheets exhibit superior adsorption capacity for removing organic dye pollutants from an aqueous environment. In this paper, the facile preparation of GO/polyethylenimine (PEI) hydrogels as efficient dye adsorbents has been reported. The GO/PEI hydrogels were achieved through both hydrogen bonding and electrostatic interactions between amine-rich PEI and GO sheets. For both methylene blue (MB) and rhodamine B (RhB), the as-prepared hydrogels exhibit removal rates within about 4 h in accordance with the pseudo-second-order model. The dye adsorption capacity of the hydrogel is mainly attributed to the GO sheets, whereas the PEI was incorporated to facilitate the gelation process of GO sheets. More importantly, the dye-adsorbed hydrogels can be conveniently separated from an aqueous environment, suggesting potential large-scale applications of the GO-based hydrogels for organic dye removal and wastewater treatment.

Highlights

Nowadays, harmful chemical compounds have become the main cause of water pollution
The dye-adsorbed hydrogels can be conveniently separated from an aqueous environment, suggesting potential large-scale applications of the graphene oxide (GO)-based hydrogels for organic dye removal and wastewater treatment
GO/PEI hydrogels were prepared by combining GO and PEI stock solutions with sonication for a few seconds or without sonication for a few minutes to form gels

Summary

Introduction

Harmful chemical compounds have become the main cause of water pollution. Organic dyes are often discharged with wastewater into the local environment without adequate treatment. Rapid and convenient removal of organic dyes from wastewater has been a challenging issue faced by scientists [1,2,3,4,5,6]. Large-scale application requires the potential dye adsorbents to exhibit a high dye removal rate within a relatively short period of time and to be environmentally friendly. For the latter, the adsorbents must be able to be properly separated from an aqueous environment after adsorbing waste dyes.

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