Stable and Water‐Dispersible Graphene Nanosheets: Sustainable Preparation, Functionalization, and High‐Performance Adsorbents for Pb²⁺

Abstract

The present study outlines a one‐step route to the preparation and functionalization of graphene nanosheets from graphene oxide using tea polyphenols as a simultaneous reductant and functionalization reagent. This method uses a “green” reductant and is free of additional functionalization reagents, thus it is environmentally friendly, simple, and low‐cost. The resulting functionalized graphene nanosheets have a mostly single‐layer structure, are stable, and have very good water dispersibility. The structure, composition, and morphology of the resulting material were characterized by using various methods including, X‐ray diffraction (XRD), UV/Vis spectroscopy, Raman spectroscopy, detailed X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Among other possible applications of the functionalized graphene, we discuss its use as an adsorbent for heavy‐metal ions in aqueous solutions.

Graphene and Graphene‐Based Composites: A Rising Star in Water Purification ‐ A Comprehensive Overview

“…Pristine graphene is hydrophobic in nature and very hard to disperse in aqueous solution to remove the contaminant . In order to improve the dispersibility of graphene, graphene surface is functionalized through chemical modification.…”

“…Graphene oxide is conjugated in the graphene plane and possesses many functional groups (epoxide, carboxyl, hydroxyl, carbonyl, etc.) on the surface . These oxygen functional groups present on the graphene oxide surface act as an adsorbent and strongly interact with metal ions, cationic dye, and pharmaceuticals in aqueous solutions.…”

A green reduction of graphene oxide via starch-based materials

“…The entire samples have a broad band at 3447 cm À1 for O-H stretching vibration, a band at 1401 cm À1 for O-H deformation vibrations, and a band at 1632 cm À1 for C]C stretching vibrations. 63,64,[70][71][72] The st-rGO was estimated to be composed of 2-4 layers, based on the analysis of the HRTEM image shown in Fig. 46,56,57 The spectrum of GO also exhibits the presence of alkoxy C-O stretching vibration at 1057 cm À1 (ref.…”

Two‐dimensional graphene oxide‐reinforced porous biodegradable polymeric nanocomposites for bone tissue engineering

“…The presence of ‐oxyl and ‐hydroxyl functional groups in oxidized graphene nanoparticles (SWGONR, MWGONR, and GONP) leads to a stronger interface between the PPF polymer matrix and nanoparticles compared to pristine CNTs. Hydroxyl groups at the end of PPF macromers can react with ‐oxyl functional groups on the GONPs during thermal cross‐linking of PPF/NVP at 80°C …”