Multifunctional aminoethylpiperazine-modified graphene oxide with high dispersion stability in polar solvents for mercury ion adsorption

Graphene-derived materials including graphene oxide (GO) have infinite potential, but proper dispersibility must be ensured for the utilization of functionalities. To strengthen the compatibility of functionality and dispersibility, a new method by simply functionalizing GO with aminoethylpiperazine (AEP) is provided. Characterization of the synthesized AEP-GO was comprehensively carried out by several spectroscopic methods. Also, as intended, AEP-GO possessed good dispersibility in common organic solvents owing to the characteristics of the polytrophic amines in AEP. In particular, we investigated the possibility of its use as adsorbent for mercury ion as a representative of heavy metals. The solution with AEP-GO of 0.1 wt% achieved Hg²⁺ removal efficiency of 97.7% at low Hg²⁺ concentration of 50 ppm. Also, among the various adsorbent concentration, maximum adsorption capacity and removal efficiency were 107.2 mg/g and 98.4%, respectively. In this regard, our findings contribute to the discovery of new approaches to preparing graphene materials.