Mussel-Inspired Synthesis of Polydopamine-Functionalized Graphene Hydrogel as Reusable Adsorbents for Water Purification

Abstract

We present a one-step approach to polydopamine-modified graphene hydrogel, with dopamine serving as both reductant and surface functionalization agents. The synthetic method is based on the spontaneous polymerization of dopamine and the self-assembly of graphene nanosheets into porous hydrogel structures. Benefiting from the abundant functional groups of polydopamine and the high specific surface areas of graphene hydrogel with three-dimensional interconnected pores, the prepared material exhibits high adsorption capacities toward a wide spectrum of contaminants, including heavy metals, synthetic dyes, and aromatic pollutants. Importantly, the free-standing graphene hydrogel can be easily removed from water after adsorption process, and can be regenerated by altering the pH values of the solution for adsorbed heavy metals or using low-cost alcohols for synthetic dyes and aromatic molecules.

Super-adsorbent material based on functional polymer particles with a multilevel porous structure

“…The functional groups in the 3D network can equivalently conjugate with target molecules, leading to unique selectivity and remarkable adsorption capacity. [36][37][38] However, for amorphous soft materials such as hydrogels, a relatively long time is required to reach a saturated state of adsorption. Meanwhile, difficulties associated with the regeneration and disposal of hydrogel adsorbents constitute major obstacles for their practical application.…”

Porous polydopamine and para-aminobenzoic acid complex membrane formed by electrochemical codeposition/degradation

“…Fig.3(B) shows the three components of N 1s peak corresponding to imino groups (=N-R, 398.5 eV), substituted amines (R-NH-R or indole groups, 399.8 eV), and amine groups (R−NH2, 401.7 eV) [31]. The peak positions and relative amount of N 1s components in PPM resembles those of the synthetic PDA film on silica wafer [32]. In Fig.…”

Activated Carbon, Carbon Nanotubes and Graphene: Materials and Composites for Advanced Water Purification

“…The inclusion of magnetic properties in this material also allowed the adsorbate to be easily separated from aqueous solution. The application of a polydopamine/GO hydrogel composite has afforded adsorption capacities for Pb(II) and Cd(II) of 336.32 and 145.48 mg/g respectively, while also facilitating the adsorption of the dye species Rhodamine B (207.06 mg/g) and p-nitrophenol (260.38 mg/g) [189]. A one-step hydrothermally assembled aerogel graphene and CNT composite has also been used for removal of the dye methylene blue from aqueous solution, with 97% of the dye captured by the material [190].…”