Dye adsorption by self-recoverable, adjustable amphiphilic graphene aerogel.

A type of self-recoverable, adjustable amphiphilic graphene aerogel (GA) was prepared and applied to the dye adsorption. The GA with polyvinyl alcohol (PVA) as its cross-linking agent has the characteristics of adjustable amphiphilicity. By adjusting the PVA content in GA, the later can be used to adsorb dyes with different hydrophobic and hydrophilic properties. Four kinds of dyes (Malachite green, Rhodamine B, Methylene blue and Methyl orange) were applied as targets and the saturated adsorption amounts were calculated. The Langmuir adsorption model and the Lagrange pseudo-second-order equation mathematical model were used to study the behavior of dye adsorption by GA, and the experimental data was in full compliance with the mathematical models. The excellent mechanical properties (compressibility and recoverability) make the GA suitable for dye adsorption. A computational simulation was also performed to verify the adsorption energy of GA to dyes. The GA was able to retain 89.5% of its initial removal efficiency (for malachite green) after 10 cycles of application.