Facile preparation of graphene oxide-based composite aerogel to efficiently adsorb methylene blue

With acrylamide (AM), diethylenetriaminepentaacetic acid (DTPA), chitosan (CS), and graphene oxide (GO) as the raw materials, a GO-based composite aerogel named as APAM/DTPA-CS/GO (APAM = Anionic polyacrylamide) was constructed by a facile method. The composite aerogel was systematically characterized by scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction to confirm the successful preparation. Methylene blue (MB) was used as the model dye molecule to evaluate the adsorption behaviors of APAM/DTPA-CS/GO. The results showed that equilibrium adsorption capacity of the aerogel toward MB could attain 652.99 mg/g at 303 K, which was more efficient than many previously reported adsorbents. The main driving forces of adsorption process were electrostatic interaction, hydrogen bond, and π-π conjugate interaction. The adsorption process of MB by the composite aerogel could be well described by pseudo-second-order kinetic model and Langmuir isothermal model. APAM/DTPA-CS/GO still maintained high equilibrium adsorption capacity of more than 600 mg/g toward MB even after six adsorption-desorption cycles, indicating that the aerogel had excellent regenerability. The efficient and recyclable adsorption performances might endow GO-based composite aerogel with considerable application prospect in the treatment of dye wastewater.