Modification of graphene aerogel with titania nanotubes for efficient methylene blue adsorption kinetics

Titania nanotubes (TNTs) with high length-diameter ratio are incorporated into reduced graphene oxide (rGO) aerogel to modify the porous structure of the obtained rGO/TNTs aerogel for efficient methylene blue (MB) adsorption. A hydrothermal method along with freeze drying is applied for the preparation of the rGO/TNTs composite aerogel. The uniformly dispersed TNTs in rGO matrix can effectively support the network structure and hinder the pi-pi bonding interaction between graphene sheets, thus resulting in a three-dimensional mesoporous network with high specific surface area. The rGO/TNTs aerogel shows favorable adsorption property toward MB and the maximum adsorption capacity can be 380.7 mg g(-1) with the adsorption efficiency of 92.2%. Besides, the adsorption kinetic analysis reveals that a dispersion process is found to be the rate-limiting step when the adsorbent dosage is low. With the increase of adsorbent content, chemical sorption such as the pi-pi interaction or the reaction of the polar functional groups between MB and rGO-TNTs-C aerogel becomes the rate-limiting step.

Automated summary

Titania nanotubes with high length-diameter ratio are incorporated into reduced graphene oxide aerogel to modify the porous structure for efficient methylene blue adsorption. The composite aerogel shows favorable adsorption properties with a high specific surface area, and the adsorption process is influenced by the adsorbent dosage.