Insight of structure-property relationship of microwave-assisted synthesized γ-AlOOH/reduced graphene oxide 3D nanocomposites in efficient adsorption of ciprofloxacin

Abstract

The structural attributes of adsorbent affect its internal pore structure, specific surface area and surface chemical properties directly, and then affect its adsorption performance. Herein, γ-AlOOH/reduced graphene oxide (rGO) 3D nanocomposites with different morphology structures were obtained following a one-step microwave-assisted hydrothermal strategy. Ciprofloxacin (CIP) adsorption experiments were performed to investigate the relationship between adsorption performance and structural properties of the products. The adsorption performance of the γ-AlOOH/rGO nanocomposites were influenced by morphology, specific surface area and pore volume. Cl-AlOOH/rGO and N-AlOOH/rGO which possessed the similar morphological structure followed Elovich model well, but the kinetics adsorption behavior of S-AlOOH/rGO could well be elaborated by the pseudo-second order model. Cl-AlOOH/rGO with the highest specific surface area (203.48 m²/g) and pore volume (0.216 m³/g) exhibited the highest the maximum adsorption capacity of 930.0076 mg/g. A multiple adsorption mechanism concerned with hydrogen bonds, π-π interaction, pore filling, complexation and van der Waals force was proposed. Benefiting from their 3D structures, all the products showed excellent reusability. This work not only gives valuable insights into the impact of structural attributes, but also provides a new thought for engineering and preparing new-type of adsorbent.