Alginate/calix[4]arenes modified graphene oxide nanocomposite beads: Preparation, characterization, and dye adsorption studies

The present study reports the preparation of novel alginate/calix[4]arenes modified graphene oxide nanocomposite beads (alginate/C4As-GOs) based on p-tert-butyl calix[4]arene and sodium p-sulfonatocalix[4]arene modified GO nanosheets (CGO and SGO). Different properties of alginate/GO and alginate/C4As-GOs nanocomposite beads were investigated by FTIR, XRD, TGA, SEM, and swelling ratio analysis. The alginate beads containing SGO nanosheets (ABSGO) showed a thin layered structure, high porosity, and high swelling ratio compared to other samples. Moreover, the batch adsorption studies on methylene blue exhibited that ABSGO beads act as a high-performance adsorbent among samples and can be introduced as a novel and efficient dye adsorbent. In the case of ABSGO adsorbent, the equilibrium adsorption data were modeled using the Langmuir and Freundlich isotherms. According to Langmuir isotherm equation, the maximum adsorption capacity of ABSGO was obtained 170.36 mg/g. The kinetic adsorption studies confirmed that the adsorption of MB onto ABSGO well obey the pseudo-second-order kinetic model.