Preparation of Carboxymethyl Cellulose-Based Hydrogel Supported by Two-Dimensional Montmorillonite Nanosheets for Methylene Blue Removal

Abstract

Carboxymethyl cellulose-based hydrogel enhanced by two-dimensional montmorillonite nanosheets (CMC-MMTs Gel) has been successfully synthesized throguh polymerization for methylene blue (MB) removal from water. Structure characterization shows that the introduction of two-dimensional montmorillonite nanosheets (2D MMTs) into CMC-based hyddrogel results in a roguh surface and increased porosity. Adsorption tests demonstrate that the adsorption rate and adsorption capacity of CMC-based hydrogel increase significantly with the increase in 2D MMTs content, and a high adsorption capacity of 410 mg g−1 can be reached. After 5 cycles, CMC-MMTs Gel still exhibits good removal performance indicating a good reusability and structural stability. The enhanced MB removal performance and improved structural stability might be due to 2D MMTs and the increased porosity. FTIR and XPS characterizations demonstrate that the adsorption mechanism of MB onto CMC-MMTs Gel might be attributed to electrostatic adsorption and ion-exchange between MB molecules and MMTs, and the interactions between MB molecules and the hydroxyl and carboxyl groups of CMC.