Novel Cellulose/Silica Microspheres as Sustainable and Efficient Adsorbents for Methyl Orange Removal

Abstract The effective removal of organic dyes from aqueous solutions is essential for environmental protection and remediation. Hence, methods for fabricating efficient and sustainable adsorbents for removing toxic dyes are urgently desired. Here, new cellulose/silica microspheres containing amino groups were prepared and applied as functional materials for capturing anionic pollutants. Tosyl cellulose, which has a high degree of substitution, was prepared from cellulose using an ionic liquid as the solvent. Further, (3-aminopropyl)trimethoxysilane was utilized as a silica precursor to prepare the microhybrids via nucleophilic substitution, followed by the sol–gel process. The fabricated microhybrids exhibited an excellent capacity for methyl orange (MO) adsorption. Furthermore, the effects of different pH values, contact times, and initial dye concentrations on the MO adsorption capacity were evaluated. The Langmuir isotherm and pseudo-second-order kinetic models were effective for modeling the adsorption of MO on the cellulose/silica microspheres. Under the established optimal conditions, the cellulose/silica microspheres exhibited a higher adsorption capacity (588 mg/g) than those in previous reports. Therefore, the proposed cellulose/silica microspheres offer a promising platform for the sustainable development of water-purification systems. Graphical Abstract