Mesoporous silica-coated α-Fe2O3/C nanoparticles as an efficient adsorbent for cationic dye removal

In this work, α-Fe2O3/C nanoparticles were synthesized through single step reaction and coated with mesoporous SiO2. Surface modification of α-Fe2O3/C using mesoporous SiO2 enhance BET surface area from 18.60 to 312.62 m2 g−1 which significantly affect the adsorption characteristics. Prepared SiO2-coated α-Fe2O3/C nanosorbent was characterized by various analytical techniques and used for the MB dye adsorption experiments. Adsorption capacity has shown higher performance for surface-modified α-Fe2O3/C compare to the bare α-Fe2O3/C nanoparticles. Adsorption influencing parameters such as pH, contact time, and effect of initial concentration were investigated. MB dye adsorption kinetics were examined by the pseudo-first-order, pseudo-second-order, and intra-particle diffusion models and found the pseudo-second-order equation well fitted in the obtained results. The maximum monolayer adsorption capacity was found to be 169.5 mg g−1 and follows the langmuir adsorption isotherm model. MB dye adsorbed nanosorbent was successfully regenerated by the heat treatment to demonstrate the 3 adsorption/desorption cycles. Further, Well water, Tap water, and Seawater were spiked with MB dye to check the adsorption ability in the real systems.