Synthesis of pore-expanded mesoporous materials using waste quartz sand and the adsorption effects of methylene blue

Mesoporous material Q-MCM and EX-Q-MCM were synthesized using waste quartz (99.9% SiO2) sand as a silicon source via the sol–gel method. The silicon source was extracted from the waste quartz sand using the hydrothermal method. This study selected methylene blue as a target dye to investigate the dye adsorption performance onto the EX-Q-MCM. The effects on adsorption performance under different initial dye concentrations and different pH values were also studied. The results show that the maximum adsorption capacity was 96.9 mg g−1 and a high pH is favorable for adsorption. Further, equilibrium isotherms of the adsorption of methylene blue on EX-Q-MCM are well described by the Freundlich model. It reveals that the adsorption of methylene blue onto the Q-MCM is a multilayer adsorption.