A series of hierarchical porous Al2O3 materials fabricated from melamine foam for dye adsorption

In this study, a series of hierarchical porous Al 2 O 3 with controlled morphology were synthesized using melamine foam (MF) as a sacrificial template. Comprehensive characterization through XRD, FTIR, Raman spectra, SEM, TEM, and N 2 adsorption-desorption confirmed the successful fabrication of graphite skeleton-guided hierarchical porousAl 2 O 3 by precise control of calcination temperature. The hierarchical porous Al 2 O 3 materials calcined at 1000 ℃,1400 ℃, and 1500 ℃ demonstrated unique structural features and higher positive Zeta potential, exhibiting remarkably fast adsorption kinetics and exceptional Congo red (CR) adsorption capacities that significantly surpassed previously reported values in literature. The adsorption process followed pseudo-second-order kinetics, indicating chemisorption as the dominant mechanism. Furthermore, the adsorption isotherm was best described by the Langmuir model, suggesting monolayer adsorption behavior. These findings demonstrate that our cost-effectively fabricated hierarchical porous Al 2 O 3 represents a highly promising adsorbent for efficient removal of organic dyes from wastewater.