Adsorption of Acid Dyes by Functionalized SBA‐15 Mesoporous Silica of Different Pore Lengths

SBA‐15 materials of different pore lengths and functionalized with various organic groups were synthesized by one‐pot co‐condensation and applied as adsorbents for the acid orange 12 (AO12) and acid red 73 (AR73) dyes. The materials were characterized by techniques such as X‐ray powder diffraction, nitrogen sorption isotherms, scanning electron microscopy, and infrared (FTIR) spectroscopy. The adsorption behaviors of the SBA‐15 materials toward AO12 and AR73 dyes were investigated by varying several factors including morphologies of adsorbents, pH of solution, functional groups on SBA‐15, and temperature. The equilibrium adsorption data agreed with Langmuir isotherms. The kinetic parameters were also calculated and the first‐order kinetic model fitted well for amino‐functionalized SBA‐15 material. The short channeling pores of the amino‐functionalized SBA‐15 platelets facilitated the diffusion of dye molecules inside the pores and prevented the aggregation of dye molecules from the blocking of the pores. To conclude, however, the adsorption capacity is dependent on the amount of amino‐loading and surface area of the SBA‐15 materials.