Tailoring the structural and textural properties of MCM-41 via myristyl trimethyl ammonium bromide templating for enhanced tetracycline adsorption

Abstract The escalation of pharmaceutical water pollution, particularly from antibiotics, poses a critical environmental crisis. Consequently, developing highly efficient adsorbents has become imperative to tackle this growing threat. Here, highly ordered pure MCM-41 was synthesized using different molar concentration ratio (0.06, 0.12, 0.25 and 0.415 M) of myristyl trimethyl ammonium bromide surfactant to the silica source. The structural, morphological and texture characteristics were investigated by X-ray diffraction (XRD), N 2 adsorption–desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR). It was found that the myristyl concentration has a profound impact on the mesostructural arrangement of the particles. Consequently, it was found that the highest quality and highly ordered pure MCM-41 structure was achieved using myristyl surfactant at concentrations of 0.25 M and 0.12 M, with the 0.25 M concentration producing a higher degree of ordered pure MCM-41 structure than the 0.12 M concentration. The potential of the prepared MCM-41 samples for adsorption of tetracycline (TC) drug was investigated using varying parameters including: adsorbent dosage, initial drug concentration, adsorption isotherms, and contact time. The MM0.25 sample showed remarkable TC-adsorption removal, with maximum adsorption capacity (q max ) of 5.4 mg g −1 at pH 5.4 and room temperature. The adsorption equilibrium data fitted well with Langmuir adsorption model, while the adsorption kinetic followed the pseudo-second-order model (R 2 = 0.99999). The calculated free adsorption energy obtained from D–R isotherm was found to be 1507.6 kJ mol −1 referring to that the adsorption of TC on MM0.25 adsorbent is chemical. These results revealed that MM0.25 sample could be used as effective adsorbent for the removal of TC drug from aqueous solutions with good recovery and recyclability.