One-Step Synthesis of Thiol-Functional Mesoporous Silica Nanospheres and Selective Removal of Cationic Dyes

The surface characteristics of nanoparticles have a huge impact on adsorption effects. In this paper, thiol-functional mesoporous silica nanospheres (MSNs-SH) are successfully prepared through simple one-step hydrolysis and co-condensation of tetraethyl orthosilicate and (3-mercaptopropyl) triethoxysilane with hexadecyltrimethylammonium bromide and sulfobetaine 12 as dual-template. The obtained MSNs-SH have high surface area (1260 m2 g-1), accessible mesopores (2.2 nm), great pore volume (1.7 cm3 g-1), and uniform adjustable diameter (90 nm). Furthermore, the diameter and pore-size of MSNs-SH can be controlled via adjusting the ethanol content in the synthesis system. MSNs-SH exhibit a fast adsorption kinetics, marked adsorption capacity of cationic rhodamine B (RB 534.2 mg g-1), and remarkable selective adsorption for cationic dyes. Theoretical analysis reveals the adsorption behavior of RB on MSNs-SH follows the Langmuir isotherm models and pseudo-second-order kinetic. Additionally, the thermodynamic results indicate that the adsorption process is a spontaneous process driven by temperature. The results demonstrate that MSNs-SH are greatly potential for effectively removing cationic dyes from wastewater, with the advantages of simple preparation, high adsorption performance and perfect selectivity. One-step co-condensation approach with CTAB and LSB were used as the dual templates to successfully prepare monodispersed thiol-functional mesoporous silica nanospheres (MSNs-SH). The MSNs-SH exhibits a fast adsorption kinetics, marked adsorption capacity of cationic rhodamine B (RB 534.2 mg g-1), and remarkable selective adsorption for cationic dyes over anionic dyes. image