Ethanolamine modified ordered mesoporous silica KIT-6: One-pot and rapid microwave synthesis, and efficient recovery for rhenium(VII)

Abstract

Rhenium (Re) is a strategic key metal for the development of modernization and its efficient recovery from liquid sources plays an important role in the field of environment and energy. In this work, ethanolamine modified ordered mesoporous silica KIT-6 using Na2SiO3 as silicon source was prepared by one-pot and rapid microwave-assisted synthesis to recover Re(VII), which solved the long time-consuming synthesis problem of mesoporous silica materials by traditional methods. The acidity experiment showed that the optimal conditions for preparing ethanolamine modified ordered mesoporous silica KIT-6 (SS-C4M3–15-EA3-KIT-6) were microwave hydrothermal treatment for 3 h, glutaraldehyde (Glu) 15 mL, ethanolamine (EA), 3.0 g. FT-IR, XPS and functional density theory (DFT) analysis showed that chelation between the Schiff base (-CN-) and ReO4‾ together with electrostatic reaction gave it excellent adsorption performance, and its maximal adsorption capability was 111.41 mg·g−1. Moreover, ethanolamine modified ordered mesoporous silica KIT-6 had good regeneration performance and high selectivity for Re(VII) in mixed solution with Cu(II), Mn(II), Fe(III) and Zn(II). These findings suggested that the modified ordered mesoporous silica KIT-6 had a promising application in recovering Re(VII) from industrial wastewater.