Metal–organic–silica nanocomposites: copper, silver nanoparticles–ethylenediamine–silica gel and their CO2 adsorption behaviour

Abstract

Metal–organic–silica (MOS) nanocomposites of copper, silver nanoparticles, Cu2+, Ag1+, propyl ethylenediamine linker and silica gel (Cu–PEDA–S, Ag–PEDA–S, Cu2+–PEDA–S and Ag1+–PEDA–S) were prepared by surface chemical modifications. Silica surface was modified with propyl ethylenediamine functional groups (PEDA–S) followed by treatment with Cu2+ and Ag1+ solutions to produce metal ion–ethylenediamine–silica nanocomposites (Cu2+–PEDA–S and Ag1+–PEDA–S). Finally, the metal–organic–silica nanocomposites of Cu–PEDA–S and Ag–PEDA–S were formed by chemical reduction of the metal ion incorporating modified silica. The nanocomposites were characterized by CHN elemental analysis, FTIR, TGA, EDAX and transmission electron microscopy. The Cu2+ ion composite provides active sites for chemisorptions of 3.0 wt% water due to Cu complex formation. The metal nanocomposites show a high dispersion of uniform Cu and Ag nanoparticles through the silica support with diameter range from 5 to 20 nm. Thermal gravimetric analysis shows the improvement of CO2 adsorption stability in the MOS nanocomposites and Cu–PEDA–S has CO2 adsorption capacity of 28% and 100% higher than that for the PEDA–S and Cu2+–PEDA–S nanocomposites, respectively. The preparation procedure is simple and favourable for the synthesis of a variety of metal–organic–silica nanocomposites for application as catalysts in greenhouse gas removal and capture.