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

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.