Effect of DMF and Heat Treatment on the Copper-Doped Silica Nanocomposite Aerogel Prepared by Ambient Drying

Using tetraethyl orthosilicate (TEOS) as silicon precursor and copper nitrate (Cu(NO3)2·3H2O) as copper source, a copper-doped silica nanocomposite aerogel with a high specific surface area (560 m2·g-1) and 5% (mass fraction) of Cu content was prepared via an in-situ sol-gel process and ambient drying by introduction of a drying control chemical additive (DCCA) N,N-dimethylformamide (DMF) to the composite sol systems. The effect of DMF on gel time, drying process, the morphology and the structure of the composite aerogel was discussed. Structure and morphology of samples were characterized by N2 physical adsorption, X-ray diffractometer (XRD), Fourier transform infrared (FT-IR) spectrometer and transmission electron microscope (TEM). Results showed that DMF was effective in preventing gel cracking and inhibiting the formation particle clusters. The diameter of composite aerogel decreased as specific surface area increased and the microstructure became more optimal. After high temperature treatment, copper species in Cu-SiO2 were still highly dispersed, which indicated good thermal stability of the composite aerogel.