The effect of thermal treatment on the structural properties of copper-containing sol-gel silica nanocomposites

Abstract

Abstract One distinct concentration of copper was embedded into a silica matrix to form xerogel using the copper source Cu(NO3)2 · 3H2O. The xerogel samples were prepared by hydrolysis and condensation of tetraethyl orthosilicate by the sol-gel method. In this investigation, the new molar ratio of H2O/TEOS (tetraethyl orthosilicate) was determined as 11.7. Also, the necessary amount of trihydrated copper nitrate was added to the solution in such a manner that the concentration of copper oxide in the final solution reached to 10 wt.%. After ambient drying, the xerogel samples were heated from 60 to 1 000 °C at a slow heating rate (323 K h– 1). Their structural properties were characterized by thermal gravimetric analysis, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, surface analysis and thermal-program reduction methods at different temperatures.