Effect of Concentration and Thermal Treatment on the Properties of Sol-Gel Derived CuO/SiO2 Nanostructure

Various concentrations of copper are embedded into silica matrix to xerogel form using copper source - Cu(NO3)2∙3H2O. The xerogel samples are prepared by hydrolysis and condensation of tetraethyl orthosilicate (TEOS) by the sol-gel method  and with determination of new molar ratio of components H2O/TEOS to be 6.2. In this investigation, the necessary amount of trihydrated copper nitrate is added to the solution in such a manner that the concentration of the copper oxide in final solution reach to 1, 2 and 5 wt% (samples A, B and C respectively). After ambient drying, the gel samples are heated from 60 to 1000˚C at a slow heating rate (50°C/h). The absorption and transmittance spectrum of  various concentrations of copper are studied by Uv-vis spectrophotometer. Thermal treatment effects are characterized by FTIR, TGA, TEM, SEM, XRD, BET and TPR methods at different temperatures.