2.1. SiC–TiO2 synthesis by sol–gel method
SiC–TiO2 were prepared using as raw materials silicon carbide
(SiC) commercial powder, mesh 200–450 (Aldrich) and titanium(
IV) isopropoxide (Aldrich 99.999%). 3 samples were prepared
in order to obtain SiC–TiO2 with different proportions of TiO2, 20,
50 and 80 wt.%, herein labeled as SG1, SG2 and SG3, respectively
[9]. First of all, SiC powder was dispersed in 30 mL of ethanol andthen was sonicated for 15 min. After that, this solution was placed
in a reflux system at 70 ◦C and titanium isopropoxide was added
slowly (1 drop/min) to achieve the amount of TiO2 desire. During
this process, the system was kept in agitation to have a homogeneous
solution. Immediately a mixture of water/acetic acid (55 wt.%
ratio) was added in order to promote the hydrolysis–condensation
process; after this step, the reaction was kept for 1 h in agitation.
The formed gel was dried below 80 ◦C for 5 h. Finally, dry powder
was milled and thermal treatment at 450 ◦C for 2 h.