Abstract
The ZnO–SiO
2
xerogel photocatalyst was prepared via the sol–gel technique and applied for photodegradation of methylene blue (MB) dye. The optimum conditions for preparation of ZnO–SiO
2
gel is 30:70 ZnO:SiO
2
molar ratio and TEOS:C
2
H
5
OH:H
2
O:HNO
3
is 1:16:12:0.04 molar ratios at 30°C for 30 min, at these conditions the photoactivity of ZnO–SiO
2
xerogel was 99% at a surface area of 500 m
2
/g after 60 min. The optimum loading of ZnO–SiO
2
photocatalyst was 0.050 wt% that gives 99% MB dye removal efficiency after 40 min. The overall kinetics of photodegradation of MB dye using ZnO–SiO
2
photocatalyst was found to be of the first order.