Effect of concentration double layer ZnO/ZnO:Ag on optical and photocatalytic properties

Abstract

ZnO is a semiconductor material that advantages in various applications, especially for photocatalysts. The catalytic activity of ZnO is much better than other materials, because ZnO can absorb light in a wider spectrum. The double layer ZnO/ZnO:Ag with various concentrations of 0.1 M, 0.3 M, and 0.5 M has been successful deposition. Double layer ZnO/ZnO:Ag deposition was carried out by sol-gel method and spray coating deposition technique. The results showed that the concentration of double layer ZnO/ZnO: Ag increased with the increase of the absorbance value. From the transmittance spectrum attempt was made to estimate the value of energy band gap of the samples. Double layer ZnO / ZnO:Ag energy gap in the range 3,2-3,3 eV. The energy gap of Double Layer ZnO/ZnO:Ag decreases with increasing concentration to 0.5 M. Double layer ZnO/ZnO: Ag 0.5 M has the smallest energy gap of 3.21 eV. Photodegradation testing was carried out to determine the ability of samples to photocatalytic activity at methylene blue dye. The optimum photocatalytic activity is indicated by the largest percentage of degradation. The largest percentage of degradation was shown by Double layer ZnO/ZnO:Ag 0.3 M at 81.5%.