Photodegradation of new methylene blue N in aqueous solution using zinc oxide titanium dioxide as catalyst

• Main Authors: Ali, Rusmidah, Ooi, Boon Siew
• Format: Article
• Language: English
• Published: Penerbit UTM Press 2006
• Subjects: QD Chemistry
• Online Access: http://eprints.utm.my/id/eprint/2491/1/JTJUN42B1.pdf; http://eprints.utm.my/id/eprint/2491/; http://www.penerbit.utm.my/onlinejournal/45/F/JT45F3.pdf
• Institution: Universiti Teknologi Malaysia

In this study, ZnO and TiO2 are used as photocatalyst to degrade the dye, New Methylene Blue N. The photodegradation rate was measured using UV-Visible spectrophotometer. New Methylene Blue N showed the absorption values at λ=590 nm and λ=286 nm. UV lamp (λ=354 nm) is used in the photodegradation process. Results showed that ZnO is a better catalyst compared to TiO2. The degradation by ZnO showed TiO2 gave 81 % at λ=590 nm and 77.75 % at λ=286 nm. In contratst, the degradation for TiO2 was 25.68 % at λ=590 nm and 26.37 % at λ=286 nm. Percent degradation for New Methylene Blue N is 88.89 % and 68.94 % at λ=590 nm and λ=286 nm respectively when H2O2 was added. The mixture of ZnO and TiO2 in the ratio of 85: 15 (0.085 g: 0.015 g) is the most optimum mixture of photocatalyst with the degradation percentage of 96.97 % and 93.61 % at λ=590 nm and λ=286 nm. The addition of Cu2+ metal ion gave the highest percentage of degradation (83.83 % at λ=590 nm) compared to other metal ions. The addition of Pb2+ gave the highest percentage of degradation at λ= 286 nm with 81.25 %. The optimum condition was achieved at pH 5.90, which gave the highest percentage of degradation, 92.84 % and 89.30 % at λ=590 nm and λ=286 nm respectively.