Adsorption and photocatalytic removal of Methylene blue using graphene oxide-supported engelhard titanosilicate-10

In this study, ETS-10 precursors were mixed with graphene oxide (GO) suspension to obtain GO incorporated ETS-10 (GO/ETS-10) with improved adsorption ability and photocatalytic activity in comparison to that of ETS-10. The GO/ETS-10 composite prepared with different GO to ETS-10 ratios, i.e. 1:15, 1...

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Main Author: Nguang, Sing Yew
Format: Thesis
Language:English
English
Published: 2017
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https://eprints.ums.edu.my/id/eprint/38962/2/FULLTEXT.pdf
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spelling my-ums-ep.389622024-06-27T07:42:06Z Adsorption and photocatalytic removal of Methylene blue using graphene oxide-supported engelhard titanosilicate-10 2017 Nguang, Sing Yew QD701-731 Photochemistry In this study, ETS-10 precursors were mixed with graphene oxide (GO) suspension to obtain GO incorporated ETS-10 (GO/ETS-10) with improved adsorption ability and photocatalytic activity in comparison to that of ETS-10. The GO/ETS-10 composite prepared with different GO to ETS-10 ratios, i.e. 1:15, 1:10 and 1:5 were confirmed by XRD, FTIR, EDX and XPS analyses. The results showed that GO and ETS-10 were chemically bound through Ti–O–C and Si–O–C bonding. SEM images showed that the truncated bipyramidal ETS-10 crystals were grown firmly on the GO surface and have crystal sizes range between 0.5 to 1.0 μm. Thermogravimetric analysis revealed that the synthesized GO/ETS-10 composite was thermally stable up to 150 ˚C and decomposed fully above 400 ˚C due to the disintegration of GO from ETS-10. The band gap energy for GO/ETS-10(1:5) was determined to be 3.12 eV which was lower than ETS-10 (3.48 eV). The adsorption study revealed that the adsorption behavior of MB onto GO/ETS-10 was mainly monolayer due to the chemisorption interaction between MB and GO/ETS-10 surface. The maximum equilibrium adsorption capacity of GO/ETS-10 was calculated to be 294 mg/g, which is much higher than ETS-10 with only 139 mg/g. Besides that, GO/ETS-10 can be photoexcited by both UV-A and visible radiations which gave similar removal of MB in water. This implies that the presence of GO can help to widen the light responsive range of ETS-10 by lowering the band gap energy and suppress the electron-hole recombination. 0.075 g/L of GO/ETS-10(1:5) in 20-ppm MB solution with UV-A irradiation (as GO/ETS-10(1:5)/UV-A), for instance, can achieve about 65 % of MB removal after 6 hours and still increasing with a consistent rate of removal in comparison to 60 % of MB removal achieved by GO/ETS-10(1:5)/Dark system, which has reached plateau after 6 hours of reaction. The results showed that the photocatalytic activity of GO/ETS-10 was low under UV-A irradiation but it is important to ensure continuous adsorption-photocatalytic removal throughout the process. Besides, it was found that addition of 5 x 10-3 mol/L H2O2 in the photocatalytic system (as GO/ETS-10(1:5)/H2O2/UV-A system) was capable to enhance about 20 % of MB removal, which giving a total of 93 % after 8 hours. This study implies that GO/ETS-10 composite can be a potential material specifically for the elimination of organic pollutant via adsorption and eventually through photocatalytic decomposition under sunlight. 2017 Thesis https://eprints.ums.edu.my/id/eprint/38962/ https://eprints.ums.edu.my/id/eprint/38962/1/24%20PAGES.pdf text en public https://eprints.ums.edu.my/id/eprint/38962/2/FULLTEXT.pdf text en validuser masters Universiti Malaysia Sabah Fakulti Sains dan Sumber Alam
institution Universiti Malaysia Sabah
collection UMS Institutional Repository
language English
English
topic QD701-731 Photochemistry
spellingShingle QD701-731 Photochemistry
Nguang, Sing Yew
Adsorption and photocatalytic removal of Methylene blue using graphene oxide-supported engelhard titanosilicate-10
description In this study, ETS-10 precursors were mixed with graphene oxide (GO) suspension to obtain GO incorporated ETS-10 (GO/ETS-10) with improved adsorption ability and photocatalytic activity in comparison to that of ETS-10. The GO/ETS-10 composite prepared with different GO to ETS-10 ratios, i.e. 1:15, 1:10 and 1:5 were confirmed by XRD, FTIR, EDX and XPS analyses. The results showed that GO and ETS-10 were chemically bound through Ti–O–C and Si–O–C bonding. SEM images showed that the truncated bipyramidal ETS-10 crystals were grown firmly on the GO surface and have crystal sizes range between 0.5 to 1.0 μm. Thermogravimetric analysis revealed that the synthesized GO/ETS-10 composite was thermally stable up to 150 ˚C and decomposed fully above 400 ˚C due to the disintegration of GO from ETS-10. The band gap energy for GO/ETS-10(1:5) was determined to be 3.12 eV which was lower than ETS-10 (3.48 eV). The adsorption study revealed that the adsorption behavior of MB onto GO/ETS-10 was mainly monolayer due to the chemisorption interaction between MB and GO/ETS-10 surface. The maximum equilibrium adsorption capacity of GO/ETS-10 was calculated to be 294 mg/g, which is much higher than ETS-10 with only 139 mg/g. Besides that, GO/ETS-10 can be photoexcited by both UV-A and visible radiations which gave similar removal of MB in water. This implies that the presence of GO can help to widen the light responsive range of ETS-10 by lowering the band gap energy and suppress the electron-hole recombination. 0.075 g/L of GO/ETS-10(1:5) in 20-ppm MB solution with UV-A irradiation (as GO/ETS-10(1:5)/UV-A), for instance, can achieve about 65 % of MB removal after 6 hours and still increasing with a consistent rate of removal in comparison to 60 % of MB removal achieved by GO/ETS-10(1:5)/Dark system, which has reached plateau after 6 hours of reaction. The results showed that the photocatalytic activity of GO/ETS-10 was low under UV-A irradiation but it is important to ensure continuous adsorption-photocatalytic removal throughout the process. Besides, it was found that addition of 5 x 10-3 mol/L H2O2 in the photocatalytic system (as GO/ETS-10(1:5)/H2O2/UV-A system) was capable to enhance about 20 % of MB removal, which giving a total of 93 % after 8 hours. This study implies that GO/ETS-10 composite can be a potential material specifically for the elimination of organic pollutant via adsorption and eventually through photocatalytic decomposition under sunlight.
format Thesis
qualification_level Master's degree
author Nguang, Sing Yew
author_facet Nguang, Sing Yew
author_sort Nguang, Sing Yew
title Adsorption and photocatalytic removal of Methylene blue using graphene oxide-supported engelhard titanosilicate-10
title_short Adsorption and photocatalytic removal of Methylene blue using graphene oxide-supported engelhard titanosilicate-10
title_full Adsorption and photocatalytic removal of Methylene blue using graphene oxide-supported engelhard titanosilicate-10
title_fullStr Adsorption and photocatalytic removal of Methylene blue using graphene oxide-supported engelhard titanosilicate-10
title_full_unstemmed Adsorption and photocatalytic removal of Methylene blue using graphene oxide-supported engelhard titanosilicate-10
title_sort adsorption and photocatalytic removal of methylene blue using graphene oxide-supported engelhard titanosilicate-10
granting_institution Universiti Malaysia Sabah
granting_department Fakulti Sains dan Sumber Alam
publishDate 2017
url https://eprints.ums.edu.my/id/eprint/38962/1/24%20PAGES.pdf
https://eprints.ums.edu.my/id/eprint/38962/2/FULLTEXT.pdf
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