Preparation and characterization of ZIF-67/ TiO₂) thin film

Khoo, Lenny (2015) Preparation and characterization of ZIF-67/ TiO₂) thin film. Universiti Malaysia Sabah. (Unpublished)

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Abstract

Titanium dioxide (TiO₂) is one of the most widely used photocatalyst due to its nontoxic, low cost, good chemical stability, elemental abundance, and photocatalytic properties. But there are some problems faced by TiO₂ first is that if TiO₂ used is in the powder form an additional separation process is needed to separate the TiO₂ particles from the wastewater after the treatment. TiO₂ has a high bandgap which requires UV-A light to activate it. The high recombination rate of electron hole pair occurs before the photocatalytic process starts. ZIF-67 is well known for its porosity properties. It is used in this study to act as an adsorbent to adsorb organic dye on the surface of TiO₂ to allow photodegradation to occur and at the same time forming synergetic effect with TiO₂ to reduce its band gap from UV region to visible light region. ZIF-67/TiO₂ thin film is form by using dip-coating method. The morphology of ZIF-67/TiO₂ is observed by using SEM. A square-like shape of ZIF-67 is observed on the surface of TiO₂ thin film. The photodegradation result obtained show that ZIF- 67/TiO₂ (43.63%) has a lower photodegradation efficiency than un-doped TiO₂ (58.81%) under the irradiation of UV-A light. This shows that ZIF-67 does not enhance the photocatalytic ability of TiO₂ under irradiation of UV-A light. This may cause by the combination of ZIF-67 with the Co-doped TiO₂ thin film does not show a synergetic effect in photodegradation. Besides that, ZIF-67 does not overcome the high recombination rate of electron hole pair of TiO₂ by adsorbing MB longer on the surface. But from this study shows that cobalt can act as a dopant to enhance the photocatalytic properties of TiO₂ in the visible light region. Co-doped TiO₂ shows a photodegradation efficiency of 25.27 % compared to un-doped TiO₂ which is only 14.36%.

Item Type: Academic Exercise
Uncontrolled Keywords: Titanium dioxide, photocatalyst, photodegradation
Subjects: Q Science > QD Chemistry
Divisions: FACULTY > Faculty of Science and Natural Resources
Depositing User: Munira
Date Deposited: 08 Dec 2017 06:21
Last Modified: 08 Dec 2017 06:21
URI: http://eprints.ums.edu.my/id/eprint/17744

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