Polyoxometalates : crystal growth, crystal structure characterization and catalysis activities

• Main Author: Chan, Yanhua
• Other Authors: Dong Zhili
• Format: Final Year Project
• Language: English
• Published: 2015
• Subjects: DRNTU::Engineering::Materials
• Online Access: http://hdl.handle.net/10356/64676
• Institution: Nanyang Technological University

Organic dye such as Methyl Blue are widely used in the textile and food industries. However, such dye causes problems to the environment and human as it is non-biodegradable and causes carcinogenic effect on human. The study of using polyoxometalates as photocatalysts in treating the dye has become popular due to its photochemical characteristic. [XM11O39]n- was formed during the degradation of Keggin structure, [XM12O40]n−, where X is the heteroatom with elements such as (P5+, Si4+, or B3+), while M is the addenda atom, normally a transition metal. In this project, Iron was chosen to be the addenda atoms as it is reported that in Fe3+ substituted POMs, Fe3+ serve as active centre for coordination with oxidants. A total of five POMs, (C4H9N)4[PW11Fe(H2O)O39]), K7PW11O39, Na7PW11O39, POM-2 and POM-1 were synthesised and studied of their crystal structure were done using equipment such as Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Electron Dispersive X-ray Spectroscopy (EDX) as well as Thermal Gravimetric Analysis (TGA). The results shows that all synthesised POMs had achieved the Keggin structure. All synthesised POMs were also tested for degradation of Methyl Blue dye under irradiation under LED light for 1 hour. The results shows that degradation of Methyl Blue happened as the solution turned from blue to transparent.