Synthesis of Fe3O4@TiO2 core-shell structure for effective particle-fluid separation after photocatalytic process

• Main Author: Ng, Che Tean
• Other Authors: Dong Zhili
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/55684
• Institution: Nanyang Technological University

The usage of TiO2 photocatalysts inside liquid medium is facing a great challenge on difficulty and cost inefficient to be collected and reused by micro- or nano-filtration. Aiming to solve some disadvantages of TiO2 photocatalyst, a facile and effective synthesis method has been successfully developed to produce Fe3O4@TiO2 Core-Shell structure with magnetic Fe3O4 as cores and anatase TiO2 as shells. Firstly, the magnetite core nanoparticles were synthesized via low temperature oxidative hydrolysis method. During synthesis, the Fe3O4 colloidal dispersion was stabilized by a surfactant called Cetyl trimethylammonium bromide (CTAB), which serves to control the particle size and enhance the particle dispersion. On the synthesized Fe3O4 particles, a layer of TiO2 was in-situ formed, followed by heat treatment at three different temperatures to form the Fe3O4@TiO2 core-shell microspheres. Different characterization methods such as Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Zeta Potential and Particle Size Analyzer, and Solar Simulator were used to analyze the synthesized products at different experimental stages. The results show that the core-shell structured particles exhibit sensitive response to an external applying magnetic field, thus the product is a promising candidate as a magnetic recoverable catalyst. Meanwhile, the visible light response of this Fe3O4@TiO2 Core-Shell structure was investigated by using Rhodamine B (RhB) solution illuminated under visible light in a solar simulator. The corresponding results show significant enhanced photoresponse to visible light compared to pure TiO2 photocatalyst, which serves as an evidence on the reduction in bandgap energy. Furthermore, the synthesized core-shell microspheres show high photocatalytic efficiency and have potential to be used in recoverable applications in waste water treatment with the help of magnetic separation.