Magnetically separable ZnS photocatalysts

• Main Author: Woo, Lewis Jian Feng.
• Other Authors: School of Chemical and Biomedical Engineering
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Chemical engineering::Industrial photochemistry
• Online Access: http://hdl.handle.net/10356/16538
• Institution: Nanyang Technological University

Core-shell particles are increasingly relevant in industry due to their various applications and controllability in many factors down to nano-scale like surface morphology and nano-architecture. The synthesis of a ZnS shell/SiO2 core nanoparticle with magnetic functionality is described in this report. From the mechanism of zinc sulfide deposition, crucial factors in the synthesis of the particle include low [H+], low [Zn2+] and low [TAA], as well as a moderate [TAA]: [Zn2+] ratio to avoid the formation of large ZnS particles while encouraging deposition of a smooth and even shell of ZnS onto the surface of the SiO2-coated α-Fe2O3 spindles. Experimental conditions were varied to avoid the formation of large ZnS particles and agglomeration of these ZnS particles. Limiting the rate of the ZnS deposition and allowing the reaction to carry on slowly for longer periods of time might be helpful in the promoting the deposition of ZnS onto the spindles instead of leading to the formation of large ZnS particles.