Fabrication of bi-doped tio2 nanofibers for clean energy and water production under visible light

• Main Author: Chua, Song Cherng
• Other Authors: Sun Delai, Darren
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Environmental engineering::Water treatment
• Online Access: http://hdl.handle.net/10356/61243
• Institution: Nanyang Technological University

The potential use of titanium dioxide (TiO2) for clean energy and water purification has been shown to tackle eminent world issues such as energy and water crisis extensively. However challenges remain as TiO2 possesses wide band gap that only allows limited photocatalytic activity under the renewable solar irradiation thus impeding the application of TiO2 to its fullest potential. Moreover, most photocatalytic H2 generation over TiO2 has been conducted under sacrificial condition using methanol, formic acid, glycerol and EDTA. This report describes a promising approach to lowering the band gap issue through the doping of Bismuth (Bi) for enhanced efficiency in concurrent generation of clean energy and water purification from organic wastewater under visible light. In this project, the simplest synthesizing method of electrospinning was adopted to produce nanofibers and usage of state-of-the-art technologies to characterize the morphology and applicability of the Bi-doped TiO2 (Bi/TiO2) photocatalyst. The electrospun Bi/TiO2 nanofibers showed positive characterization though anatase crystallinity, high specific surface area and low electron holes pair recombination rate. EDTA and glycerol were used as a novel proof-of-concept demonstration of concurrent photocatalytic process over Bi/TiO2 for clean energy production and water purification. Experimental data from the photocatalytic process of EDTA and glycerol yield positive result of 3% Bi-doped TiO2 having the highest H2 generation and TOC removal. Both results achieved an additional yield of H2 generation and TOC removal under UV-visible and visible light as compared to bare TiO2. These findings present promising potential for Bi/TiO2 nanofibers to be used in commercial industrial wastewater in both UV-visible and visible light especially glycerol, to close the energy loop as well as the additional advantage of water purification.