Laser photocatalysis.

This thesis describes the first detailed investigation of laser light sources for the activation of semiconductor photocatalysts for use in wastewater treatment. Although semiconductor photocatalysis for water treatment has been extensively investigated over the past 20 years this is the first reported use of laser light as an irradiation source. The destruction of 4-chlorophenol with conventional UV lamps and laser radiation has been compared. The laser radiation was found to be effective at inducing the photocatalytic destruction of 4-chlorophenol. The laser irradiation of TiO2 resulted in visible colour change, which was suggested to be due to the generation of Ti (III) sites. The result of this change and its impact on the photocatalysis of the TiO2 was investigated with a range of techniques. These studies showed that structural changes in TiO2 were induced on laser irradiation with a crystal phase change from anatase to rutile occurring. In the destruction of methylene blue, the modified TiO2 photocatalyst showed faster initial destruction rate than P25 TiO2. From the results, the laser modified TiO2 appeared to have several advantages compared to conventionally modified TiO2. Novel optical in situ monitoring methods were applied for the detection of laser induced modification on TiO2. These methods provided useful information directly in terms of control of the laser modification processes in terms of crystallinity changes and development of Ti (III) centres. Finally work was carried out on the direct detection of photocatalytic destruction of dyes using a hand held fluorimeter constructed at RGU. It was found that the newly designed hand held fluorimeter had a potential in the application of direct monitoring of photocatalytic destruction of dyes and kinetic studies. It was also applicable for use as a standard photocatalytic activity test system, in order to compare different TiO2 materials.

Grantor dc:publisher.institution

Robert Gordon University

Year dc:date.issued

2001

Author dc:creator

• Lee, Soo-Keun

Advisor dc:contributor.advisor

• D. McStay and P.K.J. Robertson

• Laser
• Photocatalysis
• Semiconductor
• Water treatment
• Irradiation source
• 4-chlorophenol
• Ultraviolet (UV)
• TiO2

Language dc:language

en

Identifier

oai:rgu-repository.worktribe.com:2807447
https://doi.org/10.48526/rgu-wt-2807447

OAI identifier oai:identifier

oai:rgu-repository.worktribe.com:2807447