Design of 3D Macroporous Inverse Opal TiO2 Binary and Ternary Composites Sensitized with Gold Nanoparticles and CdS Quantum Dots for Photocatalysis

<p>Materials composed of titanium (IV) oxide (TiO₂) have received enormous scientific interest due to titania’s abundance, non-toxicity, and photocatalytic proficiency, however its large band gap limits its applicability under ambient conditions. Various attempts have been made to incorporate titania into composite systems to sensitize it for activity under a broader range of wavelengths. One such method includes utilizing narrow band gap semiconductors to form an electron transfer process analogous to photosynthesis referred to as a Z-scheme. Z-scheme systems can catalyze the decomposition of aqueous pollutants via generation of reactive oxygen species after input of sunlight. This work reports the design of a photocatalyst consisting of macroporous inverse opal (<em>io</em>) TiO₂ embedded with gold nanoparticles (AuNPs) and cadmium sulfide quantum dots (CdS QDs) into binary and ternary systems. These composites, labeled <em>io</em>TiO₂-Au, <em>io</em>TiO₂-CdS, and <em>io</em>TiO₂-Au-CdS are characterized via SEM, EDX, solid-state UV-vis, and Raman, and are subsequently evaluated for their photocatalytic efficiency against the pollutant analog trypan blue (TryB) under UV and white light LED lighting conditions. It was found that binary <em>io</em>TiO₂-CdS exhibits the best photocatalytic performance, with a rate constant 7.8, 5.2, 6.5, and 1.6 times faster than singular <em>io</em>TiO₂ and CdS, binary <em>io</em>TiO₂-Au, and ternary <em>io</em>TiO₂-Au-CdS under UV, respectively. Under white light LED all systems exhibit reduced activity, with <em>io</em>TiO₂-Au-CdS and <em>io</em>TiO₂-CdS showing no statistical difference, however, the ternary system performed most consistently across both light sources, retaining 92% of its UV performance. Loss of CdS due to photocorrosion limits recyclability of the thin films.</p>

Name thesis:degree_name

Master of Science in Chemical Sciences (MSCB)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemistry

Year dc:date.available

2017

Author dc:creator

• Corella, Daniel A

Contributors dc:contributor

• Dr. Bharat Baruah
• Dr. Janet Shaw
• Dr. Heather Abbott-Lyon

• inverse opal
• photocatalysis
• nanoparticles
• quantum dots
• environmental remediation
• composite material
• Catalysis and Reaction Engineering
• Chemistry
• Inorganic Chemistry
• Materials Chemistry
• Sustainability

Repository record dc:identifier

https://digitalcommons.kennesaw.edu/mscs_etd/13

OAI identifier oai:identifier

oai:digitalcommons.kennesaw.edu:mscs_etd-1012