Acetylene Functionalized Photocatalytic COFs for PFAS Adsorption and Degradation

Covalent organic frameworks (COFs) are of deep interest in various applications due to their highly tunable architectures and porosities. COFs used as photocatalysts have great potential because they usually possess high surface areas for adsorption, tunable pore and surface functionalities, and various opto-electrical properties determined by the functional groups of building blocks. However, few examples of COFs have been successful in dealing with per- and polyfluoroalkyl substances (PFAS) due to the strong binding between fluorine and carbon atoms. The challenge is designing COFs that include electron-rich rings with a suitable pore size to absorb and degrade the contaminants. Herein, we demonstrate the novel synthesis of a series of COFs or amorphous porous organic polymers (APOP) with delocalized π-conjugated systems, followed by characterization and applications. First, we select a few monomers that contain electron-rich structures, such as pyrene and porphyrin groups, as predicted by band gap energy calculations. We then intentionally choose monomers with C-C triple bonds to combine and explore various solvent and reacting conditions. After the optimized conditions and reactants to form crystalline porous polymers have been found, we synthesize four different COFs and confirm their chemical structures and optical properties by characterizations. Finally, we explore the application of using these COFs as photocatalysts to absorb and photodegrade Perfluorooctanoic Acid (PFOA). Photodegradation experiment results indicate that the Porphyrin-COF has the highest efficiency for PFOA adsorption and degradation, with over 80% PFOA adsorbed and degraded within 3 hours of irradiation.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Engineering

Grantor

Rice University

Year dc:date.issued

2023

Author dc:creator

• Tong, Xinbo

Advisor dc:contributor.advisor

• Verduzco, Rafael

• Covalent organic frameworks
• Photocatalyst
• Per- and polyfluoroalkyl substances

Statement dc:rights

• Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1911/115200

OAI identifier oai:identifier

oai:repository.rice.edu:1911/115200