Development of Titanium Dioxide Nanocomposites for Enhanced Photocatalytic and Enzymatic Degradation of Bisphenol A
Author
Klitgaard, Kristina
Term
4. term
Education
Publication year
2026
Abstract
Bisphenol A (BPA) is an endocrine‑disrupting micropollutant; photocatalysis with titanium dioxide (TiO2) is promising but limited by poor visible‑light utilization and rapid recombination. This thesis synthesized and examined modified TiO2 nanocomposites—TiO2 with gold (TiO2/Au), with polymeric carbon nitride (TiO2/PCN), and with potassium‑doped PCN (TiO2/KPCN)—to enhance light absorption and charge separation for BPA degradation. To probe a hybrid pathway, horseradish peroxidase (HRP) was immobilized on TiO2/PCN by adsorption and covalent attachment to couple photocatalytic in situ H2O2 generation with enzymatic oxidation. BPA removal was evaluated under visible light and simulated solar irradiation. Degradation was negligible under visible light but markedly improved under simulated solar light. TiO2/PCN achieved the highest BPA removal (41.54%), followed by TiO2/Au (33.29%). HRP immobilization efficiencies were 39.6% (adsorption) and 62.9% (covalent), yet immobilization reduced the photocatalytic degradation, likely due to enzyme deactivation and reduced surface accessibility. Overall, TiO2/PCN showed the most promising photocatalytic performance, and no significant synergistic effect between photocatalysis and enzymatic treatment was observed under the tested conditions.
Bisphenol A (BPA) er en hormonforstyrrende mikropollutant; fotokatalyse med titandioxid (TiO2) er lovende, men begrænses af ringe udnyttelse af synligt lys og hurtig rekombination. Dette projekt syntetiserede og undersøgte modificerede TiO2‑nanokompositter—TiO2 med guld (TiO2/Au), med polymer kulstofnitrid (TiO2/PCN) og med kaliumdoteret PCN (TiO2/KPCN)—for at forbedre lysabsorption og ladningsseparation til BPA‑nedbrydning. For at afprøve en hybrid tilgang blev peberrodperoxidase (HRP) immobiliseret på TiO2/PCN ved adsorption og kovalent binding for at koble fotokatalytisk in situ‑dannelse af H2O2 med enzymatisk oxidation. BPA‑fjernelse blev evalueret under synligt lys og simuleret sollys. Nedbrydningen var ubetydelig under synligt lys, men markant bedre under simuleret sollys. TiO2/PCN opnåede den højeste BPA‑fjernelse (41.54%), efterfulgt af TiO2/Au (33.29%). HRP‑immobiliseringseffektiviteten var 39.6% (adsorption) og 62.9% (kovalent), men immobilisering sænkede den fotokatalytiske nedbrydning, sandsynligvis pga. enzymdeaktivering og reduceret overfladetilgængelighed. Samlet set var TiO2/PCN den mest lovende fotokatalysator, og der blev ikke observeret nogen væsentlig synergi mellem fotokatalyse og enzymbehandling under de testede betingelser.
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