Fotokatalitske lastnosti prozornih tankih plasti dopiranega $TiO_2$ z vanadijem v silikatnem vezivu

Henčič, Lara (author), Lavrenčič Štangar, Urška (mentor)

Diplomsko delo je nastalo na podlagi teoretičnih in eksperimentalnih podatkov, ki smo jih pridobili tekom predhodnih raziskav in naše raziskave. Hkrati smo želeli potrditi delno hipotezo o fotokatalitskih značilnostih iz predhodnega dela, kjer so bile raziskane koloidne raztopine $TiO_2-SiO_2$ z različnimi vsebnostmi dopiranega vanadija. Same fotokatalitske lastnosti niso bile natančneje opredeljene. Iz sintetiziranih delovnih solov z različnimi vsebnostmi vanadija sem pripravila tanke plasti s tehniko potapljanja. Najprimernejša hitrost dvigovanja stekelca iz sola, ki smo jo izbrali, je bila 20 cm/min. Glavni poudarek pri raziskovalnem delu je bila optimizacija tehnike nanosa tanke plasti maščobnega onesnaževala, s katerim smo lahko določali fotokatalitske značilnosti vpliva vanadija. Sprva sem poskusila z nanosom metil stearata, vendar je boljšo sledljivost omogočala stearinska kislina. Po uspešni optimizaciji sem lahko z nanosom stearinske kisline nadaljevala delo in določala fotokatalitske lastnosti vzorcem z različno vsebnostjo vanadija. Optične, strukturne in morfološke lastnosti vzorcev fotokatalizatorja smo določali z rentgensko praškovno difrakcijo (XRD), UV-Vis spektroskopijo, fotoluminiscenco, FTIR-ATR spektroskopijo in vrstično elektronsko mikroskopijo. Fotokatalitske lastnosti smo najprej določali z meritvami kontaktnega kota, kasneje pa smo se odločili za FTIR-ATR spektroskopijo, saj je ta tehnika omogočala boljšo resolucijo in je dala ponovljivejše rezultate. Rezultati so pokazali, da vpliv naraščajoče vsebnosti vanadija odraža pričakovano večjo absorpcijo vidne svetlobe, vendar se povečana vsebnost vanadija večinoma ne odraža v izboljšanih fotokatalitskih lastnostih.

• Language: Slovenian
• Keywords: Tanke prozorne plasti $TiO_2$, vanadij dopant, fotokataliza, sol-gel postopek, tehnika potapljanja.
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2023
• PID: 20.500.12556/RUL-152406
• COBISS.SI-ID: 176664579
• Publication date in RUL: 23.11.2023

HENČIČ, Lara, 2023, Fotokatalitske lastnosti prozornih tankih plasti dopiranega $TiO_2$ z vanadijem v silikatnem vezivu [online]. Bachelor’s thesis. [Accessed 18 March 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=152406

Secondary language

• Language: English
• Title: Photocatalytic properties of transparent thin films of $TiO_2$ doped with vanadium in a silica binder

Abstract

The diploma thesis was written on the basis of theoretical and experimental data obtained in previous research and our own research. At the same time, we wanted to confirm a partial hypothesis about the photocatalytic properties from the previous work, where colloidal solutions $TiO_2-SiO_2$ with different contents of doped vanadium were studied. The photocatalytic properties themselves have not been defined in more detail. I prepared thin films from the synthesised working sols with different vanadium contents using the dip-coating technique. The most suitable withdrawal speed for lifting the glass slide from the sol that we chose was 20 cm/min. The main focus of the research was to optimise the technique of thin film deposition of a fatty impurity used to determine the photocatalytic properties of the influence of vanadium. Initially, I tried using methyl stearate, but stearic acid offered better traceability. After successful optimization, I was able to continue the work with stearic acid and determine the photocatalytic properties of samples with different vanadium content. The optical, structural and morphological properties of the photocatalyst samples were determined by X-ray powder diffraction (XRD), UV-Vis spectroscopy, photoluminescence, FTIR-ATR spectroscopy and scanning electron microscopy. The photocatalytic properties were initially determined by measuring the contact angle. However, we later decided to use FTIR-ATR spectroscopy because this technique provided better resolution and gave more repeatable results. The results showed that the effect of increasing vanadium content reflects the expected higher absorption of visible light, but the increased vanadium content is mostly not reflected in improved photocatalytic properties.

• Keywords: $TiO_2$ transparent thin films, vanadium dopant, photocatalysis, sol-gel process, dip-coating technique.