Optimiranje ZnO slojeva za fotokatalitičku namjenu

master's thesis

• Title (english): Optimization of ZnO films for photocatalytic application
• Author: Marina Ivanko
• Mentor: Jelena Macan (mentor)
• Committee member: Jelena Macan (predsjednik povjerenstva)
• Committee member: Marica Ivanković (član povjerenstva)
• Committee member: Ivana Grčić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2017-09-26, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering; Chemical Engineering in Material Development

Abstract

Cilj ovoga rada bio je optimirati ZnO prevlake za fotokatalitičku namjenu te ispitati utjecaj dobivene strukture na fotokatalitičku aktivnost. Pripravljene su otopine koristeći cinkov acetat dihidrat kao polaznu tvar i metanol kao otapalo. Prevlake su dobivene kemijskim taloženjem iz otopine na staklenim pločicama i na staklenoj mrežici. Dobivene prevlake sušene su na 100 °C te su uzorci žareni na temperaturama od 300 °C i 400 °C da bi se uklonile preostale organske komponente te dobio kristalni ZnO. Prevlake su zatim karakterizirane pretražnom elektronskom mikroskopijom, infracrvenom spektroskopijom s Fourierovom transformacijom i rendgenskom difrakcijskom analizom. U konačnici je ispitana fotokatalitička aktivnost svih prevlaka tako što se pomoću UV-Vis spektrofotometra pratila promjena koncentracije otopine 2,5-dihidroksibenzojeve kiseline koja je služila kao modelno onečišćavalo, a koja je cirkulirala iznad prevlake izložena UV zračenju. Sve prevlake pokazale su se fotokatalitički aktivnima, smanjujući koncentraciju onečišćivala gotovo za 50 % u 4 h izlaganja UV zračenju. Primijećeno je da rezultati malo odstupaju bez obzira na način priprave prevlake, što upućuje na to da koncentracija polazne otopine cinkovog acetata, podloga na kojoj se nalazi prevlaka, njezina struktura te temperatura žarenja ne utječu previše na fotokatalitičku aktivnost.

Abstract (english)

The goal of this work was to optimise ZnO films for photocatalytic application, and test the structure on photocatalytic activity. The solutions were made using zinc acetate dihydrate as a starting compound and methanol as a solvent. The films were obtained by chemical bath deposition on glass tiles and on a glass net. Films made were dried at 100 °C, and heated at temperatures of 300 °C and 400 °C, to remove residual organic components and to obtain crystalline ZnO. The films were then characterised by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction analysis. Finally the photocatalytic activity of all the films was tested by monitoring with UV-Vis spectrometer the change in concentration of 2,5-dihydroxibenzoic acid solution, which was used as a model pollutant and which circulated above the film exposed to UV radiation. All of the films were shown to be photocatalytically active, lowering pollutant concentration by almost 50 % in 4 h of exposure to UV radiation. It was noticed the results deviate little regardless of the way the film was made, which indicates that concentration of the starting zinc acetate solution, film substrate, its structure and the temperature of thermal treatment do not affect the photocatalytic activity too much.

• Keywords: ZnO; prevlake; kemijsko taloženje iz otopine; fotokatalitička aktivnost
• Keywords (english): ZnO; films; chemical bath deposition; photocatalytic activity
• Language: croatian
• URN:NBN: urn:nbn:hr:149:835992
• Study programme: Title: Materials Science and Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Repository: Repository of Faculty of Chemical Engineering and Technology University of Zagreb
• Created on: 2020-04-23 14:09:16