Primjena nanokompozitnih materijala za fotokatalitičko dobivanje vodika

master's thesis

• Title (english): Application of nanocomposite materials for photocatalytic hydrogen production
• Author: Karla Krmek
• Mentor: Hrvoje Kušić (mentor)
• Committee member: Hrvoje Kušić (predsjednik povjerenstva)
• Committee member: Marijana Kraljić Roković (član povjerenstva)
• Committee member: Marin Kovačić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Prekomjerno korištenje neobnovljivih izvora energije potiče na uvođenje alternativnih goriva, posebice vodika primjenom fotokatalitičkog procesa cijepanja vode djelovanjem Sunčeve energije. Uloženi su brojni napori u pokušaju razvijanja učinkovitih fotokatalizatora sa širokim rasponom sakupljanja Sunčeva zračenja. Jedan od najkorištenijih fotokatalitičkih materijala je TiO2 koji, unatoč brojnim prednostima, ima ograničenja poput visoke vrijednosti energije zabranjene zone (Eg). Potencijalno rješenje za njegovo unaprjeđenje nalazi se u kompozitiranju TiO2 s ostalim fotokatalizatorima aktivnim pod zračenjem vidljivom svjetlošću. Ovim diplomskim radom provedena je detaljna fotoelektrokemijska karakterizacija kompozitnih materijala na bazi TiO2, konkretno TiO2-SnS2/GO-RGO s različitim udjelima GO-RGO, a za potpunu usporedbu analizirane su i pojedinačne komponente navedenog kompozita. Imobilizirani fotokatalizatori na FTO podloge korišteni su kao elektrode, dok su sva mjerenja provedena u 0,1 M otopini NaCl-a. Za fotoelektrokemijsku karakterizaciju korištene su sljedeće metode: LSV, EIS, OCP i MS analiza. Na temelju rezultata i izračunom konstante rekombinacije fotogeneriranih naboja, za daljnja istraživanja odabran je kompozit označen s TSG 60, koji je podvrgnut ispitivanjima u 0,1 M otopini NaCl-a uz dodatak različitih sredstava koji djeluju kao elektron-donori i na taj način utječu na smanjenje konstante rekombinacije unutar sintetiziranih kompozitnih materijala. Korišteni su etilen-glikol, metanol i trietanolamin u različitim volumnim udjelima. Najmanja konstanta rekombinacije fotogeneriranih naboja, kr = 0,007 s^-1, postignuta je u 20 vol % otopini metanola u NaCl-u, što ukazuje da u kompozitnom materijalu postoji dobar sinergistički učinak koji omogućuje dobro razdvajanje i prijenos naboja što smanjuje stopu rekombinacije naboja.

Abstract (english)

Excessive use of non-renewable energy sources encourages the introduction of alternative fuels, especially hydrogen by the application of photocatalytic water splitting employing solar energy irradiation. Numerous efforts have been made in the attempt to develop effective photocatalysts with a wide range of solar radiation activity. One of the most widely used photocatalytic materials is TiO2 which, despite its many advantages, has limitations such as rather large band gap energy (Eg). A potential solution for its improvement lies in designing composite materials of TiO2 with other photocatalysts active under visible light radiation. This work carried out a detailed photoelectrochemical characterization of composite materials based on TiO2, specifically TiO2-SnS2/GO-RGO with different proportions of GO-RGO, and for the complete comparison, the individual components of this composite were analyzed. Immobilized photocatalysts on FTO substrates were used as electrodes, while all measurements were performed in 0.1 M NaCl solution. The following methods were used for photoelectrochemical characterization: LSV, EIS, OCP and MS analysis. Based on the results and the calculation of the recombination constant of photogenerated charges, a TSG 60-labeled composite was selected for further research, which was tested in 0.1 M NaCl solution with the addition of various agents that act as electron donors and thus reduce recombination constants within the synthesized composite materials. Ethylene glycol, methanol and triethanolamine were used in different volumes. The lowest recombination constant of photogenerated charges, kr = 0.007 s^-1, was achieved in a 20 vol% solution of methanol in NaCl, indicating that there is a good synergistic effect in the composite material that allows good charge separation and transfer which reduces the charge recombination rate.

• Keywords: proizvodnja vodika; cijepanje vode; TiO2; kompozitni materijali; fotoelektrokemijska karakterizacija
• Keywords (english): hydrogen production; water splitting; TiO2; composite materials; photoelectrochemical characterization
• Language: croatian
• URN:NBN: urn:nbn:hr:149:424274
• Project: Number: IP-2018-01-1982; Title: Nano-katalizatori aktivirani Sunčevim zračenjem u tehnologijama zaštite okoliša; Title: Nano-sized solar-active catalysts for environmental technologies; Acronym: NaSCEnT; Leader: Hrvoje Kušić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Environmental Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka ekoinženjerstva (magistar/magistra inženjer/inženjerka ekoinženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2023-04-21 11:49:08