Priprema i ispitivanje višekomponentnih fotokatalizatora

undergraduate thesis

• Title (english): Preparation and investigation of multicomponent photocatalyst activity
• Author: Lucia Župan
• Mentor: Marin Kovačić (mentor)
• Committee member: Marin Kovačić (predsjednik povjerenstva)
• Committee member: Zvonimir Katančić (član povjerenstva)
• Committee member: Marijana Kraljić Roković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2020-07-10, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Farmaceutska onečišćivala predstavljaju značajni ekološki problem u svijetu. Nova onečišćivala poput diklofenaka (DCF), sveprisutna su u različitim vodenim tokovima, što može ugroziti kvalitetu vode. Nova onečišćivala ne mogu se ukloniti konvencionalnim metodama obrade te se sve veća pažnja usmjerava na fotokatalitičke procese. Fotokataliza je proces razgradnje onečišćujućih tvari pod utjecajem ultraljubičastog i vidljivog zračenja uz prisutnost fotokatalizatora na kojem dolazi do adsorpcije tih tvari i njihove razgradnje djelovanjem radikalskih vrsta na površini fotokatalizatora. U ovom radu ispitana je fotokatalitička razgradnja diklofenaka (DCF-a) pod simuliranim Sunčevim zračenjem pomoću greigita (Fe3S4), dobivenog sintezom u etilen glikolu (Fe3S4 EG) i smjesi etilen-glikola te vode (Fe3S4 EG:H2O), sol-gel (SG) i hidrotermalnim (HT) postupkom. Greigit je zanimljiv zbog male širine zabranjene zone i magnetičnosti. Sol-gel postupak nije se pokazao uspješnim dok je hidrotermalna metoda bila uspješna. Konverzija DCF-a iznosi 18,7 % (Fe3S4 EG HT), dok se Fe3S4 EG:H2O nije pokazao aktivnim za uklanjanje diklofenaka. Rezultati FTIR spektroskopije pokazuju da je Fe3S4 EG nakon fotokatalize pod simuliranim Sunčevim zračenjem nepromijenjen i spreman za ponovnu upotrebu. U svrhu daljnjeg poboljšanja fotokatalitičke aktivnosti, ispitana je priprema kompozita Fe3S4-TiO2 hidrotermalnom i sol-gel metodom. Međutim, nije postignut cilj poboljšanja aktivnosti, najvjerojatnije zbog lošeg Fe3S4-TiO2 međufaznog kontakta.

Abstract (english)

Pharmaceutical contaminants pose a significant environmental problem in the world. New pollutants, such as diclofenac (DCF), are ubiquitous in a variety of watercourses, which can compromise water quality. New contaminants cannot be removed by conventional treatment methods and increasing attention is being paid to photocatalytic processes. Photocatalysis is a process for the decomposition of pollutants under the influence of ultraviolet and visible radiation in the presence of photocatalysts. The first step is the adsorption of these substances on the surface of the photocatalyst and then their decomposition by the action of photogenerated radical species. Within this work, the photocatalytic decomposition of diclofenac (DCF) under simulated solar radiation using greigite (Fe3S4), obtained by synthesis in ethylene glycol (Fe3S4 EG) and a mixture of ethylene glycol and water (Fe3S4 EG: H2O) using sol-gel (SG) and hydrothermal (HT) methods, was observed. Greigite is an interesting photocatalyst candidate because of its small bandgap and magnetism. The sol-gel method did not prove to be successful while the hydrothermal method was successful. DCF conversion was 18.7% (Fe3S4 EG HT), while Fe3S4 EG:H2O has not shown activity for diclofenac removal. The results of FTIR spectroscopy show that Fe3S4 EG after photocatalysis under simulated solar radiation is unchanged and ready for reuse. To further improve the photocatalytic activity, the preparation of Fe3S4-TiO2 composite by hydrothermal and sol-gel methods was investigated. However, the aim of improving activity was not achieved, most likely due to poor Fe3S4-TiO2 interphase contact.

• Keywords: fotokataliza; višekomponentni fotokatalizator; titanijev dioksid; željezov sulfid
• Keywords (english): photocatalysis; composite photocatalyst; titanium dioxide; iron sulfide
• Language: croatian
• URN:NBN: urn:nbn:hr:149:558409
• 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 - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka ekoinženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka ekoinženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2023-05-09 12:21:26