Hidrotermalna sinteza i fotokatalitička aktivnost nanokristalnih čvrstih otopina sustava TiO2-Fe2O3

master's thesis

• Title (english): Hydrothermal synthesis and photocatalytic activity of nanocrystalline solid solutions of the TiO2-Fe2O3 system
• Author: Ivan Marić
• Mentor: Marijan Gotić (mentor)
• Mentor: Goran Štefanić (mentor)
• Committee member: Dubravka Matković-Čalogović (predsjednik povjerenstva)
• Committee member: Davor Kovačević (član povjerenstva)
• Committee member: Sanda Rončević (član povjerenstva)
• Committee member: Biserka Prugovečki (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2018-02-21, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

U ovom diplomskom radu sintetizirane su čvrste otopine sustava TiO2-Fe2O3 hidrotermalnim
tretmanom u velikom rasponu množinskog udjela željezovih iona (do 50 %). Uzorci su
pripravljeni iz vodenih otopina FeCl3·6H2O i TiCl4. Spojevi su analizirani rendgenskom
difrakcijom na prahu, elektronskom mikroskopijom (pretražnom i transmisijskom),
Ramanovom i Mössbauerovom spektroskopijom. Rezultati instrumentalne analize su pokazali
prisutnost dviju kristalnih faza, anatasa i hematita. Rendgenskom analizom pokazano je da se
željezovi ioni ugrađuju u kristalnu rešetku anatasa do množinskog udjela od 8 %, te da se nakon
toga željezovi ioni ugrađuju u hematit. Kako se povećava udio željezovih iona do 20 % tako se
i udio faze hematita povećava, međutim, nakon 20 % se udio hematita smanjuje te se u uzorku
s 25 % primjećuje distorzija kristalne rešetke hematitne faze. Daljnjim povećanjem udjela
željeza hematitna faza se ponovno javlja i njen udio raste. Fotokatalitička aktivnost je ispitana
za uzorke s 1 % i 25 % željeza, no ovi uzorci nisu pokazivali značajnu fotokatalitičku aktivnost
u razgradnji metilenskog modrila u vidljivom dijelu spektra.

Abstract (english)

In this diploma thesis, solid solutions of the TiO2-Fe2O3 system were synthesized by
hydrothermal treatment in a wide-compositional range with up to 50 mol% of iron cations.
The samples were prepared from aqueous solutions of FeCl3·6H2O and TiCl4. The compounds
were analysed by X-ray powder diffraction, electron microscopy (scanning and transmission),
Raman and Mössbauer spectroscopy. The results of instrumental analyses showed that the
crystal phases of the solid solutions are anatase and hematite. X-ray diffraction showed that
iron cations are incorporated in the crystal structure of anatase up to 8 mol%, and after that,
iron cations precipitate in the form of hematite. An increase of the molar fraction of iron cations
up to 20 mol% caused increase of the fraction of the hematite phase. A further increase of the
iron content up to 25 mol% caused a decrease of the hematite phase fraction and distortion of
its crystal lattice. The fraction of the hematite phase increases again with an increase of the ion
content up to 50 mol%. Photocatalytic activity was tested for the samples containing 1 % and
25 % of iron cations, but these samples showed no appreciable photocatalytic activity in
degradation of methylene blue in the visible region of electromagnetic radiation.

• Keywords: čvrste otopine; fotokataliza; hidrotermalna sinteza; metilensko modrilo; nanočestice; titan; željezo
• Keywords (english): hydrothermal synthesis; iron; methylene blue; nanoparticles; photocatalysis; solid solutions; titanium
• Language: croatian
• URN:NBN: urn:nbn:hr:217:813832
• Study programme: Title: Graduate university studies in chemistry; specializations in: Research programme; Course: Research programme; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra kemije (magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2020-02-21
• Created on: 2018-02-27 13:57:13