Ispitivanje efikasnosti PEDOT/TiO2 kompozitnog fotokatalizatora pri različitom opterećenju voda onečišćenih Acid Blue 25 bojilom

undergraduate thesis

• Title (english): Testing the efficiency of PEDOT/TiO2 composite photocatalyst at different load of Acid Blue 25 dye contaminant in water
• Author: Tina Posedi
• Mentor: Zlata Hrnjak-Murgić (mentor)
• Committee member: Zlata Hrnjak-Murgić (predsjednik povjerenstva)
• Committee member: Zvonimir Katančić (član povjerenstva)
• Committee member: Suzana Sopčić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2017-09-21, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering; Chemical Engineering in Material Development

Abstract

Fotokataliza je jedna od kemijskih metoda obrade otpadnih voda koje su često opterećene raznim organskim spojevima. Proces fotokatalize uključuje razgradnju onečišćenja uz prisutnost fotokatalizatora pod utjecajem svjetlosti. Jedan od najčešćih fotokatalizatora je TiO2, ali zbog široke zabranjene zone aktivan je samo pod UV svjetlom. Kao aktivatori TiO2 koriste se elektrovodljivi polimeri koji imaju malu širinu zabranjene zone i zbog toga apsorbiraju vidljivi dio zračenja te proširuju fotokatalitičku aktivnost u vidljivi dio spektra. U radu su sintetizirani nanokompozitni fotokatalizatori elektrovodljivog polimera poli(3,4-etilendioksitiofen) i titanijevog oksid (PEDOT-TiO2) metodom kemijske oksidacijske polimerizacije uz prisutnosti FeCl3 kao oksidansa. Omjeri EDOT-a i TiO2 prilikom sinteze bili su 1:2, 1:3, 1:4, 1:5, 1:10 i 1:20 zbog čega nastali kompoziti imaju različiti sastav. Sintetizirani fotokatalizatori karakterizirani su mjerenjem elektrovodljivosti metodom četiri točke i ispitivanjem morfološke strukture pretražnom elektronskom mikroskopijom (SEM). Fotokatalitička aktivnost ispitana je praćenjem razgradnje Acid Blue 25 bojila (γ = 30 mg/L) u vodi uz prisutnost simuliranog Sunčevog zračenja i određivanjem apsorbancije na UV/ViS spektrofotometru. Nanokompozitni fotokatalizator PEDOT-TiO2 omjera 1:20 upotrijebljen je za određivanje fotokatalitičke aktivnosti i ukupnog organskog ugljika (TOC) za različite koncentracije AB25 bojila (20, 30, 40, 60 mg/L). Rezultati ispitivanja pokazali su da se povećanjem koncentracije Acid Blue 25 bojila smanjuje fotokatalitička aktivnost nanokompozitnog fotokatalizatora PEDOT-TiO2 omjera 1:20. Također, smanjuje se i prividna brzina razgradnje.

Abstract (english)

Photocatalysis is one of the chemical methods used for treatment of wastewaters, usually loaded with differentorganic compounds. Photocatalysis process involves pollutant degradation in the presence of the photocatalyst under light irradiation. Most widely used photocatalyst is TiO2, but because of its wide band gap it is active only under UV light. Conductive polymers have low band gap, they absorb visible light irradiation and therefore can be used as TiO2 activator, extending its activity to visible part of the spectrum. In this work the nanocomposite photocatalysts of conductive polymer poly(3,4-ethylenedioxythiophene) and titanium oxide (PEDOT-TiO2) were synthesized with FeCl3 oxidant by chemical oxidative polymerization. Composites were synthesized with ratios of EDOT:TiO2 during synthesis of 1:2, 1:3, 1:4, 1:5, 1:10 and 1:20 which resulted in different composition of obtained photocatalysts. They were characterized by measuring the conductivity with four point probe test and determination of morphological structure by scanning electron microscope (SEM). The photocatalytic activity was investigated by monitoring the removal of Acid Blue 25 dye (γ = 30 mg/L) in water under the simulated solar irradiation and by determining absorbance on the UV/Vis spectrophotometer. Nanocomposite photocatalyst PEDOT-TiO2 1:20 was used to determine photocatalytic activity and total organic carbon (TOC) for different concentrations of AB25 dye (20, 30, 40, 60 mg/L). The results showed that higher concentration of Acid Blue 25 dye caused lower photocatalytic activity of nanocomposite photocatalyst PEDOT-TiO2 1:20. The apparent rate of degradation was also decreasing.

• Keywords: otpadne vode; fotokataliza; poli(3 4-etilendioksitiofen); kompozitni fotokatalizator; Acid Blue 25 bojilo
• Keywords (english): wastewaters; photocatalyst; poly(3 4-ethylenedioxythiophene); composite photocatalyst; Acid Blue 25 dye
• Language: croatian
• URN:NBN: urn:nbn:hr:149:175369
• Study programme: Title: Chemical Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-03-18 12:50:44