Primjena metalni oksid/rGO elektroda u fotoelektrokemijskoj razgradnji farmaceutika

undergraduate thesis

• Title (english): Application of metal oxide/rGO electrodes for the photoelectrocatalytic degradation of pharmaceuticals
• Author: Marija Lovrić
• Mentor: Marijana Kraljić Roković (mentor)
• Committee member: Marijana Kraljić Roković (predsjednik povjerenstva)
• Committee member: Marin Kovačić (član povjerenstva)
• Committee member: Irena Ivanišević (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-21, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Cilj ovog rada je bio ispitati ponašanje fotokatalizatora TiO2 i TiO2/SnS2 u otopini fosfatnog pufera sa i bez vitamina C koncentracija od 0.1 mmol dm^-3 do 10 mmol dm^-3. Mjerenja su provedena za osvijetljene i neosvijetljene elektrode, a izvor svjetla su bile UVA i LED lampa. Metode koje su korištene za ispitivanje ovih materijala su linearna polarizacija, elektrokemijska impedancijska spektroskopija, Mott-Schottky analiza i potencijal otvorenog kruga. Rezultati su pokazali da su u prisutnost svjetla dobivene fotostruje te da one rastu uz dodatak C vitamina što nam ukazuje da je došlo do uspješnog razdvajanja parova elektron-šupljina i da vitamin C sprječava njihovu rekombinaciju, odnosno da je dobar hvatača šupljina (''hole scavenger''). Impedancijska mjerenja su pokazala da su otpori prolasku struje manji u sustavu u kojem je prisutan C vitamin te da se smanjuju s porastom koncentracije C vitamina. Mott-Schottky analizom dobili smo uvid o djelovanju C vitamina na potencijal ravnih vrpci. U slučaju TiO2 elektrode dodatak C vitamina pomiče potencijal ravnih vrpci prema pozitivnim vrijednostima, dok je u slučaju TiO2/SnS2 zabilježeno obrnuto ponašanje. Ispitivanje provedeno praćenjem potencijala otvorenog kruga pokazalo je kako potencijal ovisi o pH vrijednosti otopine te koncentraciji C vitamina.

Abstract (english)

The purpose of this study was to examine the behavior of photocatalysts TiO2 i TiO2/SnS2 in the phosphate buffer solution with and without vitamin C at concentrations from
0.1 mmol dm^-3 to 10 mmol dm^-3. Measurements were performed for illuminated and dark conditions, with the light source of UVA and LED lamp. The methods used to test these materials were linear polarization, electrochemical impedance spectroscopy, Mott-Schottky analysis, and open circuit potential monitoring. Good photocatalytic activity of electrodes is evident from high photocurrents that additionally increase with the addition of vitamin C. It indicates successful separation of electron-hole pairs and prove vitamin C ability to prevent recombination due to the a good hole scavenger properties. Impedance measurements have shown low resistance in the presence of vitamin C, as well as, that resistance decreases with increasing vitamin C concentration. Mott-Schottky analysis gave us an insight into the effect of vitamin C on the flat band potential. In the case of TiO2 with the addition of vitamin C, the flat band potential shifts towards positive values, while in the case of TiO2/SnS2 the opposite behavior is observed. An examination conducted by monitoring the open-circuit potential showed that the potential depends on the pH of the solution and the concentration of
vitamin C.

• Keywords: elektrokemijske metode karakterizacije; fotoelektrokataliza; fotokataliza; poluvodiči; vitamin C
• Keywords (english): electrochemical characterization methods; photoelectrocatalysis; photocatalysis; semiconductors; vitamin C
• Language: croatian
• URN:NBN: urn:nbn:hr:149:054703
• 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
• Project: Number: KK.01.1.1.04.0001; Title: Pročišćavanje vode i dobivanje energije korištenjem novih kompozitnih materijala uz Sunčevo zračenje; Leader: Hrvoje Kušić; Jurisdiction: eu; Funder: EC; Funding stream: KF
• Study programme: Title: Materials Science and 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: 2023-04-06 12:41:53