Sinteza in uporaba fotokatalizatorjev v naprednih oksidacijskih postopkih za oksidativno razgradnjo organskih onesnažil v odpadnih vodah

magistrsko delo

Marcel Žafran (Author), Matjaž Finšgar (Mentor), Gregor Žerjav (Co-mentor)

Abstract

Namen magistrskega dela je bila sinteza fotokatalizatorjev z uporabo nosilcev g-C3N4 ali TiO2, pri čemer smo v sistem vpeljali Pt, ki izkazuje pojav lokalizirane površinske plazmonske resonance. Tako pripravljene fotokatalizatorje smo uporabili za proučevanje fotokatalitske aktivnosti v vodi raztopljenega organskega onesnažila bisfenola A (BPA), nadalje pa smo najoptimalnejšega med g-C3N4 preizkusili še za fotokatalitsko razgradnjo aktivnih farmacevtskih učinkovin (paracetamola, acetilsalicilne kisline in kofeina) v odpadnih vodah. Z raziskavami smo se osredotočili na karakterizacijo katalizatorjev pred in po uporabi v heterogenih fotokatalitskih oksidacijskih procesih s poudarkom na podrobnem proučevanju strukturnih, elektronskih in optičnih lastnosti razvitih materialov. Omenjene lastnosti sintetiziranih materialov smo preverili z naslednjimi analitskimi tehnikami: infrardečo spektroskopijo s Fourierovo transformacijo na oslabljen totalni odboj, rentgensko praškovno difrakcijo, dušikovo fizisorpcijo, fotoluminiscenco in UV Vis difuzno refleksijo. Na osnovi lovilca reaktivnih kisikovih vrst – kumarina, smo sintetiziranim fotokatalizatorjem ocenili sposobnost tvorbe hidroksilnih radikalov. Fotokatalitsko aktivnost preiskovanih vzorcev smo spremljali s testom fotooksidacije modelnega onesnažila BPA pri osvetljevanju z vidno svetlobo. V sklopu opravljenih analiz smo izvedli še meritve celokupnega ogljika v organskih snoveh, CHNS-elementno analizo in določitev stopnje razgradnje s tehniko tekočinske kromatografije visoke ločljivosti. Ugotovili smo, da z depozicijo plazmonske Pt na površino osnovnih nosilcev g-C3N4 ali TiO2 zmanjšamo možnost rekombinacije nosilcev naboja, razširimo absorpcijski spekter TiO2 na področje vidne svetlobe in povečamo fotokatalitsko aktivnost katalizatorjev pri razgradnji BPA. Potrdili smo, da se z večanjem specifične površine g-C3N4 povečuje tudi njegova fotoaktivnost. Z združenjem vzorcev MR12 + 1-% Pt in TNR + 1-% Pt smo dognali, da izkazujeta sinergijski učinek.

Keywords

TiO2;g-C3N4;heterogena fotokataliza;plazmonska kovina;bisfenol A;karakterizacija;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2023
Typology:	2.09 - Master's Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
UDC:	544.526.5:[628.349:66.094.3](043.2)
COBISS:	165527299
Views:	100
Downloads:	26
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Synthesis and application of photocatalysts in advanced oxidation processes for the oxidative degradation of organic pollutants in wastewater
Secondary abstract:	The aim of this master thesis was to synthesise photocatalysts on g-C3N4 or TiO2 supports, introducing Pt into the system, which exhibits the phenomenon of localised surface plasmon resonance. The photocatalysts prepared in this way were used to study the photocatalytic activity of the organic pollutant bisphenol A (BPA) dissolved in water, and the most optimal among the g-C3N4 was further tested for the photocatalytic degradation of active pharmaceutical ingredients (paracetamol, acetylsalicylic acid, and caffeine) in wastewater. Our research focused on the characterization of the catalysts before and after their use in heterogeneous photocatalytic oxidation processes, with emphasis on a detailed study of the structural, electronic, and optical properties of the developed materials. The above properties of the synthesised materials were verified by the following analytical techniques: attenuated total reflectance Fourier transform infrared spectroscopy, X-ray powder diffraction, nitrogen physisorption, photoluminescence, and UV-Vis diffuse reflectance. Based on the reactive oxygen species scavenger coumarin, the synthesised photocatalysts were evaluated for their ability to form hydroxyl radicals. The photocatalytic activity of the investigated samples was monitored by a photooxidation test of the model pollutant BPA under visible light illumination. As part of the analyses performed, measurements of total organic carbon, CHNS elemental analysis, and determination of the rate of degradation by high-performance liquid chromatography were also performed. We found that the deposition of plasmonic Pt on the surface of g-C3N4 or TiO2 base supports reduces the possibility of charge carrier recombination, extends the absorption spectrum of TiO2 into the visible light region, and increases the photocatalytic activity of the catalysts in the degradation of BPA. We confirmed that as the specific surface area of g-C3N4 increases, the photoactivity also increases. By combining MR12 + 1 % Pt and TNR + 1 % Pt, we found that they have a synergistic effect.
Secondary keywords:	TiO2;g-C3N4;heterogeneous photocatalysis;plasmonic metal;bisphenol A;characterization;
Type (COBISS):	Master's thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	1 spletni vir (1 datoteka PDF (XII, 56 f.))
ID:	19825097