diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje
Tija Mrak (Author), Matjaž Finšgar (Mentor), Gregor Žerjav (Co-mentor)

Abstract

Namen diplomskega dela je bila mehanska sinteza kompozitov g-C3N4/TiO2 (grafitni ogljikov nitrid/titanov dioksid) ter preučiti vpliv frekvence in čas mletja v krogličnem mlinu na fotokatalitsko oksidacijo bisfenola A (BPA) ob osvetljevanju z vidno svetlobo. G-C3N4 smo sintetizirali s preprosto enostopenjsko kalcinacijo diciandiamida (DCDA) v zraku. Kompozite smo pripravili z mletjem komercialnega TiO2 in g-C3N4 v krogličnem mlinu v masnem razmerju 1 : 1 pri različni frekvenci in času mletja. Lastnosti sintetiziranih kompozitov smo preučili z različnimi analitskimi metodami, kot so: infrardeča spektroskopija, rentgenska praškovna difrakcija, dušikova fizisorpcija, termogravimetrična analiza, temperaturno programirana desorpcija, UV-Vis difuzna refleksija in fotoluminiscenca. S pomočjo lovilcev reaktivnih kisikovih vrst (ROS) kumarin in ABTS smo ovrednotili sposobnost sintetiziranih fotokatalizatorjev za tvorbo ROS ob osvetljevanju z vidno svetlobo. Možnost uporabe sintetiziranih kompozitov za remediacijo odpadnih voda smo preverili na fotooksidaciji motilca endokrinega sistema BPA kot modelnega onesnaževala. Ugotovili smo, da je najbolj aktiven kompozit za razgradnjo BPA z najmanjšim prepovedanim pasom Tija1, ki smo ga mleli 15 minut pri frekvenci 15 Hz. Krajši čas mletja pri nižjih frekvencah namreč izboljša stično površino med komponentama, kar izboljša dinamiko prenosa nosilcev naboja, hkrati pa ohrani višjo specifično površino in nižjo vrednost prepovedanega pasu. Višja frekvenca in daljši čas mletja namreč pomembno spremenita strukturi TiO2 in g-C3N4, s čimer smo potrdili hipotezo, da imata čas in frekvenca mletja vpliv na morfološke, strukturne in elektronske lastnosti kompozitov.

Keywords

TiO2;g-C3N4;kompoziti;fotokatalizatorji;karakterizacija;diplomske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [T. Mrak]
UDC: 544.526.5(043.2)
COBISS: 132493571 Link will open in a new window
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Downloads: 34
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Other data

Secondary language: English
Secondary title: Application of a mechanical-chemical synthesis process for the preparation of TiO2/g-C3N4 photocatalysts used in advanced oxidation processes for wastewater treatment
Secondary abstract: The aim of this thesis was the mechanical synthesis of composites g-C3N4/TiO2 (graphitic carbon nitride/titanium dioxide) and to study the influence of the frequency and the time of grinding in a ball mill on the photocatalytic oxidation of bisphenol A (BPA) under visible light illumination. We synthesized g-C3N4 by simple one-step calcination of dicyandiamide (DCDA) in the air. We prepared the composites by grinding commercial TiO2 and g-C3N4 in a ball mill at a mass ratio of 1 : 1 at different grinding frequencies and times. We studied the characteristics of the synthesized composites using various analytical methods, such as infrared spectroscopy, X-ray powder diffraction, nitrogen physisorption, thermogravimetric analysis, temperature-programmed desorption, UV-Vis diffuse reflection, and photoluminescence. Utilizing reactive oxygen species (ROS) coumarins and ABTS catchers, we evaluated the ability of the synthesized photocatalysts to generate ROS upon illumination with visible light. We tested the possibility of using synthesized composite photocatalysts for wastewater remediation on the photooxidation of the endocrine system disruptor BPA as a model pollutant. We ascertained that the most active BPA-degrading composite with the smallest band gap was Tija1 which we milled for 15 minutes at the frequency of 15 Hz. Namely, a shorter grinding time at lower frequencies improves the contact surface between the components, which improves the dynamics of the transfer of charge carriers while, at the same time, maintaining a higher specific surface area and a lower value of the forbidden band. Higher frequency and longer grinding time change the structures of TiO2 and g-C3N4 significantly by which we confirmed the hypothesis that grinding time and frequency influence the morphological, structural, and electronic properties of composites.
Secondary keywords: TiO2;g-C3N4;composites;photocatalyst;characterization;
Type (COBISS): Bachelor thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: 1 spletni vir (1 datoteka PDF (X, 39 f.))
ID: 16222842