Fotokatalitski filter na osnovi TiO2 za čiščenje zraka

magistrsko delo

Luka Romanić (Author), Matjaž Finšgar (Mentor), Regina Fuchs-Godec (Co-mentor), Dejan Verhovšek (Co-mentor)

Abstract

Čiščenje zraka je vedno bolj bistvenega pomena, saj poskrbimo za zdravo bivalno okolje, ustreznost zakonodajnim zahtevam in nenazadnje znižanje družbenih stroškov. Lahkohlapne organske spojine (VOC) so prepoznane kot eno glavnih onesnažil zraka. Znaten vpliv imajo tudi na kakovost zraka v zaprtih prostorih. Dolgotrajna izpostavljenost tem toksičnim snovem, pa predstavlja tako grožnjo za zdravje ljudi, kot za ravnovesje ekosistemov. Fotokataliza je ena izmed številnih ukrepov za reševanje tega problema. Tekom naše študije smo preučili tri različne komercialno dostopne tipe fotokatalizatorja (CCA 100BS, CCR 200N in S5 300B) na osnovi titanovega dioksida (TiO2). Preučili smo lastnosti materialov, ki vplivajo na fotokatalitsko aktivnost TiO2 kot katalizatorja. Ker smo želeli pridobiti mehansko dovolj stabilne vzorce smo fotokatalizator imobilizirali na dva različna tipa nosilca. Na ploščice anodiziranega aluminija različnih hrapavosti in na keramično peno različne poroznosti. Kot vezivo smo uporabili peroksotitanovo kislino (PTK), v katero smo vmešali vsak tip fotokatalizatorja posebej, tako da smo dobili suspenzijo (UF TiO2 + PTK), različnih masnih koncentracij γ(TiO2) = 5, 10, 20 in 40 g/L. S potopitveno metodo smo nato oslojili nosilce. Fotokatalitska aktivnost tvorjene plasti (UF TiO2 + PTK) na substratih, je bila ocenjena na podlagi fotorazgradnje izopropanola in acetona, kot modelnih VOC pod UV/VIS svetlobo v pretočnem fotoreaktorju. Za primerjavo in potrditev fotokatalitske aktivnosti pripravljenih substratov, smo izvedli še elektrokemijsko analizo vzorcev anodiziranega aluminija, potopljenih v tri odstotni raztopini NaCl. To smo izvedli z merjenjem impedance v prisotnosti UV-svetlobe in brez UV-svetlobe, v različnih časovnih intervalih od 1, 3, 5, 7 do 10 ur. Z vrstičnim elektronskim mikroskopom smo analizirali morfologijo tvorjene plasti. Ugotovili smo, da je plast kompaktna in da se z višanjem koncentracije fotoatalizatorja viša fotokatalitska aktivnost substrata. Prav tako se z višanjem specifične površine substrata, viša tudi fotokatalitska učinkovitost. Preučevani materiali so izkazali primerno visoko fotokatalitsko učinkovitost in tako kažejo potencial kot filtri za čiščenje zraka.

Keywords

titanov dioksid;TiO2;fotokataliza;lahkohlapne organske spojine;elektrokemijska impedančna spektroskopija;peroksotitanova kislina;meritev fotokatalitske aktivnosti;magistrske naloge;

Data

Language:	Slovenian
Year of publishing:	2018
Typology:	2.09 - Master's Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[L. Romanić]
UDC:	66.067.11:62-73(043.2)
COBISS:	21928726
Views:	1372
Downloads:	189
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	TiO2 based photocatalytic filter for air purification
Secondary abstract:	Air purification has become vital, since we thereby ensure a healthy living environment, the adequacy of regulatory requirements, and, finally, a reduction in social costs. Volatile organic compounds (VOC) have been recognised as one of the main air pollutants. They are also known to have a significant impact on indoor air quality. Long-term exposure to these toxic substances presents both a threat to human health and to the balance of ecological systems. Photocatalysis is one of many measures for solving this problem. During our research, three different types of commercially available photocatalysts (CCA 100BS, CCR 200N and S5 300B) based on titanium dioxide (TiO2) were studied. We investigated the properties of the materials that influenced the photocatalytic activity of TiO2 as a catalyst. Since we wanted to obtain mechanically sufficiently stable samples, the photocatalyst was immobilized on two different carriers. On the tiles of anodized aluminium of various roughness and on ceramic foam of various porosities. Peroxotitan acid (PTA) was used as a binder, with which each type of photocatalyst was mixed so that a suspension (UF TiO2 + PTA) of various mass concentrations γ(TiO2) = 5, 10, 20 in 40 g/L was obtained. The carriers were then coated by the immersion method. Photocatalytic activity of the formed layers (UF TiO2 + PTA) on substrates was evaluated based on the photodegradation of isopropanol to acetone as a model VOC under UV/ VIS light in a flow photoreactor. In order to compare and confirm the photocatalytic activity of our substrates, an electrochemical analysis of anodized aluminium samples immersed in 3 wt.% NaCl solution was performed. This was accomplished by measuring the impedance response under the UV light and without it, at different time intervals of 1, 3, 5, 7 to 10 hours. With a scanning electron microscope, we examined the morphology of the created layers in detail. We found that the layer is compact and that the photocatalytic activity of the substrate gets higher by increasing the concentration of the photocatalyst. Also, the increase in the specific surface of the substrate increases the photocatalytic efficiency. All materials showed an appropriate high photocatalytic efficiency and therefore can be used as air purifying filters.
Secondary keywords:	titanum dioxide;photocatalysis;volatile organic compounds;electrochemical impedance spectroscopy;peroxotitanic acid;photocatalytic activity measurements;
URN:	URN:SI:UM:
Type (COBISS):	Master's thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	X, 47 f.
ID:	10956016