Ultraviolet photocatalytic degradation of cholesterol on TiO2: secondary ion mass spectrometry

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F17%3A00112484" target="_blank" >RIV/00216224:14310/17:00112484 - isvavai.cz</a>

Výsledek na webu

<a href="https://onlinelibrary.wiley.com/doi/pdf/10.1002/sia.6129" target="_blank" >https://onlinelibrary.wiley.com/doi/pdf/10.1002/sia.6129</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/sia.6129" target="_blank" >10.1002/sia.6129</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Ultraviolet photocatalytic degradation of cholesterol on TiO2: secondary ion mass spectrometry

Popis výsledku v původním jazyce

Cholesterol (C27H46O stated as M) is used as a model of bio-organic contamination, because this compound is in almost every living organism, and its photocatalytic degradation on titanium oxide (TiO2) surface with UV exposure is investigated. Secondary ion mass spectrometry as a surface-sensitive technique is suited to study this degradation process with focus on intermediates. A fragment of M-OH represents the intact molecule of cholesterol and provides its relative concentration on the surface. The intensity of M-OH decreases after 24-h UV irradiation, and the level of degradation is 89% with the pseudo-first kinetic constant of 0.0207min(-1) within 2h. A fragment of MO-H represents an intermediate as one of the cholesterol oxidation products. The irradiation from a bottom in comparison with a top reveals the differences in the mechanism of the intermediate formation through the intensity and the kinetics with values of factor of 1/3 and 30min, respectively. The roles of electrons and holes, primarily generated in TiO2 by UV, and also of superoxide anion radical and hydroxyl radical, as the secondary reactive species, are discussed to illustrate the bottom/top mechanisms.

Název v anglickém jazyce

Ultraviolet photocatalytic degradation of cholesterol on TiO2: secondary ion mass spectrometry

Popis výsledku anglicky

Cholesterol (C27H46O stated as M) is used as a model of bio-organic contamination, because this compound is in almost every living organism, and its photocatalytic degradation on titanium oxide (TiO2) surface with UV exposure is investigated. Secondary ion mass spectrometry as a surface-sensitive technique is suited to study this degradation process with focus on intermediates. A fragment of M-OH represents the intact molecule of cholesterol and provides its relative concentration on the surface. The intensity of M-OH decreases after 24-h UV irradiation, and the level of degradation is 89% with the pseudo-first kinetic constant of 0.0207min(-1) within 2h. A fragment of MO-H represents an intermediate as one of the cholesterol oxidation products. The irradiation from a bottom in comparison with a top reveals the differences in the mechanism of the intermediate formation through the intensity and the kinetics with values of factor of 1/3 and 30min, respectively. The roles of electrons and holes, primarily generated in TiO2 by UV, and also of superoxide anion radical and hydroxyl radical, as the secondary reactive species, are discussed to illustrate the bottom/top mechanisms.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Surface and Interface Analysis

ISSN

0142-2421

e-ISSN

1096-9918

Svazek periodika

49

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

6

Strana od-do

278-283

Kód UT WoS článku

000397496800006

EID výsledku v databázi Scopus

2-s2.0-84981742475