Publication detail

Koncepce dynamického aktivního centra v heterogenní fotokatalytické oxidační reakci

KLUSOŇ, P. KRÝSA, J. STAVÁREK, P. HEJDA, S. VYCHODILOVÁ, H. DZIK, P. VESELÝ, M. KRYSTYNÍK, P.

Original Title

English Title

The Concept of a Dynamic Active Site in a Heterogeneous Photocatalytic Oxidation Reaction

Type

journal article in Web of Science

Language

Czech

Original Abstract

Zavedení koncepce dynamického aktivního centra (DAS) v heterogenní fotokatalytické oxidaci umožňuje pro materiály, u nichž byl tento typ reakčního místa identifiko-ván, využít standardní kinetické algoritmy a rovnice použí-vané v heterogenní katalýze. Použití DAS je však z praktických důvodů spíše omezeno na částicové tenké vrstvy, u kterých lze bez větších experimentálních potíží provést světlem indukovaný elektrochemický experiment. Jeho cílem je především vyhodnotit kvalitativní charakter odezvy světlocitlivé vrstvy na přítomnost fotonů. Kvantita-tivní popis je rovněž důležitý, ovšem pro objektivizaci existence DAS není klíčový.

English abstract

In this communication we wished to introduce the concept of a dynamic active site (CDAS) for oxidation of thin films photocatalysts as a certain analogy to the com-mon conceptions of active sites in heterogeneous catalysts. The main intention was to show an experimental algorithm which should be applied if two (or more) different thin film photocatalysts are to be compared in a particular reac-tion. It is unfortunately very common that the performanc-es of two particular photocatalysts are compared and con-clusions are drawn, but such a comparison is incorrect from principle reasons. It was shown here that the exist-ence of a dynamic active site must be validated first for both (or more) catalytic species being compared, and only if it is successful at this stage. standard kinetic data treat-ment and their comparisons are possible. Polarization curves provided by the linear voltammetry (I-E/current-voltage) reflect the ability of the light sensitive semicon-ducting films to generate the carriers (electrons and holes) upon illumination. The stability of the generated photocur-rent level (the plateau) indicates the same rate of the for-mation of charges and their recombination. If this is true, the electrochemical system occurs in the state of dynamic equilibrium. Under model conditions, it is thus possible to assess whether or not a particular photocatalytic material tends to generate h+ species in the same rate as it vanishes. If the answer is positive, the holes h+ might be formally referred to as standard active sites since upon fixed illumi-nation their abundance is constant in time.

Keywords

active centre, reaction rate, photon, transport phenomena, photo-induced activity

Key words in English

active centre, reaction rate, photon, transport phenomena, photo-induced activity

Authors

KLUSOŇ, P.; KRÝSA, J.; STAVÁREK, P.; HEJDA, S.; VYCHODILOVÁ, H.; DZIK, P.; VESELÝ, M.; KRYSTYNÍK, P.

Released

1. 8. 2019

Publisher

CHEMICKE LISTY

Location

PRAGUE

ISBN

0009-2770

Periodical

Chemické listy

Year of study

113

Number

State

Czech Republic

Pages from

391

Pages to

396

Pages count

URL

http://www.chemicke-listy.cz/ojs3/index.php/chemicke-listy/article/view/3383/3341

BibTex

@article{BUT162451,
  author="Petr {Klusoň} and Josef {Krýsa} and Petr {Stavárek} and Stanislav {Hejda} and Hana {Vychodilová} and Petr {Dzik} and Michal {Veselý} and Pavel {Krystyník}",
  title="Koncepce dynamického aktivního centra v heterogenní fotokatalytické oxidační reakci",
  journal="Chemické listy",
  year="2019",
  volume="113",
  number="6",
  pages="391--396",
  issn="0009-2770",
  url="http://www.chemicke-listy.cz/ojs3/index.php/chemicke-listy/article/view/3383/3341"
}