Surface Reactions and Electronic Structure of Carboxylic Acid Porphyrins Adsorbed on TiO2(110)

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F21%3A10439683" target="_blank" >RIV/00216208:11320/21:10439683 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=ny7lUw5PrD" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=ny7lUw5PrD</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpcc.1c01133" target="_blank" >10.1021/acs.jpcc.1c01133</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Surface Reactions and Electronic Structure of Carboxylic Acid Porphyrins Adsorbed on TiO2(110)

Popis výsledku v původním jazyce

We studied the coverage- and temperature-dependent proton transfer and self-metalation reactions of tetraphenylporphyrin molecules containing a carboxyl functional group (MCTPP) on rutile TiO2(110) surfaces. Furthermore, we also determined changes in the molecular geometric and electronic structures as a function of coverage and temperature. The investigation was carried out by means of synchrotron radiation X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure measurements. We found that at a coverage of 0.2 ML, most MCTPP molecules adsorb with the iminic nitrogen atoms protonated; at 0.5 ML, a decrease in the proportion of protonated molecules is observed; and at a monolayer coverage, most molecules are not protonated. Raising the temperature to above 500 K, where hydroxyl groups recombine to desorb as water, causes a decrease in the number of protonated porphyrin molecules. In roughly the same temperature range, we start to observe the self-metalation of the free-base molecules, which produces flat-lying titanyl porphyrin molecules on the TiO2(110) surface. This reaction is found to be coverage dependent: For 0.2 ML, it starts above 450 K, and for 1.0 ML, temperatures above 650 K are needed. Metalation shifts the surface state located in the semiconductor band gap to lower energies. Our results suggest that protonation and self-metalation depend on the proximity of the macrocycle to the surface and show that metalation modifies the molecular occupied and vacant electronic states.

Název v anglickém jazyce

Surface Reactions and Electronic Structure of Carboxylic Acid Porphyrins Adsorbed on TiO2(110)

Popis výsledku anglicky

We studied the coverage- and temperature-dependent proton transfer and self-metalation reactions of tetraphenylporphyrin molecules containing a carboxyl functional group (MCTPP) on rutile TiO2(110) surfaces. Furthermore, we also determined changes in the molecular geometric and electronic structures as a function of coverage and temperature. The investigation was carried out by means of synchrotron radiation X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure measurements. We found that at a coverage of 0.2 ML, most MCTPP molecules adsorb with the iminic nitrogen atoms protonated; at 0.5 ML, a decrease in the proportion of protonated molecules is observed; and at a monolayer coverage, most molecules are not protonated. Raising the temperature to above 500 K, where hydroxyl groups recombine to desorb as water, causes a decrease in the number of protonated porphyrin molecules. In roughly the same temperature range, we start to observe the self-metalation of the free-base molecules, which produces flat-lying titanyl porphyrin molecules on the TiO2(110) surface. This reaction is found to be coverage dependent: For 0.2 ML, it starts above 450 K, and for 1.0 ML, temperatures above 650 K are needed. Metalation shifts the surface state located in the semiconductor band gap to lower energies. Our results suggest that protonation and self-metalation depend on the proximity of the macrocycle to the surface and show that metalation modifies the molecular occupied and vacant electronic states.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název periodika

Journal of Physical Chemistry C

ISSN

1932-7447

e-ISSN

—

Svazek periodika

125

Číslo periodika v rámci svazku

12

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

8

Strana od-do

6708-6715

Kód UT WoS článku

000636924700020

EID výsledku v databázi Scopus

2-s2.0-85104999874