N-Doped titanium dioxide nanosheets: Preparation, characterization and UV/visible-light activity

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F18%3A00490488" target="_blank" >RIV/61388955:_____/18:00490488 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61388980:_____/18:00490488 RIV/60461373:22310/18:43917375

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.apcatb.2018.03.053" target="_blank" >http://dx.doi.org/10.1016/j.apcatb.2018.03.053</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.apcatb.2018.03.053" target="_blank" >10.1016/j.apcatb.2018.03.053</a>

Jazyk výsledku

angličtina

Název v původním jazyce

N-Doped titanium dioxide nanosheets: Preparation, characterization and UV/visible-light activity

Popis výsledku v původním jazyce

A series of nitrogen-doped 2D-titanium dioxide nanosheets was synthesized via green and facile procedure from the lyophilized aqueous colloids of peroxo titanic acid by urea addition and annealing in the temperature range of 350-500 degrees C. Detailed structural characterization (SEM, TEM with EDX, XRD) of N-doped TiO2 confirmed their 2D-foil morphology composed of packed anatase nanocrystals. CHNS analysis showed that the total nitrogen content in the N-doped TiO2 nanosheets is comparable (0.3 wt. %), and as shown in the EPR measurements in solid state, the annealing temperature determines the character of the nitrogen species incorporated in the anatase lattice. Paramagnetic nitrogen bulk centers (N-b(.)) dominate the X- and Q-band EPR spectra of the synthesized N-doped TiO2 annealed up to 400 degrees C, while NO species were detected in samples annealed at higher temperatures. The photoexcitation of the N-doped anatase nanosheets resulted in an intense increase of the N-b(.) signal intensity, especially upon VIS-light exposure, reflecting the selective photoexcitation of the material via diamagnetic N-b(-), centers. Nevertheless, the situation upon irradiation of dispersed systems is rather different and to link the information on the structure of the nanosheets with their photoinduced performance in suspensions, the indirect techniques of EPR spectroscopy were applied. Effective generation of paramagnetic reactive oxygen species (ROS) upon UV photoexcitation of the N-doped TiO2 nanopowders dispersed in water or dimethylsulfoxide was confirmed by EPR spin trapping technique. The VIS-light-induced ROS formation was significantly lower and correlates well with the results obtained by the photocatalytic decomposition of 4-chlorophenol upon VIS light. Even though the center dot OH-induced capacity of N-doped TiO2 prevails upon UV exposure, the VIS irradiation evokes the formation of photoelectrons capable of the selective reduction processes as demonstrated by the one-electron reduction of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) radical cation, where the form of nitrogen dopant (e. g. the presence of N-b(-)/N-b(.)) in the anatase structure showed a clear effect on the reaction rate. The prepared visible-light active N-doped TiO2 nanosheets exhibiting also adequate UV photoactivity represent promising materials for further development of solar-light active photocatalysts.

Název v anglickém jazyce

N-Doped titanium dioxide nanosheets: Preparation, characterization and UV/visible-light activity

Popis výsledku anglicky

A series of nitrogen-doped 2D-titanium dioxide nanosheets was synthesized via green and facile procedure from the lyophilized aqueous colloids of peroxo titanic acid by urea addition and annealing in the temperature range of 350-500 degrees C. Detailed structural characterization (SEM, TEM with EDX, XRD) of N-doped TiO2 confirmed their 2D-foil morphology composed of packed anatase nanocrystals. CHNS analysis showed that the total nitrogen content in the N-doped TiO2 nanosheets is comparable (0.3 wt. %), and as shown in the EPR measurements in solid state, the annealing temperature determines the character of the nitrogen species incorporated in the anatase lattice. Paramagnetic nitrogen bulk centers (N-b(.)) dominate the X- and Q-band EPR spectra of the synthesized N-doped TiO2 annealed up to 400 degrees C, while NO species were detected in samples annealed at higher temperatures. The photoexcitation of the N-doped anatase nanosheets resulted in an intense increase of the N-b(.) signal intensity, especially upon VIS-light exposure, reflecting the selective photoexcitation of the material via diamagnetic N-b(-), centers. Nevertheless, the situation upon irradiation of dispersed systems is rather different and to link the information on the structure of the nanosheets with their photoinduced performance in suspensions, the indirect techniques of EPR spectroscopy were applied. Effective generation of paramagnetic reactive oxygen species (ROS) upon UV photoexcitation of the N-doped TiO2 nanopowders dispersed in water or dimethylsulfoxide was confirmed by EPR spin trapping technique. The VIS-light-induced ROS formation was significantly lower and correlates well with the results obtained by the photocatalytic decomposition of 4-chlorophenol upon VIS light. Even though the center dot OH-induced capacity of N-doped TiO2 prevails upon UV exposure, the VIS irradiation evokes the formation of photoelectrons capable of the selective reduction processes as demonstrated by the one-electron reduction of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) radical cation, where the form of nitrogen dopant (e. g. the presence of N-b(-)/N-b(.)) in the anatase structure showed a clear effect on the reaction rate. The prepared visible-light active N-doped TiO2 nanosheets exhibiting also adequate UV photoactivity represent promising materials for further development of solar-light active photocatalysts.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10301 - Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)

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

2018

Kód důvěrnosti údajů

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

Název periodika

Applied Catalysis B - Environmental

ISSN

0926-3373

e-ISSN

—

Svazek periodika

232

Číslo periodika v rámci svazku

SEP

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

397-408

Kód UT WoS článku

000434004300044

EID výsledku v databázi Scopus

2-s2.0-85044611201