2D-Titanium dioxide nanosheets modified with Nd, Ag and Au: Preparation, characterization and photocatalytic activity

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388980%3A_____%2F17%3A00466295" target="_blank" >RIV/61388980:_____/17:00466295 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/60461373:22310/17:43902227 RIV/60461373:22350/17:43902227

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.cattod.2016.08.013" target="_blank" >http://dx.doi.org/10.1016/j.cattod.2016.08.013</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.cattod.2016.08.013" target="_blank" >10.1016/j.cattod.2016.08.013</a>

Jazyk výsledku

angličtina

Název v původním jazyce

2D-Titanium dioxide nanosheets modified with Nd, Ag and Au: Preparation, characterization and photocatalytic activity

Popis výsledku v původním jazyce

2D-Titanium dioxide nanosheets modified by the addition of Nd, Au and Ag dopant in the first reaction step were synthesized from the lyophilized aqueous colloids of peroxo titanic acid by high-temperature treatment. The concentration of the dopant in the sample was 1 at.% towards Ti. The results of their detailed morphological and phase characterization (SEM, TEM with EDX, XRD) evidenced that annealing temperatures 500, 650 and 800 °C caused the formation of 2D-foils composed of packed anatase nanocrystals samples annealed at 950 °C represent anatase/rutile mixture. While neodymium dopant is built into the structure of anatase causing the changes in the parameters of anatase crystal lattice, such alterations were not found for Au- and Ag-modified samples, with gold or silver nanoparticles dispersed on surface detected by TEM/ED/EDX. Q-band EPR spectra of modified 2D-TiO2 annealed at 800 °C measured at room temperature or 100 K revealed the presence of paramagnetic signals corresponding to Ti(III) centers inside the anatase lattice, along with signals associated with medium-polarized conduction electrons, already before exposure. The photoinduced generation of paramagnetic species (e.g., Ti(III), O−, O2radical dot−) upon UVA exposure of modified 2D-TiO2 was confirmed by X-band EPR spectroscopy. Moreover, EPR spectra evidenced that Au- or Ag-modified samples annealed at 500 °C contained nitrogen paramagnetic species (View the MathML source and NO) coming from the aqueous ammonia used in synthesis, which are responsible for the visible-light activity of these samples. The tests of photocatalytic activity of modified 2D-TiO2 dispersed in water or dimethylsulfoxide performed using EPR spin trapping technique or via the decomposition of 4-chlorophenol showed a decline in UVA photoactivity for all modified titania samples in comparison to the unmodified 2D-TiO2 visible-light activity of modified 2D-TiO2 nanosheets annealed at 800 °C was almost negligible.

Název v anglickém jazyce

2D-Titanium dioxide nanosheets modified with Nd, Ag and Au: Preparation, characterization and photocatalytic activity

Popis výsledku anglicky

2D-Titanium dioxide nanosheets modified by the addition of Nd, Au and Ag dopant in the first reaction step were synthesized from the lyophilized aqueous colloids of peroxo titanic acid by high-temperature treatment. The concentration of the dopant in the sample was 1 at.% towards Ti. The results of their detailed morphological and phase characterization (SEM, TEM with EDX, XRD) evidenced that annealing temperatures 500, 650 and 800 °C caused the formation of 2D-foils composed of packed anatase nanocrystals samples annealed at 950 °C represent anatase/rutile mixture. While neodymium dopant is built into the structure of anatase causing the changes in the parameters of anatase crystal lattice, such alterations were not found for Au- and Ag-modified samples, with gold or silver nanoparticles dispersed on surface detected by TEM/ED/EDX. Q-band EPR spectra of modified 2D-TiO2 annealed at 800 °C measured at room temperature or 100 K revealed the presence of paramagnetic signals corresponding to Ti(III) centers inside the anatase lattice, along with signals associated with medium-polarized conduction electrons, already before exposure. The photoinduced generation of paramagnetic species (e.g., Ti(III), O−, O2radical dot−) upon UVA exposure of modified 2D-TiO2 was confirmed by X-band EPR spectroscopy. Moreover, EPR spectra evidenced that Au- or Ag-modified samples annealed at 500 °C contained nitrogen paramagnetic species (View the MathML source and NO) coming from the aqueous ammonia used in synthesis, which are responsible for the visible-light activity of these samples. The tests of photocatalytic activity of modified 2D-TiO2 dispersed in water or dimethylsulfoxide performed using EPR spin trapping technique or via the decomposition of 4-chlorophenol showed a decline in UVA photoactivity for all modified titania samples in comparison to the unmodified 2D-TiO2 visible-light activity of modified 2D-TiO2 nanosheets annealed at 800 °C was almost negligible.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10402 - Inorganic and nuclear chemistry

Projekt

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

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

Catalysis Today

ISSN

0920-5861

e-ISSN

—

Svazek periodika

281

Číslo periodika v rámci svazku

MAR

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

16

Strana od-do

165-180

Kód UT WoS článku

000390515800019

EID výsledku v databázi Scopus

2-s2.0-84995639322