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

SYSNO ASEP	0466295
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	2D-Titanium dioxide nanosheets modified with Nd, Ag and Au: Preparation, characterization and photocatalytic activity
Author(s)	Pližingrová, Eva (UACH-T)_{SAI, ORCID} Klementová, Mariana (UACH-T)_{RID, SAI, ORCID} Bezdička, Petr (UACH-T)_{SAI, RID, ORCID} Boháček, Jaroslav (UACH-T)_SAI Barbieriková, Z. (SK) Dvoranová, D. (SK) Mazúr, M. (SK) Krýsa, J. (CZ) Šubrt, Jan (UACH-T)_{SAI, RID} Brezová, V. (SK)
Number of authors	10
Source Title	Catalysis Today. - : Elsevier - ISSN 0920-5861 Roč. 281, MAR (2017), s. 165-180
Number of pages	16 s.
Language	eng - English
Country	NL - Netherlands
Keywords	Modified titanium dioxide ; Photocatalysis ; Plasmonic effect ; EPR spectroscopy ; Lyophilization ; Spin trapping
Subject RIV	CA - Inorganic Chemistry
OECD category	Inorganic and nuclear chemistry
R&D Projects	GA14-20744S GA ČR - Czech Science Foundation (CSF)
	7AMB14SK178 GA MŠMT - Ministry of Education, Youth and Sports (MEYS)
Institutional support	UACH-T - RVO:61388980
UT WOS	000390515800019
EID SCOPUS	84995639322
DOI	10.1016/j.cattod.2016.08.013
Annotation	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.
Workplace	Institute of Inorganic Chemistry
Contact	Jana Kroneislová, krone@iic.cas.cz, Tel.: 311 236 931
Year of Publishing	2017

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