Introduction of oxygen vacancies and fluorine into TiO2 nanoparticles by co-milling with PTFE

Senna, Mamoru; Šepelák, V.; Shi, Jianmin; Bauer, Benjamin; Feldhoff, Armin; Laporte, Vincent; Becker, Klaus‐Dieter

doi:10.1016/j.jssc.2011.12.036

Cited by 43 publications

(36 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…730 The entire process is triggered by the partial oxidative decomposition of PTFE, accompanied by the abstraction of oxygen from the TiO 2 . This, in turn, results in the formation of the diverse states of locally distorted coordination units of titania, i.e.…”

Section: Role Of Water In Mechanochemistrymentioning

confidence: 99%

Hallmarks of mechanochemistry: from nanoparticles to technology

et al. 2013

Self Cite

View full text Add to dashboard Cite

The aim of this review article on recent developments of mechanochemistry (nowadays established as a part of chemistry) is to provide a comprehensive overview of advances achieved in the field of atomistic processes, phase transformations, simple and multicomponent nanosystems and peculiarities of mechanochemical reactions. Industrial aspects with successful penetration into fields like materials engineering, heterogeneous catalysis and extractive metallurgy are also reviewed. The hallmarks of mechanochemistry include influencing reactivity of solids by the presence of solid-state defects, interphases and relaxation phenomena, enabling processes to take place under non-equilibrium conditions, creating a well-crystallized core of nanoparticles with disordered near-surface shell regions and performing simple dry time-convenient one-step syntheses. Underlying these hallmarks are technological consequences like preparing new nanomaterials with the desired properties or producing these materials in a reproducible way with high yield and under simple and easy operating conditions. The last but not least hallmark is enabling work under environmentally friendly and essentially waste-free conditions (822 references).

show abstract

Section: Role Of Water In Mechanochemistrymentioning

confidence: 99%

Hallmarks of mechanochemistry: from nanoparticles to technology

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…[18][19][20] Comilling of titania nanoparticles with polytetrafluoroethylene (PTFE) in air, for instance, brings about fluorinedoped TiO 2 nanoparticles, as we reported recently. 21 The associated reaction processes, i.e., oxidative decomposition of PTFE, extraction of oxygen ion from the substrate titania, and transfer of fluorine from the partially decomposed PTFE, are the consequences of serial mechanochemical reactions. While these dry comilling processes look promising, they are often accompanied by severe agglomeration of the particles.…”

Section: Introductionmentioning

confidence: 99%

Modification of titania nanoparticles for photocatalytic antibacterial activity via a colloidal route with glycine and subsequent annealing

et al. 2012

Self Cite

View full text Add to dashboard Cite

Changes in the colloid-chemical and photocatalytic properties of titania nanoparticles by attrition milling in the presence of glycine (Gly) and subsequent heat treatment were examined. By milling at 1500 rpm for 6 h, the average particle size was decreased from 123 to 85 nm, with simultaneous decrease in the specific surface area from 35.1 to 23.5 m 2 /g. Interfacial reactions between titania and Gly were confirmed by Fourier transform infrared spectroscopy, from the blue shift of the COO À related vibrational bands by 25 cm À1, relative to the same band from the pristine Gly. The bimodal N1s x-ray photoelectron spectroscopy peak similar to that from the reported titania-amino acid complex is another indication of the complex formation with the participation of nitrogen. When the dispersion was dried and calcined at 500°C in air, the powder exhibited pale yellow color. Diffuse reflectance spectroscopy showed significant visible light absorption, suggesting nitrogen incorporation into titania. The fired product showed high photocatalytic antibacterial activity by irradiation of blue light centered at around 440 nm, using Escherichia coli as a specimen of bacterial species. Thus, the present Gly-modified titania nanoparticles could be used for eliminating indoor bacteria under soft blue illumination. The series of interfacial chemical processes involved are also discussed.

show abstract

“…Raman spectroscopy was carried out using an WiTec CRM200 Raman microscope with laser excitation at 633 nm. 19 F MAS NMR measurements were carried out with an Avance III NMR spectrometer (Bruker Biospin) operating at 564.7 MHz. A commercial 1.3 mm pencil spinner MAS probe was used for recording the spectra.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Transfer and State Changes of Fluorine at Polytetrafluoroethylene/Titania Boundaries by Mechanical Stressing and Thermal Annealing

Senna

Düvel²,

Šepelák

et al. 2013

J. Phys. Chem. C

Self Cite

View full text Add to dashboard Cite

Fluorine in polytetrafluoroethylene (PTFE) changes its states and transfers to titania by comilling and annealing of a titania−PTFE mixture. XPS, 19 F MAS NMR, FT-IR, Raman spectra, TEM and EDX analyses consistently indicated the oxidative decomposition of PTFE, inducing partial fluorination of titania. Incorporation of fluorine into titania was unambiguously confirmed by the appearance of a new XPS F1s peak at ∼685 eV, similar to those observed from TiOF 2 . The intensity of the new F1s peak increased with comilling time and became a sole peak after milling for 3 h. At the same time, 19 F MAS NMR lines specific to PTFE disappeared. From these observations, we concluded that extensive decomposition of PTFE with simultaneous change in the chemical states of fluorine took place with the aid of titania. Upon annealing the comilled mixture in air, the amount of fluorine in the mixture decreased with increasing temperature, while the remaining fluorine migrated into the titania lattice, as confirmed by the decrease in the chemical shift of the 19 F MAS NMR lines and the decrease in the rutile (211) and (220) interplanar distances. These findings allow us to devise how to control the amount, states, and spatial distribution of the fluorine incorporated into titania.

show abstract

Introduction of oxygen vacancies and fluorine into TiO2 nanoparticles by co-milling with PTFE

Cited by 43 publications

References 58 publications

Hallmarks of mechanochemistry: from nanoparticles to technology

Hallmarks of mechanochemistry: from nanoparticles to technology

Modification of titania nanoparticles for photocatalytic antibacterial activity via a colloidal route with glycine and subsequent annealing

Transfer and State Changes of Fluorine at Polytetrafluoroethylene/Titania Boundaries by Mechanical Stressing and Thermal Annealing

Contact Info

Product

Resources

About