Jenny Schneider,*,† Masaya Matsuoka,‡ Masato Takeuchi,‡ Jinlong Zhang, Yu Horiuchi,‡ Masakazu Anpo,‡ and Detlef W. Bahnemann*,† †Institut fur Technische Chemie, Leibniz Universitaẗ Hannover, Callinstrasse 3, D-30167 Hannover, Germany ‡Faculty of Engineering, Osaka Prefecture University, 1 Gakuen-cho, Sakai Osaka 599-8531, Japan Key Lab for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, China

Understanding TiO2 photocatalysis: mechanisms and materials.

We present the science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems, targeting an evolution in technology, that might lead to impacts and benefits reaching into most areas of society. This roadmap was developed within the framework of the European Graphene Flagship and outlines the main targets and research areas as best understood at the start of this ambitious project. We provide an overview of the key aspects of graphene and related materials (GRMs), ranging from fundamental research challenges to a variety of applications in a large number of sectors, highlighting the steps necessary to take GRMs from a state of raw potential to a point where they might revolutionize multiple industries. We also define an extensive list of acronyms in an effort to standardize the nomenclature in this emerging field.

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Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems

UV-Visible ار راد ن .د TiO2 ( تیفرظ راون مان هب نورتکلا یاراد یژرنا زارت لماش VB و ) رگید زارت ی یژرنا اب ( ییاناسر راون مان هب نورتکلا زا یلاخ و رتلااب VB یم ) .دشاب ت ود نیا نیب یژرنا توافت یژرنا فاکش زار ، پگ دناب هدیمان یم .دوش هک ینامز زا نورتکلا لاقتنا VB هب VB یم ماجنا دریگ ، TiO2 اب ودح یژرنا بذج د ev 2 / 3 ، نورتکلا تفج کی دیلوت یم هرفح .دیامن و نورتکلا هرفح ی نا اب هدش دیلوت یم کرتشم حطس هب لاقت ثعاب دناوت شنکاو ماجنا اه یی ددرگ . TiO2 دربراک ،دراد یدایز یاه هلمج زا یم ناوت اوه یگدولآ هیفصت یارب (CO2) و بآ و ... نآ زا هدافتسا درک .

Advanced Nanoarchitectures for Solar Photocatalytic Applications

Generations Yi Ma,† Xiuli Wang,† Yushuai Jia,† Xiaobo Chen,‡ Hongxian Han,*,† and Can Li*,† †State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Dalian National Laboratory for Clean Energy, 457 Zhongshan Road, Dalian 116023, China ‡Department of Chemistry, College of Arts and Sciences, University of Missouri-Kansas City, 5100 Rockhill Road, Kansas City, Missouri 64110, United States

Titanium dioxide-based nanomaterials for photocatalytic fuel generations.

A surface science perspective on TiO2 photocatalysis

Photoluminescence in TiO2 anatase single crystals

The fundamental absorption edge of the anatase phase of ${\mathrm{TiO}}_{2}$ has been studied by performing polarized optical transmission measurements on single crystals at temperatures ranging from 4.2 to 300 K. An Urbach tail has been found that shows an exponential spectral dependence down to liquid-helium temperature. The optical gap of anatase has been estimated to be 3.420 eV in polarization E\ensuremath{\perp}c, and 3.460 eV in polarization E\ensuremath{\parallel}c. Our experimental results can be accounted for in terms of the theory of Toyozawa and co-workers, which ascribes the Urbach tail to the momentary localization of excitons due to phonon interaction. Comparing, in this case, the measured abosrption spectra of anatase and rutile, we conclude that the excitons in anatase are self-trapped while those in rutile are free. This opposite nature of exciton states in anatase and rutile is consistent with the results of previous photoluminescence studies.

Urbach tail of anatase TiO2.

Optical properties of anatase (TiO2)

The complete Fermi surface of ${\mathrm{ZrTe}}_{5}$ has been determined to consist of three independent surfaces: one hole-type, (the largest surface) and two electron-type surfaces. The surfaces are all of ellipsoidal form, with at least the electron surfaces mutually nested with common centers and principal axes. In addition, along certain high-symmetry directions, they nearly touch. Within experimental error, the volume of the largest surface is equal to the sum of the volumes of the smaller surfaces. Also determined are the anisotropy of the effective masses, the electron scattering times, and a model of the energy bands as they cross the Fermi level. In the direction of highest conductivity, the effective masses of the electrons and holes are found to be nearly equal and small (3--4 % of the free-electron mass), and the relaxation time for the electrons is more than twice that of the holes.

Fermi surface, effective masses, and Dingle temperatures of ZrTe 5 as derived from the Shubnikov – de Haas effect

Recently, the unusual behaviour of the specific heat of the superconductors YBa2Cu3O7, Y2Ba4Cu7O15, and YBa2Cu4O8 at high field and low temperature was attributed to Zeeman splitting of localized states in the vortex cores [D. Sanchez et al., Physica C 200 (1992) 1]. In an attempt to detect similar effects in classic high-κ superconductors, we have measured the mixed-state specific heat of NbSe2 single crystals in magnetic fields up to Hc2(0). The specific heat in the superconducting state and zero field is found to follow accurately a strong-coupling model that takes into account the anisotropy of the gap. We analyse then the mixed-state specific heat using the London model. A small Schottky-like excess specific heat remains unexplained. In qualitative agreement with the observations made in YBaCuO, this contribution is suggested to originate from the localized vortex core levels observed by STM techniques.

F. Levy

Papers

Photoluminescence in TiO2 anatase single crystals

Urbach tail of anatase TiO2.

Optical properties of anatase (TiO2)

Fermi surface, effective masses, and Dingle temperatures of ZrTe 5 as derived from the Shubnikov – de Haas effect

Specific heat of 2H-NbSe2 in high magnetic fields