Non-equilibrium electron transport induced by terahertz radiation in the topological and trivial phases of Hg_1−xCd_xTe

• Alexandra V. Galeeva,
• Alexey I. Artamkin,
• Alexey S. Kazakov,
• Sergey N. Danilov,
• Sergey A. Dvoretskiy,
• Nikolay N. Mikhailov,
• Ludmila I. Ryabova and
• Dmitry R. Khokhlov

Beilstein J. Nanotechnol. 2018, 9, 1035–1039, doi:10.3762/bjnano.9.96

• concentrations correspond to the Fermi level position not lower than at 3 meV, 5 meV, and 7 meV above the conduction band edge for the samples with x = 0.13, 0.15, 0.17, respectively. The energy distance between the conduction band and the light-hole valence subband used in the Kane model calculations was

• band structure) in the samples with x < 0.16. Variable position edges of the conduction (Ec) band, the heavy hole valence (Ev) subband, and the light hole subband in the heterojunction are schematically shown by black solid lines. The Fermi level is shown by the dash-dot line. The topological layer

An implementation of spin–orbit coupling for band structure calculations with Gaussian basis sets: Two-dimensional topological crystals of Sb and Bi

• Sahar Pakdel,
• Mahdi Pourfath and
• J. J. Palacios

Beilstein J. Nanotechnol. 2018, 9, 1015–1023, doi:10.3762/bjnano.9.94

• feature a band inversion. In a gedanken experiment, one can imagine tuning the SOC at will. As the SOC is increased from zero towards its nominal value, it pushes up the valence band while bringing down the conduction band of the imaginary SOC-free material. In this process, the gap closes and reopens

• , however, are usually restricted to the description of valence electrons, implicitly by assuming a minimal basis set of spd orbitals. The SOC is included by adding the matrix elements of the operator where λ is taken as an atomic parameter [8]. Although the simplicity of TB modeling is appealing, this

• for the interstitial or valence electrons, while approaching the core electrons differently. Since localized orbitals are convenient for a number of reasons, for instance for quantum transport calculations [15][16], a Kohn–Sham Hamiltonian obtained from plane-wave DFT codes may be transformed into a

Cyclodextrin inhibits zinc corrosion by destabilizing point defect formation in the oxide layer

• Abdulrahman Altin,
• Maciej Krzywiecki,
• Adnan Sarfraz,
• Cigdem Toparli,
• Claudius Laska,
• Philipp Kerger,
• Aleksandar Zeradjanin,
• Karl J. J. Mayrhofer,
• Michael Rohwerder and
• Andreas Erbe

Beilstein J. Nanotechnol. 2018, 9, 936–944, doi:10.3762/bjnano.9.86

• valence band (VB) edge region. The ZnO VB region contains contributions from overlapping Zn 4s/4p, O 2p and C 2p levels [29][30]. Because of (i) the significantly bigger excitation cross-section for ZnO compared to β-CD, and (ii) the expected atomic contributions to the VB region, this region can be

• ) Zn 2p3/2, (d) Zn 3d - valence band (VB) energy region, with ZnO VB onset and ZnO VB maximum as functions of the TOA (inset). (e) Binding-energy variations for recorded spectral regions with TOA; (f) UPS HOMO onset of β-CD recorded with He II excitation. The Auger parameter α is shown as inset in (c

Effect of annealing treatments on CeO₂ grown on TiN and Si substrates by atomic layer deposition

• Silvia Vangelista,
• Rossella Piagge,
• Satu Ek and
• Alessio Lamperti

Beilstein J. Nanotechnol. 2018, 9, 890–899, doi:10.3762/bjnano.9.83

• permittivity (κ) of 23–24 [5]. In all the cases, the valence of the Ce ions is fundamental, since it determines some of the material specific ability, such as the oxygen storage. More generally, the structure of cerium oxide is essential in defining its specific capabilities [6]. At the thermodynamic

• phase or sub-stoichiometric CeO2 (CeO2−δ) can easily form. The cerium ion valence and the ceria structure can be influenced by the substrate onto which the film is grown and by thermal treatment after its deposition [7]. Also, the structural and/or the chemical composition of the substrate can influence

Facile chemical routes to mesoporous silver substrates for SERS analysis

• Elina A. Tastekova,
• Alexander Y. Polyakov,
• Anastasia E. Goldt,
• Alexander V. Sidorov,
• Alexandra A. Oshmyanskaya,
• Irina V. Sukhorukova,
• Dmitry V. Shtansky,
• Wolgang Grünert and
• Anastasia V. Grigorieva

Beilstein J. Nanotechnol. 2018, 9, 880–889, doi:10.3762/bjnano.9.82

• valence state of the silver at the surface of the mp-Ag (Figure 1f) obtained in 1:10 Ag2O/NaBH4 molar ratio. The binding energies at 368.3(2) eV and 374.2(2) eV are related to Ag 3d5/2 and Ag 3d3/2 binding energies, respectively. According to the NIST database (CAS registry No 7440-22-4) these bands

Facile synthesis of a ZnO–BiOI p–n nano-heterojunction with excellent visible-light photocatalytic activity

• Mengyuan Zhang,
• Jiaqian Qin,
• Pengfei Yu,
• Bing Zhang,
• Mingzhen Ma,
• Xinyu Zhang and
• Riping Liu

Beilstein J. Nanotechnol. 2018, 9, 789–800, doi:10.3762/bjnano.9.72

• out for the chemical composition and valence state analysis of various species. The foreign impurity C at 284.6 eV is used to calibrate peak positions in all the XPS results. High-resolution narrow-scan spectra of O, Bi, Zn and I are also conducted for the study of surface chemical state in detail

• -resolution scan of Bi 4f is displayed in Figure 4b. Both pure BiOI and the nanocomposite sample consist of a doublet which can be well-assigned to Bi 4f5/2 at 164.5 eV and Bi 4f3/2 at 159.2 eV with an energy difference of 5.3 eV [39][46], revealing that +3 is the main valence state of the Bi element in B-1

• coupling with ZnO, however, the satellite peaks appeared in the B-4 sample, demonstrating the chemistry state of I is changed. This probably resulted from the partial substitution of I for oxidic sites in the ZnO framework [49]. The density of electronic state (DOS) of the valence band was also

A review of carbon-based and non-carbon-based catalyst supports for the selective catalytic reduction of nitric oxide

• Shahreen Binti Izwan Anthonysamy,
• Syahidah Binti Afandi,
• Mehrnoush Khavarian and
• Abdul Rahman Bin Mohamed

Beilstein J. Nanotechnol. 2018, 9, 740–761, doi:10.3762/bjnano.9.68

• air at 300 °C for 50 min) and MnOx/CNT-N3 (calcined in N2 at 300 °C for 2 h) catalysts. This is greatly associated with the CNTs reducing MnOx to a lower valence state during the calcination process. Thus, thermal treatment condition plays a vital role in obtaining the best NO removal for CNT-based

Perovskite-structured CaTiO₃ coupled with g-C₃N₄ as a heterojunction photocatalyst for organic pollutant degradation

• Ashish Kumar,
• Christian Schuerings,
• Suneel Kumar,
• Ajay Kumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2018, 9, 671–685, doi:10.3762/bjnano.9.62

• a distinct absorption edge in the visible region corresponding to the band gap of 2.75 eV resulting from the transfer of electrons from the valence band to the conduction band [50]. The absorption edge for CT nanoflakes lies in the UV region exhibiting a band gap of 3.45 eV. The DRS profile of CTCN

• percentage of RhB upon irradiation under different light sources. It can be seen from Figure 8d that in the presence of UV light irradiation, bare g-C3N4 degrades ≈50% of the RhB dye. This degradation is obvious because high-energy UV light can also cause excitation of electrons from the valence band to the

• responsible for the separation and migration of photogenerated charges. The appropriate band positions of the semiconductor materials produce space charge accumulation/depletion at the interfaces, which helps in the effective separation of photogenerated charge carriers [59]. In this regard, the valence band

Mechanistic insights into plasmonic photocatalysts in utilizing visible light

• Kah Hon Leong,
• Azrina Abd Aziz,
• Lan Ching Sim,
• Pichiah Saravanan,
• Min Jang and
• Detlef Bahnemann

Beilstein J. Nanotechnol. 2018, 9, 628–648, doi:10.3762/bjnano.9.59

• semiconductor through the LSPR decay effect as illustrated in Figure 4 and Figure 5 [30], leaving behind positively charged holes at the valence band or their transfer to the counter electrode preventing recombination [16][31][32][33][34][35]. Figure 4a demonstrates the excited electron mobility from the

• which has a distinctive electronic configuration structure (filled valence band and an empty conduction band). When exposed to direct sunlight irradiation, the UV light breaks the band gap energy of TiO2 (3.2 eV) and then activates the electrons in the valence band. Thus, activated electrons move to the

• during the photocatalysis react with DMPO to convert stable DMPO–OH radicals and are detected by ESR spectroscopy. There is a high probability that the valence-band holes might alternatively oxidize the spin-trapping reagents before the formation of •OH radicals. Figure 16 shows a three-step process for

Green synthesis of fluorescent carbon dots from spices for in vitro imaging and tumour cell growth inhibition

• Nagamalai Vasimalai,
• Vânia Vilas-Boas,
• Juan Gallo,
• María de Fátima Cerqueira,
• Mario Menéndez-Miranda,
• José Manuel Costa-Fernández,
• Lorena Diéguez,
• Begoña Espiña and
• María Teresa Fernández-Argüelles

Beilstein J. Nanotechnol. 2018, 9, 530–544, doi:10.3762/bjnano.9.51

• attributed to surface state emission, intrinsic band emission, triple ground state emission, dipole emission involving electron–phonon coupling, transition from surface electrons to valence holes, self-trapped excitons and to the presence of small organic molecules. Moreover, the characteristic excitation

Influence of the preparation method on the photocatalytic activity of Nd-modified TiO₂

• Patrycja Parnicka,
• Paweł Mazierski,
• Tomasz Grzyb,
• Wojciech Lisowski,
• Ewa Kowalska,
• Bunsho Ohtani,
• Adriana Zaleska-Medynska and
• Joanna Nadolna

Beilstein J. Nanotechnol. 2018, 9, 447–459, doi:10.3762/bjnano.9.43

• are shown in Figure 3. The optical absorption of TiO2 in the UV region below 400 nm can be mainly attributed to the charge transfer, related to electron excitation from the valence band to the conduction band (band-to-band transition, O2p→Ti3d) [30]. Modification of TiO2 with neodymium significantly

• energy level in the band gap and charge transfer between the TiO2 valence band and Nd3+ ion levels [36]. Furthermore, there are four absorption bands in the vis region typical for neodymium located at 520, 585, 745 and 805 nm. They correspond to transitions from the 4I9/2 ground state to the excited

Facile synthesis of ZnFe₂O₄ photocatalysts for decolourization of organic dyes under solar irradiation

• Arjun Behera,
• Debasmita Kandi,
• Sanjit Manohar Majhi,
• Satyabadi Martha and
• Kulamani Parida

Beilstein J. Nanotechnol. 2018, 9, 436–446, doi:10.3762/bjnano.9.42

• material is an n-type semiconductor and the flat-band potential (Efb) was calculated to be −0.69 eV (vs Ag/AgCl) or −0.09 eV (vs RHE). From UV–vis DRS measurements, the band gap of was found to be 1.81 V. So, the valence band position of ZFO is calculated as +1.72 eV (vs RHE). By considering the calculated

Sugarcane juice derived carbon dot–graphitic carbon nitride composites for bisphenol A degradation under sunlight irradiation

• Lan Ching Sim,
• Jing Lin Wong,
• Chen Hong Hak,
• Jun Yan Tai,
• Kah Hon Leong and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2018, 9, 353–363, doi:10.3762/bjnano.9.35

• because the addition of dimethylsulfoxide (DMSO) and isopropyl alchohol (IPA) did not exert a significant effect on the degradation rate of BPA. Based on the above results, a degradation mechanism is proposed in Figure 6. The edge potential of the conduction band (CB) and the valence band (VB) of a

Review: Electrostatically actuated nanobeam-based nanoelectromechanical switches – materials solutions and operational conditions

• Liga Jasulaneca,
• Jelena Kosmaca,
• Raimonds Meija,
• Jana Andzane and
• Donats Erts

Beilstein J. Nanotechnol. 2018, 9, 271–300, doi:10.3762/bjnano.9.29

• carry the risk of switch failure at higher operation voltages. In NEM switches with metal–semiconductor contacts, the type of the contact is determined by the mutual arrangement of the Fermi level of the metal and the valence and conduction bands of the semiconductor. The contact has a Schottky barrier

• if the Fermi level of the metal falls in between the valence and conduction bands of the semiconductor. The type of the contact (ohmic or Schottky) between two semiconductors is determined by the Fermi energies of contacting materials. The presence of a nonconductive oxide layer between the

Atomic layer deposition and properties of ZrO₂/Fe₂O₃ thin films

• Kristjan Kalam,
• Helina Seemen,
• Peeter Ritslaid,
• Mihkel Rähn,
• Aile Tamm,
• Kaupo Kukli,
• Aarne Kasikov,
• Joosep Link,
• Raivo Stern,
• Salvador Dueñas,
• Helena Castán and
• Héctor García

Beilstein J. Nanotechnol. 2018, 9, 119–128, doi:10.3762/bjnano.9.14

• iron and zirconium oxides, the amount of defects (in particular oxygen vacancies) is increased due to the substitutive exchange between metal ions of different valence, resulting in an increase also in the leakage currents. Pure ZrO2 exhibited the lowest leakage current (Figure 7) and did not show any

Review on optofluidic microreactors for artificial photosynthesis

• Xiaowen Huang,
• Jianchun Wang,
• Tenghao Li,
• Jianmei Wang,
• Min Xu,
• Weixing Yu,
• Abdel El Abed and
• Xuming Zhang

Beilstein J. Nanotechnol. 2018, 9, 30–41, doi:10.3762/bjnano.9.5

• energy could be offered by external light. In principle, a semiconductor photocatalyst (e.g., TiO2, C3N4) absorbs the appropriate photon (hν ≥ E0, where E0 is the bandgap of the semiconductor photocatalyst) to excite an electron in the conduction band, leaving a hole in the valence band. The electron

Facile synthesis of silver/silver thiocyanate (Ag@AgSCN) plasmonic nanostructures with enhanced photocatalytic performance

• Xinfu Zhao,
• Dairong Chen,
• Abdul Qayum,
• Bo Chen and
• Xiuling Jiao

Beilstein J. Nanotechnol. 2017, 8, 2781–2789, doi:10.3762/bjnano.8.277

• absorption of Ag@AgSCN in both the UV and visible region, which is beneficial for application as a visible-light catalyst. The bandgap of AgSCN can be determined according to the Kubelka–Munk equation, which is estimated as 3.4 eV for sample M0 (Figure 2b), and the valence band value of 1.12 eV is obtained

• the reduction of AgSCN, and enhance the stability of Ag@AgSCN. The degradation mechanism suggested that electrons of Ag@AgSCN were prompted to the conduction band and holes were left in the valence band of AgSCN under irradiation (Figure 6a). The electrons were rapidly trapped by Ag nanoparticles

CdSe nanorod/TiO₂ nanoparticle heterojunctions with enhanced solar- and visible-light photocatalytic activity

• Fakher Laatar,
• Hatem Moussa,
• Halima Alem,
• Lavinia Balan,
• Emilien Girot,
• Ghouti Medjahdi,
• Hatem Ezzaouia and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2017, 8, 2741–2752, doi:10.3762/bjnano.8.273

• . Photodegradation mechanism Under simulated solar light irradiation, electron (e−)/hole (h+) pairs are generated both in CdSe NRs and TiO2 nanoparticles. The holes in the valence band (VB) of TiO2 are transferred to the VB of CdSe NRs while electrons are transferred from the conduction band (CB) of CdSe NRs to the

Enhanced photoelectrochemical water splitting performance using morphology-controlled BiVO₄ with W doping

• Xin Zhao and
• Zhong Chen

Beilstein J. Nanotechnol. 2017, 8, 2640–2647, doi:10.3762/bjnano.8.264

• precursor solution. Considering the poor electron conductivity of BiVO4, which leads to a poor photoelectrochemical performance (see Figure S1, Supporting Information File 1), we employed tungsten as a doping element because it has a higher valence than vanadium and an ionic radius close to that of vanadium

Inelastic electron tunneling spectroscopy of difurylethene-based photochromic single-molecule junctions

• Youngsang Kim,
• Safa G. Bahoosh,
• Dmytro Sysoiev,
• Thomas Huhn,
• Fabian Pauly and
• Elke Scheer

Beilstein J. Nanotechnol. 2017, 8, 2606–2614, doi:10.3762/bjnano.8.261

• functional theory (DFT) for charge transport through C5F-ThM molecular junctions. DFT, as implemented in the TURBOMOLE software package [26], was employed for the calculations using the exchange-correlation functional PBE [27][28][29][30] and the def-SV(P) [31][32] basis set, which is of split-valence

Adsorption of iron tetraphenylporphyrin on (111) surfaces of coinage metals: a density functional theory study

• Hao Tang,
• Nathalie Tarrat,
• Véronique Langlais and
• Yongfeng Wang

Beilstein J. Nanotechnol. 2017, 8, 2484–2491, doi:10.3762/bjnano.8.248

• , respectively) [20][21]. The deformation energy of the adsorbed FeTPP is found to be +1.08 eV (0.03 eV for the gold surface), while the intramolecular vdW energy is −3.12 eV. The charge transfer defined as the difference between the number of valence electron in the adsorbed molecule and in the free molecule in

Fabrication of CeO₂–MO_x (M = Cu, Co, Ni) composite yolk–shell nanospheres with enhanced catalytic properties for CO oxidation

• Ling Liu,
• Jingjing Shi,
• Hongxia Cao,
• Ruiyu Wang and
• Ziwu Liu

Beilstein J. Nanotechnol. 2017, 8, 2425–2437, doi:10.3762/bjnano.8.241

• , CeO2-based composite oxides by combining ceria with other low-valence metal oxides have been widely studied. Importantly, due to the synergistic effect between the two components, CeO2-based composite oxides exhibit a remarkable catalytic activity that is comparable with or even superior to that of

• of M2+ is embedded into the CeO2 lattice and replaces Ce4+, the Raman band shifts to lower wavenumbers because additional oxygen vacancies form to compensate for the valence mismatch between M2+ and Ce4+ ions [31]. Additionally, the weak peaks of pure CeO2 at 592 and 1177 cm−1 can be assigned to the

Hydrothermal synthesis of ZnO quantum dot/KNb₃O₈ nanosheet photocatalysts for reducing carbon dioxide to methanol

• Xiao Shao,
• Weiyue Xin and
• Xiaohong Yin

Beilstein J. Nanotechnol. 2017, 8, 2264–2270, doi:10.3762/bjnano.8.226

• photogenerated electron–hole pairs. The conduction band and the valence band of the catalyst were calculated by the empirical equations [13]: ECB = X − Ec − 0.5Eg; EVB = ECB + Eg where X is the absolute electronegativity of the semiconductor, Ec is the energy of the free electrons under standard hydrogen

• /CH3OH = −0.38 V) [29], the valence band of pure ZnO quantum dots (EVB = 1.6 V) and pure KNb3O8 nanosheets (EVB = 2.52 V) which are more positive than that of the isopropanol oxidation to acetone (EC3H8O/C3H6O = 0.49 V) [30], which made the reduction of CO2 to methanol and the oxidation of isopropanol to

• acetone possible. Under UV irradiation, photoinduced electrons in the conduction band (CB) of KNb3O8 migrate to the valence band (VB) of ZnO quantum dots and combine with the holes to efficiently prevent photogenerated electron–hole pairs from vast and fast recombination. Therefore, the lifetime of free

Dissociative electron attachment to coordination complexes of chromium: chromium(0) hexacarbonyl and benzene-chromium(0) tricarbonyl

• Janina Kopyra,
• Paulina Maciejewska and
• Jelena Maljković

Beilstein J. Nanotechnol. 2017, 8, 2257–2263, doi:10.3762/bjnano.8.225

• that only one atom within the ligand binds to the central metal atom. C6H6 is a η6 (hexahapto) ligand which corresponds to a contiguous series of six atoms that coordinate to the metal center. The molecular structure of both complexes is depicted in Figure 1. Cr(CO)6 is a complex with 18 valence

Comprehensive investigation of the electronic excitation of W(CO)₆ by photoabsorption and theoretical analysis in the energy region from 3.9 to 10.8 eV

• Mónica Mendes,
• Khrystyna Regeta,
• Filipe Ferreira da Silva,
• Nykola C. Jones,
• Søren Vrønning Hoffmann,
• Gustavo García,
• Chantal Daniel and
• Paulo Limão-Vieira

Beilstein J. Nanotechnol. 2017, 8, 2208–2218, doi:10.3762/bjnano.8.220

• of the outermost valence orbitals for the ground state 1A1g being (7eg)4 (3t2g)6 (1t1g)6 (11t1u)6 (4t2g)6, and only optically allowed 1A1g→1T1u transitions. The analysis of the ground-state Kohn–Sham (KS) orbitals (Figure 2 and Figure S1 in Supporting Information File 1) shows that the highest

• strongest absorption band where the difference amounts to an overestimation of 0.5 eV. Nonetheless, this level of accuracy is reasonable for describing the VUV photoabsorption features. The TDDFT absorption spectrum of W(CO)6 without SOC is depicted in Figure S2 of Supporting Information File 1. Valence

• range of 3.9–10.8 eV. The blue curve has the (right) ordinate set to a maximum of 50 Mb to bring out the rich fine structure in the spectrum. Valence Kohn–Sham orbitals of W(CO)6 in its electronic ground state. High-resolution VUV photoabsorption spectrum of W(CO)6 in the photon energy range of 3.9–5.0