Revealing local structural properties of an atomically thin MoSe₂ surface using optical microscopy

• Lin Pan,
• Peng Miao,
• Anke Horneber,
• Alfred J. Meixner,
• Pierre-Michel Adam and
• Dai Zhang

Beilstein J. Nanotechnol. 2022, 13, 572–581, doi:10.3762/bjnano.13.49

• the interaction with local dipoles in plasma-treated MoS2 [22]. Additionally, the electronic band structure of MoS2 can be significantly modified after oxygen incorporation into MoS2. The charge transfer from the valence band of partially oxidized MoS2 to the LUMO of R6G can be tuned in resonance with

• transfer from MoSe2 to CuPc is more efficient through the first-layer effect. In this case, more electrons in the valence band of MoSe2 can be involved in the Raman scattering process of CuPc through the ground-state charge transfer (blue arrow), which enhances the Raman scattering as shown by the yellow

• arrow [36]. In the meantime, less electrons can be excited from the valence band to the conduction band of the MoSe2 flake (red arrow). Thus, radiative electron–hole pair recombination (wine-red arrow) is less strong than it is with radial polarization, giving rise to the lower photoluminescence

Zinc oxide nanostructures for fluorescence and Raman signal enhancement: a review

• Ioana Marica,
• Fran Nekvapil,
• Maria Ștefan,
• Cosmin Farcău and
• Alexandra Falamaș

Beilstein J. Nanotechnol. 2022, 13, 472–490, doi:10.3762/bjnano.13.40

• nanostructures, however, are significantly inferior to those on noble metals since the LSPR is centred in the near-infrared in the case of the conduction band (CB) and in the UV region in the case of the valence band (VB) [14]. Therefore, concrete solutions have been proposed to improve the EM enhancement in ZnO

• unoccupied molecular orbital level (LUMO) of the analyte molecules match the conduction band (CB) and valence band (VB) of the semiconductor. The EM effect can be amplified by shifting the LSPR peak to the near infrared (NIR) or visible spectral region by doping the semiconductor and, thus, increasing the

• . [70] reported that, from a theoretical point of view, there is no preferred charge transfer route between the non-plasmonic substrate and the analyte. However, the experimental observations on three different semiconductor–analyte systems showed that the charge transfer from the substrate valence band

Investigation of a memory effect in a Au/(Ti–Cu)Ox-gradient thin film/TiAlV structure

• Damian Wojcieszak,
• Jarosław Domaradzki,
• Michał Mazur,
• Tomasz Kotwica and
• Danuta Kaczmarek

Beilstein J. Nanotechnol. 2022, 13, 265–273, doi:10.3762/bjnano.13.21

• related to lattice oxygen (for TiO2 and CuO), hydroxy groups (OH−) and adsorbed water molecules (H2Oads). The UPS spectrum of the (Ti0.48Cu0.52)Ox thin film is shown in Figure 7. The position of the valence band maximum (VBM) was determined from the extrapolation of the line fit to the leading edge of the

• film: a) Cu 2p, b) Ti 2p, and c) O 1s core levels. (a) Photoelectron spectrum of the valence band, (b) schematic energy diagram of the surface of the (Ti0.48Cu0.52)Ox thin film. Results of TEM analysis and distribution of Cu, Ti, O, and Si in the gradient (Ti–Cu)Ox thin film with correlation to U

Engineered titania nanomaterials in advanced clinical applications

• Padmavati Sahare,
• Paulina Govea Alvarez,
• Juan Manual Sanchez Yanez,
• Gabriel Luna-Bárcenas,
• Samik Chakraborty,
• Sujay Paul and
• Miriam Estevez

Beilstein J. Nanotechnol. 2022, 13, 201–218, doi:10.3762/bjnano.13.15

• photocatalytic activity. Upon UV irradiation, the electrons in the valence band get excited to the conduction band, leading to the formation of electron–hole pairs and the generation of ROS. Subsequently, the generated holes (h+) convert water/hydroxide molecules to peroxide/hydroxyl radicals by oxidation. The

Theoretical understanding of electronic and mechanical properties of 1T′ transition metal dichalcogenide crystals

• Seyedeh Alieh Kazemi,
• Sadegh Imani Yengejeh,
• Vei Wang,
• William Wen and
• Yun Wang

Beilstein J. Nanotechnol. 2022, 13, 160–171, doi:10.3762/bjnano.13.11

• generalized gradient approximation (GGA) level was used [37]. Electron-ion interactions were described using PAW potentials [38], with valence configurations of 4s24p65s14d5 for Mo (Mo_sv), 4s25p66s15d5 for W (W_sv), 3s23p4 for S (S), and 4s24p4 for Se (Se). A plane-wave basis set with a cutoff kinetic energy

• energy level is small. The large overlap between the X p states and TM d states suggests the strong covalent bonding strength. Both TM d states and X p states make similar contributions to the valence bands. In the conduction bands, the main contribution is from the TM d states. This feature is similar

A comprehensive review on electrospun nanohybrid membranes for wastewater treatment

• Senuri Kumarage,
• Imalka Munaweera and
• Nilwala Kottegoda

Beilstein J. Nanotechnol. 2022, 13, 137–159, doi:10.3762/bjnano.13.10

Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review

• Viet Van Pham,
• Hong-Huy Tran,
• Thao Kim Truong and
• Thi Minh Cao

Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7

• working scheme of semiconductor photocatalysts for NO oxidation. Light generates holes (h+) in the valence band (VB) and electrons (e–) in the conduction band (CB) of the photocatalytic material. Electrons at the material surface will react with oxygen molecules to form superoxide radicals (•O2

• oxide (not to be confused with stannous oxide with tin in the oxidation state of 2+ [13], also known as cassiterite [14]. SnO2 materials have many interesting properties. For instance, the structure and electronic structure can be manipulated easily due to the highly tunable valence state and oxygen

• reports still proposed its photocatalytic behaviors partly based on •O2− species via the combination of experimental physicochemical analyses, such as electron spin resonance (ESR) spectroscopy, active species trapping experiments, valence band X-ray photoelectron spectroscopy (XPS), and diffuse

Measurement of polarization effects in dual-phase ceria-based oxygen permeation membranes using Kelvin probe force microscopy

• Kerstin Neuhaus,
• Christina Schmidt,
• Liudmila Fischer,
• Wilhelm Albert Meulenberg,
• Ke Ran,
• Joachim Mayer and
• Stefan Baumann

Beilstein J. Nanotechnol. 2021, 12, 1380–1391, doi:10.3762/bjnano.12.102

• microscopy; oxygen permeation; Introduction Acceptor-doped cerium dioxide, where cerium is partially substituted by cations of lower valence (most prominently Gd3+), is a fluorite material with a very high oxide ion conductivity at comparably moderate temperatures (around 600 °C). It has already been in

Plasmon-enhanced photoluminescence from TiO₂ and TeO₂ thin films doped by Eu³⁺ for optoelectronic applications

• Marcin Łapiński,
• Jakub Czubek,
• Katarzyna Drozdowska,
• Anna Synak,
• Wojciech Sadowski and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2021, 12, 1271–1278, doi:10.3762/bjnano.12.94

• , correspond to tellurium in the fourth valence state (Te4+) and are consistent with literature data [27][38]. The highly oxidative atmosphere during the sputtering process results in a lack of metallic tellurium in the deposited film. The Eu 4d spectrum can be deconvoluted into two doublets, which suggests

• the presence of europium in two valence states. Lines recorded at 142.36 and 136.76 eV correspond to Eu3+, while those observed at 136.40 and 130.90 eV were assigned to Eu2+. The energy separation in both doublets equals to 5.60 and 5.50 eV for Eu3+ and Eu2+, respectively, in accordance with

Impact of electron–phonon coupling on electron transport through T-shaped arrangements of quantum dots in the Kondo regime

• Patryk Florków and
• Stanisław Lipiński

Beilstein J. Nanotechnol. 2021, 12, 1209–1225, doi:10.3762/bjnano.12.89

• valence, and spin Fano–Kondo state, respectively. For Ef = U/2 all four states degenerate and below this value spin fluctuations gradually take over the leading role. In the region of low values of e and d amplitudes the spin Kondo resonance will form. This time the amplitudes of pσ operators take values

• transition point, the two mentioned cases are clearly different. For Ef = 1.5 all sixteen states of different occupancies are degenerate in the transition point (e = pjσ = dj = dσσ′ = tjσ = f = 1/4). Interacting dots in this case are in mixed valence state and real-charge fluctuations between different

• coupled to a single phonon. (a) Ef = 3 (0→4 transition with charge Kondo state for λI ≈ 0.96), (b) Ef = 1.5 (0→4 mixed valence type transition), (c) Ef = 0.5 (0→1→2→4 sequence of transitions), (d) Ef = −2 (0→1→2→3→4 sequence of transitions). Additional lower insets of (a) and (b) show corresponding

Irradiation-driven molecular dynamics simulation of the FEBID process for Pt(PF₃)₄

• Alexey Prosvetov,
• Alexey V. Verkhovtsev,
• Gennady Sushko and
• Andrey V. Solov’yov

Beilstein J. Nanotechnol. 2021, 12, 1151–1172, doi:10.3762/bjnano.12.86

• molecular topology of the system changes. The bond energy given by Equation 1 asymptotically approaches zero at large interatomic distances. The rupture of covalent bonds in the course of simulation employs the following reactive potential for the valence angles [17]: where θ0 is the equilibrium angle, kθ

First-principles study of the structural, optoelectronic and thermophysical properties of the π-SnSe for thermoelectric applications

• Muhammad Atif Sattar,
• Najwa Al Bouzieh,
• Maamar Benkraouda and
• Noureddine Amrane

Beilstein J. Nanotechnol. 2021, 12, 1101–1114, doi:10.3762/bjnano.12.82

• hierarchical architecture [2][11][12] as well as through nanostructuring [13][14][15]), retaining the hole mobility [16][17], and by improving the value of the Seebeck coefficient (by tuning the band structure [18] along with a large conduction (valence) band convergence [19][20], electron energy barrier

• parameter close to the experimental value, we investigated the electronic structure of π-SnSe. The density of states (DOS) plot for the π-SnSe calculated by the meta GGA-mBJ is presented in Figure 3. The upper valence band is majorly contributed by the p states of Se and Sn atoms with a small share of Sn s

• lie around the energy level of −5 to −6 eV. The valence bands before the Fermi level are mainly contributed by the p states of Sn and Se atoms whereas the p states of Se are mostly found in the energy range of −1.8–4.0 eV. The lower conduction band is mainly associated with p states of Sn. An indirect

Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules

• Sabine Maier and
• Meike Stöhr

Beilstein J. Nanotechnol. 2021, 12, 950–956, doi:10.3762/bjnano.12.71

• bandgap. Hence, Yousofnejad et al. [85] found using MoS2 on Ag(111) as substrate that the HOMO of tetracyanoquinodimethane (TNCQ) is not decoupled because it is located in the MoS2 valence band, while the lowest unoccupied molecular orbital narrows but still suffers from lifetime broadening because it is

Prediction of Co and Ru nanocluster morphology on 2D MoS₂ from interaction energies

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2021, 12, 704–724, doi:10.3762/bjnano.12.56

• ]. Valence electrons were described explicitly using a plane-wave basis set with an energy cutoff of 450 eV. The valence electron configurations are as follows: Co = 4s2 3d7, Ru = 5s1 4d7, Mo = 5s1 4d5, and S = 3s2 3p4. The core electrons were treated with the projector-augmented wave potential (PAW) [51]. A

• variation arises only from the structure. Further details on addition energy are given in section S1.2 of Supporting Information File 1. We now discuss the electronic properties of Co and Ru clusters adsorbed on MoS2. From the computed Bader charges, a metallic Co atom has 9.0 valence electrons, while a Co

• atom is considered oxidised when it has a Bader charge of less than 9.0 electrons. Similarly, metallic Ru has 8.0 valence electrons, and oxidised Ru will have a Bader charge of less than 8.0 electrons. Analysis of the Bader charges for Co adsorption shows that, in general, atoms bound to the MoS2 ML

Electromigration-induced formation of percolating adsorbate islands during condensation from the gaseous phase: a computational study

• Alina V. Dvornichenko,
• Vasyl O. Kharchenko and
• Dmitrii O. Kharchenko

Beilstein J. Nanotechnol. 2021, 12, 694–703, doi:10.3762/bjnano.12.55

• between anode and cathode); e is the electron charge. The direction of the force Fel is defined by the effective valence Z, which is negative for most metals. Thus, the adsorbed atoms move in the opposite direction to the electric field. In the general case if the electric field is applied across the

Nanoporous and nonporous conjugated donor–acceptor polymer semiconductors for photocatalytic hydrogen production

• Zhao-Qi Sheng,
• Yu-Qin Xing,
• Yan Chen,
• Guang Zhang,
• Shi-Yong Liu and
• Long Chen

Beilstein J. Nanotechnol. 2021, 12, 607–623, doi:10.3762/bjnano.12.50

• unoccupied molecular orbital (LUMO) or conduction band (CB), while holes remain in the highest occupied molecular orbital (HOMO) or valence band (VB). Second, the electron–hole pairs are transferred to the surface through thermodynamic driving forces and are captured by H+ and a sacrificial electron donor

• , studies regarding the long-term stability of CPs are still needed. (Left) Schematic diagram of the mechanism of semiconducting catalyst-mediated photocatalytic hydrogen production (CB: conduction band, VB: valence band, SED: sacrificial electron donors). (Right) Charge separation in a CP-based

Impact of GaAs(100) surface preparation on EQE of AZO/Al₂O₃/p-GaAs photovoltaic structures

• Piotr Caban,
• Rafał Pietruszka,
• Jarosław Kaszewski,
• Monika Ożga,
• Bartłomiej S. Witkowski,
• Krzysztof Kopalko,
• Piotr Kuźmiuk,
• Katarzyna Gwóźdź,
• Ewa Płaczek-Popko,
• Krystyna Lawniczak-Jablonska and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 578–592, doi:10.3762/bjnano.12.48

• = 4.50 eV [48] and effective density of states in the conduction band Nc = 2.2 × 1018 cm−3 [49], while for GaAs we used χGaAs = 4.07 eV, effective density of states in the valence band Nv = 7 × 1018 cm−3 as well as bandgap size of Eg(GaAs) = 1.42 eV [50]. The bandgap offset values were determined

The preparation temperature influences the physicochemical nature and activity of nanoceria

• Robert A. Yokel,
• Wendel Wohlleben,
• Johannes Georg Keller,
• Matthew L. Hancock,
• Jason M. Unrine,
• D. Allan Butterfield and
• Eric A. Grulke

Beilstein J. Nanotechnol. 2021, 12, 525–540, doi:10.3762/bjnano.12.43

• treatment of nanoceria can produce significant differences in solubility and surface cerium valence, which affect the biological and catalytic properties of nanoceria. Keywords: cerium; dissolution; nanoparticles; physicochemical properties; valence state; Introduction The long-term fate of engineered

• solvothermally synthesized nanoceria cerium surface valence was predominantly Ce3+ (Supporting Information File 1, Table S1), consistent with the increase in Ce3+ as the size of nanoceria decreases [53]. The calcined solvothermally synthesized nanoceria cerium had a predominance of Ce4+ (Figure 6). NM-212 was

• valence state difference on the nanoceria surface may contribute to the dissolution rate difference. As the nanoceria size decreases, the Ce3+/Ce4+ ratio increases (Figure 13). The edge and core of NM-212 had about 90% Ce4+ whereas the 4 nm solvothermally synthesized ceria exhibited predominantly Ce3

Boosting of photocatalytic hydrogen evolution via chlorine doping of polymeric carbon nitride

• Malgorzata Aleksandrzak,
• Michalina Kijaczko,
• Wojciech Kukulka,
• Daria Baranowska,
• Martyna Baca,
• Beata Zielinska and
• Ewa Mijowska

Beilstein J. Nanotechnol. 2021, 12, 473–484, doi:10.3762/bjnano.12.38

• harvesting with PCN and promotes visible-light photocatalytic activity [55]. To estimate the valence band position of PCN and Cl-PCN, VB XPS spectra were measured and are presented in Figure 8c. Furthermore, the conduction band (CB) position of the samples was calculated from the formula ECB = Eg − EVB, and

• ) valence band (VB) XPS spectra, and (d) band diagram of PCN and Cl-PCN. (a) Photocurrent response and (b) EIS spectra of PCN and Cl-PCN. C, N, O, and Cl atomic concentration in PCN and Cl-PCN. Chemical composition of PCN and Cl-PCN calculated from the peak-fitting procedure applied to the N 1s and C 1s

Structural and optical characteristics determined by the sputtering deposition conditions of oxide thin films

• Petronela Prepelita,
• Florin Garoi and
• Valentin Craciun

Beilstein J. Nanotechnol. 2021, 12, 354–365, doi:10.3762/bjnano.12.29

• . The obtained values were between 3.92–4.0 eV for the SiO2 samples and between 3.2–3.3 eV for ZnO films. The band difference of the ZnO films indicated a direct band-to-band transition between the valence and conduction band, while the film stress determined the improvement of the bandgap. The obtained

Nickel nanoparticle-decorated reduced graphene oxide/WO₃ nanocomposite – a promising candidate for gas sensing

• Ilka Simon,
• Alexandr Savitsky,
• Rolf Mülhaupt,
• Vladimir Pankov and
• Christoph Janiak

Beilstein J. Nanotechnol. 2021, 12, 343–353, doi:10.3762/bjnano.12.28

• the conduction band toward the valence band. Processes on the WO3 surface make it possible for the work function of WO3 to lower to a point close to that of rGO [37]. The latter facilitates transfer of electrons at the rGO/WO3 interface. The continuous capture of electrons by chemisorption of NO2

TiO_x/Pt₃Ti(111) surface-directed formation of electronically responsive supramolecular assemblies of tungsten oxide clusters

• Marco Moors,
• Yun An,
• Agnieszka Kuc and
• Kirill Yu. Monakhov

Beilstein J. Nanotechnol. 2021, 12, 203–212, doi:10.3762/bjnano.12.16

• electronic properties were obtained by employing PBE exchange–correlation functional [32] with the D3(BJ) dispersion correction [33][34][35], the valence triple-zeta polarized (TZP) basis sets composed of Slater-type and numerical orbitals, and scalar zero-order regular approximation (ZORA) [36]. STM images

ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• in semiconductors is fundamentally the same, regardless of composition. Defects generate bandgap states that either generate electrons in the conduction band or holes in the valence band. Therefore, we believe that the discussion, based on experimental results, of the magnitude of this effect for 2D

Free and partially encapsulated manganese ferrite nanoparticles in multiwall carbon nanotubes

• Saja Al-Khabouri,
• Salim Al-Harthi,
• Toru Maekawa,
• Mohamed E. Elzain,
• Ashraf Al-Hinai,
• Ahmed D. Al-Rawas,
• Abbsher M. Gismelseed,
• Ali A. Yousif and
• Myo Tay Zar Myint

Beilstein J. Nanotechnol. 2020, 11, 1891–1904, doi:10.3762/bjnano.11.170

• are the first UPS measurements carried out for this system. Figure 1e provides the structure of the valence band of free MnFe2O4 nanoparticles. Experimental results indicate that the density of states (DOS) at the Fermi level, EF (i.e., at a zero binding energy in the UPS spectrum) is consistent with

• that of half-metallic behavior (Figure 1e, inset). Ideally, stoichiometric MnFe2O4 is predicted to be a half metal with a low carrier density [17]. A valence band maximum of 0.85 eV, derived from the spectrum, is in line with its predicted half-metallic behavior. However, it is to be noted that

• semiconducting structures [31][32]. The valence edge of the CNTs correspond to the work function [33]. The well-known features of three-fold coordination of C atoms are the deep-lying σ band, corresponding to a strong in-plane bonding located at 8.1 eV, and delocalized π bands, representing the weak bonding

Kondo effects in small-bandgap carbon nanotube quantum dots

• Patryk Florków,
• Damian Krychowski and
• Stanisław Lipiński

Beilstein J. Nanotechnol. 2020, 11, 1873–1890, doi:10.3762/bjnano.11.169

• dots (CNTQDs) is an extended two-orbital Anderson model: where the dot Hamilonian reads: with site dot energies: depending on the magnetic field B∥ and the gate voltage Vg. The upper and lower signs, ±, refer to conduction or valence states, μo is orbital magnetic moment μo = evFD/4, where vF is the