DFT study of binding and electron transfer from colorless aromatic pollutants to a TiO₂ nanocluster: Application to photocatalytic degradation under visible light irradiation

• Corneliu I. Oprea,
• Petre Panait and
• Mihai A. Gîrţu

Beilstein J. Nanotechnol. 2014, 5, 1016–1030, doi:10.3762/bjnano.5.115

• ]. Building upon the experience gained while modeling materials for photoelectrochemical cells, we report here results of DFT and time dependent DFT (TD-DFT) calculations performed on several colorless aromatic pollutants, as well as complex systems consisting of benzene derivatives adsorbed on a TiO2

• of vibrational analyses. Time-dependent DFT [37] calculations of the molecular orbitals and the electronic transitions were performed in water by means of the polarizable continuum model (PCM) [38][39]. We used the same B3LYP functional and TZVP basis sets [36]. In the case of the pollutants adsorbed

Double layer effects in a model of proton discharge on charged electrodes

• Johannes Wiebe and
• Eckhard Spohr

Beilstein J. Nanotechnol. 2014, 5, 973–982, doi:10.3762/bjnano.5.111

• charge on the metal slab. Far from the electrode only the two charged states can contribute to the EVB ground state so that the state of a proton is a time-dependent superposition state of two different H3O+ states. The proton complex thus dynamically moves between more hydronium and more Zundel like

• developed by Warshel to study proton transfer mechanisms in biological systems [19][20][21]. This methodology was later extended by various groups to study proton dynamics in water [22][23] in a chemically intuitive picture, in which the proton state is described as (to a first approximation) a time

• -dependent superposition of Eigen, H9O4+, and Zundel, H5O2+, cations. Multistate generalizations of this simple picture were later applied to a variety of physical, chemical and biological problems [24][25][26][27][28]. In order to utilize the methodology for highly acidic environments such as a fuel cell

Designing magnetic superlattices that are composed of single domain nanomagnets

• Derek M. Forrester,
• Feodor V. Kusmartsev and
• Endre Kovács

Beilstein J. Nanotechnol. 2014, 5, 956–963, doi:10.3762/bjnano.5.109

• the x and y components, is applied with frequency fapplied = fγMs and amplitude Ha = Msha. The angle of deviation between the applied field and the x-axis of the superlattice is β, and λ is a small time-dependent perturbation in hy with amplitude 0.02 (the perturbation has its origin in a thermally

Controlling mechanical properties of bio-inspired hydrogels by modulating nano-scale, inter-polymeric junctions

• Seonki Hong,
• Hyukjin Lee and
• Haeshin Lee

Beilstein J. Nanotechnol. 2014, 5, 887–894, doi:10.3762/bjnano.5.101

• and height of 1 mm. The time dependent rheology test showed that the sol–gel transition was finished within 1 min (data not shown). In order to test the mechanical properties of the hydrogels in a stable condition, we carried out the frequency and strain sweep test 10 min after the gel formed

Classical molecular dynamics investigations of biphenyl-based carbon nanomembranes

• Andreas Mrugalla and
• Jürgen Schnack

Beilstein J. Nanotechnol. 2014, 5, 865–871, doi:10.3762/bjnano.5.98

• first step towards a deeper understanding of the structure and formation of carbon nanomembranes. Future investigations will focus on the dynamical aspects of the membrane formation. For such simulations thermostatted classical molecular dynamics [29][30][31][32][33], with possibly time-dependent

Fibrillar adhesion with no clusterisation: Functional significance of material gradient along adhesive setae of insects

• Stanislav N. Gorb and
• Alexander E. Filippov

Beilstein J. Nanotechnol. 2014, 5, 837–845, doi:10.3762/bjnano.5.95

• . Stiff, medium and soft segments are marked by black, red and green circles respectively. The subplots in the bottom (from left to right) show time dependent vertical force, evolution of the array of distances dxj = xj+1 − xj between contact ends of nearest neighbors and instant histogram P(dx) of the

• , because flexible filaments are too long in the case (b). Last case (c) with long hard filaments rotating around their flexible roots, cannot perfectly adapt to the surface. As a result, maximum of the attachment force here remains much lower than in two previous cases (a) and (b). To accumulate time

• -dependent information about deformations of the fibers we calculate array {dxj}, j = 1,2,…Nx of the distances between contact ends of the nearest neighbors dxj = xj+1 − xj. Let us note that we are using dxj for small but finite distances (not differential). We use this notation to conserve coincidence with

Scale effects of nanomechanical properties and deformation behavior of Au nanoparticle and thin film using depth sensing nanoindentation

• Dave Maharaj and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2014, 5, 822–836, doi:10.3762/bjnano.5.94

• understanding of materials behavior during contact. Mechanical properties of interest comprise hardness, Young’s modulus of elasticity, bulk modulus, elastic–plastic deformation, scratch resistance, residual stresses, time-dependent creep and relaxation properties, fracture toughness, fatigue and yield strength

Antimicrobial properties of CuO nanorods and multi-armed nanoparticles against B. anthracis vegetative cells and endospores

• Pratibha Pandey,
• Merwyn S. Packiyaraj,
• Himangini Nigam,
• Gauri S. Agarwal,
• Beer Singh and
• Manoj K. Patra

Beilstein J. Nanotechnol. 2014, 5, 789–800, doi:10.3762/bjnano.5.91

• (qualigens) consists of spheroidal micrometer-scaled particles up to 100 µm size having rough surfaces [16]. Antibacterial test against B. anthracis vegetative cells The time dependent antibacterial efficacy of CuO nanorods (PS2) against B. anthracis bacterial cells and E. coli cells at a dose of 1 mg/mL is

• very limited penetration and accumulation inside the cell [22]. The dose- and time-dependent bactericidal activity of multi-armed CuO nanoparticles (P5) against 7.0 × 105 CFU/mL B. anthracis vegetative cells at dose range of 0.5 to 6 mg/mL is shown in Figure 4. The graph also compares bactericidal

• -synthesized precursor of PS2. d) EDX spectrum of PS2. Time dependent bactericidal activity of CuO nanorods (PS2) at a dose of 1 mg/mL against B. anthracis vegetative cells and E. coli cells in saline media. Time dependent bactericidal activity of CuO multi-armed NPs (P5) at doses of 0.5 and 2 mg/mL against B

Artificial sunlight and ultraviolet light induced photo-epoxidation of propylene over V-Ti/MCM-41 photocatalyst

• Van-Huy Nguyen,
• Shawn D. Lin,
• Jeffrey Chi-Sheng Wu and
• Hsunling Bai

Beilstein J. Nanotechnol. 2014, 5, 566–576, doi:10.3762/bjnano.5.67

• experiments using only UV light. Figure 6 shows the time-dependent behavior of the photocatalytic reaction when using artificial sunlight. With respect to time on stream, the PO formation rate increased to a peak value of 151 µmol·gcat−1·h−1 after 1 h and then it decayed to 81 µmol·gcat−1·h−1 after 24 h

• illumination. Figure 8 shows the time-dependent behavior of the photocatalytic reaction when using different filters with UV light. The PO selectivity was stable even under UV-C range of 250–400 nm. On the whole, an increase in light intensity promoted the activity and resulted in increased C3H6 consumption

Control theory for scanning probe microscopy revisited

• Julian Stirling

Beilstein J. Nanotechnol. 2014, 5, 337–345, doi:10.3762/bjnano.5.38

• linearity of the feedback response. We shall refer to this log tunnel current as where is the time dependent operator fully describing the tunnel junction, the I–V amplifier, and the logarithm operation. The feedback controller then compares I(t) with a set-point, P, and tries to correct for discrepancies

• by modifying the output, O(t), to the z-piezo. We can write the feedback controller as the time-dependent operator , and hence Finally, we can link the z-piezo extension to the feedback controller output with an operator, . This describes both the high voltage amplifier use for the piezoelectric

Frequency, amplitude, and phase measurements in contact resonance atomic force microscopies

• Gheorghe Stan and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 278–288, doi:10.3762/bjnano.5.30

• band excitation (BE) method, a time-dependent signal containing a band of frequencies around the desired resonance is applied at each pixel of the scan, such that the frequency response at that location can be rapidly obtained through a Fourier transform of the cantilever tip response and a fit to a

Constant-distance mode SECM as a tool to visualize local electrocatalytic activity of oxygen reduction catalysts

• Michaela Nebel,
• Thomas Erichsen and
• Wolfgang Schuhmann

Beilstein J. Nanotechnol. 2014, 5, 141–151, doi:10.3762/bjnano.5.14

• pulse profile and the time of data acquisition [29]. Due to this complex multiparameter system, the experimental conditions for the best data acquisition varies for each measurement. By means of the 4D SF/CD-RC-SECM a technique is accessible that enables a time-dependent data acquisition at various

• closest approach. To additionally implement the redox competition mode, a variable potential pulse profile is performed at each tip-to-sample distance. During a competition pulse tip and sample compete for the oxygen inside the gap and a time-dependent current decay curve is recorded at the tip enabling a

Manipulation of nanoparticles of different shapes inside a scanning electron microscope

• Boris Polyakov,
• Sergei Vlassov,
• Leonid M. Dorogin,
• Jelena Butikova,
• Mikk Antsov,
• Sven Oras,
• Rünno Lõhmus and
• Ilmar Kink

Beilstein J. Nanotechnol. 2014, 5, 133–140, doi:10.3762/bjnano.5.13

• known to be time-dependent [4]. The initial displacement was followed by a controlled manipulation of the particle by pushing it with the tip while simultaneously recording the force in the scan regime (a detailed description of SmarAct manipulator regimes is given in Supporting Information File 1

In situ growth optimization in focused electron-beam induced deposition

• Paul M. Weirich,
• Marcel Winhold,
• Christian H. Schwalb and
• Michael Huth

Beilstein J. Nanotechnol. 2013, 4, 919–926, doi:10.3762/bjnano.4.103

• mutation method. The parents of the new parameter sets are chosen via an uniform distributed random choice. The crossover method is performed by exchanging parameters of the parents. For the mutation method parameters are chosen randomly within the given parameter-range. A representative time-dependent

• -time and pitch as obtained from the GA experiments, the resistivity of W–C–O samples can be tuned by one order of magnitude. Time-dependent rate of change of conductance for Pt–C deposits - The GA is applied for the optimization of conductance during post-irradiation with electrons (U = 5 kV, Inominal

Peak forces and lateral resolution in amplitude modulation force microscopy in liquid

• Horacio V. Guzman and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2013, 4, 852–859, doi:10.3762/bjnano.4.96

• time dependent vertical displacement of the differential element of the beam placed at the x position, and Fts tip–sample interaction force. Equations 1 and 2 are numerically solved by using a fourth-order Runge–Kutta algorithm [40]. One should note that the use of Equations 1 and 2 in environments of

Dynamic nanoindentation by instrumented nanoindentation and force microscopy: a comparative review

• Sidney R. Cohen and
• Estelle Kalfon-Cohen

Beilstein J. Nanotechnol. 2013, 4, 815–833, doi:10.3762/bjnano.4.93

• impression. This model is applicable for flat, homogeneous and isotropic samples, without nonidealities such as adhesion [11][12], pile-up [26][27][28], and time-dependent effects [29][30][31][32][33][34][35]. In practice, this fundamental equation has been extended to samples which do not, in principle

• tangential stress so that forces are restricted to the surface normal – all these are difficult to maintain in AFM. Dynamic nanoindentation Background and relevant models Time-dependent phenomena, i.e., when the material strain is not synchronous with the force or displacement applied to the perturbation

• ” in the curve (as shown in Figure 3) and, in extreme cases, to an apparent negative stiffness. This phenomenon will depend on the rate of change of the force. Computational approaches exist that modify the Sneddon contact mechanics model to remove the time-dependent effects of viscoelastic materials

AFM as an analysis tool for high-capacity sulfur cathodes for Li–S batteries

• Renate Hiesgen,
• Seniz Sörgel,
• Rémi Costa,
• Linus Carlé,
• Ines Galm,
• Natalia Cañas,
• Brigitta Pascucci and
• K. Andreas Friedrich

Beilstein J. Nanotechnol. 2013, 4, 611–624, doi:10.3762/bjnano.4.68

• was observed that was attributed to the formation of a non-conductive Li2S layer. The stability of Li2S in air was analysed by means of XRD. Li2S powder was exposed to air, and the subsequent reaction was measured in a time-dependent sequence. Figure 3 shows the X-ray patterns of the Li2S sample

Large-scale atomistic and quantum-mechanical simulations of a Nafion membrane: Morphology, proton solvation and charge transport

• Pavel V. Komarov,
• Pavel G. Khalatur and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 567–587, doi:10.3762/bjnano.4.65

• function of simulation time. The time autocorrelation functions, C(A;t), calculated for these processes and the time-dependent cross-correlation functions, C(A,B;t), characterizing the correlation between three different pairs of the same complexes are shown in Figure 15. It is notable that the C(A;t

The role of electron-stimulated desorption in focused electron beam induced deposition

• Willem F. van Dorp,
• Thomas W. Hansen,
• Jakob B. Wagner and
• Jeff T. M. De Hosson

Beilstein J. Nanotechnol. 2013, 4, 474–480, doi:10.3762/bjnano.4.56

• precursor molecules that arrive at the writing location through surface diffusion is time-dependent. If the contribution of the surface diffusion to the precursor transport is significant, this becomes apparent when the dwell time is varied. We deposited arrays with dwell times ranging from 0.1 s to 12.0 s

Kelvin probe force microscopy of nanocrystalline TiO₂ photoelectrodes

• Alex Henning,
• Gino Günzburger,
• Res Jöhr,
• Yossi Rosenwaks,
• Biljana Bozic-Weber,
• Catherine E. Housecroft,
• Edwin C. Constable,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2013, 4, 418–428, doi:10.3762/bjnano.4.49

• conduction band of TiO2, the dye is oxidized and charged more positive relative to its ground state. Hence, the surface dipole is reduced and detected as a change in the CPD. Time evolution of the SPV Time-dependent SPV measurements were performed at specific positions above single TiO2 particles. Since KPFM

Polynomial force approximations and multifrequency atomic force microscopy

• Daniel Platz,
• Daniel Forchheimer,
• Erik A. Tholén and
• David B. Haviland

Beilstein J. Nanotechnol. 2013, 4, 352–360, doi:10.3762/bjnano.4.41

• drive force and a time-dependent tip–surface force where the dot denotes differentiation with respect to time, ω0, Q and kc are the mode’s resonance frequency, quality factor and spring constant respectively, and h is the static equilibrium position of the tip above the surface. One should note that the

• surface is known, one can easily solve Equation 2 for the spectrum of the tip–surface force With the inverse Fourier transform, the time-dependent force acting on the tip can be readily determined from Equation 5. Since the result of an experiment is a vector of time-discrete samples of the continuous

• Since is not invertable we cannot determine the complete force spectrum from Equation 9, and thus the time-dependent force remains unknown. To reconstruct the complete force spectrum from the measured partial motion spectrum , we expand the tip–surface force into a finite series from a set of basis

Hydrogen-plasma-induced magnetocrystalline anisotropy ordering in self-assembled magnetic nanoparticle monolayers

• Alexander Weddemann,
• Judith Meyer,
• Anna Regtmeier,
• Irina Janzen,
• Dieter Akemeier and
• Andreas Hütten

Beilstein J. Nanotechnol. 2013, 4, 164–172, doi:10.3762/bjnano.4.16

• equilibrium states. The experimental results will be compared to numerical calculations based on the idea that the plasma induces a process comparable to the time-dependent creep under tension in which the plasma acts as thermal activation. Experimental Measurements were carried out with two different species

• . A solution is obtained by consideration of its time-dependent extension [25] with γ the gyromagnetic ratio and α a dimensionless damping constant. The microscopic relaxation occurs on time scales significantly shorter than the time scales on which external fields change. Therefore, the microscopic

• with the stray field of contiguous nanocrystals. The process is comparable to the time-dependent creep under tension with the plasma acting as the thermal activation. For uniaxial magnetocrystalline anisotropy, the migration of the magnetocrystalline easy axes results in an increase of the effective

Towards 4-dimensional atomic force spectroscopy using the spectral inversion method

• Jeffrey C. Williams and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2013, 4, 87–93, doi:10.3762/bjnano.4.10

• on it is the time-dependent tip–sample interaction, fd(t) = Fts[zc(t) + zp(t)], which generates a torsional response that can be linearized in the z-direction, zp(t). Here Fts is the tip–sample interaction force, which is a function of the distance between the tip and the sample (tip position). The

• order to obtain fd(t), that is, the time-dependent tip–sample interaction force acting on the cantilever tip. Finally the force curves are obtained by plotting fd(t) as a function of the vertical tip position, which is generally approximated by the position of the cantilever flexural oscillation, zc(t

• use of the correct expression describing the time-dependent tip position is mathematically straightforward, but is not trivial in an experiment, where there can be signal cross-talk [8][11] and where calibration and noise limitations are present. For all these reasons, it is recommended to apply the

Interpreting motion and force for narrow-band intermodulation atomic force microscopy

• Daniel Platz,
• Daniel Forchheimer,
• Erik A. Tholén and
• David B. Haviland

Beilstein J. Nanotechnol. 2013, 4, 45–56, doi:10.3762/bjnano.4.5

• frequencies close to a cantilever resonance, and those that use off-resonance components. Off-resonance techniques typically measure higher harmonics of the tip motion, which allows for a reconstruction of time-dependent surface forces acting on the tip. Due to the lack of transfer gain off resonance, these

• ' increases only in steps of 2, n' can only take odd values. Additionally, we define new Fourier coefficients such that the signal Fourier series becomes We identify the terms in parentheses as the Fourier series of a complex-valued time-dependent envelope function expanded in the base frequency Δω/2, and

• term in Equation 13. When we represent by a time-dependent amplitude A(t) and a time-dependent phase (t), such that the signal x(t) is completely described by a modulated oscillation amplitude and a modulated oscillation phase: We would like to emphasize that the narrow-band frequency comb can also

Nanostructure-directed chemical sensing: The IHSAB principle and the dynamics of acid/base-interface interaction

• James L. Gole and
• William Laminack

Beilstein J. Nanotechnol. 2013, 4, 20–31, doi:10.3762/bjnano.4.3

• concentrations of 4, 5, and 10 ppm, is suggested to result from a continual if not less pronounced change of the competing NiO-decorated interface and NO. The time-dependent competition between NO and the NiO-decorated interface means that the sensors return slowly to a baseline response. This will be the

• developing IHSAB model. We have also considered the conversion of the metal oxides in situ to their oxinitrides and the enhanced basicity that this introduces to a nanostructure-decorated PS interface. These systems also display time-dependent dynamics, which must be incorporated into the IHSAB model. This