A TiO₂@MWCNTs nanocomposite photoanode for solar-driven water splitting

• Anh Quynh Huu Le,
• Ngoc Nhu Thi Nguyen,
• Hai Duy Tran,
• Van-Huy Nguyen and
• Le-Hai Tran

Beilstein J. Nanotechnol. 2022, 13, 1520–1530, doi:10.3762/bjnano.13.125

• spectra of the prepared catalysts are shown in Figure 6b. The optical absorption of TiO2 is in the UV region, while the light absorption edge of TiO2@MWCNTs redshifts to the visible-light region. As seen from the Tauc plots (inset of Figure 6b), the optical band gap of TiO2 and TiO2@MWCNTs catalysts are

• exhibits poor hydrogen production under sunlight irradiation. It could be explained by the 3.14 eV optical band gap of TiO2, which absorbs only UV light. In addition, the fast recombination of the photogenerated (h+/e−) pairs contributes to the poor photochemical catalysis activity of the TiO2 electrode

Coherent amplification of radiation from two phase-locked Josephson junction arrays

• Mikhail A. Galin,
• Vladimir M. Krasnov,
• Ilya A. Shereshevsky,
• Nadezhda K. Vdovicheva and
• Vladislav V. Kurin

Beilstein J. Nanotechnol. 2022, 13, 1445–1457, doi:10.3762/bjnano.13.119

• transform an applied constant voltage V into electromagnetic (EM) oscillations. The fundamental Josephson frequency, fJ, is connected to V via the ac-Josephson relation, hfJ = 2eV, where h is the Planck constant and e is the elementary charge. Josephson generation occurs up to the superconducting gap

• voltage. Therefore, fJ can be up to about 1 THz for low-Tc JJs [1] and can reach tens of terahertz for high-Tc JJs [2][3]. Thus, a JJ has the potential to be the basis of compact, continuous-wave and tunable terahertz generators, which would facilitate solving the problem of so-called “THz gap” [4]. A

• of the opposite long side. All lumped elements are connected by ideal conductors located at the edges of mesh. The gap between two arrays is 0.1 mm. The JJs are described by the RSJ model [20]. The corresponding equations of junction dynamics are solved self-consistently with Maxwell equations, which

Density of states in the presence of spin-dependent scattering in SF bilayers: a numerical and analytical approach

• Tairzhan Karabassov,
• Valeriia D. Pashkovskaia,
• Nikita A. Parkhomenko,
• Anastasia V. Guravova,
• Elena A. Kazakova,
• Boris G. Lvov,
• Alexander A. Golubov and
• Andrey S. Vasenko

Beilstein J. Nanotechnol. 2022, 13, 1418–1431, doi:10.3762/bjnano.13.117

• is well-known [1][2][3][79]. It has a so-called mini-gap at the subgap energies E < Δ (where Δ is the superconducting gap), whose magnitude depends on the NS interface parameters and the thickness of the N layer [79][80]. Replacing the N layer with a ferromagnetic metal F results in a more

• particular, we can see the evolution of the DOS peaks. For h = 0, that is, for the case of an SN bilayer, we see the well-known DOS structure with the characteristic mini-gap at energies E < Δ (Figure 2a, black dotted line) [79]. This proximity-induced mini-gap originates from the effective backscattering of

• the quasiparticles at the SN interface due to a finite interface resistance [99]. As h increases, the DOS splits for the spin-up and spin-down electrons, which results in the mini-gap peak splitting. For a certain value of h, the mini-gap closes, resulting in the DOS enhancement at zero energy as seen

Straight roads into nowhere – obvious and not-so-obvious biological models for ferrophobic surfaces

• Wilfried Konrad,
• Christoph Neinhuis and
• Anita Roth-Nebelsick

Beilstein J. Nanotechnol. 2022, 13, 1345–1360, doi:10.3762/bjnano.13.111

• , which attempts to bridge the gap between biology and engineering (or applied sciences in general). This gap is quite profound: Whereas biologists are interested in organisms, engineers are interested in designing successful technical constructions. Naturally, the aim of an applied science project (a

Recent trends in Bi-based nanomaterials: challenges, fabrication, enhancement techniques, and environmental applications

• Vishal Dutta,
• Ankush Chauhan,
• Ritesh Verma,
• C. Gopalkrishnan and
• Van-Huy Nguyen

Beilstein J. Nanotechnol. 2022, 13, 1316–1336, doi:10.3762/bjnano.13.109

• . This gap is essential for improving the material’s light-harvesting capabilities [78][79]. Consequently, in an attempt to improve the photocatalytic efficiency for water purification and other environmental applications, a variety of techniques, such as defect formation, metal/non-metal doping

• , Cl), Br (I). Dong et al. [88] reported the fabrication of boron-doped Bi3O4Cl ultrathin nanosheets via a solvothermal technique, which were found to have enhanced solar absorption and efficient electron–hole separation. The B atoms enhance the photocatalytic performance via (1) producing mid-gap

• shown in Figure 5a may be used to classify the heterojunctions between semiconductors as either a straddling gap (type I), an uneven gap (type II), or a broken gap (type III). Type-II heterojunctions have garnered the most interest because of the improved photogenerated electron–hole separation they

Roll-to-roll fabrication of superhydrophobic pads covered with nanofur for the efficient clean-up of oil spills

• Patrick Weiser,
• Robin Kietz,
• Marc Schneider,
• Matthias Worgull and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2022, 13, 1228–1239, doi:10.3762/bjnano.13.102

• slightly above the melting point of the respective PP type (170 °C in our case). For this temperature the viscosity of the polymer melt was sufficient to enable the hot-pulling process. The second roller of the calender was unheated and had a smooth surface. The gap between the rollers was adjusted to be

• uniformity over the whole film area. The most important parameter for high-quality nanofur is the gap size between the upper and lower roller. It should be set to a few tens of micrometers below the nominal material thickness; the contact angle is highest if the roller just touches the surface without

• applying high embossing forces. In this case it was set to 350 µm (the nominal thickness of the PP/COC laminate was 400 µm). Since the polymer laminate has small variations in thickness, a tradeoff must be made between setting the gap at the optimal thickness for maximum contact angle and setting it below

A cantilever-based, ultrahigh-vacuum, low-temperature scanning probe instrument for multidimensional scanning force microscopy

• Hao Liu,
• Zuned Ahmed,
• Sasa Vranjkovic,
• Manfred Parschau,
• Andrada-Oana Mandru and
• Hans J. Hug

Beilstein J. Nanotechnol. 2022, 13, 1120–1140, doi:10.3762/bjnano.13.95

• cantilever-based AFM offers experimental flexibility by permitting multimodal or multifrequency operations with superior force derivative sensitivities and bandwidths. Our instrument has a sub-picometer gap stability and can simultaneously map not only vertical and lateral forces with atomic-scale resolution

• noise and measurement bandwidths”, and “STM noise spectrum and tip–sample gap stability measurements”. Finally, various atomic-scale STM and AFM results described in section “Results and Discussion” structured into various subsections demonstrate the performance of our new AFM for such work. The last

• suspension springs that reach through cylindrical tubes running through the LHe tank and are mounted on top of the tank. Together with the Eddy current damping system mounted at the bottom of the cryostat, this provides excellent vibration isolation such that a tip–sample gap stability better than 1 pm can

Recent advances in green carbon dots (2015–2022): synthesis, metal ion sensing, and biological applications

• Aisha Kanwal,
• Naheed Bibi,
• Sajjad Hyder,
• Arif Muhammad,
• Hao Ren,
• Jiangtao Liu and
• Zhongli Lei

Beilstein J. Nanotechnol. 2022, 13, 1068–1107, doi:10.3762/bjnano.13.93

• structure for endogenous nitrogen-doping in a green synthesis of CD-based room-temperature phosphorescent (RTP) materials. The materials had lifetimes of up to 271.2 ms with a lower energy gap and 350 nm of excitation (0.32 eV). Furthermore, when iron ions (Fe3+) were introduced, they displayed appropriate

• though they have the same chemical surface groups and particle size distribution, they both have varying levels of surface oxidation. The emission wavelength moved from 518 to 543 nm as the degree of surface oxidation increased, which gives an indication about the reduction of band gap between LUMO and

Spindle-like MIL101(Fe) decorated with Bi₂O₃ nanoparticles for enhanced degradation of chlortetracycline under visible-light irradiation

• Chen-chen Hao,
• Fang-yan Chen,
• Kun Bian,
• Yu-bin Tang and
• Wei-long Shi

Beilstein J. Nanotechnol. 2022, 13, 1038–1050, doi:10.3762/bjnano.13.91

• use carbon nanotubes or carbon quantum dots to modify MIL101(Fe) to enhance its conductivity and broaden its visible-light response [37][38]. Another strategy is to construct MIL101-based heterostructures with the aid of narrow-gap semiconductors to promote the separation and transfer of

Analytical and numerical design of a hybrid Fabry–Perot plano-concave microcavity for hexagonal boron nitride

• Felipe Ortiz-Huerta and
• Karina Garay-Palmett

Beilstein J. Nanotechnol. 2022, 13, 1030–1037, doi:10.3762/bjnano.13.90

• parameters of the plano-concave microcavity When a polymer layer is added inside a bare microcavity, as in our case, two fundamental Gaussian beams are formed inside the air gap and polymer layer, respectively (Figure 3) [16]. The spotsize W02 (Figure 3) of the fundamental Gaussian mode (TEM00 ) inside the

• known as the q-parameters for the Gaussian beams, where z2 = L2 − Lp, z1 = L1 and zR,1,2 is the Rayleigh length for each beam. For a Gaussian beam passing through a plane dielectric interface, we have A = B = C = 0, and D = n2/n1, where n1 = 1 is the refractive index of the air gap, therefore, by

Numerical study on all-optical modulation characteristics of quantum cascade lasers

• Biao Wei,
• Haijun Zhou,
• Guangxiang Li and
• Bin Tang

Beilstein J. Nanotechnol. 2022, 13, 1011–1019, doi:10.3762/bjnano.13.88

• noting that, when the wavelength of the modulating light is close to the band gap of the active region of the QCL, most of the injected light energy excites the electrons in the valence band to transition to the conduction band and then to the upper laser subband, thereby increasing the power of the

• modulating light. However, with a decrease in the modulated laser wavelength, its energy becomes greater than the band gap between the valence band and the lower laser subband of the conduction band of the QCL active region, with the excess energy exciting the electrons to a higher energy level or high

Comparing the performance of single and multifrequency Kelvin probe force microscopy techniques in air and water

• Jason I. Kilpatrick,
• Emrullah Kargin and
• Brian J. Rodriguez

Beilstein J. Nanotechnol. 2022, 13, 922–943, doi:10.3762/bjnano.13.82

• performance gap narrows significantly, and the technique choice will likely be based on ease of implementation and spatial resolution requirements of the experiment. For operation in liquid environments, ED-based modes offer very low VAC requirements, optimal CPD detection, and high SNR. This mode is a clear

Efficiency of electron cooling in cold-electron bolometers with traps

• Dmitrii A. Pimanov,
• Vladimir A. Frost,
• Anton V. Blagodatkin,
• Anna V. Gordeeva,
• Andrey L. Pankratov and
• Leonid S. Kuzmin

Beilstein J. Nanotechnol. 2022, 13, 896–901, doi:10.3762/bjnano.13.80

• is the NIS junction voltage, Te and Ts are the electron temperatures in the normal metal and the superconductor, is the density of states in the superconductor, Δ is the superconducting gap, and kB is the Boltzmann constant. Using the integral of the tunneling current through the NIS junction

Self-assembly of C₆₀ on a ZnTPP/Fe(001)–p(1 × 1)O substrate: observation of a quasi-freestanding C₆₀ monolayer

• Guglielmo Albani,
• Michele Capra,
• Alessandro Lodesani,
• Alberto Calloni,
• Gianlorenzo Bussetti,
• Marco Finazzi,
• Franco Ciccacci,
• Alberto Brambilla,
• Lamberto Duò and
• Andrea Picone

Beilstein J. Nanotechnol. 2022, 13, 857–864, doi:10.3762/bjnano.13.76

• metallic substrates. Here, the hybridization between the molecular orbitals and the electronic states of the substrate generally modifies the intrinsic properties of the molecules, inducing the broadening of the molecular resonances, the narrowing of the band gap, and the development of interface states

• to C 2p electrons [56]. Therefore, it is present with only slight modifications both in ZnTPP/Fe(001)–p(1 × 1)O and C60/ZnTPP/Fe(001)–p(1 × 1)O samples. In order to determine the HOMO–LUMO gap of the C60 film, STS measurements have been acquired for both negative and positive bias to investigate the

• electronic gap equal to 3.75 eV. Finally, work function measurements have been performed to evaluate the charge transfer between the different layers constituting the heterostructure. Generally, electron transfer from the substrate (overlayer) to the overlayer (substrate) induces an increase (decrease) of

Modeling a multiple-chain emeraldine gas sensor for NH₃ and NO₂ detection

• Hana Sustkova and
• Jan Voves

Beilstein J. Nanotechnol. 2022, 13, 721–729, doi:10.3762/bjnano.13.64

• central benzene region (0D+0U+1C), see Figure 4, and (v) their combinations were modeled. The relative resistance was estimated in the same way as for one chain with ammonia and nitrogen dioxide described above. As a first step, the effect of a discontinued polyaniline chain was studied. The gap between

• in position “u” (undoped), also denominated 2D+2U. Two PANI chains overlapping in the middle with a gap of 3 Å. The position (c) is for ammonia or nitrogen dioxide molecules. Further positions are doped (d) and undoped (u), shown here with an ammonia molecule. Two PANI chains overlapping in the

• middle with a gap of 3 Å top view. Between the chains one ammonia molecule is located. The relative resistance change of emeraldine salt, one molecule chain was taken into account, by the presence of several ammonia gas molecules near the chain, in the positions as described above. The relative

Experimental and theoretical study of field-dependent spin splitting at ferromagnetic insulator–superconductor interfaces

• Peter Machon,
• Michael J. Wolf,
• Detlef Beckmann and
• Wolfgang Belzig

Beilstein J. Nanotechnol. 2022, 13, 682–688, doi:10.3762/bjnano.13.60

• gap edge. Such shifts and following possibility to create of Shiba bands [33][34] have been investigated theoretically also recently in related systems [35][36]. Spin-active scattering in FI–S bilayers has been discussed, for example , in [29] in the clean and in [37] in the dirty limit. Here, we

• effects. On one hand, the initial peaks at the T = 0 superconductor gap Δ0 are spin-split into two separated peaks, each positioned depending on δφ and Δ. On the other hand, Δ self-consistently also depends on the spin mixing angle. In Figure 3, we plot the density of states for T ≪ Tc with self

• fabrication, magnetic properties, and experimental procedures can be found in [42][43]. Examples of the conductance spectra measured for different applied fields in one of the junctions are shown in Figure 5a. At small fields, the spectra exhibit a well-defined gap with negligible subgap conductance

A superconducting adiabatic neuron in a quantum regime

• Marina V. Bastrakova,
• Dmitrii S. Pashin,
• Dmitriy A. Rybin,
• Andrey E. Schegolev,
• Nikolay V. Klenov,
• Igor I. Soloviev,
• Anastasiya A. Gorchavkina and
• Arkady M. Satanin

Beilstein J. Nanotechnol. 2022, 13, 653–665, doi:10.3762/bjnano.13.57

• preservation of the interlevel distance is observed during the rise/fall periods of the signal. A different behavior is observed for l > l* where during the rise/fall periods of the signal, a double-well potential appears (Figure 2d). Here, the two lowest close energy levels are separated by an energy gap from

Fabrication and testing of polymer microneedles for transdermal drug delivery

• Vahid Ebrahiminejad,
• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2022, 13, 629–640, doi:10.3762/bjnano.13.55

• master MN arrays (9 × 9) were fabricated using two-photon polymerization (TPP). A previous gap in the detailed characterization of the embossing process was investigated, showing an average of 4.99 ± 0.35% longitudinal shrinkage and 2.15 ± 0.96% lateral enlargement in the molded MN replicas. The effects

Approaching microwave photon sensitivity with Al Josephson junctions

• Andrey L. Pankratov,
• Anna V. Gordeeva,
• Leonid S. Revin,
• Dmitry A. Ladeynov,
• Anton A. Yablokov and
• Leonid S. Kuzmin

Beilstein J. Nanotechnol. 2022, 13, 582–589, doi:10.3762/bjnano.13.50

• understood from Figure 2b. The superconducting gap decreases by a few percent due to the temperature increase from 265 to 500 mK according to the BCS model. It leads to a minor decrease in the JJ critical current. Thus, the qualitative picture remains the same for 265 and 500 mK: The height of the potential

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

• effects strongly influence the optical and electronic properties of 2D-TMDC materials. Optical second harmonic generation (SHG) spectroscopy has been recently used to study the presence of mid-gap states in the electronic band structure of WS2 flakes, which are induced by sulfur vacancies [14]. In

Effects of substrate stiffness on the viscoelasticity and migration of prostate cancer cells examined by atomic force microscopy

• Xiaoqiong Tang,
• Yan Zhang,
• Jiangbing Mao,
• Yuhua Wang,
• Zhenghong Zhang,
• Zhengchao Wang and
• Hongqin Yang

Beilstein J. Nanotechnol. 2022, 13, 560–569, doi:10.3762/bjnano.13.47

• stiffness dependent. As the stiffness of the substrate increased, the cell migration rate also increased. Specifically, compared to HPV-PZ-7 cells on stiff substrates (35 kPa), PC-3 cells moved in a sheet-like fashion and nearly closed the gap. Cells on intermediate substrates (19 kPa) had the next lowest

• cell migration, cells were cultured on PAA gels with different stiffness for 48 h, removed by trypsinization, and seeded at a density of 2 × 106 cells/mL in six-well plates to a confluent monolayer. A 10 µL pipet tip was used to scrape the cell monolayer in a straight line to create an empty gap. The

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

• detection of 1.49 × 10−13 and 9.99 × 10−12 were reported by Kumar et al. for 4-nitrophenol (4-NP) and R6G, respectively, adsorbed onto a ZnO multipod suspension containing Ag nanospheres [69]. Increasing the sputtering time leads to an increase of the Au NPs size and a decrease of the interparticle gap

• , which is known to enhance the SERS signal. An optimum value for interparticle gap and size of Au NPs is needed to enhance the SERS signal. In [68] and [34], the fabrication of highly ordered flower-like ZnO nanorods decorated with Ag NPs is described. Sub-10 nm nanogaps between adjacent Ag NPs were the

• . Introducing defects reduces the optical gap, which allows for a more effective charge transfer between ZnO–Ag nanowires and the molecules attached. Also, the interstitial oxygen defects change the wettability of ZnO–Ag nanowires, which reduces the spreading of Ag NPs or probe molecules on the surface, which

Electrostatic pull-in application in flexible devices: A review

• Teng Cai,
• Yuming Fang,
• Yingli Fang,
• Ruozhou Li,
• Ying Yu and
• Mingyang Huang

Beilstein J. Nanotechnol. 2022, 13, 390–403, doi:10.3762/bjnano.13.32

• , Kaul et al. [15][16] prepared a two-terminal SWCNT NEM switch. The response time of the switch is nanoseconds, and the voltage is 3.5–4.5 V. Cha et al. [21] prepared a multiwalled carbon nanotube (MWCNT) NEM switch. The switch length is 800 nm, the diameter is 20–40 nm, the initial gap is 40–60 nm, and

• -terminal cantilever MWCNT NEM switch. The diameter of the CNTs is 50 nm, the length is 2 µm, and the gap is 150 nm. When Vds is 0.5 V, Vgs is in the range of 6–30 V. Loh et al. [24] prepared a cantilever SWCNT and diamond electrode structure with a pull-in voltage of 23.4 V. C–C bonds can greatly improve

• the life cycles of the switch. The MWCNTs prepared by Dujardin et al. [17] had a diameter of 22 nm and a length of 115 nm. The pull-in voltage was reduced to 2.9 V as the gap was only 4 nm. Vertical model: On the basis of the cantilever model, Jang et al. [18][19][20] and Kaul et al. [4] aligned CNTs

Micro- and nanotechnology in biomedical engineering for cartilage tissue regeneration in osteoarthritis

• Zahra Nabizadeh,
• Mahmoud Nasrollahzadeh,
• Hamed Daemi,
• Mohamadreza Baghaban Eslaminejad,
• Ali Akbar Shabani,
• Mehdi Dadashpour,
• Majid Mirmohammadkhani and
• Davood Nasrabadi

Beilstein J. Nanotechnol. 2022, 13, 363–389, doi:10.3762/bjnano.13.31

• nanotubes enhanced the biocompatibility and bioactivity of the PCL microspheres and provided an excellent biomaterial for cell differentiation and mineralization. In recent years, numerous efforts have been made to evaluate new candidate biomaterials to bridge the gap between material sciences and

A broadband detector based on series YBCO grain boundary Josephson junctions

• Egor I. Glushkov,
• Alexander V. Chiginev,
• Leonid S. Kuzmin and
• Leonid S. Revin

Beilstein J. Nanotechnol. 2022, 13, 325–333, doi:10.3762/bjnano.13.27

• a wide frequency range from tens of gigahertz to several terahertz [13][14], which exceeds the gap limitation of low-Tc detectors. So, in [12] the spectrum of a quantum cascade laser emission has been recovered by an YBaCuO detector at a central frequency around 2.2 THz. However, for some