Photoactive nanoarchitectures based on clays incorporating TiO₂ and ZnO nanoparticles

• Eduardo Ruiz-Hitzky,
• Pilar Aranda,
• Marwa Akkari,
• Nithima Khaorapapong and
• Makoto Ogawa

Beilstein J. Nanotechnol. 2019, 10, 1140–1156, doi:10.3762/bjnano.10.114

• @montmorillonite materials can be synthesized from a Zn solution and cetyltrimethylammonium (CTA)-montmorillonite organoclays. In these materials, the bandgap energy of ZnO is decreased compared to bare ZnO NPs, which results in a faster photodegradation of MB. In experiments to prepare ZnO@clay nanoarchitectures

• perspectives Nanoparticulated TiO2 has almost the same bandgap characteristics than ZnO, with bandgap energies of 3.20 eV and 3.37 eV, respectively [48][134][135][136]. Therefore, the photocatalytic capability of both types of NPs should be quite similar. Apart from these large bandgap energy values, both

• transition metals or with other semiconductors. Among them, semiconductor heterojunctions have attracted great attention [139]. The doping of TiO2 and ZnO NPs with the aim to conveniently tuning the bandgap energy values can be a suitable option. In this context, it has been verified for both types of NPs, a

CuInSe₂ quantum dots grown by molecular beam epitaxy on amorphous SiO₂ surfaces

• Henrique Limborço,
• Pedro M.P. Salomé,
• Rodrigo Ribeiro-Andrade,
• Jennifer P. Teixeira,
• Nicoleta Nicoara,
• Kamal Abderrafi,
• Joaquim P. Leitão,
• Juan C. Gonzalez and
• Sascha Sadewasser

Beilstein J. Nanotechnol. 2019, 10, 1103–1111, doi:10.3762/bjnano.10.110

• formation of a Cu–In–Se ordered defect compound, which has been reported to form along the tie-line of the (Cu2Se)x–(In2Se3)1−x pseudo-binary system [38][39], and which has a bandgap energy very close to that of CuInSe2 [40]. In this compositional region, i.e., low amounts of Cu compared with In, the so

• energy for the QD [48] and QW [49] can be calculated as: where Eg is the CIS low-temperature bandgap energy, h is the Planck constant, me is the effective conduction-band mass, mh is the effective valence-band mass, e is the rest electron charge, ε is the CIS dielectric constant and Ex is the exciton

Electronic properties of several two dimensional halides from ab initio calculations

• Mohamed Barhoumi,
• Ali Abboud,
• Lamjed Debbichi,
• Moncef Said,
• Torbjörn Björkman,
• Dario Rocca and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2019, 10, 823–832, doi:10.3762/bjnano.10.82

• PBE. The top of the valence band (blue) and bottom of conduction band (red) are indicated. The Fermi level is set to 0 eV. Comparison of our calculated (PBE) lattices constants (Å) with the experimental (E) values of the bulk structures [41]. Comparison of theoretical bandgap energy Eg (eV) of

Zn/F-doped tin oxide nanoparticles synthesized by laser pyrolysis: structural and optical properties

• Florian Dumitrache,
• Iuliana P. Morjan,
• Elena Dutu,
• Ion Morjan,
• Claudiu Teodor Fleaca,
• Monica Scarisoreanu,
• Alina Ilie,
• Marius Dumitru,
• Cristian Mihailescu,
• Adriana Smarandache and
• Gabriel Prodan

Beilstein J. Nanotechnol. 2019, 10, 9–21, doi:10.3762/bjnano.10.2

• . As shown in Figure 5b and reported in Table 3, the bandgap energy of the SnO2 materials show a decrease with decreasing F doping concentration and with the increase of Zn doping concentration. The bandgap of our standard undoped sample was found to be 3.55 eV, which is lower than that of bulk SnO2

Enhancement of X-ray emission from nanocolloidal gold suspensions under double-pulse excitation

• Wei-Hung Hsu,
• Frances Camille P. Masim,
• Armandas Balčytis,
• Hsin-Hui Huang,
• Tetsu Yonezawa,
• Aleksandr A. Kuchmizhak,
• Saulius Juodkazis and
• Koji Hatanaka

Beilstein J. Nanotechnol. 2018, 9, 2609–2617, doi:10.3762/bjnano.9.242

• speed of light in vacuum, A is the absorbance, εb is the binding energy [eV/atom], and Ji is the ionization potential. The threshold fluence for the creation of the ENZ state is calculated for full ionization, i.e., with the bandgap energy Δg in Equation 3 instead of (εb + Ji). For water, Δg = 9.5 eV

• of solvated electrons. When the bandgap energy of water Δg = 9.5 eV is taken as the ionization threshold, a slightly larger fluence of = 60 mJ/cm2 will result. For the metal (gold nanoparticles) we consider the ablation threshold expression equivalent to Equation 3 in which binding energy and

High-contrast and reversible scattering switching via hybrid metal-dielectric metasurfaces

• Jonathan Ward,
• Khosro Zangeneh Kamali,
• Lei Xu,
• Guoquan Zhang,
• Andrey E. Miroshnichenko and
• Mohsen Rahmani

Beilstein J. Nanotechnol. 2018, 9, 460–467, doi:10.3762/bjnano.9.44

• metasurface. The geometrical parameters are Lx = 100 nm, Ly = 600 nm, Lz = 200 nm, t = 200 nm, d = 400 nm, h = 400 nm, g = 60 nm, p1 = 850 nm, p2 = 850 nm. (a) Bandgap energy (blue curve) and variation of refractive index (dark curve) versus temperature change for bulk silicon [40]. (b) Transmission of

Substrate and Mg doping effects in GaAs nanowires

• Perumal Kannappan,
• Nabiha Ben Sedrine,
• Jennifer P. Teixeira,
• Maria R. Soares,
• Bruno P. Falcão,
• Maria R. Correia,
• Nestor Cifuentes,
• Emilson R. Viana,
• Marcus V. B. Moreira,
• Geraldo M. Ribeiro,
• Alfredo G. de Oliveira,
• Juan C. González and
• Joaquim P. Leitão

Beilstein J. Nanotechnol. 2017, 8, 2126–2138, doi:10.3762/bjnano.8.212

• for application in solar cells owing to their high absorption, direct bandgap, high carrier mobility and well-developed synthesis techniques [5][6][7][8][9]. Among the group III–V semiconductors, GaAs is one of the most intensively studied materials and has a suitable bandgap energy value for solar

• bandgap in the whole temperature range for several semiconductors, namely for the ZB crystalline phase of GaAs, was proposed by Pässler [63]: where Eg(0) is the bandgap energy at 0 K, α is the T→∞ limit of −dEg(T)/dT, Θ is a parameter related with the Debye temperature, and q is an adjustable parameter

High photocatalytic activity of Fe₂O₃/TiO₂ nanocomposites prepared by photodeposition for degradation of 2,4-dichlorophenoxyacetic acid

• Shu Chin Lee,
• Hendrik O. Lintang and
• Leny Yuliati

Beilstein J. Nanotechnol. 2017, 8, 915–926, doi:10.3762/bjnano.8.93

• additional absorption peak corresponding to the Fe species. The bandgap energy (Eg) of the unmodified TiO2 and the nanocomposites were studied by a Tauc plot, considering the indirect transition in anatase TiO2 [34]. The Tauc plot of the TiO2 (NT) and the Fe2O3/TiO2 (IM) nanocomposites was derived by

Morphology control of zinc oxide films via polysaccharide-mediated, low temperature, chemical bath deposition

• Florian Waltz,
• Hans-Christoph Schwarz,
• Andreas M. Schneider,
• Stefanie Eiden and
• Peter Behrens

Beilstein J. Nanotechnol. 2015, 6, 799–808, doi:10.3762/bjnano.6.83

• properties were determined under UV irradiation corresponding to the bandgap energy (370 nm). The values of the sheet resistance as well as the specific resistance of completely processed ZnO films after the second CBD are listed in Table 2. The sheet resistance of our films was above 1 kΩ/sq and the sheet

Optimizing the synthesis of CdS/ZnS core/shell semiconductor nanocrystals for bioimaging applications

• Li-wei Liu,
• Si-yi Hu,
• Ying Pan,
• Jia-qi Zhang,
• Yue-shu Feng and
• Xi-he Zhang

Beilstein J. Nanotechnol. 2014, 5, 919–926, doi:10.3762/bjnano.5.105

• material with a high bandgap energy of 3.66 eV, the use of ZnS leads to enhanced stability and luminescence intensity. The ZnS protective shell not only enhances the brightness of the QDs but also improves their stability in a biological environment. This study provides a useful synthetic route for

Biomolecule-assisted synthesis of carbon nitride and sulfur-doped carbon nitride heterojunction nanosheets: An efficient heterojunction photocatalyst for photoelectrochemical applications

• Hua Bing Tao,
• Hong Bin Yang,
• Jiazang Chen,
• Jianwei Miao and
• Bin Liu

Beilstein J. Nanotechnol. 2014, 5, 770–777, doi:10.3762/bjnano.5.89

• properties including chemical and thermal stability, physical abundance, as well as suitable bandgap energy and band position [1][2][3][4]. The polymeric nature of CN could facilitate the tuning of the physical and chemical properties by simply changing the CN precursors, by varying the pyrolysis conditions

• attributed to the interband transition induced by defects through sulfur doping. The bandgap energy (Eg) estimated from the (αhν)2 versus hν plots are 2.79 and 2.82 eV for CN and CNS, respectively. Mott–Schottky measurements were conducted to estimate the relative conduction band position. From the

• intersects of the Mott–Schottky plots, the flatband potential and thus the conduction band edge of CN and CNS are estimated to be about −1.22 and −1.01 eV vs Ag/AgCl, respectively. Together with the bandgap energy obtained from optical absorption measurements, the valence band position for CN and CNS are

An analytical approach to evaluate the performance of graphene and carbon nanotubes for NH₃ gas sensor applications

• Elnaz Akbari,
• Vijay K. Arora,
• Aria Enzevaee,
• Mohamad. T. Ahmadi,
• Mehdi Saeidmanesh,
• Mohsen Khaledian,
• Hediyeh Karimi and
• Rubiyah Yusof

Beilstein J. Nanotechnol. 2014, 5, 726–734, doi:10.3762/bjnano.5.85

• zero bandgap energy, graphene has a high electron mobility at room temperature. The electron transfer in graphene is 100 times faster than that in silicon. A zero band gap with massless Dirac fermions makes graphene theoretically lossless, making it a perfect two-dimensional (2D) semiconductor [19][20

Template based precursor route for the synthesis of CuInSe₂ nanorod arrays for potential solar cell applications

• Mikhail Pashchanka,
• Jonas Bang,
• Niklas S. A. Gora,
• Ildiko Balog,
• Rudolf C. Hoffmann and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2013, 4, 868–874, doi:10.3762/bjnano.4.98

• range and a part of the near infrared diapason as well (with a threshold that corresponds to a bandgap energy of 1.03 eV). A future challenge would be the incorporation of the 3D aligned CISe nanorod arrays as absorber material in a solar cell. Obviously, one of the main challenges towards this end is

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

• the incident light wavelength approaches the bandgap energy of TiO2 higher SPVs result leading to steeper slopes of the SPV-versus-intensity curves. The SPV is proportional to the number of photogenerated charge carriers. It is evident from Figure 6a that more electrons are generated with higher

• material [48], α is therefore expected to show a quadratic dependence on the illumination wavelength for energies just above the bandgap. Figure 5a presents an SPS measurement taken on a cluster of sintered anatase particles showing a quadratic dependence on the wavelength. By linear fitting, a bandgap

• energy of Eg = 3.2 eV was extracted using Equation 1, assuming a phonon energy Ep ≈ 0. Figure 5b depicts the SPV of bare TiO2 as a function of the light intensity for super-bandgap illumination with a wavelength of 380 nm. The negative SPV indicates an n-type behavior of the material. The SPV exhibits a

Precursor concentration and temperature controlled formation of polyvinyl alcohol-capped CdSe-quantum dots

• Chetan P. Shah,
• Madhabchandra Rath,
• Manmohan Kumar and
• Parma N. Bajaj

Beilstein J. Nanotechnol. 2010, 1, 119–127, doi:10.3762/bjnano.1.14

• the effective mass of the hole, d is the size of the nanoparticle, and h is the Planck constant. For CdSe nanoparticles, me* and mh* are 0.13 m0 and 0.45m0, respectively [27], and Eg(0) is 1.7 eV [28]. Therefore, the size of CdSe nanoparticles is given by Equation 2. where d is in nm. The bandgap

• energy was obtained from the absorption spectrum. The sizes of the CdSe nanoparticles determined, using the above equation, for various concentrations of the precursors, by keeping the concentration of Cd(OAc)2 fixed, and varying the concentration of Na2SeSO3, and vice versa, are listed in Table 1. The