Functional materials for environmental sensors and energy systems

• Michele Penza,
• Anita Lloyd Spetz,
• Albert Romano-Rodriguez and
• Meyya Meyyappan

Beilstein J. Nanotechnol. 2017, 8, 2015–2016, doi:10.3762/bjnano.8.201

• nanomaterials (e.g., nanowires, nanotubes, graphene, metal oxides, carbon nanostructures, large band gap semiconductors, and metals) with new sensing properties (e.g., ppb-level detection, high sensitivity, selectivity) that are self-heating and provide durable operation for low-power devices (tens of μW to

Intercalation of Si between MoS₂ layers

• Rik van Bremen,
• Qirong Yao,
• Soumya Banerjee,
• Deniz Cakir,
• Nuri Oncel and
• Harold J. W. Zandvliet

Beilstein J. Nanotechnol. 2017, 8, 1952–1960, doi:10.3762/bjnano.8.196

• [6]. The broken sub-lattice symmetry of silicene allows for the opening of a band gap in this material [8][9][10][11][12]. This band gap makes silicene a very appealing candidate for field-effect-based devices. Another attractive property of silicene is its spin–orbit coupling, which is substantially

• Fermi level. Van der Waals materials with a band gap do not suffer from this limitation. Molybdenum disulfide (MoS2) is a member of the transition metal dichalcogenide (TMD) family that belongs to the class of van der Waals materials. Bulk MoS2 has a band gap of 1.29 eV, which increases to 1.90 eV for a

Coexistence of strongly buckled germanene phases on Al(111)

• Weimin Wang and
• Roger I. G. Uhrberg

Beilstein J. Nanotechnol. 2017, 8, 1946–1951, doi:10.3762/bjnano.8.195

• metallic substrates and band gap materials. Bampoulis et al. [7] proposed a germanene layer with very small buckling (0.2 Å) when they made Pt/Ge crystals by depositing and annealing of Pt on Ge(110). In an inverse case, Li et al. [8] chose Pt(111) as a substrate onto which Ge was evaporated at room

Adsorption and diffusion characteristics of lithium on hydrogenated α- and β-silicene

• Fadil Iyikanat,
• Ali Kandemir,
• Cihan Bacaksiz and
• Hasan Sahin

Beilstein J. Nanotechnol. 2017, 8, 1742–1748, doi:10.3762/bjnano.8.175

• -hydrogenated silicene exhibits ferromagnetic semiconducting behavior with a band gap of 0.95 eV [27]. Hydrogenation leads indirect-to-direct gap transitions in bilayer silicene [28]. In the experimental study of Qiu et al., the ordered and reversible hydrogenation of silicene was performed [29]. Moreover

Group-13 and group-15 doping of germanane

• Nicholas D. Cultrara,
• Maxx Q. Arguilla,
• Shishi Jiang,
• Chuanchuan Sun,
• Michael R. Scudder,
• R. Dominic Ross and
• Joshua E. Goldberger

Beilstein J. Nanotechnol. 2017, 8, 1642–1648, doi:10.3762/bjnano.8.164

• layered van der Waals materials [20][21][22]. Germanane, a hydrogen-terminated graphane analogue of germanium, has garnered considerable attention in the field of 2D materials on account of its direct band gap [5][23][24], large predicted electron mobility, and the ability to controllably tune the

Charge transfer from and to manganese phthalocyanine: bulk materials and interfaces

• Florian Rückerl,
• Daniel Waas,
• Bernd Büchner,
• Martin Knupfer,
• Dietrich R. T. Zahn,
• Francisc Haidu,
• Torsten Hahn and
• Jens Kortus

Beilstein J. Nanotechnol. 2017, 8, 1601–1615, doi:10.3762/bjnano.8.160

• moments. MnPc is characterized by hybrid states between the Mn 3d orbitals and the π orbitals of the ligand very close to the Fermi level. This causes particular physical properties, different from those of the other phthalocyanines, such as a rather small ionization potential, a small band gap and a

Two-dimensional carbon-based nanocomposites for photocatalytic energy generation and environmental remediation applications

• Suneel Kumar,
• Ashish Kumar,
• Ashish Bahuguna,
• Vipul Sharma and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2017, 8, 1571–1600, doi:10.3762/bjnano.8.159

• environmental remediation and energy generation applications [29][30][31][32]. Semiconductor nanocomposite-based photocatalytic reactions are generally initiated by absorbing light energy equal to or more than the band gap of semiconductor photocatalyst [4]. This leads to the excitation of electrons from the

• photocatalysis [47]. As graphene is a zero band gap material and susceptible to oxidative reactions, it is often combined with other semiconductors and metallic nanostructures to form composite materials suitable for various applications, including photocatalysis. Furthermore, due to the exceptional electrical

• -heptazine and g-o-triazine, which exhibit the band gaps of 5.49, 4.85, 4.30, 4.13, 2.97, 2.88 and 0.93 eV, respectively [62]. Among these seven phases, the β-C3N4 crystalline phase possess similar hardness as compared to that of diamond, and the pseudocubic-C3N4 and g-h-triazine-C3N4 possess direct band gap

Calcium fluoride based multifunctional nanoparticles for multimodal imaging

• Marion Straßer,
• Joachim H. X. Schrauth,
• Sofia Dembski,
• Daniel Haddad,
• Bernd Ahrens,
• Stefan Schweizer,
• Bastian Christ,
• Alevtina Cubukova,
• Marco Metzger,
• Heike Walles,
• Peter M. Jakob and
• Gerhard Sextl

Beilstein J. Nanotechnol. 2017, 8, 1484–1493, doi:10.3762/bjnano.8.148

• biocompatible agents for bone and teeth reconstruction [23]. Calcium fluoride exhibits a wide transparent spectral window (190–1100 nm), large band gap (approx. 12 eV), low refractive index and low phonon energy [14]. Because of the high stability and flexibility of the fluorite structure, a number of various

Adsorption and electronic properties of pentacene on thin dielectric decoupling layers

• Sebastian Koslowski,
• Daniel Rosenblatt,
• Alexander Kabakchiev,
• Klaus Kuhnke,
• Klaus Kern and
• Uta Schlickum

Beilstein J. Nanotechnol. 2017, 8, 1388–1395, doi:10.3762/bjnano.8.140

• to sufficiently separate (electronically decouple) the molecules from the underlying metal substrate by means of thin insulating layers (decoupling layers) [6]. To achieve this, a thin spacer layer with a large band gap of several electronvolts can be used that acts as a tunnel barrier towards the

Two-dimensional silicon and carbon monochalcogenides with the structure of phosphorene

• Dario Rocca,
• Ali Abboud,
• Ganapathy Vaitheeswaran and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2017, 8, 1338–1344, doi:10.3762/bjnano.8.135

• monochalcogenides, some preliminary remarks on phosphorene are necessary. The band gap of phosphorene has been evaluated by different ab initio methods to be about 0.8 or 0.91 eV at the PBE level of theory [35][39], 1.61 eV at the HSE level of theory [35], and 2.0 eV at the GW level of theory [39]. In [8] a value

Enhanced catalytic activity without the use of an external light source using microwave-synthesized CuO nanopetals

• Govinda Lakhotiya,
• Sonal Bajaj,
• Arpan Kumar Nayak,
• Debabrata Pradhan,
• Pradip Tekade and
• Abhimanyu Rana

Beilstein J. Nanotechnol. 2017, 8, 1167–1173, doi:10.3762/bjnano.8.118

• carbon monoxide (CO) [7][8][9]. CuO is one of the few p-type metal oxide semiconductors with a narrow band gap ≈1.24 eV [10]. The properties of CuO nanomaterials (nanoparticles, nanowires, nanosheets, etc.) are closely related to morphology and crystallite size [7]. These different nanoscale morphologies

• absorption onset was estimated from the Tauc’s plot as shown in Figure 2b. The band gap of CuO nanopetals was calculated by extrapolating the linear part of the plot of (αhν)1/2 vs hν and is found to be ≈1.85 eV as shown in Figure 2b. This is different from the bulk bandgap of CuO, which is 1.24 eV [10

• the degradation through the formation of radicals [6][25]. The wide band gap, high surface area of CuO nanopetals was expected to be suitable for the photocatalytic activity for the degradation of the common cationic dye methylene blue (MB), and hence initially, a study has been carried out in which

AgCl-doped CdSe quantum dots with near-IR photoluminescence

• Pavel A. Kotin,
• Sergey S. Bubenov,
• Natalia E. Mordvinova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2017, 8, 1156–1166, doi:10.3762/bjnano.8.117

• , biolabels and for the sensibilization of Si-solar cells. But the optical properties of CdSe QDs are limited by the band-gap energy of the bulk material (Eg = 1.74 eV) [10][11], which makes exciton IR-PL impossible. Therefore, the development of new synthetic methods for CdSe QDs with non-excitonic IR-PL is

Hierarchically structured nanoporous carbon tubes for high pressure carbon dioxide adsorption

• Julia Patzsch,
• Deepu J. Babu and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2017, 8, 1135–1144, doi:10.3762/bjnano.8.115

• attractive as a potential material for catalysis and electronic and photonic devices due to its semiconducting nature with a wide band gap, excellent mechanical properties, chemical inertness and thermal conductivity [13][14][15][16][17]. Especially, one-dimensional SiC in the form of nanowires or nanorods

The integration of graphene into microelectronic devices

• Guenther Ruhl,
• Sebastian Wittmann,
• Matthias Koenig and
• Daniel Neumaier

Beilstein J. Nanotechnol. 2017, 8, 1056–1064, doi:10.3762/bjnano.8.107

• -micrometers. Metal contacts can interact with graphene in different ways [52], as shown in Figure 6. Metals physisorbed on graphene cause charge-transfer-induced doping of the graphene sheet because of the difference in work function values [53]. Metals chemisorbed on graphene are open a band gap in graphene

Energy-level alignment at interfaces between manganese phthalocyanine and C₆₀

• Daniel Waas,
• Florian Rückerl,
• Martin Knupfer and
• Bernd Büchner

Beilstein J. Nanotechnol. 2017, 8, 927–932, doi:10.3762/bjnano.8.94

• states close to the Fermi energy, MnPc differs significantly from other transition-metal phthalocyanines, as it is characterized by the smallest ionization potential, the largest electron affinity, the smallest band gap and the largest exciton-binding energy [37][38][39][40][41][42]. Furthermore, it has

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

• an additional photodeposition treatment was carried out on the sample. Proposed mechanism for major charge transfer pathways on Fe2O3(0.5)/TiO2 (PD) for degradation of 2,4-D. Crystallite size and band gap energy (Eg) of the unmodified TiO2 and Fe2O3/TiO2nanocomposites prepared by impregnation (IM

Synthesis of coaxial nanotubes of polyaniline and poly(hydroxyethyl methacrylate) by oxidative/initiated chemical vapor deposition

• Alper Balkan,
• Efe Armagan and
• Gozde Ozaydin Ince

Beilstein J. Nanotechnol. 2017, 8, 872–882, doi:10.3762/bjnano.8.89

• annealed (80 °C) and as-deposited PANI samples were found using the UV–vis spectra (Figure 2b). The band gap of PANI can be calculated from the wavelength of the polaron band excitation [45]. The onset of absorption of the polaron band excitation was used to find the band gap energies, Eg, of both samples

• . The Eg of as-deposited and annealed samples were calculated as 2.38 and 2.26 eV, respectively. The slight decrease in the band gap with increasing annealing temperature is consistent with previous PANI studies. Joshi et al. reported that the band gap of PANI decreases as the annealing temperature

• the band gap energy. The crystallinity of the deposited films was studied by using XRD analysis (Figure 3). The spectra of the non-annealed, as-deposited samples did not show any distinct peaks, indicating the amorphous state of the films. However, after an annealing process at 80 °C for 4 h, the

Investigation of growth dynamics of carbon nanotubes

• Marianna V. Kharlamova

Beilstein J. Nanotechnol. 2017, 8, 826–856, doi:10.3762/bjnano.8.85

• SWCNTs. In [104], the control of the growth mode of SWCNTs led to the synthesis of semiconducting SWCNTs with a narrow band-gap distribution. SWCNTs were grown on acorn-like partially carbon-coated Co nanoparticles. The inner Co particle was an active catalytic phase, whereas the outer carbon layer

Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields

• Arpita Jana,
• Elke Scheer and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2017, 8, 688–714, doi:10.3762/bjnano.8.74

• tendency to agglomerate due to van der Waals interaction between the graphene layers, which inhibits its application is various fields – this drawback can be eliminated by hybridising graphene with NPs. Graphene is a zero band gap material and the main disadvantage of using graphene alone as a catalyst is

• ]. The practical use of the entire surface area of a graphene sample is difficult so it is often used in combination with an active metal oxide for application as an electrode material in supercapacitors. The main drawback of graphene for optical applications is its zero band gap. However, the

• development of a heterostructure with a direct band gap semiconductor allows this material to be applied in light emitting diodes (LEDs). In most cases, the other counterpart of graphene–NP hybrids are either transition metal or metal oxide NPs. However, in some cases, depending on the scientific requirements

Investigation of the photocatalytic efficiency of tantalum alkoxy carboxylate-derived Ta₂O₅ nanoparticles in rhodamine B removal

• Subia Ambreen,
• Mohammad Danish,
• Narendra D. Pandey and
• Ashutosh Pandey

Beilstein J. Nanotechnol. 2017, 8, 604–613, doi:10.3762/bjnano.8.65

• nanoparticles efficiently removed rhodamine B under UV light irradiation. Keywords: alkoxy carboxylates; band gap; dynamic light scattering (DLS); rhodamine B; scanning electron microscopy (SEM); tantalum(V) oxide (Ta2O5) nanoparticles; TEM; X-ray diffraction (XRD); Introduction Nowadays, the purification of

• and CeO2, serve as potential photocatalysts [1][2][3][4]. The properties of the metal oxide nanoparticles (surface area, band gap, porosity) determine its photocatalytic activity for the degradation of organic pollutants from water. Because of properties such as high refractive index and large band

• gap energy [5][6][7][8], Ta2O5 nanoparticles are an open area for researchers. Tantalum pentoxide is an n-type semiconductor. It absorbs only UV light due to its wide band gap. Nevertheless, band gap modification through various methods has been proven to be successful for the red-shift of the optical

Impact of air exposure and annealing on the chemical and electronic properties of the surface of SnO₂ nanolayers deposited by rheotaxial growth and vacuum oxidation

• Monika Kwoka and
• Maciej Krzywiecki

Beilstein J. Nanotechnol. 2017, 8, 514–521, doi:10.3762/bjnano.8.55

• stoichiometry are not supposed to significantly influence the band gap value [38]. The statement is additionally supported by the results of air-exposed and UHV-annealed samples. After annealing the VB edge moved toward the initial energetic position (the shift was about 0.29 eV) so the difference to pristine

Role of oxygen in wetting of copper nanoparticles on silicon surfaces at elevated temperature

• Tapas Ghosh and
• Biswarup Satpati

Beilstein J. Nanotechnol. 2017, 8, 425–433, doi:10.3762/bjnano.8.45

• nanostructure fabrication have been carried out. CuO is a p-type semiconductor with a band gap of 1.4 eV [1][2]. Higher conductivity has been observed in CuO as compared to Cu2O, although higher carrier mobility has been observed in Cu2O [3]. However, the higher stability of CuO makes it more applicable. In the

• various metal as well as semiconductor surfaces [14][15][16][17][18][19]. Different nanostructures have been fabricated using the galvanic displacement reaction which leads to many practical applications [20][21][22]. CuO has important applications in solar cells. With a suitable band gap, CuO has a

In-situ monitoring by Raman spectroscopy of the thermal doping of graphene and MoS₂ in O₂-controlled atmosphere

• Aurora Piazza,
• Filippo Giannazzo,
• Gianpiero Buscarino,
• Gabriele Fisichella,
• Antonino La Magna,
• Fabrizio Roccaforte,
• Marco Cannas,
• Franco Mario Gelardi and
• Simonpietro Agnello

Beilstein J. Nanotechnol. 2017, 8, 418–424, doi:10.3762/bjnano.8.44

• [1]. Graphene (Gr) is a 2D carbon material with zero-energy band gap and turned out to be relevant because of its electrical, transport and optical properties. It is considered the lead example of the emerging 2D solids [2][3][4]. For example, optical transparency and bipolar charge carrier

• ]. Especially the possibility to produce van der Waals heterostructures combining Gr and MoS2, is pushing the study of this subject [1]. Indeed, the non-zero band gap, good chemical sensitivity and photo response of MoS2 pave the way for its application in optoelectronics, sensing and photovoltaic devices [22

Template-controlled piezoactivity of ZnO thin films grown via a bioinspired approach

• Nina J. Blumenstein,
• Fabian Streb,
• Stefan Walheim,
• Thomas Schimmel,
• Zaklina Burghard and
• Joachim Bill

Beilstein J. Nanotechnol. 2017, 8, 296–303, doi:10.3762/bjnano.8.32

• . Keywords: piezoresponse force microscopy; template-controlled deposition; ZnO; Introduction Zinc oxide is a wide band gap semiconductor. Thin films of it can be applied in, e.g., LEDs [1][2][3] or transistors [4][5][6]. Furthermore, due to its piezoelectricity, it can be incorporated in actuators [7] or

Performance of natural-dye-sensitized solar cells by ZnO nanorod and nanowall enhanced photoelectrodes

• Saif Saadaoui,
• Mohamed Aziz Ben Youssef,
• Moufida Ben Karoui,
• Rached Gharbi,
• Emanuele Smecca,
• Vincenzina Strano,
• Salvo Mirabella,
• Alessandra Alberti and
• Rosaria A. Puglisi

Beilstein J. Nanotechnol. 2017, 8, 287–295, doi:10.3762/bjnano.8.31

• represents the photoelectrode, composed of a wide band gap semiconductor thin layer coated on transparent conducting oxide (TCO) films. A mesoporous film layer is used as a semiconductor in the photoelectrode. Because of its stability and easy synthesis, titanium dioxide (TiO2) is mostly used as the

• semiconductor in DSSCs [2][3][4][5]. Besides, the TiO2 offers high electronic mobility for photogenerated electron collection, a suitable band gap, which adapts to the injection of the electrons of most studied dyes, and high surface area to enhance the dye loading by anchoring the dye [6][7]. Zinc oxide (ZnO

• ) has been studied as a mesoporous wide band gap semiconductor for use in DSSCs. It presents itself in the form of different morphological nanostructures, such as nanorods, nanocrystals, nanowires, nanotubes and nanowalls that can be exploited to optimize the dye loading [6][7][8][9]. The main purpose