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

• the Fe(III) complex at 400 °C [5]. This is in contrast to the one prepared by the sol–gel method that showed an obviously reduced Eg value as the Fe ions were incorporated into the TiO2 lattice [7][19]. Diffuse reflectance (DR) UV–vis spectra and Tauc plots of the nanocomposites prepared by the

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

• excellent thermal (≈5000 W·m−1·K−1) [6] and electrical conductivity (up to 6000 S·cm−1) [7] and high theoretical specific surface area (2630 m2·g−1) [8]. Graphene is highly optically transparent (transmittance ≈97.7%) with absorption of <2.3% for visible light [9] and negligible reflectance (<0.1

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

• . The distribution of particles is more uniform in the nanoparticles derived from carboxylato alkoxides than in those derived from alkoxides. UV–vis spectroscopy The optical properties of synthesized Ta2O5 nanoparticles were studied by UV–vis diffuse reflectance spectroscopy (DRS). The synthesized Ta2O5

• Ta2O5 synthesized from (a) Ta(On-Bu)4(OOCCH2Cl), (b) Ta(On-Bu)4(OOCCHCl2) and (c) Ta(On-Bu)4(OOCCCl3). Solid-state diffuse reflectance UV–vis spectrum and extrapolation of the band gap energy of Ta2O5 nanoparticles prepared from Ta(OEt)5. Degradation of RhB by Ta2O5 nanoparticles synthesized from (a) Ta

Graphene functionalised by laser-ablated V₂O₅ for a highly sensitive NH₃ sensor

• Margus Kodu,
• Artjom Berholts,
• Tauno Kahro,
• Mati Kook,
• Peeter Ritslaid,
• Helina Seemen,
• Tea Avarmaa,
• Harry Alles and
• Raivo Jaaniso

Beilstein J. Nanotechnol. 2017, 8, 571–578, doi:10.3762/bjnano.8.61

• observed as the result of the reaction of NH3 with two V2O5 adsorption sites, one with a surface OH group, forming positively charged NH4+, and the other with oxygen vacancy, forming species denoted as “coordinated NH3”. At the same time, the intensity of the V5+=O related band in the infrared reflectance

Thin SnO_x films for surface plasmon resonance enhanced ellipsometric gas sensing (SPREE)

• Daniel Fischer,
• Andreas Hertwig,
• Uwe Beck,
• Volkmar Lohse,
• Detlef Negendank,
• Martin Kormunda and
• Norbert Esser

Beilstein J. Nanotechnol. 2017, 8, 522–529, doi:10.3762/bjnano.8.56

• complex reflectance ratio ρ after irradiation of a sample with linear polarized light is measured. For a simple two-media dielectric interface, the complex reflectance ratio is given by [26][27] with rp,s as the Fresnel coefficent and δp,s as the phase for the p- and s-polarization state. tanΨ and Δ are

• intermediate layer is gold, the effect of the surface plasmon resonance has to be taken into account for the description of the reflection coefficients. Because this phenomenon effects mostly the reflection coefficient of the p-polarized part Rp, the SPR effect can be described by the reflectance = |Rp|2

• . Close to the surface plasmon resonance, the reflectance can be written as with kx0 as the component of the wave vector of the incident light in the direction of the surface plasmon propagation and kSP = + iΓ∞ as the wave vector of a surface plasmon on an interface of two semi-infinite media according

Fiber optic sensors based on hybrid phenyl-silica xerogel films to detect n-hexane: determination of the isosteric enthalpy of adsorption

• Jesús C. Echeverría,
• Ignacio Calleja,
• Paula Moriones and
• Julián J. Garrido

Beilstein J. Nanotechnol. 2017, 8, 475–484, doi:10.3762/bjnano.8.51

• , controlled porous texture that includes a specific surface area and average pore size distribution, and tunable surface chemistry. In the case of fiber optic reflectance sensors (FORSs), these sensitive films vary their optical properties upon interaction with the analyte, thereby resulting in a change in

• xerogel film covering the tip of the optical fiber, which acts as an optical cavity for which the fiber–xerogel provides the first interface and the xerogel–vapor provides the second interface. The reflectance of this sensing element may be expressed as follows [7][8][9]: In this equation, the

• the reflectance at the fiber–film interface and the sensor output signal. Furthermore, the reflectance is independent of temperature. The response of fiber optic sensors operating on reflection relies on the complex refractive index of the film and on the adsorption properties, which are related to

Fabrication of black-gold coatings by glancing angle deposition with sputtering

• Alan Vitrey,
• Rafael Alvarez,
• Alberto Palmero,
• María Ujué González and
• José Miguel García-Martín

Beilstein J. Nanotechnol. 2017, 8, 434–439, doi:10.3762/bjnano.8.46

• ), on a Hitachi equipment working at 5 kV, and atomic force microscopy (AFM), on a Dimension Icon microscope from Bruker with super-sharp tips (radius about 3 nm) to minimize the inherent convolution with the shape of the probe. In order to study the optical behavior, spectral reflectance and

• the samples are responsible for their different appearance shown in Figure 2 and their distinctive spectral behavior presented in Figure 4, where the reflectance of the samples with black and golden color is plotted. For the sake of comparison, the calculated reflectance of a bare Si substrate and

• ). The most significant fact in Figure 4a is that the nanostructured samples deposited at high tilt angle exhibit low reflectance in the visible range (400–700 nm), less than 10% for the sample prepared with σ = 87° and less than 15% for that prepared with σ = 85°. Taking into account that the optical

Tailoring bifunctional hybrid organic–inorganic nanoadsorbents by the choice of functional layer composition probed by adsorption of Cu²⁺ ions

• Veronika V. Tomina,
• Inna V. Melnyk,
• Yuriy L. Zub,
• Aivaras Kareiva,
• Miroslava Vaclavikova,
• Gulaim A. Seisenbaeva and
• Vadim G. Kessler

Beilstein J. Nanotechnol. 2017, 8, 334–347, doi:10.3762/bjnano.8.36

• surface layers were analyzed by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, and 13C and 29Si solid-state NMR spectroscopy revealing their composition and organization. The fine chemical structure of the surface in the produced hybrid adsorbent particles and the ligand distribution

• were further investigated by electron paramagnetic resonance (EPR) and electron spectroscopy of diffuse reflectance (ESDR) spectroscopy using Cu2+ ion coordination as a probe. The composition and structure of the emerging surface complexes were determined and used to provide an insight into the

• potentially strong van der Waals bonding such as fluorinated groups. We also aimed to test the availability and reactivity of the amino function via Cu2+-cation adsorption as a probe, using electron paramagnetic resonance (EPR) and electron spectroscopy of diffuse reflectance (ESDR) spectroscopy. This

Colorimetric gas detection by the varying thickness of a thin film of ultrasmall PTSA-coated TiO₂ nanoparticles on a Si substrate

• Urmas Joost,
• Andris Šutka,
• Meeri Visnapuu,
• Aile Tamm,
• Meeri Lembinen,
• Mikk Antsov,
• Kathriin Utt,
• Krisjanis Smits,
• Ergo Nõmmiste and
• Vambola Kisand

Beilstein J. Nanotechnol. 2017, 8, 229–236, doi:10.3762/bjnano.8.25

• regression algorithm. Ellipsometric measurements were generally performed at incidence and reflectance angles of 75°. TiO2 films made from NPs were modelled as homogeneous mixtures of supposedly dense materials, with the addition of voids for the adjustment of n and k. The optical properties of the thin

• equipped with an internal diffuse reflectance accessory (DRA). The DRA was configured so that both diffuse reflectance and specular reflectance were measured. The flow cell was attached to the measurement window of the DRA and was fastened securely. The flow cell (Figure 1) was constructed using 1 mm thick

• . Before filling the syringe with 20 mL of the gas mixture the gas was stirred for 3 min. During measurements, 20 mL of air with certain amounts of VOC vapor was injected with a syringe through the cell and the reflectance spectra were measured. After measurements, the cell was purged with 200 mL clean air

Performance of colloidal CdS sensitized solar cells with ZnO nanorods/nanoparticles

• Anurag Roy,
• Partha Pratim Das,
• Mukta Tathavadekar,
• Sumita Das and
• Parukuttyamma Sujatha Devi

Beilstein J. Nanotechnol. 2017, 8, 210–221, doi:10.3762/bjnano.8.23

• reflectance spectra were measured on a UV–vis–NIR spectrometer (Shimadzu, UV-3600) on the considered films. Contact angle (CA) measurements were performed on a KRUSS Drop Shape Analyser, Germany (DSA-4). The photovoltaic J–V characteristics were measured using a solar simulator (Newport) at 100 mW/cm2 (1 sun

• sensitization on the photoanode. It is also interesting to notice the increased intensity of X-ray reflections of CdS after sensitization over ZnO-P compared to ZnO-R. The relatively lower reflectance spectrum of the CdS-sensitized ZnO-P illustrates a better CdS sensitization phenomenon and corroborates the XRD

• ) Diffuse reflectance spectrum of the same films compared to bare ZnO and (c) a digital image showing the difference in contact angle for ethanolic solution of N719 dye for ZnO-R and ZnO-P films. (a,b) Microstructural FESEM and TEM bright field images of synthesized ZnO-P and (c,d) ZnO-R. FESEM images of

Optical and photocatalytic properties of TiO₂ nanoplumes

• Viviana Scuderi,
• Massimo Zimbone,
• Maria Miritello,
• Giuseppe Nicotra,
• Giuliana Impellizzeri and
• Vittorio Privitera

Beilstein J. Nanotechnol. 2017, 8, 190–195, doi:10.3762/bjnano.8.20

• , and as a consequence could favor the photocatalytic activity. In order to gain more insight into the realized structure, we performed transmittance (T) and reflectance (R) measurements in the range of 200–800 nm. The optical spectra are reported in Figure 4. The transmittance spectra (Figure 4a) show

• , and the dashed with the continuous line). The reflectance measurements are reported in Figure 4b. The total reflectance spectra of Ti (70-60) and Ti (70-150) present a shift in the reflectance peak, from 302 to 314 nm. This shift may be related to the variation on the sample thickness, due to the

• different chemical etching time. Although the measured spectra include wavelengths from 200 to 800 nm we will focus on the UV region, since the light source of photocatalytic experiments emits in this range (dashed vertical line). In this region the absolute values of reflectance for Ti (70-60) and Ti (70

Grazing-incidence optical magnetic recording with super-resolution

• Gunther Scheunert,
• Sidney. R. Cohen,
• René Kullock,
• Ryan McCarron,
• Katya Rechev,
• Ifat Kaplan-Ashiri,
• Ora Bitton,
• Paul Dawson,
• Bert Hecht and
• Dan Oron

Beilstein J. Nanotechnol. 2017, 8, 28–37, doi:10.3762/bjnano.8.4

• absorption. Thermal modelling was done in Comsol MultiphysicsTM Version 5.2, using the heat module and the “Deposited Beam Power” feature. A loss of 5% at the DLC surface due to reflection was assumed, describing the case of p-polarized incident light, for which DLC has a particularly low reflectance at 70

Intercalation and structural aspects of macroRAFT agents into MgAl layered double hydroxides

• Dessislava Kostadinova,
• Ana Cenacchi Pereira,
• Muriel Lansalot,
• Franck D’Agosto,
• Elodie Bourgeat-Lami,
• Fabrice Leroux,
• Christine Taviot-Guého,
• Sylvian Cadars and
• Vanessa Prevot

Beilstein J. Nanotechnol. 2016, 7, 2000–2012, doi:10.3762/bjnano.7.191

• Fullprof suite program [57]. ChemBio 3D Ultra suite program was used to draw the molecular structure of macroRAFT copolymers, running MM2 energy-minimization. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra were measured in the range 400–4000 cm−1 on a FTIR Nicolet 5700 (Thermo

Monolayer graphene/SiC Schottky barrier diodes with improved barrier height uniformity as a sensing platform for the detection of heavy metals

• Ivan Shtepliuk,
• Jens Eriksson,
• Volodymyr Khranovskyy,
• Tihomir Iakimov,
• Anita Lloyd Spetz and
• Rositsa Yakimova

Beilstein J. Nanotechnol. 2016, 7, 1800–1814, doi:10.3762/bjnano.7.173

• The top-down sublimation growth process in an inductively heated furnace at 2000 °C under an argon pressure of 1 atm [50] was used to synthesize the 1 ML epitaxial graphene on n-type (nitrogen-doped) 4H-SiC (0001) substrates. A study of the grown samples by reflectance mapping and Raman

• our sample is characterized by the smallest value of the standard deviation for the Schottky barrier height. It can be explained by assuming a high uniformity of thickness (99% according to reflectance mapping) and barrier height. The derived values of the ideality factor of a diode junction suggest

Precise in situ etch depth control of multilayered III−V semiconductor samples with reflectance anisotropy spectroscopy (RAS) equipment

• Ann-Kathrin Kleinschmidt,
• Lars Barzen,
• Johannes Strassner,
• Christoph Doering,
• Henning Fouckhardt,
• Wolfgang Bock,
• Michael Wahl and
• Michael Kopnarski

Beilstein J. Nanotechnol. 2016, 7, 1783–1793, doi:10.3762/bjnano.7.171

• Institut für Oberflächen- und Schichtanalytik (IFOS) GmbH, Trippstadter Str. 120, D-67663 Kaiserslautern, Germany 10.3762/bjnano.7.171 Abstract Reflectance anisotropy spectroscopy (RAS) equipment is applied to monitor dry-etch processes (here specifically reactive ion etching (RIE)) of monocrystalline

• sample in order to make RAS control possible. Keywords: broad area semiconductor lasers (BAL); dry-etch monitoring (RIE); precise etch depth control; reflectance anisotropy spectroscopy (RAS); III–V semiconductors; Introduction Reflectance anisotropy/difference spectroscopy (RAS/RDS) [1][2][3][4][5] is

• axes): with the reflectances/reflectivities R of the relevant directions of linear polarization designated by Miller’s indices of the corresponding principal axes (in this example [110] and ) and the total average reflectance/reflectivity [3][4][6][8]. In case the signal is given as a function of

Surface-enhanced infrared absorption studies towards a new optical biosensor

• Lothar Leidner,
• Julia Stäb,
• Jennifer T. Adam and
• Günter Gauglitz

Beilstein J. Nanotechnol. 2016, 7, 1736–1742, doi:10.3762/bjnano.7.166

• results are compared with a similar experiment performed with an ATR (attenuated total reflectance) set-up. Keywords: attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR); direct optical sensing; mid-infrared regime (MIR); reflectometric interference spectroscopy; surface

• perpendicular incidence, the reflectance R at the interfaces defined by the film and the surrounding media (substrate and superstrate) can be calculated according to where R1, R2 are the Fresnel reflectances at the two interfaces, d is the physical thickness, and n the refractive index of the film [14]. Moving

• Reflectance measurements of the RIfS set-up show an interference pattern caused by a polymer film on top of the GaAs substrate. Model calculations were performed in order to avoid coincidence between a minimum of reflectance and the spectroscopically interesting region between 3000 and 3400 cm−1 (data not

Role of RGO support and irradiation source on the photocatalytic activity of CdS–ZnO semiconductor nanostructures

• Suneel Kumar,
• Rahul Sharma,
• Vipul Sharma,
• Gurunarayanan Harith,
• Vaidyanathan Sivakumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2016, 7, 1684–1697, doi:10.3762/bjnano.7.161

• K8002AA Carry 660 FTIR instrument. Optical properties were analyzed by UV–vis diffuse reflectance spectroscopy (DRS) using a Perkin Elmer UV/VIS/NIR Lambda 750 spectrophotometer, in which polytetrafluroethylene (PTFE) polymer was employed as internal reflectance standard. Morphology of the samples was

• characteristic diffraction peak around 2θ = 24° due to RGO is also absent in the ternary composite, which indicates that RGO sheets are not stacked due to the CdS–ZnO composite which inhibits the stacking. UV–vis diffuse reflectance spectroscopy (DRS) The optical properties of all prepared samples were analyzed

• by using UV–vis diffuse reflectance spectroscopy (DRS), the results of which are presented in Figure 2. It is clear from the DRS spectra that ZnO NR have an absorption band edge at 390 nm corresponding to a band gap value of 3.23 eV, which is in agreement with the reported band gap value of ZnO [45

Development of adsorptive membranes by confinement of activated biochar into electrospun nanofibers

• Mehrdad Taheran,
• Mitra Naghdi,
• Satinder K. Brar,
• Emile Knystautas,
• Mausam Verma,
• Rao. Y. Surampalli and
• Jose. R. Valero

Beilstein J. Nanotechnol. 2016, 7, 1556–1563, doi:10.3762/bjnano.7.149

• with a thin layer of gold–palladium alloy using a SPI Module sputter coater. Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectra were recorded on a Nicolet iS50 spectrometer (Thermo Scientific, USA) at 0.04 cm−1 resolution and in the range of 400–4000 cm−1. Brunauer–Emmett–Teller

Nanostructured germanium deposited on heated substrates with enhanced photoelectric properties

• Ionel Stavarache,
• Valentin Adrian Maraloiu,
• Petronela Prepelita and
• Gheorghe Iordache

Beilstein J. Nanotechnol. 2016, 7, 1492–1500, doi:10.3762/bjnano.7.142

• stronger light source in the NIR range. Reflectance spectra were obtained using a double beam UV–vis–NIR spectrophotometer (250–3000 nm, Perkin Elmer 950) with specular reflectance accessory (B0086703) at a fixed incidence angle (6°). The response speed of the photodetector test structure was measured by

The effect of dry shear aligning of nanotube thin films on the photovoltaic performance of carbon nanotube–silicon solar cells

• Benedikt W. Stolz,
• Daniel D. Tune and
• Benjamin S. Flavel

Beilstein J. Nanotechnol. 2016, 7, 1486–1491, doi:10.3762/bjnano.7.141

• this could change the reflectance of the silicon surface differently to when an as-prepared film was deposited. However, reflectance measurements taken of the completed devices not only showed that this was not the case, but that the devices with the DSA films were, on average, 5–10% less reflective

Microwave synthesis of high-quality and uniform 4 nm ZnFe₂O₄ nanocrystals for application in energy storage and nanomagnetics

• Christian Suchomski,
• Ben Breitung,
• Ralf Witte,
• Michael Knapp,
• Sondes Bauer,
• Tilo Baumbach,
• Christian Reitz and
• Torsten Brezesinski

Beilstein J. Nanotechnol. 2016, 7, 1350–1360, doi:10.3762/bjnano.7.126

• an Agilent 5973 MSD. Diffuse reflectance ultraviolet–visible spectra were collected on a Lambda 750 UV–vis–NIR spectrophotometer (PerkinElmer) equipped with a Praying Mantis diffuse reflectance accessory. An MPMS XL-5 superconducting quantum interference device magnetometer (Quantum Design) was used

High performance Ce-doped ZnO nanorods for sunlight-driven photocatalysis

• Bilel Chouchene,
• Tahar Ben Chaabane,
• Lavinia Balan,
• Emilien Girot,
• Kevin Mozet,
• Ghouti Medjahdi and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2016, 7, 1338–1349, doi:10.3762/bjnano.7.125

• [53]. Finally, the relative contributions of Ce4+ and Ce3+ states at the surface of ZnO rods were estimated to be 79 and 21%, respectively. To evaluate the photo-absorption behaviors of the ZnO:Ce materials, the UV–visible diffuse reflectance spectra (DRS) were recorded and shown in Figure 4 (undoped

• increasing Ce concentrations. The redshift in absorption probably originates from sub-bandgap transitions originating from Ce doping [34][54]. These electronic transitions from the VB of ZnO to the Ce energy levels require less energy than that of the VB to the CB of ZnO. Reflectance spectra have been

• converted to the absorbance spectra using the Kubelka–Munk function FKM(R) = (1 − R)2/2R, where R is the reflectance recorded for the sample (Figure S1 in the Supporting Information File 1). The bandgap energies determined by an extrapolation method vary between 3.29 and 3.30 eV for ZnO and ZnO:Ce rods and

Photocurrent generation in carbon nanotube/cubic-phase HfO₂ nanoparticle hybrid nanocomposites

• Protima Rauwel,
• Augustinas Galeckas,
• Martin Salumaa,
• Frédérique Ducroquet and
• Erwan Rauwel

Beilstein J. Nanotechnol. 2016, 7, 1075–1085, doi:10.3762/bjnano.7.101

• with the fundamental absorption edge of HfO2 building up at around 5.6 eV. These assertions are supported by the similarity of the absorption edge and absence of CNT-related features in the spectrum of free-standing cubic HfO2 nanoparticles obtained earlier from the diffuse reflectance measurements [21

• CNT. (a) Absorption spectrum of MWCNTs decorated with cubic HfO2 nanoparticles obtained from the transmittance measurements of colloidal suspension in ethanol (blue curve) against that of free-standing HfO2 nanoparticles from the diffuse reflectance measurements (red curve). (b) Tauc plots of the

Optical absorption signature of a self-assembled dye monolayer on graphene

• Tessnim Sghaier,
• Sylvain Le Liepvre,
• Céline Fiorini,
• Ludovic Douillard and
• Fabrice Charra

Beilstein J. Nanotechnol. 2016, 7, 862–868, doi:10.3762/bjnano.7.78

• -3,4,9,10-tetracarboxylic dianhydride (PTCDA), have become archetypes for photonic applications of dyes [12], for self-organized adsorption on various atomically flat surfaces [13], and for their combination. Indeed, optical differential reflectance spectroscopy [14], photoluminescence, or Raman diffraction

Selective photocatalytic reduction of CO₂ to methanol in CuO-loaded NaTaO₃ nanocubes in isopropanol

• Tianyu Xiang,
• Feng Xin,
• Jingshuai Chen,
• Yuwen Wang,
• Xiaohong Yin and
• Xiao Shao

Beilstein J. Nanotechnol. 2016, 7, 776–783, doi:10.3762/bjnano.7.69

• –precipitation mechanism, where the concentration of the NaOH solution played a crucial role on the morphology of the crystal. This was confirmed in our work. Figure 3 shows UV–vis diffuse reflectance spectra and optical absorption edges of NaTaO3 nanocubes prepared with different concentrations of NaOH. From

• particles were dispersed on the surface of the NaTaO3 nanocubes with an average size of tens of nanometers (Figure 5b and Figure 5c). When the loading reached 5 wt %, the CuO nanoparticles began to aggregate and large clusters were formed (Figure 5d). The UV–vis diffuse reflectance spectra of CuO–NaTaO3 are

• isopropanol to methanol was also proposed and explained by band theory. XRD patterns of NaTaO3 nanocubes. SEM images of NaTaO3 nanocubes: (a) 1M-NaTaO3, (b) 2M-NaTaO3, (c) 3M-NaTaO3, and (d) 4M-NaTaO3. UV–vis diffuse reflectance spectra (a) and optical absorption band edges (b) of NaTaO3 nanocubes. XRD