Sodium doping in brookite TiO₂ enhances its photocatalytic activity

• Boxiang Zhuang,
• Honglong Shi,
• Honglei Zhang and
• Zeqian Zhang

Beilstein J. Nanotechnol. 2022, 13, 599–609, doi:10.3762/bjnano.13.52

• understand the photocatalytic behavior of a given material. The bandgap values were determined from the diffuse reflectance spectra using the Tauc plot method [26]: where A in Equation 1 is a proportional constant, α is the absorption coefficient, and n depends on the type of electron transition. The bandgap

• Eg is the x-axis interception when linear fitting the absorption edge of the Tauc plot. As both the direct and the indirect electron transition in the brookite were reported, two transitions were considered in this work. Figure 2 shows the Tauc plot derived from the diffuse reflectance spectra of

• of the MB (≈665 nm) acquired by a UV–vis spectrophotometer. The diffuse reflectance spectra were measured in the wavelength range of 300–800 nm using a UV–vis spectrophotometer. The bandgap was determined by linear fitting the absorption edge of the Tauc plot of the absorption spectra. Structure

A photonic crystal material for the online detection of nonpolar hydrocarbon vapors

• Evgenii S. Bolshakov,
• Aleksander V. Ivanov,
• Andrei A. Kozlov,
• Anton S. Aksenov,
• Elena V. Isanbaeva,
• Sergei E. Kushnir,
• Aleksei D. Yapryntsev,
• Aleksander E. Baranchikov and
• Yury A. Zolotov

Beilstein J. Nanotechnol. 2022, 13, 127–136, doi:10.3762/bjnano.13.9

• array with a sensing matrix of polydimethylsiloxane, have been determined by using scanning electron microscopy and by the results of specular reflectance spectroscopy based on the Bragg–Snell law. A new approach has been proposed for the application of this sensor in chemical analysis for the

• qualitative detection of saturated vapors of volatile organic compounds due to configuration changes of the photonic bandgap, recorded by diffuse reflectance spectroscopy. The exposure of the sensor to aromatic (benzene, toluene and p-xylene) and aliphatic (n-pentane, n-heptane, n-octane and n-decane

• ) hydrocarbons has been analyzed. The reconstitution of spectral parameters of the sensor during the periodic detection of saturated vapors of toluene has been evaluated. Keywords: diffuse reflectance spectroscopy; photonic crystal sensor; stimuli-responsive materials; Introduction Photonic crystals (PhCs

Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review

• Viet Van Pham,
• Hong-Huy Tran,
• Thao Kim Truong and
• Thi Minh Cao

Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7

• reflectance spectroscopy (DRS) [35][36][37][38][39][40]. This promotes a new avenue for diverse analyses of semiconductor photocatalysts in addition to the traditional theories and conclusions. Previous studies have shown that the photocatalytic activity of NOx decomposition of materials in general and SnO2

• photoinduced electrons from the CB of BiOBr to that of SnO2, thus prolonging the lifetime of photogenerated electron–hole pairs (Figure 8). The NO-to-NO2 conversion and intermediates and products were confirmed via in situ diffuse reflectance infrared Fourier transform spectroscopy during NO oxidation [70

• –210, Copyright (2017), with permission from Elsevier. This content is not subject to CC BY 4.0. (a) Diffuse reflectance spectra of SnO2 and SnO2/GQDs composites. Inset is the absorption spectrum of GQDs dispersed in water. (b) PL spectra of SnO2 and SnO2/GQDs composites. Excitation wavelength: 260 nm

Revealing the formation mechanism and band gap tuning of Sb₂S₃ nanoparticles

• Maximilian Joschko,
• Franck Yvan Fotue Wafo,
• Christina Malsi,
• Danilo Kisić,
• Ivana Validžić and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 1021–1033, doi:10.3762/bjnano.12.76

• /aggregates, the size and aspect ratios of the crystalline particles, the corresponding molar ratio of Sb and S obtained by EDX, and the associated band gap obtained by reflectance measurements (see discussion of the optical data below). XRD measurements of an orange-red (30 min) and a grayish-black (18 h

• the amorphous particles, until a grayish-black mixture of crystalline material without spherical, amorphous particles (≈18 h) was finally obtained. Optical characterization The optical properties of the materials were measured by reflectance spectroscopy and analyzed by applying the Tauc plot to

• transition factor γ depends on the type of the band gap transition. It equals 1/2 for a direct allowed transition and 2 for an indirect allowed transition. For reflectance data, α is expressed by the Kubelka–Munk function F(R∞) (Equation 2), which is the quotient of the absorption coefficient k and the

A Au/CuNiCoS₄/p-Si photodiode: electrical and morphological characterization

• Adem Koçyiğit,
• Adem Sarılmaz,
• Teoman Öztürk,
• Faruk Ozel and
• Murat Yıldırım

Beilstein J. Nanotechnol. 2021, 12, 984–994, doi:10.3762/bjnano.12.74

• results of the CuNiCoS4 nanocrystals confirmed that the nanocrystals are suitable for interfacial layers of photodiodes. Optical properties The optical properties of CuNiCoS4 nanocrystals were investigated by absorbance and diffuse reflectance spectroscopy (Figure 3). As can be seen in Figure 3a, the

• synthesized nanocrystals exhibit strong absorption over a broad spectrum including the ultraviolet and the near-infrared region. Furthermore, the graph of the diffuse reflectance spectroscopy is given as an inset in Figure 3a. The obtained result show that the absorption of CuNiCoS4 nanocrystals increases

• reflectance graph) and (b) bandgap energy diagram of CuNiCoS4 nanocrystals. The I–V characteristics as well as RR changes of the Au/CuNiCoS4/p-Si photodiode under different illumination intensities. The values of n and ϕb of the Au/CuNiCoS4/p-Si photodiode as functions of the illumination power density. Rj–V

Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules

• Sabine Maier and
• Meike Stöhr

Beilstein J. Nanotechnol. 2021, 12, 950–956, doi:10.3762/bjnano.12.71

• successfully employed hBN to investigate the pristine properties of particular molecules. Schaal et al. [86] showed that hBN on Ni(111) electronically decoupled tetraphenyldibenzoperiflanthene such that the molecular vibronic progression was observable by in situ differential reflectance spectroscopy, which is

Impact of GaAs(100) surface preparation on EQE of AZO/Al₂O₃/p-GaAs photovoltaic structures

• Piotr Caban,
• Rafał Pietruszka,
• Jarosław Kaszewski,
• Monika Ożga,
• Bartłomiej S. Witkowski,
• Krzysztof Kopalko,
• Piotr Kuźmiuk,
• Katarzyna Gwóźdź,
• Ewa Płaczek-Popko,
• Krystyna Lawniczak-Jablonska and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 578–592, doi:10.3762/bjnano.12.48

• characteristics were collected under standard test conditions (STC) using a PET solar simulator, model #SS100AAA. UV–vis absorbance and reflectance measurements were conducted with the use of a Varian Cary 5000 spectrophotometer equipped with a DRA 2500 integrating sphere accessory. The XPS measurements were

• Figure 1) might induce specific initial growth conditions of proximate layers, possibly resulting in various bandgap sizes of deposited AZO. In order to verify the influence of potential differences of Eg on the quantum efficiency of the devices, reflectance (diffuse and specular) examinations were

• conducted. The obtained reflectance spectra were then transformed in order to get the dependence of [F(R)·hν]2 as a function of the energy in eV (where h is the Planck’s constant and ν is the frequency of the photon), following the Kubelka–Munk theory and the equation F(R) = α/s = (1 − R)2/2R, where F(R) is

Boosting of photocatalytic hydrogen evolution via chlorine doping of polymeric carbon nitride

• Malgorzata Aleksandrzak,
• Michalina Kijaczko,
• Wojciech Kukulka,
• Daria Baranowska,
• Martyna Baca,
• Beata Zielinska and
• Ewa Mijowska

Beilstein J. Nanotechnol. 2021, 12, 473–484, doi:10.3762/bjnano.12.38

• -PCN were investigated via UV–vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) emission spectroscopy. Figure 8a shows the Kubelka–Munk function curves of the fabricated materials. The bandgap is 2.78 and 2.77 eV for PCN and Cl-PCN, respectively, indicating that the Cl-doping had no

Mapping the local dielectric constant of a biological nanostructured system

• Wescley Walison Valeriano,
• Rodrigo Ribeiro Andrade,
• Juan Pablo Vasco,
• Angelo Malachias,
• Bernardo Ruegger Almeida Neves,
• Paulo Sergio Soares Guimarães and
• Wagner Nunes Rodrigues

Beilstein J. Nanotechnol. 2021, 12, 139–150, doi:10.3762/bjnano.12.11

• optical reflectance measurements and simulation, we were able to describe the origin of the strongly iridescent wing colors of this Amazonian rainforest damselfly. The method we demonstrate here should be useful for the study of other biological nanostructured systems. Keywords: dielectric constant

• different strategies found in nature, is astonishing [5][6]. Studies of the origin of physical colors in insects are numerous in the literature and the most commonly used tools are non-local optical reflectance, electron microscopy, and scanning probe microscopy techniques, which give support to theoretical

• [17][18][19]; nanostructures which make it a natural photonic crystal. We obtain quantitative information about the wing structure and its local relative permittivity values. We also simulate the optical reflectance using the extracted spatial profile of the relative permittivity and compare it with

ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• band gap in semiconductors. However, this approach has major problems. It is semi-empiric and indirect via the Tauc formula [12]. Therefore, it contains highly erroneous data. Here, the approach is to measure the reflectance data and accordingly plot the Tauc formula as a function of the energy

• . Typical plots of the Tauc formula from UV–vis reflectance spectra are given in Figure 1c. The intersection point at the energy axis gives the value of Eg. However, the determination of the intersection point is not very accurate. According to Figure 1c, defective nanoscale ZnO has a higher value of Eg

• ionized oxygen vacancies located either in volume or at the surface of the material. (b) PL spectra showing all possible defect centers, including non-paramagnetic ones. The defects emit visible light yielding a broad emission band [4]. (c) Tauc plot obtained from UV–vis reflectance measurements

Unravelling the interfacial interaction in mesoporous SiO₂@nickel phyllosilicate/TiO₂ core–shell nanostructures for photocatalytic activity

• Bridget K. Mutuma,
• Xiluva Mathebula,
• Isaac Nongwe,
• Bonakele P. Mtolo,
• Boitumelo J. Matsoso,
• Rudolph Erasmus,
• Zikhona Tetana and
• Neil J. Coville

Beilstein J. Nanotechnol. 2020, 11, 1834–1846, doi:10.3762/bjnano.11.165

• . Therefore, in this study we report on the growth of mesoporous SiO2@NiPS and titania-coated mSiO2@NiPS (mSiO2@NiPS/TiO2) core–shell nanostructures using a simple deposition-precipitation method. Transmission electron microscopy (TEM), N2 physisorption analysis, diffuse reflectance UV–visible spectroscopy

• functionality of nanomaterials greatly influence their photoactivity. UV–vis diffuse reflectance spectroscopy is a useful technique for probing the optoelectronic properties, band structure and molecular energy levels of semiconductors. It gives relevant information on the optical activity of nanomaterials as

• it involves the excitation of photogenerated electrons and holes. The bandgap energy values of nanomaterials can be estimated by direct extrapolation of either the F(R) spectrum or from the maximum absorption wavelength [47][50]. The solid-state UV–visible reflectance spectra of mSiO2@NiPS and mSiO2

Nanocasting synthesis of BiFeO₃ nanoparticles with enhanced visible-light photocatalytic activity

• Thomas Cadenbach,
• Maria J. Benitez,
• A. Lucia Morales,
• Cesar Costa Vera,
• Luis Lascano,
• Francisco Quiroz,
• Alexis Debut and
• Karla Vizuete

Beilstein J. Nanotechnol. 2020, 11, 1822–1833, doi:10.3762/bjnano.11.164

• -fabricated metal carboxylates as metal precursors. To the best of our knowledge, the synthesized particles are the smallest BiFeO3 particles ever prepared by any method. The samples were characterized by X-ray powder diffraction, transmission electron microscopy and UV–vis diffuse reflectance spectroscopy

• analyze the BiFeO3 nanomaterial are powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV–visible reflectance spectroscopy. Furthermore, we investigated the photocatalytic efficiency of this nanomaterial under visible light in the degradation of rhodamine B (RhB) as a model

• non-agglomerated nanoparticles. We would like to point out that, to the best of our knowledge, the present pure-phase 5.5 nm BiFeO3 nanoparticles are the smallest nanoparticles of that material so far. In order to investigate the optical properties of the nanocast BiFeO3 powder, diffuse reflectance UV

Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir

• Mathias Franz,
• Romy Junghans,
• Paul Schmitt,
• Adriana Szeghalmi and
• Stefan E. Schulz

Beilstein J. Nanotechnol. 2020, 11, 1439–1449, doi:10.3762/bjnano.11.128

• metals (Au, Pt, Pd, Cu, and Ir) were investigated to derive a set of technologies as platform for specific applications. Especially, the shape of the 3D structures and the resulting reflectance have been investigated. The Si nanostructures fabricated using Au nanoparticles show a perfect light absorption

• with a reflectance below 0.3%. The demonstrated technology can be integrated into common fabrication processes for microelectromechanical systems. Keywords: black silicon; bottom-up; metal-assisted chemical etching (MACE); nanowires; wafer-level integration; Introduction Silicon nanostructures

• random structures are typically vertically aligned nanowires, also called nanorods. Silicon nanowire arrays can be designed to have a low reflectance of about 1% in a broad spectral range, depending on their geometry. These silicon structures exhibit efficient light trapping because photons are scattered

Structural and electronic properties of SnO₂ doped with non-metal elements

• Jianyuan Yu,
• Yingeng Wang,
• Yan Huang,
• Xiuwen Wang,
• Jing Guo,
• Jingkai Yang and
• Hongli Zhao

Beilstein J. Nanotechnol. 2020, 11, 1321–1328, doi:10.3762/bjnano.11.116

• reflectivity in the infrared region, and the reflectance of the crystals doped with N, C, S, and B decreased sequentially. Based on this theoretical calculations, F-doped SnO2 is found to be the best photoelectric material for preparing low-emissivity coatings. Keywords: density functional theory (DFT); doped

• -emissivity glass. The most important property of low-emissivity is the reflectivity in the infrared region. According to the reflectance spectrum of the material, a good adiabatic behavior of the material requires the plasma frequency to be close to the visible region. Plasma is a system in which the

• transparent. Otherwise, it is impossible for the light to pass through, showing metallic reflectivity. The reflectance spectra of SnO2 crystals doped with non-metal elements are shown in Figure 4. It shows that SnO2 doped with F had the highest reflectance, followed by doping with N, C, S, and B in this order

Role of redox-active axial ligands of metal porphyrins adsorbed at solid–liquid interfaces in a liquid-STM setup

• Thomas Habets,
• Sylvia Speller and
• Johannes A. A. W. Elemans

Beilstein J. Nanotechnol. 2020, 11, 1264–1271, doi:10.3762/bjnano.11.110

• ) substrate and an n-tetradecane solution of the compound [7]. From real-time topographic signature changes in the STM images (Figure 1c), combined with optical reflectance spectroscopy, it was concluded that Mn=O complexes were readily formed in the presence of O2 gas. This was a surprising result, since a

Hybridization vs decoupling: influence of an h-BN interlayer on the physical properties of a lander-type molecule on Ni(111)

• Maximilian Schaal,
• Takumi Aihara,
• Marco Gruenewald,
• Felix Otto,
• Jari Domke,
• Roman Forker,
• Hiroyuki Yoshida and
• Torsten Fritz

Beilstein J. Nanotechnol. 2020, 11, 1168–1177, doi:10.3762/bjnano.11.101

• atomically thin h-BN interlayer to investigate its possible decoupling effect. To this end, we use in situ differential reflectance spectroscopy as an established method to distinguish between hybridized and decoupled molecules. By inserting an h-BN interlayer we fabricate a buried interface and show that

• comprehensive study we utilized differential reflectance spectroscopy (DRS), low-energy electron diffraction (LEED), low-temperature scanning tunneling microscopy (LT-STM), as well as photoelectron spectroscopy (PES). Our results reveal that DBP on h-BN/Ni(111) is well decoupled from the metal substrate Ni(111

• ). Furthermore, it was possible to obtain large domains of highly ordered molecules by depositing at an elevated substrate temperature of 170 °C. Results and Discussion Optical spectroscopy Figure 1 shows the comparison of the differential reflectance (DR) spectra (definition see Experimental section) of DBP on

Excitonic and electronic transitions in Me–Sb₂Se₃ structures

• Nicolae N. Syrbu,
• Victor V. Zalamai,
• Ivan G. Stamov and
• Stepan I. Beril

Beilstein J. Nanotechnol. 2020, 11, 1045–1053, doi:10.3762/bjnano.11.89

• crystal layers were characterized by a high reflectance, which is characteristic of metallic aluminum mirrors. Some measurements were also carried out on the spectrometer DFS-32 coupled with a Specord M-40 and a Jasco V-670. The photoconductivity spectra were obtained on a single spectrometer (MDR-2) with

Highly sensitive detection of estradiol by a SERS sensor based on TiO₂ covered with gold nanoparticles

• Andrea Brognara,
• Ili F. Mohamad Ali Nasri,
• Beatrice R. Bricchi,
• Andrea Li Bassi,
• Caroline Gauchotte-Lindsay,
• Matteo Ghidelli and
• Nathalie Lidgi-Guigui

Beilstein J. Nanotechnol. 2020, 11, 1026–1035, doi:10.3762/bjnano.11.87

• TiO2 porosity. Optical properties Figure 4 reports the optical transmittance of the TiO2/Au samples. Our previous studies involving TiO2/Au systems have shown that the reflectance has low values of about 5% and can thus be considered negligible [28]. A general decrease of the optical transmittance was

A 3D-polyphenylalanine network inside porous alumina: Synthesis and characterization of an inorganic–organic composite membrane

• Jonathan Stott and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2020, 11, 938–951, doi:10.3762/bjnano.11.78

• ALOX surface and the crystal of the ATR module could not be achieved, therefore we employed diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) to analyze surface-grafted polymers. Figure 7 shows the NIR spectra of the outer surface of the pPA-functionalized ALOX-membranes. All observed

A set of empirical equations describing the observed colours of metal–anodic aluminium oxide–Al nanostructures

• Cristina V. Manzano,
• Jakob J. Schwiedrzik,
• Gerhard Bürki,
• Laszlo Pethö,
• Johann Michler and
• Laetitia Philippe

Beilstein J. Nanotechnol. 2020, 11, 798–806, doi:10.3762/bjnano.11.64

• aluminium oxide films and a metal layer (8 nm Cr and 25, 17.5 and 10 nm of Au), respectively. AAO films of different thickness were anodized and the Yxy values (Y is the luminance value, and x and y are the chromaticity values) were obtained via reflectance measurements. An empirical model based on the

• (AAO) films; anodization; structural colours; reflectance; polar coordinates; plasmonic effects; Introduction Recently, the reproduction of the vivid colours found in nature has received increasing interest [1]. These colours appear when light interacts with periodic structures. With regard to this

• design of colours by choosing a specific thickness [14]. Also, there is a model based on optical measurements (ellipsometry integrating indirectly thickness, porosity) in combination with total reflectance measurements to access the colours, in terms of L*a*b* values, of AAO–Al nanostructures filled with

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• means, such as optical reflectance and absorption, electron energy loss spectroscopy, X-ray absorption, emission, and inelastic scattering. Regarding luminescence studies, PL is the light emission, i.e., the electromagnetic radiation from matter after the absorption of photons. It is originated by

Effect of Ag loading position on the photocatalytic performance of TiO₂ nanocolumn arrays

• Jinghan Xu,
• Yanqi Liu and
• Yan Zhao

Beilstein J. Nanotechnol. 2020, 11, 717–728, doi:10.3762/bjnano.11.59

• the array was measured using a laser of 325 nm excitation wavelength and a grating spectrometer (Horiba, JY iHR550). The diffuse reflectance absorption spectrum of the array was measured using an ultraviolet–visible spectrophotometer (UV–vis, Shimadzu, UV-3600). Photocatalytic experiments. The

Nanoparticles based on the zwitterionic pillar[5]arene and Ag⁺: synthesis, self-assembly and cytotoxicity in the human lung cancer cell line A549

• Dmitriy N. Shurpik,
• Denis A. Sevastyanov,
• Pavel V. Zelenikhin,
• Pavel L. Padnya,
• Vladimir G. Evtugyn,
• Yuriy N. Osin and
• Ivan I. Stoikov

Beilstein J. Nanotechnol. 2020, 11, 421–431, doi:10.3762/bjnano.11.33

• solutions was 3–5%. The attenuated total internal reflectance IR spectra were recorded with a Spectrum 400 (Perkin Elmer) Fourier spectrometer. Elemental analysis was performed with a Perkin Elmer 2400 Series II instrument. Mass spectra (MALDI-TOF) were recorded on an Ultraflex III mass spectrometer in a 4

Synthesis and enhanced photocatalytic performance of 0D/2D CuO/tourmaline composite photocatalysts

• Changqiang Yu,
• Min Wen,
• Zhen Tong,
• Shuhua Li,
• Yanhong Yin,
• Xianbin Liu,
• Yesheng Li,
• Tongxiang Liang,
• Ziping Wu and
• Dionysios D. Dionysiou

Beilstein J. Nanotechnol. 2020, 11, 407–416, doi:10.3762/bjnano.11.31

• ) spectra. UV–visible diffuse reflectance spectra were measured using a Lambda 750S UV–vis spectrophotometer (Perkin-Elmer, USA) calibrated using barium sulfate. Photoluminescence (PL) spectra were measured with a F-4600 fluorescence spectrophotometer (Hitachi, Japan) with an excitation wavelength of 400 nm

• (15.219 nm, 0.049 cm3 g−1) were analyzed according to the Barrett–Joyner–Halenda (BJH) method (Figure 4b). The larger pore volume and BET specific surface area confirmed that the CuO/tourmaline composite with 0D/2D CuO structure possessed an increased number of active sites. UV–vis diffuse reflectance

• ) BJH pore size distribution of the CuO, tourmaline, and CuO/tourmaline composite. (a) UV–vis diffuse reflectance spectra, (b) plots of (Ahν)2 vs hν, (c) transient photocurrent, and (d) time-resolved PL spectra of the CuO and CuO/tourmaline composite. (a) MB degradation, (b) the apparent pseudo-first

Facile biogenic fabrication of hydroxyapatite nanorods using cuttlefish bone and their bactericidal and biocompatibility study

• Satheeshkumar Balu,
• Manisha Vidyavathy Sundaradoss,
• Swetha Andra and
• Jaison Jeevanandam

Beilstein J. Nanotechnol. 2020, 11, 285–295, doi:10.3762/bjnano.11.21

• attenuated total reflectance (ATR) mode. Transmission electron microscopy and energy dispersive X-ray analysis (EDX) TEM micrographs of CB Hap NRs were obtained using TEM (model JEOL, Japan) at an operation voltage of 200 kV. A sufficient quantity of CB-Hap NR powder was placed on the carbon-coated copper