Surface processes during purification of InP quantum dots

• Natalia Mordvinova,
• Pavel Emelin,
• Alexander Vinokurov,
• Sergey Dorofeev,
• Artem Abakumov and
• Tatiana Kuznetsova

Beilstein J. Nanotechnol. 2014, 5, 1220–1225, doi:10.3762/bjnano.5.135

• analysis (a) and the EDX spectrum (b). UV–vis absorption spectra of InP QDs before purification and after the last precipitation with acetone. Size distribution of purified InP QDs. IR spectra of QDs precipitated with acetone. Scheme of QD at different steps of purification. (a) after the first

• occasional stacking faults related to a replacement of “cubic” layers with “hexagonal” layers. The EDX analysis confirms the presence of both In and P in QDs (Figure 3) and reveals the In:P ratio of 1.14(2):0.86(2). The EDX spectra reveal that the QDs are noticeably oxidized. Figure 4 shows the UV–vis

• absorption spectra of InP QDs before purification and after the last precipitation with acetone. These spectra are the same. The spectrum of the sample purified with electrophoresis completely matches with these spectra. Thus, we can conclude that small as well as large particles could be completely

Characterization and photocatalytic study of tantalum oxide nanoparticles prepared by the hydrolysis of tantalum oxo-ethoxide Ta₈(μ₃-O)₂(μ-O)₈(μ-OEt)₆(OEt)₁₄

• Subia Ambreen,
• N D Pandey,
• Peter Mayer and
• Ashutosh Pandey

Beilstein J. Nanotechnol. 2014, 5, 1082–1090, doi:10.3762/bjnano.5.121

• process with Mr. Shiv K. Pandey, MNNIT, Allahabad. Authors are grateful to Dr. Tamal Ghosh, Department of Chemistry, MNNIT, Allahabad, for providing UV–vis absorption facilities to perform the photocatalytic experiment. Authors also acknowledge the Department of Physics, MNNIT, Allahabad, for DRS and CIR

DFT study of binding and electron transfer from colorless aromatic pollutants to a TiO₂ nanocluster: Application to photocatalytic degradation under visible light irradiation

• Corneliu I. Oprea,
• Petre Panait and
• Mihai A. Gîrţu

Beilstein J. Nanotechnol. 2014, 5, 1016–1030, doi:10.3762/bjnano.5.115

• intensity is extremely weak. The stronger UV–vis absorption bands of the adsorbed pollutants are located below 475 nm. Except for BA, whose key orbital seems to be HOMO-1, for the other adsorbed pollutants the transitions with noticeable oscillator strengths are from the HOMO to states above the conduction

• deprotonated forms, calculated at DFT/B3LYP/TZVP level in solution. In the case of pHBA and SA the deprotonation is on the carboxy group. Simulated UV–vis absorption spectra of the first 10 transitions for neutral pollutants in water, calculated by TD-DFT. The spectral lines were convoluted with Gaussian

• systems calculated at DFT/B3LYP/3-21G* level; pHBA is anchored either through the hydroxy (h) or the carboxy (c) groups. Optimized geometry of SA adsorbed on titania, calculated at DFT/B3LYP/3-21G* level. Simulated UV–vis absorption spectra of the pollutants bound to the TiO2 cluster, calculated by TD-DFT

Enhancement of photocatalytic H₂ evolution of eosin Y-sensitized reduced graphene oxide through a simple photoreaction

• Weiying Zhang,
• Yuexiang Li,
• Shaoqin Peng and
• Xiang Cai

Beilstein J. Nanotechnol. 2014, 5, 801–811, doi:10.3762/bjnano.5.92

• with a ZnSe crystal horizontal ATR unit. UV–vis absorption spectra were measured on a Hitachi U-3310 spectrophotometer with distilled water for reference. The fluorescence spectra were measured on a Hitachi F-7000 fluorescence spectrophotometer. The transmission electron microscopy (TEM) and high

• function of the wavelength of the incident light. Conditions: 10 μg mL−1 RGO24; 5.0 × 10−4 mol L−1 EY; 4.6 × 10−6 mol L−1 H2PtCl6; 7.7 × 10−2 mol L−1 TMA, pH 10.0; irradiation 2 h. The inset is the UV–vis absorption spectrum of EY in TMA solution. TEM images of GO (A), RGO24 (B), RGO24 with deposited Pt (C

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

• eV than for that at 168.2 eV suggests that the replacement of the secondary nitrogen with sulfur in CN is more favorable. The effects of sulfur doping on the optical and energy band structure were investigated by UV–vis absorption and Mott–Schottky measurements. Figure 2a shows the UV–vis diffuse

A visible-light-driven composite photocatalyst of TiO₂ nanotube arrays and graphene quantum dots

• Donald K. L. Chan,
• Po Ling Cheung and
• Jimmy C. Yu

Beilstein J. Nanotechnol. 2014, 5, 689–695, doi:10.3762/bjnano.5.81

• ), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and UV–vis absorption spectroscopy. The product exhibited high photocatalytic performance in the photodegradation of methylene blue and enhanced photocurrent under visible

• image and a corresponding height profile in Figure 1b suggest that the thickness of the GQDs were between 0.5 and 3 nm, corresponding to one to few layers of graphene [39]. According to the UV–vis absorption spectrum in Figure 1c, GQDs show a broad absorption below 600 nm and a small peak at ca. 340 nm

• , Supporting Information File 1). Figure 4 shows the UV–vis absorption spectra of the samples. For pristine TNAs, the absorption edge extends up to about 550 nm instead of a typical value of TiO2 (400 nm). This phenomenon can be explained by the incorporation of nitrogen into the nanotubes from NH4F during

Artificial sunlight and ultraviolet light induced photo-epoxidation of propylene over V-Ti/MCM-41 photocatalyst

• Van-Huy Nguyen,
• Shawn D. Lin,
• Jeffrey Chi-Sheng Wu and
• Hsunling Bai

Beilstein J. Nanotechnol. 2014, 5, 566–576, doi:10.3762/bjnano.5.67

• –vis absorption of V-Ti/MCM-41, and emission of (b) 200 W mercury arc lamp, (c) 300 W Xe lamp (extracted from [22]) and (d) AM1.5G filter [31]. The low-angle XRD pattern of V-Ti/MCM-41. The HRTEM images of V-Ti/MCM-41 photocatalyst. Summary of the V K-edge characterization of V-Ti/MCM-41 with

• ionization detector (FID) and a thermal conductivity detector (TCD) and the analysis was performed with both molecular sieve 5 Å and Porapak-N columns. The product formation rate, propylene consumption rate and the product selectivity were defined according to the following equations. The spectrum of: (a) UV

In vitro toxicity and bioimaging studies of gold nanorods formulations coated with biofunctional thiol-PEG molecules and Pluronic block copolymers

• Tianxun Gong,
• Douglas Goh,
• Malini Olivo and
• Ken-Tye Yong

Beilstein J. Nanotechnol. 2014, 5, 546–553, doi:10.3762/bjnano.5.64

• electron microscope (TEM) was used with JEOL JEM-1010 to characterize the shapes and sizes of the AuNRs. The TEM specimens were prepared on 200 mesh nickel-coated grids. UV–vis absorption spectra of AuNRs were obtained by using a Hitachi U-2900 with a double-beam optical system and a spectral bandpass of

• particles form aggregates. To better understand this process UV–vis absorption spectra were measured for AuNR formulations before and after different treatments with washing steps. Figure 1 shows the normalized absorption spectra of AuNRs at different stages of washing treatments. A comparison of the

• for applications ranging from cell imaging to targeted in vivo drug delivery. Normalized UV–vis absorption spectra of as-synthesized AuNRs and AuNRs washed one, two , three and four times by centrifugation. TEM images of (a) as-synthesized AuNRs, (b) AuNRs washed 4 times by centrifugation, (c

One-step synthesis of high quality kesterite Cu₂ZnSnS₄ nanocrystals – a hydrothermal approach

• Vincent Tiing Tiong,
• John Bell and
• Hongxia Wang

Beilstein J. Nanotechnol. 2014, 5, 438–446, doi:10.3762/bjnano.5.51

• a JEOL JEM-1400 microscope. High-resolution TEM (HRTEM) and selected area electron diffraction (SAED) images were obtained using JEOL JEM-2100 microscope at an accelerating voltage of 200 kV. Ultraviolet–visible (UV–vis) absorption spectrum of the sample was measured at room temperature using a

One pot synthesis of silver nanoparticles using a cyclodextrin containing polymer as reductant and stabilizer

• Arkadius Maciollek and
• Helmut Ritter

Beilstein J. Nanotechnol. 2014, 5, 380–385, doi:10.3762/bjnano.5.44

• result of surface plasmon resonance of noble metal nanoparticles [22]. UV–vis absorption spectroscopy is an established method to characterize the formation of silver nanoparticles and their shape [23]. Figure 2 shows the UV–vis absorption spectra of the metallopolymer solution 2a. The spectra exhibit

• stabilization mechanism. The AgNP’s are stable in aqueous medium for weeks. No bathochromic shift of the absorption maximum in the UV–vis absorption spectrum or an increase in the hydrodynamic diameter could be detected and confirm the stability of AgNP’s 2. Furthermore the optical properties of the polymer

• properties of nanoparticles 2 have been characterized by UV–vis absorption spectroscopy. Figure 4b shows the absorption spectra of a solution of particles 2a below and upon its LCST. The surface plasmon resonance band λmax = 450 nm at 25 °C is red shifted to λmax = 459 nm when the solution of 2a is heated

Energy transfer in complexes of water-soluble quantum dots and chlorin e6 molecules in different environments

• Irina V. Martynenko,
• Anna O. Orlova,
• Vladimir G. Maslov,
• Alexander V. Baranov,
• Anatoly V. Fedorov and
• Mikhail Artemyev

Beilstein J. Nanotechnol. 2013, 4, 895–902, doi:10.3762/bjnano.4.101

•  4 and Equation 5 provides a sufficient estimation of the FRET efficiency. UV–vis absorption and photoluminescence detection A spectrophotometer, UV-Probe 3600 (Shimadzu) and a spectrofluorometer, Cary Eclipse (Varian) were used for steady-state absorption and PL measurements, respectively. A 475 nm

Structural, optical and photocatalytic properties of flower-like ZnO nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Neha Bhardwaj,
• Jaspal Singh,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2013, 4, 763–770, doi:10.3762/bjnano.4.87

• UV–vis absorption spectroscopy. SEM and TEM studies revealed flower-like structures consisting of nanosheets, formed due to oriented attachment of ZnO nanoparticles. Flower-like ZnO structures showed enhanced photocatalytic activity towards sun-light driven photodegradation of methylene blue dye (MB

• ) as compared to ZnO nanoparticles. XRD, UV–vis absorption, PL, FTIR and TEM studies revealed the formation of Zn(OH)2 surface layer on ZnO nanostructures upon ageing. We demonstrate that the formation of a passivating Zn(OH)2 surface layer on the ZnO nanostructures upon ageing deteriorates their

• Figures 4a–c show the UV–vis absorption spectra of an aqueous solution of 22.4 μM MB with either photocatalyst S1, S2 or S3 after irradiation with sunlight for different durations of time. The characteristic absorption peak of MB at 664 nm is monitored as a function of the sunlight exposure time. It can

Modulation of defect-mediated energy transfer from ZnO nanoparticles for the photocatalytic degradation of bilirubin

• Tanujjal Bora,
• Karthik K. Lakshman,
• Soumik Sarkar,
• Abhinandan Makhal,
• Samim Sardar,
• Samir K. Pal and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2013, 4, 714–725, doi:10.3762/bjnano.4.81

• absorbance at 450 nm) in the absence (control) and presence of ZnO nanoparticle catalysts air annealed at different temperatures. The adsorption of BR on the ZnO surface under no light condition was carried out for 30 min prior to the UV light irradiation. The inset shows the UV–vis absorption spectrum of

Optimization of solution-processed oligothiophene:fullerene based organic solar cells by using solvent additives

• Gisela L. Schulz,
• Marta Urdanpilleta,
• Roland Fitzner,
• Eduard Brier,
• Elena Mena-Osteritz,
• Egon Reinold and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2013, 4, 680–689, doi:10.3762/bjnano.4.77

• (trans-2[3-4-tert-butylphenyl]-2-methyl-2-propenylidene)-malononitrile) as matrices. UV–vis absorption spectroscopy was carried out on a Perkin Elmer Lambda 19 using Merck Uvasol grade solvents. The maximum solubility of DCV5T-Bu4 was measured by using UV–vis absorption spectroscopy. After determination

• chromatography (HPLC) and differential scanning calorimetry (DSC), respectively (see Supporting Information File 1). The optical properties of DCV5T-Bu4 were investigated by using UV–vis absorption spectroscopy and are displayed in Figure 1a and summarized in Table 1. In dilute chloroform solutions, absorption

Photocatalytic antibacterial performance of TiO₂ and Ag-doped TiO₂ against S. aureus. P. aeruginosa and E. coli

• Kiran Gupta,
• R. P. Singh,
• Ashutosh Pandey and
• Anjana Pandey

Beilstein J. Nanotechnol. 2013, 4, 345–351, doi:10.3762/bjnano.4.40

• TiO2 nanoparticles annealed at 450 °C. TEM images of (a) TiO2 and (b) 3% and (c) 7% Ag-doped TiO2 nanoparticles annealed at 450 °C. UV–vis absorption spectra of the annealed (a) TiO2 and (b) 3% and (c) 7% Ag-doped TiO2 nanoparticles. Band gap obtained by extrapolating the linear portion of the (αhν)1/2

Photoelectrochemical and Raman characterization of In₂O₃ mesoporous films sensitized by CdS nanoparticles

• Mikalai V. Malashchonak,
• Sergey K. Poznyak,
• Eugene A. Streltsov,
• Anatoly I. Kulak,
• Olga V. Korolik and
• Alexander V. Mazanik

Beilstein J. Nanotechnol. 2013, 4, 255–261, doi:10.3762/bjnano.4.27

• sensitized by CdS nanoparticles and to characterize these systems by using different methods (SEM, TEM, AES, UV–vis absorption, BET surface area measurements and Raman spectroscopy). Experimental Mesoporous In2O3 films were prepared by spin-coating deposition of a colloidal indium hydroxide solution onto

• chopper (0.3 Hz). Spectral dependencies of the photocurrent were corrected for the spectral intensity distribution of the monochromator output. UV–vis absorption spectra of the films deposited onto quartz substrates were recorded on a Shimadzu UV-2550 spectrophotometer. Raman spectra were taken at room

Magnetic-Fe/Fe₃O₄-nanoparticle-bound SN38 as carboxylesterase-cleavable prodrug for the delivery to tumors within monocytes/macrophages

• Hongwang Wang,
• Tej B. Shrestha,
• Matthew T. Basel,
• Raj K. Dani,
• Gwi-Moon Seo,
• Sivasai Balivada,
• Marla M. Pyle,
• Heidy Prock,
• Olga B. Koper,
• Prem S. Thapa,
• David Moore,
• Ping Li,
• Viktor Chikan,
• Deryl L. Troyer and
• Stefan H. Bossmann

Beilstein J. Nanotechnol. 2012, 3, 444–455, doi:10.3762/bjnano.3.51

• , CA) triple quadrupole mass spectrometer with electrospray ionization (ESI). Fluorescence measurements of free SN38 and SN38-loaded MNPs were performed on a Fluoro Max-2 instrument (HORIBA Jobin Yvon Company). The samples were excited at λ = 380 nm. UV–vis absorption analysis was carried out on a Cary

• ascorbic acid and 5.0 M ammonium acetate in distilled water. After the incubation period, 0.20 mL of ferrozine reagent solution was added. The complexation of iron(II) was complete within 30 min at room temperature, as indicated by UV–vis absorption spectrometry. The absorbance was recorded at 562 nm. Iron

Conducting composite materials from the biopolymer kappa-carrageenan and carbon nanotubes

• Ali Aldalbahi,
• Jin Chu,
• Peter Feng and
• Marc in het Panhuis

Beilstein J. Nanotechnol. 2012, 3, 415–427, doi:10.3762/bjnano.3.48

• that excess sonication leads to damage of the nanotubes [15][48]. The optimum sonication time was determined as defined in [8], by establishing the time it takes for the UV–vis absorption intensity to level out and the visible aggregates to disappear. CNTs absorb at most wavelengths, while KCs do not

Variations in the structure and reactivity of thioester functionalized self-assembled monolayers and their use for controlled surface modification

• Inbal Aped,
• Yacov Mazuz and
• Chaim N. Sukenik

Beilstein J. Nanotechnol. 2012, 3, 213–220, doi:10.3762/bjnano.3.24

• wavelengths. This was compared to irradiations done with a broad-spectrum, longer-wavelength UV lamp (UV-A, 320–400 nm). Since the UV–vis absorption spectra of all compounds 1 were the same, only 1a was used in the comparisons to the photo-oxidation behavior of compounds 2–4 at longer wavelength. The SAMs

Surface functionalization of aluminosilicate nanotubes with organic molecules

• Wei Ma,
• Weng On Yah,
• Hideyuki Otsuka and
• Atsushi Takahara

Beilstein J. Nanotechnol. 2012, 3, 82–100, doi:10.3762/bjnano.3.10

• P3HT/HT3P-imogolite nanofiber hybrid. Reprinted with permission from W. O. Yah et al., J. Phys.: Conf. Ser. 2011, 272, 012021 [86]. © IOP Publishing 2011. UV–vis absorption spectra of P3HT (a) and P3HT/HT3P-imogolite hybrid (b) in anisole (0.0005%) during cooling. Reprinted with permission from W. O

Novel acridone-modified MCM-41 type silica: Synthesis, characterization and fluorescence tuning

• Maximilian Hemgesberg,
• Gunder Dörr,
• Yvonne Schmitt,
• Andreas Seifert,
• Zhou Zhou,
• Robin Klupp Taylor,
• Sarah Bay,
• Stefan Ernst,
• Markus Gerhards,
• Thomas J. J. Müller and
• Werner R. Thiel

Beilstein J. Nanotechnol. 2011, 2, 284–292, doi:10.3762/bjnano.2.33

• absorption emerges at 1613 cm−1. The redshift of the absorption frequency is conclusive with respect to the weakened C=O double bond caused by the electron donation from the carbonyl unit to the scandium(III) cation, which is also evident in the UV–vis absorption of MCM-ACR (see below in Figure 9). According

• 0.17 nm point resolution. The UV–vis absorption and fluorescence of the precursor were measured using a Perkin–Elmer Lambda 900 and a Horiba Jobin–Yvon Fluorolog 3-22 τ in steps of 0.1 nm and 1.0 nm, respectively, the SiO2-cuvettes used had a width of 1.0 cm. Solid state UV–vis measurements were

• ). Overlay of the solid state UV-vis (top) and fluorescence (bottom) spectra of MCM-ACR, MCM-ACR + Sc(OTf)3 and pure Sc(OTf)3 (fluorescence excitation wavelength λex. = 400 nm). UV–vis-absorption intensities are not normalized to a given value; fluorescence has been normalized to an intensity of 1.0. Sc(OTf

Twofold role of calcined hydrotalcites in the degradation of methyl parathion pesticide

• Alvaro Sampieri,
• Geolar Fetter,
• María Elena Villafuerte-Castrejon,
• Adriana Tejeda-Cruz and
• Pedro Bosch

Beilstein J. Nanotechnol. 2011, 2, 99–103, doi:10.3762/bjnano.2.11

• the ability to regenerate the layered structures of HTs by the “memory effect” in the presence of anions released during MP degradation. Degradation of MP: Figure 1 shows the UV–vis absorption spectra of the solution after stirring MP with the Mg–Al, Zn–Al and Ni–Al mixed oxides (see Supporting

Enhanced visible light photocatalysis through fast crystallization of zinc oxide nanorods

• Sunandan Baruah,
• Mohammad Abbas Mahmood,
• Myo Tay Zar Myint,
• Tanujjal Bora and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2010, 1, 14–20, doi:10.3762/bjnano.1.3

• polar face. Degradation of methylene blue as a function of ln(C/C0) versus the time of exposure to light in the presence of ZnO nanorods synthesized by the conventional method (Sample 2 with surface area ≈ 47.54 cm2) and the fast crystallization method (surface area ≈ 33.74 cm2). Inset: UV–vis

• absorption spectra of ZnO nanorods grown by the conventional hydrothermal method and by microwave irradiation of comparable exposed surface area. Estimated effective area of ZnO nanorod surfaces on substrates of size 1 × 3 cm, grown at different reactant concentrations during the hydrothermal growth process