Showing papers on "Infrared spectroscopy published in 2017"
TL;DR: AFM-IR applications that will be discussed include those in polymers, life sciences, photonics, solar cells, semiconductors, pharmaceuticals, and cultural heritage.
Abstract: Atomic force microscopy-based infrared spectroscopy (AFM-IR) is a rapidly emerging technique that provides chemical analysis and compositional mapping with spatial resolution far below conventional optical diffraction limits. AFM-IR works by using the tip of an AFM probe to locally detect thermal expansion in a sample resulting from absorption of infrared radiation. AFM-IR thus can provide the spatial resolution of AFM in combination with the chemical analysis and compositional imaging capabilities of infrared spectroscopy. This article briefly reviews the development and underlying technology of AFM-IR, including recent advances, and then surveys a wide range of applications and investigations using AFM-IR. AFM-IR applications that will be discussed include those in polymers, life sciences, photonics, solar cells, semiconductors, pharmaceuticals, and cultural heritage. In the Supporting Information, the authors provide a theoretical section that reviews the physics underlying the AFM-IR measurement and d...
652 citations
TL;DR: First applications such as the detection of proteins, the monitoring of dynamic processes, and hyperspectral infrared chemical imaging are discussed, demonstrating the sensitivity and broad applicability of resonant SEIRA.
Abstract: Infrared spectroscopy is a powerful tool widely used in research and industry for a label-free and unambiguous identification of molecular species. Inconveniently, its application to spectroscopic analysis of minute amounts of materials, for example, in sensing applications, is hampered by the low infrared absorption cross-sections. Surface-enhanced infrared spectroscopy using resonant metal nanoantennas, or short “resonant SEIRA”, overcomes this limitation. Resonantly excited, such metal nanostructures feature collective oscillations of electrons (plasmons), providing huge electromagnetic fields on the nanometer scale. Infrared vibrations of molecules located in these fields are enhanced by orders of magnitude enabling a spectroscopic characterization with unprecedented sensitivity. In this Review, we introduce the concept of resonant SEIRA and discuss the underlying physics, particularly, the resonant coupling between molecular and antenna excitations as well as the spatial extent of the enhancement and...
431 citations
TL;DR: In this article, the authors reported the modification of graphene oxide by thermal reduction to obtain reduced graphene oxide (RGO) and subsequent modification by sulfophenyl groups as well as the characterization of these materials by thermogravimetric analysis coupled with mass spectroscopy (TGA-MS).
Abstract: We report the modification of graphene oxide (GO) by thermal reduction to obtain reduced graphene oxide (RGO) and subsequent modification by sulfophenyl groups as well as the characterization of these materials by thermogravimetric analysis coupled with mass spectroscopy (TGA-MS) The chemical modification of RGO was carried out by the spontaneous reaction of RGO with in situ generated sulfophenyl diazonium ions The three different types of materials were also characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) The characteristic absorption band at 1034 and 1160 cm−1 in the FTIR spectrum of the sulfophenyl-modified RGO (SRGO), as well as Raman spectroscopy and TGA-MS data indicated that sulfophenyl groups were successfully grafted on RGO The presence of organic molecules at the SRGO surface was also demonstrated by elemental analysis, transmission electron microscopy, energy dispersive X-ray spectroscopy and XPS TGA data and elemental analysis results showed that the loading of sulfophenyl groups was about 12 wt% and UV-visible-near IR spectroscopy confirms the slight increase of the optical band gap of RGO after covalent grafting of sulfophenyl groups on its surface
327 citations
TL;DR: In this paper, the reaction mechanism of silver as a CO2 reduction catalyst using in situ attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) during electrochemical cycling was studied.
Abstract: The electrocatalytic reduction of CO2 to chemical fuels has attracted significant attention in recent years. Among transition metals, silver shows one of the highest faradaic efficiencies for CO formation as the main reaction product; however, the exact mechanism for this conversion is not fully understood. In this work, we study the reaction mechanism of silver as a CO2 reduction catalyst using in situ attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) during electrochemical cycling. Using ATR-FTIR, it is possible to observe the reaction intermediates on the surface of Ag thin films formed during the CO2 electroreduction reaction. At a moderate overpotential, a proton coupled electron transfer reaction mechanism is confirmed to be the dominant CO2 reduction pathway. However, at a more negative applied potential, both the COO– and the COOH intermediates are detected using ATR-FTIR, which indicates that individual proton and electron transfer steps occur, offering a different pa...
261 citations
TL;DR: It is unambiguously demonstrated that controllable uniaxial strain can be used as a convenient and effective approach to tune the electronic structure of few-layer black phosphorus, paving the way for black phosphorus applications in infrared photonics and optoelectronics.
Abstract: Black phosphorus is an infrared layered material. Its bandgap complements other widely studied two-dimensional materials: zero-gap graphene and visible/near-infrared gap transition metal dichalcogenides. Although highly desirable, a comprehensive infrared characterization is still lacking. Here we report a systematic infrared study of mechanically exfoliated few-layer black phosphorus, with thickness ranging from 2 to 15 layers and photon energy spanning from 0.25 to 1.36 eV. Each few-layer black phosphorus exhibits a thickness-dependent unique infrared spectrum with a series of absorption resonances, which reveals the underlying electronic structure evolution and serves as its infrared fingerprints. Surprisingly, unexpected absorption features, which are associated with the forbidden optical transitions, have been observed. Furthermore, we unambiguously demonstrate that controllable uniaxial strain can be used as a convenient and effective approach to tune the electronic structure of few-layer black phosphorus. Our study paves the way for black phosphorus applications in infrared photonics and optoelectronics. Few-layered black phosphorus offers an infrared bandgap, complementing that of graphene and transition metal dichalcogenides. Here, the authors investigate the thickness- and strain-dependent electronic structure of black phosphorus using polarised infrared spectroscopy.
227 citations
TL;DR: The as-prepared Pd@B.tea NPs catalyst could be used as an efficient and heterogeneous catalyst for Suzuki coupling reactions between phenylboronic acid and a range of aryl halides and also the reduction of 4-nitrophenol using sodium borohydride in an environmental friendly medium.
205 citations
TL;DR: A new ultrasensitive infrared antenna designed to bring surface-enhanced infrared absorption (SEIRA) spectroscopy into the few-molecule detection range is reported, which offers a new platform for analyzing the IR vibrations of minute quantities of molecules and lends insight into the ultimate limit of single-Molecule SEIRA detection.
Abstract: Surface-enhanced infrared absorption (SEIRA) spectroscopy has outstanding potential in chemical detection as a complement to surface-enhanced Raman spectroscopy (SERS), yet it has historically lagged well behind SERS in detection sensitivity. Here we report a new ultrasensitive infrared antenna designed to bring SEIRA spectroscopy into the few-molecule detection range. Our antenna consists of a bowtie-shaped Au structure with a sub-3 nm gap, positioned to create a cavity above a reflective substrate. This three-dimensional geometry tightly confines incident mid-infrared radiation into its ultrasmall junction, yielding a hot spot with a theoretical SEIRA enhancement factor of more than 107, which can be designed to span the range of frequencies useful for SEIRA. We quantitatively evaluated the IR detection limit of this antenna design using mixed monolayers of 4-nitrothiophenol (4-NTP) and 4-methoxythiolphenol (4-MTP). The optimized antenna structure allows the detection of as few as ∼500 molecules of 4-NT...
173 citations
TL;DR: In this paper, a novel adsorbent, namely, β-cyclodextrin/poly ( l -glutamic acid) supported magnetic graphene oxide (CGMG), was synthesized through a facile chemical route and its application as an excellent adsorent for 17β-estradiol (E2) removal from aqueous solution was also demonstrated.
171 citations
TL;DR: In this paper, a bifunctional catalyst of partially reducible manganese oxide in combination with SAPO-34 catalyzes the selective formation of light olefins, which validates the generality of the OX-ZEO (oxide-zeolite) concept for syngas conversion.
Abstract: The key of syngas (a mixture of CO and H2) chemistry lies in controlled dissociative activation of CO and C–C coupling. We demonstrate here that a bifunctional catalyst of partially reducible manganese oxide in combination with SAPO-34 catalyzes the selective formation of light olefins, which validates the generality of the OX-ZEO (oxide-zeolite) concept for syngas conversion. Results from in situ ambient-pressure X-ray photoelectron spectroscopy, infrared spectroscopy, and temperature-programmed surface reactions reveal the critical role of oxygen vacancies on the oxide surface, where CO dissociates and is converted into surface carbonate and carbon species. They are converted to CO2 and CHx in the presence of H2. The limited C–C coupling and hydrogenation activities of MnO enable the reaction selectivity to be controlled by the confined pores of SAPO-34. Thus, a selectivity of light olefins up to 80% is achieved, far beyond the limitation of Anderson–Shultz–Flory distribution. These findings open up pos...
169 citations
TL;DR: In this paper, the authors used several spectroscopic techniques, including laser confocal microscopy, Fourier transform infrared (FTIR) spectroscopy and photoacousitc FTIR spectrograms, to characterize both the bulk and surface chemistry of the source material and printed samples.
Abstract: Polylactic acid (PLA) is an organic polymer commonly used in fused deposition (FDM) printing and biomedical scaffolding that is biocompatible and immunologically inert. However, variations in source material quality and chemistry make it necessary to characterize the filament and determine potential changes in chemistry occurring as a result of the FDM process. We used several spectroscopic techniques, including laser confocal microscopy, Fourier transform infrared (FTIR) spectroscopy and photoacousitc FTIR spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) in order to characterize both the bulk and surface chemistry of the source material and printed samples. Scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were used to characterize morphology, cold crystallinity, and the glass transition and melting temperatures following printing. Analysis revealed calcium carbonate-based additives which were reacted with organic ligands and potentially trace metal impurities, both before and following printing. These additives became concentrated in voids in the printed structure. This finding is important for biomedical applications as carbonate will impact subsequent cell growth on printed tissue scaffolds. Results of chemical analysis also provided evidence of the hygroscopic nature of the source material and oxidation of the printed surface, and SEM imaging revealed micro- and submicron-scale roughness that will also impact potential applications.
162 citations
TL;DR: In this paper, the thermal stability of Li2CO3, LMC, and LEDC in the presence of LiPF6 in dimethyl carbonate (DMC), a common salt and solvent, respectively, in lithium ion battery electrolytes, has been investigated to afford a better understanding of the evolution of the SEI.
Abstract: The anode solid electrolyte interface (SEI) on the anode of lithium ion batteries contains lithium carbonate (Li2CO3), lithium methyl carbonate (LMC), and lithium ethylene dicarbonate (LEDC). The development of a strong physical understanding of the properties of the SEI requires a strong understanding of the evolution of the SEI composition over extended timeframes. The thermal stability of Li2CO3, LMC, and LEDC in the presence of LiPF6 in dimethyl carbonate (DMC), a common salt and solvent, respectively, in lithium ion battery electrolytes, has been investigated to afford a better understanding of the evolution of the SEI. The residual solids from the reaction mixtures have been characterized by a combination of X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy with attenuated total reflectance (IR-ATR), while the solution and evolved gases have been investigated by nuclear magnetic resonance (NMR) spectroscopy and gas chromatography with mass selective detection (GC-MS). The thermal deco...
TL;DR: In this review, the importance of water in hydrogel (HG) properties and structure is analyzed and a variety of methods such as 1H NMR, DSC, and XRD (X-ray powder diffraction) are used to study water in HG.
Abstract: In this review, the importance of water in hydrogel (HG) properties and structure is analyzed. A variety of methods such as ¹H NMR (nuclear magnetic resonance), DSC (differential scanning calorimetry), XRD (X-ray powder diffraction), dielectric relaxation spectroscopy, thermally stimulated depolarization current, quasi-elastic neutron scattering, rheometry, diffusion, adsorption, infrared spectroscopy are used to study water in HG. The state of HG water is rather non-uniform. According to thermodynamic features of water in HG, some of it is non-freezing and strongly bound, another fraction is freezing and weakly bound, and the third fraction is non-bound, free water freezing at 0 °C. According to structural features of water in HG, it can be divided into two fractions with strongly associated and weakly associated waters. The properties of the water in HG depend also on the amounts and types of solutes, pH, salinity, structural features of HG functionalities.
TL;DR: It is predicted that future application of IR spectroscopy to other challenging systems, including polar oxide surfaces with their often complex reconstruction patterns and oxide-supported highly dispersed metal particles, will provide a major advancement in the understanding of heterogeneous catalysts.
Abstract: In this review, we highlight recent progress (2008–2016) in infrared reflection absorption spectroscopy (IRRAS) studies on oxide powders achieved by using different types of metal oxide single crystals as reference systems. Precise polarization- and azimuth-dependent IRRAS data recorded for single crystal substrates has allowed for fundamental insights into the surface chemistry and photochemistry of numerous probe molecules on various surfaces exposed by three very important metal oxides (ZnO, TiO2, and CeO2). When using carbon monoxide (CO) as a probe molecule, deep insight into the role of defects in the surface chemistry of oxides can be gained, as will be demonstrated by the characterization of different imperfections (e.g., O vacancies, nanofacets) present at oxidic samples. In addition, photostimulated excitations, e.g., electron or hole polaronic trap states, can be studied using IR-spectroscopy. Reliable and comprehensive reference data acquired for different oxide monocrystal model systems enables atomic-level insights into the structural, electronic, and reactive properties of the substantially more complex nanostructured oxide particles. We foresee that future application of IR spectroscopy to other challenging systems, including polar oxide surfaces with their often complex reconstruction patterns and oxide-supported highly dispersed metal particles, will provide a major advancement in the understanding of heterogeneous catalysts (539 references).
TL;DR: In this paper, a facile hydrothermal process was used to prepare the NSs of ZnO/Yb2O3 in an alkaline medium (pH ∼ 10.5), at a low temperature.
Abstract: In this study, a facile hydrothermal process was used to prepare the NSs of ZnO/Yb2O3 in an alkaline medium (pH ∼ 10.5), at a low temperature. The calcined NSs were characterized by Fourier-transform infrared spectroscopy (FTIR), ultraviolet visible spectroscopy (UV/vis), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and powder X-ray diffraction (XRD). A thin layer of NSs was coated on a glassy carbon electrode (GCE) with the help of a nafion conducting binder to be used as a sensor. This assembled sensor was implemented to the successful detection of 4-AP and exhibited good sensitivity (5.063 μA μM−1 cm−2) and a low detection limit (DL = 0.019 ± 0.001 nM at a signal to noise ratio of 3). The calibration plot (attained at a potential of +1.0 V) is linear (r2 = 0.9836) in the concentration range of 0.1 nM to 0.1 mM of 4-AP. Therefore, the chemical sensor fabricated with ZnO/Yb2O3 NSs may be a promising sensitive chemical sensor in a reliable I–V method for the effective detection of hazardous and carcinogenic chemicals in environmental and healthcare sectors on broad scales.
TL;DR: In this paper, the polyaniline copolymers were synthesized for 1:1 and 1:4 M ratios of aniline and o-nitroanilines in an acidic medium using ammonium persulfate as oxidant.
TL;DR: In this article, a novel Schiff base was synthesized from the condensation of 2-hydroxy-1-naphthaldehyde and isatin with 4-nitro-o-phenylenediamine.
Abstract: A novel Schiff base, namely Z-3-((2-((E)-(2-hydroxynaphthyl)methylene)amino)-5-nitrophenylimino)-1,3-dihydroindin-2-one, was synthesized from the condensation of 2-hydroxy-1-naphthaldehyde and isatin with 4-nitro-o-phenylenediamine. It was structurally characterized on the basis of 1H NMR, 13C NMR and infrared spectra and elemental analyses. In addition, Ni(II) and Cu(II) complexes of the Schiff base ligand were prepared. The nature of bonding and the stereochemistry of the investigated complexes were elucidated using several techniques, including elemental analysis (C, H, N), Fourier transform infrared and electronic spectroscopies and molar conductivity. The thermal behaviours of the complexes were studied and kinetic–thermodynamic parameters were determined using the Coats–Redfern method. Density functional theory calculations at the B3LYP/6-311G++ (d, p) level of theory were carried out to explain the equilibrium geometry of the ligand. The optimized geometry parameters of the complexes were evaluated using LANL2DZ basis set. The total energy of highest occupied and lowest unoccupied molecular orbitals, Mullikan atomic charges, dipole moment and orientation are discussed. Moreover, the interaction of the metal complexes with calf thymus DNA (CT-DNA) was explored using electronic spectra, viscosity measurements and gel electrophoresis. The experimental evidence indicated that the two complexes could strongly bind to CT-DNA via an intercalation mechanism. The intrinsic binding constants of the investigated Ni(II) and Cu(II) complexes with CT-DNA were 1.02 × 106 and 2.15 × 106 M−1, respectively, which are higher than that of the standard ethidium bromide. Furthermore, the bio-efficacy of the ligand and its complexes was examined in vitro against the growth of bacteria and fungi to evaluate the antimicrobial potential. Based on the obtained results, the prepared complexes have promise for use as drugs. Copyright © 2016 John Wiley & Sons, Ltd.
TL;DR: ATR-FTIR measurements provide a simple and reproducible method for the screening of extracellular vesicle preparations and the potential applicability of this technique for fast and efficient characterization of vesicular components is high as the investigated samples require no further preparations and all the different molecular species can be determined in the same sample.
TL;DR: In this article, a one-pot method for the preparation of g-C 3 N 4 /reduced graphene oxide (rGO) composite photocatalysts with controllable band structures is presented.
TL;DR: In this paper, the U(VI) sorption on the surface of double hydroxides (LDH) nanocomposites was explored as a function of ionic strength, solution pH, contact time, initial concentrations and temperature.
Abstract: Graphene oxide and Ni-Al layered double hydroxides (GO@LDH) nanocomposites were synthesized via a one-pot hydrothermal process, and characterized by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy in detail. The exploration of U(VI) sorption on GO@LDH surface was performed as a function of ionic strength, solution pH, contact time, U(VI) initial concentrations and temperature. Results of Langmuir isotherms showed that the sorption capacity of GO@LDH (160 mg/g) was much higher than those of LDH (69 mg/g) and GO (92 mg/g). The formed surface complexes between surface oxygen-containing functional groups of GO@LDH and U(VI) turned out to be the interaction mechanism of U(VI) with GO@LDH. According to the thermodynamic studies results, the sorption interaction was actually a spontaneous and endothermic chemical process. The sorption isotherms were better fitted with the Langmuir model compared with other models, which suggested the interaction was mainly dominated by monolayer coverage. The GO@LDH nanocomposites provide potential applications as adsorbents in the enrichment of radionuclides from wastewater in nuclear waste management and environmental remediation.
TL;DR: The results not only prove Ta2NiS5 is a promising in-plane anisotropic 2D material but also provide an interesting platform for future functionalized electronic devices.
Abstract: An interesting in-plane anisotropic layered dimetal chalcogenide Ta2NiS5 is introduced, and the optical and electrical properties with respect to its in-plane anisotropy are systematically studied. The Raman vibration modes have been identified by Raman spectra measurements combined with calculations of phonon-related properties. Importantly, the Ta2NiS5 flakes exhibit strong anisotropic Raman response under the angle-resolved polarized Raman spectroscopy measurements. We found that Raman intensities of the Ag mode not only depend on rotation angle but are also related to the sample thickness. In contrast, the infrared absorption with light polarized along the a axis direction is always larger than that in the c axis direction regardless of thickness under the polarization-resolved infrared spectroscopy measurements. Remarkably, the first-principles calculations combined with angle-resolved conductance measurements indicate strong anisotropic conductivity of Ta2NiS5. Our results not only prove Ta2NiS5 is ...
TL;DR: This review introduces the basic principles of the different methods of 2D vibrational spectroscopy at surfaces along with a balanced overview on the technological aspects as well as benefits and shortcomings, and discusses the current scope of applications.
Abstract: Ultrafast two-dimensional infrared spectroscopy (2D IR) has been advanced in recent years toward measuring signals from only a monolayer of sample molecules at solid–liquid and solid–gas interfaces. A series of experimental methods has been introduced, which in the chronological order of development are 2D sum-frequency-generation (2D SFG), transmission 2D IR, and reflection 2D IR, the latter in either internal, attenuated total reflection (ATR), or external reflection configuration. The different variants of 2D vibrational spectroscopy are based on either the even-order or the odd-order nonlinear susceptibility, and all allow resolving similar molecular temporal and spectral information. In this review, we introduce the basic principles of the different methods of 2D vibrational spectroscopy at surfaces along with a balanced overview on the technological aspects as well as benefits and shortcomings. We furthermore discuss the current scope of applications for 2D vibrational surface spectroscopy, which sp...
TL;DR: The unprecedented resolution of cold-ion spectroscopy coupled with tandem MS may render this the key technology to unravel complex glycomes.
Abstract: The diversity of stereochemical isomers present in glycans and glycoconjugates poses a formidable challenge for comprehensive structural analysis Typically, sophisticated mass spectrometry (MS)-based techniques are used in combination with chromatography or ion-mobility separation However, coexisting structurally similar isomers often render an unambiguous identification impossible Other powerful techniques such as gas-phase infrared (IR) spectroscopy have been limited to smaller glycans, since conformational flexibility and thermal activation during the measurement result in poor spectral resolution This limitation can be overcome by using cold-ion spectroscopy The vibrational fingerprints of cold oligosaccharide ions exhibit a wealth of well-resolved absorption features that are diagnostic for minute structural variations The unprecedented resolution of cold-ion spectroscopy coupled with tandem MS may render this the key technology to unravel complex glycomes
TL;DR: In this paper, the mechanism and kinetics of interactions between DMMP and Zr6-based metal organic frameworks (MOFs) have been investigated with in situ infrared spectroscopy (IR), X-ray photoelectron spectra (XPS), powder Xray diffraction (PXRD), and DFT calculations.
Abstract: The mechanism and kinetics of interactions between dimethyl methylphosphonate (DMMP), a key chemical warfare agent (CWA) simulant, and Zr6-based metal organic frameworks (MOFs) have been investigated with in situ infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (PXRD), and DFT calculations. DMMP was found to adsorb molecularly to UiO-66 through the formation of hydrogen bonds between the phosphoryl oxygen and the free hydroxyl groups associated with Zr6 nodes on the surface of crystallites and not within the bulk MOF structure. Unlike UiO-66, the infrared spectra for UiO-67 and MOF-808, recorded during DMMP exposure, suggest that uptake occurs through both physisorption and chemisorption. The XPS spectra of MOF-808 zirconium 3d electrons reveal a charge redistribution following exposure to DMMP. In addition, analysis of the phosphorus 2p electrons following exposure and thermal annealing to 600 K indicates that two types of stable phosphorus-containing species e...
TL;DR: The CA/RGO coating significantly improves the sensitivity of electrochemical responses and separation of heavy metals.
29 Mar 2017
TL;DR: In this paper, a simple one-step hydrothermal route using (water: ethanol) (1:1) as a mixed solvents at optimum conditions was used to synthesize monoclinic bismuth oxide nanorods.
Abstract: In this study, Monoclinic bismuth oxide nanorods (α-Bi2O3 NRs) were successfully synthesized by a simple one-step hydrothermal route using (water: ethanol) (1:1) as a mixed solvents at optimum conditions. The Bi2O3 nano-powder was characterized in detail by different techniques in terms of their structural, morphological, compositional, optical and photocatalytic properties. X-ray diffraction (XRD) analysis indicated that the as-synthesized Bi2O3 NRs exhibited high purity with monoclinic structure (α-Bi2O3) and good crystallinity. The Transmission electron microscope (TEM), Energy dispersive x-ray spectroscopy (EDXS) and Field Emission scanning electron microscope (FE-SEM) analysis clearly confirmed the high purity and the nanorod morphology of the as-synthesized Bi2O3 sample. The optical band gap of α-Bi2O3 NRs was estimated using the UV–Vis diffuse reflectance spectroscopy (UV–Vis DRS) analysis according to the Kubelka–Munk theory. The optical band gap of α-Bi2O3 NRs was found to be 3.55 eV for an indirect allowed transition and 3.63 eV for a direct allowed transition. The Fourier transfer infrared spectroscopy (FTIR) was employed to check the structure as well as to evaluate the phonon vibration modes corresponding to Bi2O3. Photocatalytic activity of α-Bi2O3 NRs was investigated using UV source lamp. The as-synthesized α-Bi2O3 NRs photocatalyst exhibited better performance for degradation and decolorization of Methylene blue (MB) under ultraviolet (UV) irradiation. MB was completely photodegraded after 210 min under UV irradiation using α-Bi2O3 NRs as photocatalyst.
TL;DR: In this paper, the infrared absorption properties of Li-Zn ferrite (Li0.5Fe2.0) powder samples were reported by combustion synthesis and the observed infrared absorption bands were explained based on the structure and the occupancy of the cations.
TL;DR: In this article, the synthesis, characterization and electrochemical study of a nanostructured magnetic molecularly imprinted polymer (Fe 3 O 4 -MIP) for the determination of 17-β-Estradiol (17-β -E2) was reported.
Abstract: The authors report the synthesis, characterization and electrochemical study of a nanostructured magnetic molecularly imprinted polymer (Fe 3 O 4 -MIP) for the determination of 17-β-Estradiol (17-β-E2) The synthesized magnetic nanoparticles (Fe 3 O 4 -NPs) and Fe 3 O 4 -MIP were investigated using High Resolution Transmission Electron Microscopy (HRTEM), High Resolution Scanning Electron Microscopy (HRSEM), X-Ray Diffraction (XRD) and Fourrier Transform Infrared spectroscopy (FT-IR) as characterization techniques The electrochemical characterization was studied by cyclic voltammetry and electrochemical impedance spectroscopy Several important parameters controlling the performance of the Fe 3 O 4 -MIP based sensor such as the choice of electrochemical analysis technique, the frequency, the effect of pH and the incubation time were investigated Under the optimal conditions, the oxidation peak current was linearly related to 17-β-E2 concentration in the range of 005–10 μM The Fe 3 O 4 -MIP based sensor amplifies the oxidation current in square-wave voltammetric measurements which allows reaching 20 nM as detection limit Furthermore, the Fe 3 O 4 -MIP sensing system exhibits a high selectivity towards 17-β-E2 and was applied successfully for its determination in river water samples
TL;DR: The nanoparticles have been utilized as a convenient catalyst for synthesizing a variety of N-substituted pyrroles via Paal-Knorr reactions of γ-diketones with amines, diamines or triamines at room temperature under solvent-free conditions.
TL;DR: The influence of coupling strength and relative detuning between the molecular vibration and LSPR on the enhancement factor is described and the basis of the observed Fano line shape is explained by deconvoluting the combined response of the L SPR and molecular vibration in transmission, absorption and reflection.
Abstract: Doped metal oxides are plasmonic materials that boast both synthetic and postsynthetic spectral tunability. They have already enabled promising smart window and optoelectronic technologies and have been proposed for use in surface enhanced infrared absorption spectroscopy (SEIRA) and sensing applications. Herein, we report the first step toward realization of the former utilizing cubic F and Sn codoped In2O3 nanocrystals (NCs) to couple to the C–H vibration of surface-bound oleate ligands. Electron energy loss spectroscopy is used to map the strong near-field enhancement around these NCs that enables localized surface plasmon resonance (LSPR) coupling between adjacent nanocrystals and LSPR-molecular vibration coupling. Fourier transform infrared spectroscopy measurements and finite element simulations are applied to observe and explain the nature of the coupling phenomena, specifically addressing coupling in mesoscale assembled films. The Fano line shape signatures of LSPR-coupled molecular vibrations are...