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https://www.readbyqxmd.com/read/28742359/pressure-induced-structural-and-optical-properties-of-inorganic-halide-perovskite-cspbbr3
#1
Long Zhang, Qingxin Zeng, Kai Wang
Perovskite photovoltaic materials are gaining sustained attention because of their excellent photovoltaic properties and extensive practical applicability. In this letter, we discussed the changes in the structure and optical properties of CsPbBr3 under high pressure. As the pressure increases, the band gap initially begun to redshift before 1.0 GPa followed by continuous blue shift until the crystal was completely amorphized. An isostructural phase transition at 1.2 GPa was determined by high-pressure synchrotron X-ray and Raman spectroscopy...
July 25, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28742340/structure-and-electrical-transport-relations-in-ba-zr-pr-o3-%C3%AE-perovskites
#2
Isabel Antunes, Ulises Amador, Adriana Alves, Maria Rosário Correia, Clemens Ritter, Jorge Ribeiro Frade, Domingo Pérez-Coll, Glenn C Mather, Duncan Paul Fagg
Members of the perovskite solid solution BaZr1-xPrxO3-δ (0.2 ≤ x ≤ 0.8) with potential high-temperature electrochemical applications were synthesized via mechanical activation and high-temperature annealing at 1250 °C. Structural properties were examined by Rietveld analysis of neutron powder diffraction and Raman spectroscopy at room temperature, indicating rhombohedral symmetry (space group R3̅c) for members x = 0.2 and 0.4 and orthorhombic symmetry (Imma) for x = 0.6 and 0.8. The sequence of phase transitions for the complete solid solution from BaZrO3 to BaPrO3 is Pm3̅m → R3̅c → Imma → Pnma...
July 25, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28741933/functionalized-cobalt-triarylcorrole-covalently-bonded-with-graphene-oxide-a-selective-catalyst-for-the-two-or-four-electron-reduction-of-oxygen
#3
Jijun Tang, Zhongping Ou, Rui Guo, Yuanyuan Fang, Dong Huang, Jing Zhang, Jiaoxia Zhang, Song Guo, Frederick M McFarland, Karl M Kadish
A cobalt triphenylcorrole (CorCo) was covalently bonded to graphene oxide (GO), and the resulting product, represented as GO-CorCo, was characterized by UV-vis, FT-IR, and micro-Raman spectroscopy as well as by HRTEM, TGA, XRD, XPS, and AFM. The electrocatalytic activity of GO-CorCo toward the oxygen reduction reaction (ORR) was then examined in air-saturated 0.1 M KOH and 0.5 M H2SO4 solutions by cyclic voltammetry and linear sweep voltammetry using a rotating disk electrode and/or a rotating ring-disk electrode...
July 25, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28738633/application-of-raman-spectroscopy-for-direct-analysis-of-carlina-acanthifolia-subsp-utzka-root-essential-oil
#4
Maciej Strzemski, Magdalena Wójciak-Kosior, Ireneusz Sowa, Monika Agacka-Mołdoch, Piotr Drączkowski, Dariusz Matosiuk, Łukasz Kurach, Ryszard Kocjan, Sławomir Dresler
Carlina genus plants e.g. Carlina acanthifolia subsp. utzka have been still used in folk medicine of many European countries and its biological activity is mostly associated with root essential oils. In the present paper, Raman spectroscopy (RS) was applied for the first time for evaluation of essential oil distribution in root of C. acnthifolia subsp. utzka and identification of root structures containing the essential oil. Furthermore, RS technique was applied to assess chemical stability of oil during drying of plant material or distillation process...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738584/production-of-stable-and-sensitive-sers-substrate-based-on-commercialized-porous-material-of-silanized-support
#5
Han Zhang, Lin Sun, Yuan Zhang, Yan Kang, Huilian Hu, Huirong Tang, Yiping Du
This paper reports accurate synthesis of a new type of surface-enhanced Raman spectroscopy (SERS) substrate based on gold nanoparticles decorated 201 red silanized diatomaceous supports. The developed SERS substrate is easy to fabricate, cost effective and offers sensitive rapid detection. The performance and stability of the SERS substrate was investigated and the results showed good SERS activity of substrate that can last for more than 6 months. Tiazophos and phosmet pesticides in aqueous solutions can be detected clearly at a low concentration of 0...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738278/well-dispersed-rhenium-nanoparticles-on-three-dimensional-carbon-nanostructures-efficient-catalysts-for-the-reduction-of-aromatic-nitro-compounds
#6
Pitchaimani Veerakumar, Pounraj Thanasekaran, King-Chuen Lin, Shang-Bin Liu
Rhenium nanoparticles (ReNPs) supported on ordered mesoporous carbon (OMC) as a catalyst (Re/OMC) through a solvent-evaporation induced self-assembly (ELSA) method were prepared. The synthesized heterogonous catalyst was fully characterized using X-ray diffraction, field emission transmission electron microscopy, N2 sorption, metal dispersion, thermogravimetric analysis, Raman, Fourier-transform infrared, and X-ray photon spectroscopies. In addition, the catalyst was applied to reduce the aromatic nitro compounds (ANCs) for the first time in aqueous media and the reactions were monitored by following the intensity changes in the UV-vis absorption spectra with respect to time...
July 18, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28737910/raman-and-ir-spectroscopy-studies-on-propane-at-pressures-of-up-to-40-gpa
#7
Daniil Kudryavtsev, Aleksandr Serovaiskii, Elena Mukhina, Anton Kolesnikov, Biliana Gasharova, Vladimir Kutcherov, Leonid S Dubrovinsky
Raman and IR spectroscopy studies on propane were performed at pressures of up to 40 GPa at ambient temperatures using the diamond anvil cell technique. Propane undergoes three phase transitions at 6.4(5) GPa, 14.5(5) GPa, and 26.5(5) GPa in Raman spectroscopy and at 7.0(5) GPa, 14.0(5) GPa and 27.0(5) GPa in IR spectroscopy. The phase transitions were identified using the Raman and IR splitting modes and the appearance or disappearance of peaks, which clearly corresponded to the changes in the frequencies of the modes as the pressure changed...
July 24, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28737720/a-simple-and-highly-sensitive-thymine-sensor-for-mercury-ion-detection-based-on-surface-enhanced-raman-spectroscopy-and-the-mechanism-study
#8
Hao Yang, Sui-Bo Ye, Yu Fu, Weihong Zhang, Fangyan Xie, Li Gong, Ping-Ping Fang, Jian Chen, Yexiang Tong
Mercury ion (Hg(2+)) is recognized as one of the most toxic metal ions for the environment and for human health. Techniques utilized in the detection of Hg(2+) are an important factor. Herein, a simple thymine was successfully employed as the surface enhanced Raman spectroscopy sensor for Hg(2+) ion detection. The limit of detection (LOD) of the developed sensor is better than 0.1 nM (0.02 ppb). This sensor can also selectively distinguish Hg(2+) ions over 7 types of alkali, heavy metal and transition-metal ions...
July 24, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28736959/in-vivo-raman-spectroscopy-assisted-early-identification-of-potential-second-primary-recurrences-in-oral-cancers-an-exploratory-study
#9
Akshat Malik, Aditi Sahu, S P Singh, Atul Deshmukh, Pankaj Chaturvedi, Deepa Nair, Sudhir Nair, C Murali Krishna
BACKGROUND: Higher rates of local recurrences and second primaries, ascribable to field cancerization, are known problem in oral cancers. The present study explored utility of identification of potential recurrences by Raman spectroscopy, which has been shown to identify oral precancers, cancers, and field cancerization in humans and micro-sized mechanical irritation-induced tumors in animals. METHODS: Raman spectra were acquired from tumor and contralateral normal mucosa in 99 patients with oral cancer who were then followed up for appearance of clinically apparent cancerous lesions...
July 24, 2017: Head & Neck
https://www.readbyqxmd.com/read/28736586/photothermal-microscopy-of-coupled-nanostructures-and-the-impact-of-nanoscale-heating-in-surface-enhanced-raman-spectroscopy
#10
Zhi-Cong Zeng, Hao Wang, Paul Johns, Gregory V Hartland, Zachary D Schultz
The optical properties of plasmonic nanoparticles are strongly dependent on interactions with other nanoparticles, which complicates analysis for systems larger than a few particles. In this work we examined heat dissipation in aggregated nanoparticles, and its influence on surface enhanced Raman scattering (SERS), through correlated photothermal heterodyne imaging, electron microscopy and SERS measurements. For dimers the per particle absorption cross-sections show evidence of interparticle coupling, however, the effects are much smaller than those for the field enhancements that are important for SERS...
June 1, 2017: Journal of Physical Chemistry. C, Nanomaterials and Interfaces
https://www.readbyqxmd.com/read/28734606/thiol-yne-click-synthesis-of-boronic-acid-functionalized-silica-nanoparticle-graphene-oxide-composites-for-highly-selective-enrichment-of-glycoproteins
#11
Jingai Yang, Xiwen He, Langxing Chen, Yukui Zhang
In this work, a facile novel strategy is developed for the preparation of 4-mercapto-phenylboronic acid functionalized silica nanoparticle-graphene oxide composite (GO@MPBA) via thiol-yne click reaction. The morphology, structure and composition of the resulting GO@MPBA was characterized by transmission electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, Fourier transform Raman spectroscopy, Thermogravimetric analysis and X-ray photoelectron spectrometry. GO@MPBA exhibited the high binding capacity towards glycoproteins such as ovalbumin (1288...
July 13, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28733614/raman-evidence-for-pressure-induced-formation-of-diamondene
#12
Luiz Gustavo Pimenta Martins, Matheus J S Matos, Alexandre R Paschoal, Paulo T C Freire, Nadia F Andrade, Acrísio L Aguiar, Jing Kong, Bernardo R A Neves, Alan B de Oliveira, Mário S C Mazzoni, Antonio G Souza Filho, Luiz Gustavo Cançado
Despite the advanced stage of diamond thin-film technology, with applications ranging from superconductivity to biosensing, the realization of a stable and atomically thick two-dimensional diamond material, named here as diamondene, is still forthcoming. Adding to the outstanding properties of its bulk and thin-film counterparts, diamondene is predicted to be a ferromagnetic semiconductor with spin polarized bands. Here, we provide spectroscopic evidence for the formation of diamondene by performing Raman spectroscopy of double-layer graphene under high pressure...
July 21, 2017: Nature Communications
https://www.readbyqxmd.com/read/28733014/removal-of-congo-red-dye-from-aqueous-solution-with-nickel-based-metal-organic-framework-graphene-oxide-composites-prepared-by-ultrasonic-wave-assisted-ball-milling
#13
Shuaiqi Zhao, Ding Chen, Fuhua Wei, Nini Chen, Zhao Liang, Yun Luo
Metal-organic frameworks (MOFs) were successfully synthesized by ultrasonic wave-assisted ball milling. In the absence of organic solvent, the coupling effect of ultrasonic wave and mechanical force played an significant role in the synthesis of MOFs. Adsorption of Congo red (CR) was studied in view of adsorption kinetic, isotherm and thermodynamics. The adsorbent was carried out using X-ray diffraction (XRD), thermogravimetric analysis (TGA), N2 adsorption-desorption isotherms, Raman spectroscopy and scanning electron microscope (SEM) methods...
November 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28732984/ultrasonic-assisted-biosurface-modification-of-multi-walled-carbon-nanotubes-with-thiamine-and-its-influence-on-the-properties-of-pvc-tm-mwcnts-nanocomposite-films
#14
Shadpour Mallakpour, Amir Abdolmaleki, Faezeh Azimi
The present paper represents a simple and efficient technique via ultrasonic irradiation, which utilized for chemical treatment of carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) with Thiamine (Tm). Poly(vinyl chloride) (PVC) based nanocomposites (NC)s were prepared by the incorporation of various amounts of modified MWCNTs (4, 8, and 12wt%) within the PVC matrix by blending solution and ultrasonic distribution methods. The morphological, chemical structure and thermal stability of the PVC/Tm-MWCNT NCs were identified via Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, and thermogravimetric analysis...
November 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28732957/sonochemical-synthesis-of-silver-nanoparticles-anchored-reduced-graphene-oxide-nanosheets-for-selective-and-sensitive-detection-of-glutathione
#15
Victor Vinoth, Jerry J Wu, Abdullah M Asiri, Sambandam Anandan
Developed here an eco-friendly, one-pot approach toward rapid synthesis of silver nanoparticles anchored reduced graphene oxide (AgNPs(TMSPED)-rGO) nanosheets via sonochemical irradiation method, using an aqueous solution mixture of GO and AgNO3 in the presence of N-[3(trimethoxysilyl)propyl] ethylenediamine (TMSPED) without any reducing agent. As synthesized decorated nanosheets was thoroughly characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS)...
November 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28732952/ultrasound-promoted-direct-functionalization-of-multi-walled-carbon-nanotubes-in-water-via-diels-alder-click-chemistry
#16
Cuong M Q Le, Xuan Thang Cao, Kwon Taek Lim
A facile and environmentally friendly strategy for grafting polymers onto the surface of multi-walled carbon nanotubes (CNTs) was demonstrated by Diels-Alder "click chemistry". Firstly, the copolymers of poly(styrene-alt-maleic anhydride) (PSM) were prepared by the reversible addition-fragmentation chain transfer (RAFT) polymerization and subsequently functionalized with furfuryl amine to introduce anchoring groups. The copolymers were then grafted on CNTs via the Diels-Alder reaction in water through a conventional heating-stirring route and ultrasound-assisted method...
November 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28732935/preparation-of-nanostructured-and-nanosheets-of-mos2-oxide-using-oxidation-method
#17
Majed Amini, Ahmad Ramazani S A, Morteza Faghihi, Seyyedfaridoddin Fattahpour
Molybdenum disulfide (MoS2), a two-dimensional transition metal has a 2D layered structure and has recently attracted attention due to its novel catalytic properties. In this study, MoS2 has been successfully intercalated using chemical and physical intercalation techniques, while enhancing its surface properties. The final intercalated MoS2 is of many interests because of its low-dimensional and potential properties in in-situ catalysis. In this research, we report different methods to intercalate the layers of MoS2 successfully using acid-treatment, ultrasonication, oxidation and thermal shocking...
November 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28732897/preparation-and-characterization-of-novel-chitosan-and-%C3%AE-cyclodextrin-polymer-sponges-for-wound-dressing-applications
#18
Claudia Flores, Marco Lopez, Nicolas Tabary, Christel Neut, Feng Chai, Didier Betbeder, Clément Herkt, Frederic Cazaux, Valerie Gaucher, Bernard Martel, Nicolas Blanchemain
Chitosan (CS) presents antibacterial, mucoadhesive and hemostatic properties and is an ideal candidate for wound dressing applications. This work reports the development of sponge-like materials obtained from physical hydrogels after the interaction between CS and a β-cyclodextrin polymer (PCD) in acidic conditions to provoke immediate gelation. Characterization consisted of zeta potential (ZP) measurements, rheology analysis, Fourier transform infrared (FTIR), Raman spectroscopy, wide angle X-ray scattering (WAXS) and scanning electron microscopy (SEM)...
October 1, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28732285/infrared-dispersion-analysis-and-raman-scattering-spectra-of-taurine-single-crystals
#19
Roberto L Moreira, Ricardo P S M Lobo, Anderson Dias
A comprehensive set of optical vibrational modes of monoclinic taurine crystals was determined by Raman scattering, and infrared reflectivity and transmission spectroscopies. By using appropriate scattering/reflection geometries, the vibrational modes were resolved by polarization and the most relevant modes of the crystal could be assigned. In particular, we were able to review the symmetry of the gerade modes and to resolve ambiguities in the literature. Owing to the non-orthogonal character of Bu modes in monoclinic crystals (lying on the optic axial plane), we carried out a generalized Lorentz dispersion analysis consisting of simultaneous adjust of infrared-reflectivity spectra at various light polarization angles...
July 14, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28732164/electrochemical-intercalation-of-mg-2-into-anhydrous-and-hydrated-crystalline-tungsten-oxides
#20
Ruocun Wang, Ching-Chang Chung, Yang Liu, Jacob L Jones, Veronica Augustyn
The reversible intercalation of multivalent cations, especially Mg(2+), into a solid-state electrode is an attractive mechanism for next-generation energy storage devices. These reactions typically exhibit poor kinetics due to a high activation energy for interfacial charge-transfer and slow solid-state diffusion. Interlayer water in V2O5 and MnO2 has been shown to improve Mg(2+) intercalation kinetics in non-aqueous electrolytes. Here, the effect of structural water on Mg(2+) intercalation in non-aqueous electrolytes is examined in crystalline WO3 and the related hydrated and layered WO3·nH2O (n = 1, 2)...
July 21, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
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