scholarly journals Evaluation of two processing routes for the synthesis of molybdenum oxide with cobalt addition

Cerâmica ◽  
2020 ◽  
Vol 66 (377) ◽  
pp. 21-29
Author(s):  
C. P. B. Araujo ◽  
A. V. V. M. Frota ◽  
M. V. M. Souto ◽  
C. M. Barbosa ◽  
M. M. S. Silva ◽  
...  
Keyword(s):  
Solid State ◽  
Molybdenum Oxide ◽  
Crystal Size ◽  
Catalytic Properties ◽  
Cobalt Nitrate ◽  
Ammonium Molybdate ◽  
Molybdenum Oxides ◽  
Vis Spectroscopy ◽  
Cobalt Addition ◽  
Electronic Behavior

Abstract Molybdenum oxides are very interesting technologic materials, which present several industrial uses. The addition of a second metal may enhance its catalytic properties as well as change electronic behavior. Several methodologies for adding a second metal can be found in the literature, however, the comparison between them is hardly ever found. Here two processing routes were tested for the synthesis of molybdenum oxide with cobalt addition: solid-state and wet routes. Ammonium molybdate and cobalt nitrate were used as starting materials and cobalt addition was carried out before calcination. Starting materials were characterized by SEM, FTIR, XRF, and XRD. Calcination products were evaluated by SEM, XRF, XRD and UV-vis spectroscopy. Calcined products whose doping was performed via solid-state presented smaller crystal size (~25 nm), larger cobalt retention (deviation, δ ~10%) and slightly smaller band gap in comparison to those doped via the wet route (~40 nm and δ>11%).

scholarly journals Synthesis, Fabrication, and Characterization of Functionalized Polydiacetylene Containing Cellulose Nanofibrous Composites for Colorimetric Sensing of Organophosphate Compounds

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1869
Author(s):  
A K M Mashud Alam ◽  
Donovan Jenks ◽  
George A. Kraus ◽  
Chunhui Xiang
Keyword(s):  
Solid State ◽  
Hydroxyl Groups ◽  
Colorimetric Sensing ◽  
Electrospinning Technique ◽  
Hazardous Chemical ◽  
Tensile Tester ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Landmark Study

Organophosphate (OP) compounds, a family of highly hazardous chemical compounds included in nerve agents and pesticides, have been linked to more than 250,000 annual deaths connected to various chronic diseases. However, a solid-state sensing system that is able to be integrated into a clothing system is rare in the literature. This study aims to develop a nanofiber-based solid-state polymeric material as a soft sensor to detect OP compounds present in the environment. Esters of polydiacetylene were synthesized and incorporated into a cellulose acetate nanocomposite fibrous assembly developed with an electrospinning technique, which was then hydrolyzed to generate more hydroxyl groups for OP binding. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), Instron® tensile tester, contact angle analyzer, and UV–Vis spectroscopy were employed for characterizations. Upon hydrolysis, polydiacetylene esters in the cellulosic fiber matrix were found unaffected by hydrolysis treatment, which made the composites suitable for OP sensing. Furthermore, the nanofibrous (NF) composites exhibited tensile properties suitable to be used as a textile material. Finally, the NF composites exhibited colorimetric sensing of OP, which is visible to the naked eye. This research is a landmark study toward the development of OP sensing in a protective clothing system.

scholarly journals Spectroscopic, X-ray Diffraction and Density Functional Theory Study of Intra- and Intermolecular Hydrogen Bonds in Ortho-(4-tolylsulfonamido)benzamides

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 926
Author(s):  
Malose J. Mphahlele ◽  
Eugene E. Onwu ◽  
Marole M. Maluleka
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Density Functional ◽  
Tetrahedral Geometry ◽  
Hindered Rotation ◽  
Hydrogen Bond Acceptor ◽  
Functional Theory ◽  
Vis Spectroscopy ◽  
Hydrogen Bonded

The conformations of the title compounds were determined in solution (NMR and UV-Vis spectroscopy) and in the solid state (FT-IR and XRD), complemented with density functional theory (DFT) in the gas phase. The nonequivalence of the amide protons of these compounds due to the hindered rotation of the C(O)–NH2 single bond resulted in two distinct resonances of different chemical shift values in the aromatic region of their 1H-NMR spectra. Intramolecular hydrogen bonding interactions between the carbonyl oxygen and the sulfonamide hydrogen atom were observed in the solution phase and solid state. XRD confirmed the ability of the amide moiety of this class of compounds to function as a hydrogen bond acceptor to form a six-membered hydrogen bonded ring and a donor simultaneously to form intermolecular hydrogen bonded complexes of the type N–H···O=S. The distorted tetrahedral geometry of the sulfur atom resulted in a deviation of the sulfonamide moiety from co-planarity of the anthranilamide scaffold, and this geometry enabled oxygen atoms to form hydrogen bonds in higher dimensions.

Facile Solid State Method Route Synthesis and Enhance Visible Light Activities of BiVO4 by Doping Co

2016 ◽  
Vol 703 ◽  
pp. 316-320
Author(s):  
Hai Feng Chen ◽  
Jing Ling Hu ◽  
Bing Xu
Keyword(s):  
Solid State ◽  
Visible Light ◽  
Catalytic Effect ◽  
Catalytic Properties ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
Illumination Time ◽  
X Ray ◽  
State Method

Using NH4VO3, Bi (NO3)3•5H2O and Co (NO3)2•6H2O as raw materials, Co doped BiVO4 (Co/BiVO4) photocatalysts were successfully prepared by solid state method. And the photo catalytic properties were test in this work. Crystal structures of these samples were characterized by X-ray diffraction (XRD). The Methyl Orange (MO) was simulated as the sewage under the visible light to explorer the influence of the illumination time and the mass of photocatalyst. The visible-light absorption spectrum of BiVO4 was broadening with doping Co. It was found that the Co/BiVO4 had higher photocatalytic activity than pure BiVO4 .The reason of enhanced catalytic effect also had been analyzed and discussed in the article.

Substituent Effect on the Solid-State Photoinduced Luminescence of α-Cyanostilbene Derivatives

2019 ◽  
Vol 41 (5) ◽  
pp. 868-868
Author(s):  
Huan Yuan Long Huan Yuan Long ◽  
Jin Zhang Jin Zhang ◽  
Zi Wei Li Zi Wei Li ◽  
Peng Zhou Peng Zhou ◽  
Tian Ying Peng and Guo Wen He Tian Ying Peng and Guo Wen He
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Solid State ◽  
Magnetic Resonance ◽  
Substituent Effect ◽  
Software Package ◽  
Luminescence Properties ◽  
Dilute Solutions ◽  
Yellow Color ◽  
Vis Spectroscopy ◽  
Color Emission

A series of α-cyanostilbene derivatives with aggregation-induced enhanced emission （AIEE） was obtained. All the compounds were characterized by UV−vis spectroscopy, fluorescence and nuclear magnetic resonance. These compounds exhibited blue, green and yellow color emission in solid state but non-fluorescent in dilute solutions. The electronic characteristics were examined by GAMESS Interface software package. The results indicate that the luminescence properties are affected by the substituents.

Structural and Catalytic Properties of the Alkali Metal Ion-Exchanged Y-Zeolites by 29Si and 27Al Solid-State NMR and FT-IR Spectroscopy

2005 ◽  
Vol 277-279 ◽  
pp. 708-719
Author(s):  
Chang Seop Lee ◽  
Hee Jung Lee ◽  
Sung Woo Choi ◽  
Jahun Kwak ◽  
Charles H.F. Peden
Keyword(s):  
Solid State ◽  
Alkali Metal ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Nmr Spectra ◽  
Catalytic Properties ◽  
Nox Reduction ◽  
29Si Nmr ◽  
Y Zeolites ◽  
X Ray

A series of cation exchanged Y-zeolites were prepared by exchanging cations with various alkali (M+, M= Li, Na, K, Cs) metals. The structural and catalytic properties of the alkali metal exchanged Y-zeolites have been investigated by a number of analytical techniques. Comparative elemental analyses were determined by an Energy Dispersive Spectroscopy X-ray (EDS), X-ray Photoelectron Spectroscopy (XPS), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) and X-ray Fluorescence (XRF) before and after cation substitution. The framework and non-framework Al coordination and the Si/Al ratios of the Y-zeolites were investigated by MAS Solid-State Nuclear Magnetic Resonance (NMR) spectroscopy. The Al NMR spectra were characterized by two 27Al resonance signals at 12 and 59 ppm, indicating the presence of the non-framework and framework Al respectively. The intensities of these resonances were used to monitor the amount of the framework and non-framework Al species in the series of exchanged zeolites. The 29Si NMR spectra were characterized by four resonance signals at -79, -84, -90, and -95 ppm. Changing the alkali metal cations in the exchanged Y-zeolites significantly altered the extent of the octahedral/tetrahedral coordination and the Si/Al ratio. The Fourier Transform Infrared spectra of the CO2 adsorbed on to the exchanged Y-zeolites showed a low frequency shift, as the atomic number of the exchanged alkali metal increased. In addition, the catalytic activity of these samples for NOx reduction were tested in combination with a non-thermal plasma technique and interpreted based on the above structural and spectroscopic information.

Sign in / Sign up

Export Citation Format

Share Document