Laser Raman Spectra Research Articles

Chemical Characteristics of Zircon from Khaldzan Burgedei Peralkaline Complex, Western Mongolia

The Khaldzan Burgedei peralkaline complex is one of the potential rare metal (Zr–Nb–REE) deposits in Mongolia. The complex consists mainly of quartz syenite and granite, and zircon is the most common accessory mineral in the rocks. Based on texture and mineral paragenesis, zircon is classified into three types. Type-I zircons in the quartz syenite and granite are generally isolated and euhedral to subhedral, 25–100 μm in size, enclosed by albite, K-feldspar, and quartz. Type-II zircons occur as subhedral to euhedral 20–150 μm grains, with quartz, and fluorite in the metasomatized zone in the quartz syenite as well as an upper part of the granite near the contact with the quartz syenite. These zircons contain porous core parts (Type-I) or remnants of corroded xenotime-(Y) and synchysite-(Ce). Type-III zircons are observed in the hydrothermally altered zone in quartz syenite and pegmatite. These zircons are anhedral, fine-grained, 10–30 μm in size, and occur in amphibole pseudomorphs which were replaced by quartz, fluorite, chlorite, and hematite. Laser Raman spectra show that Type-I and Type-II zircons contain high amounts of water. Among these, three types of zircons, Type-II zircons are most enriched in REE, Nb, and Th. The texture and composition of the three types of zircons indicate that Type-I, Type-II, and Type-III zircons are magmatic, metasomatic and late hydrothermal in origin, respectively, and they experienced remobilization and recrystallization during the transition from a magmatic to a hydrothermal system.

Significant enhancement of photoresponsive characteristics and mobility of MoS2-based transistors through hybridization with perovskite CsPbBr3 quantum dots

Inorganic perovskite CsPbBr3 quantum dots (QDs) are potential nanoscale photosensitizers; moreover, two-dimensional (2-D) molybdenum disulfide (MoS2) has been intensively studied for application in the active layers of optoelectronic devices. In this study, heterostructures of 2D-monolayered MoS2 with zero-dimensional functionalized CsPbBr3 QDs were prepared, and their nanoscale optical characteristics were investigated. The effect of n-type doping on the MoS2 monolayer after hybridization with perovskite CsPbBr3 QDs was observed using laser confocal microscope photoluminescence (PL) and Raman spectra. Field-effect transistors (FETs) using MoS2 and the MoS2–CsPbBr3 QDs hybrid were also fabricated, and their electrical and photoresponsive characteristics were investigated in terms of the charge transfer effect. For the MoS2–CsPbBr3 QDs-based FETs, the field effect mobility and photoresponsivity upon light irradiation were enhanced by ~ 4 times and a dramatic ~ 17 times, respectively, compared to the FET prepared without the perovskite QDs and without light irradiation. It is noteworthy that the photoresponsivity of the MoS2–CsPbBr3 QDs-based FETs significantly increased with increasing light power, which is completely contrary to the behavior observed in previous studies of MoS2-based FETs. The increased mobility and significant enhancement of the photoresponsivity can be attributed to the n-type doping effect and efficient energy transfer from CsPbBr3 QDs to MoS2. The results indicate that the optoelectronic characteristics of MoS2-based FETs can be significantly improved through hybridization with photosensitive perovskite CsPbBr3 QDs.

Gaussian numerical analysis and terahertz spectroscopic measurement of homocysteine.

Homocysteine is an amino acid related to metabolism in human vivo, which is closely related to cardiovascular disease, senile dementia, bone fracture, et al. Currently, the usual medical test methods for homocysteine include high performance liquid chromatography (HPLC), fluorescence polarization immunoassay (FPIA) and enzyme-linked immunosorbent assay (ELISA), which are time-consuming or expensive. In this paper, we first analyze the vibration and rotation of homocysteine molecules by using density functional theory, and then we ensure that the theoretical absorption peaks are located in the range of the terahertz spectrum. Then, based on the terahertz time-domain spectroscopy system, we measured the absorption spectrum of homocysteine under different concentrations. It is found that as the detection of the concentration, the terahertz results present higher accuracy than that of the laser Raman spectrum, which can be used as the reference for the evaluation of pathological stage. These results are of great significance for the exact and quick diagnosis of homocysteine-related diseases in clinical medicine.

Blue TiO2 nanosheets as a high-performance electrode material for supercapacitors

We are reporting the use of blue titanium oxide (b-TiO2) nanostructures as advanced electrode material for high performance supercapacitor for the first time. A one-pot hydrothermal route was employed for the oxidation of layered titanium diboride (TiB2) into b-TiO2 nanosheets. The b-TiO2 nanosheets are prepared via hydrothermal oxidation of TiB2. Physico-chemical characterizations such as X-ray diffraction, UV–visible, photoluminescence spectroscopy, electron spin resonance spectroscopy, laser Raman spectrum, X-ray photoelectron spectroscopy, and morphological studies revealed the formation of sheet-like b-TiO2 nanostructures. The energy storage properties of the b-TiO2 electrode were examined using aqueous and organic electrolytes. The cyclic voltammetry and charge-discharge analysis of b-TiO2 electrode using 1 M Na2SO4 revealed their pseudocapacitive nature with a high specific capacitance (∼19 mF cm−2). The b-TiO2 based symmetric supercapacitor (SSC) device using organic liquid (1 M TEABF4) works over a wide operating potential window (3 V) and delivered a high specific capacitance (6.67 F g−1 or 3.58 mF cm−2), possess high energy density and power density with excellent cyclic stability over 10,000 cycles. Collectively, these studies demonstrated the usefulness of b-TiO2 as a novel electrode material for high performance supercapacitor.

Fluid Inclusions and CHOSPb Isotopes: Implications for the Genesis of the Zhuanshanzi Gold Deposit on the Northern Margin of the North China Craton

AbstractThe Zhuanshanzi gold deposit lies in the eastern section of the Xingmeng orogenic belt and the northern section of the Chifeng‐Chaoyang gold belt. The gold veins are strictly controlled by a NW‐oriented shear fault zone. Quartz veins and altered tectonic rock‐type gold veins are the main vein types. The deposits can be divided into four mineralization stages, and the second and third metallogenic stages are the main metallogenic stages. In this paper, based on the detailed field geological surveys, an analysis of the orebody and ore characteristics, microtemperature measurement of fluid inclusions, the Laser Raman spectrum of the inclusions, determination of CHOSPb isotopic geochemical characteristics, and so on were carried out to explore the origin of the ore‐forming fluids, ore‐forming materials, and the genesis of the deposits. The results show that the fluid inclusions can be divided into four types: type I – gas–liquid two‐phase inclusions; type II – gas‐rich inclusions; type III– liquid inclusions; and type IV – CO2‐containing three‐phase inclusions. However, they are dominated by type Ib – gas liquid inclusions and type IV – three‐phase inclusions containing CO2. The gas compositions are mainly H2O and CO2, indicating that the metallogenic system is a CO2H2ONaCl system. The homogenization temperature of the ore‐forming fluid evolved from a middle temperature to a low temperature, and the temperature of the fluid was further reduced due to meteoric water mixing during the late stage, as well as a lack of CO2 components, and eventually evolved into a simple NaClH2O hydrothermal system. CHOSPb isotope research proved that the ore‐forming fluids are mainly magmatic water during the early stage, with abundant meteoric water mixed in during the late stage. Ore‐forming materials originated mostly from hypomagma and were possibly influenced by the surrounding rocks, suggesting that the ore‐forming materials were mainly magmatic hydrothermal deposits, with a small amount of crustal component. The fluid immiscibility and the CO2 and CH4 gases in the fluids played an active and important role in the precipitation and enrichment of Au during different metallogenic stages. The deposit is considered a magmatic hydrothermal deposit of middle–low temperature.

High energy symmetric supercapacitor based on mechanically delaminated few-layered MoS2 sheets in organic electrolyte

Electrochemical energy storage devices based on the two-dimensional metal chalcogenides have great interest due to their intriguing physical and chemical properties. In this work, we are reporting the high-performance supercapacitive properties of few-layered MoS2 (prepared via ball milling process) in an organic electrolyte. The physico-chemical characterizations such as X-ray diffraction, X-ray photoelectron spectroscopy, high-resolution transmission electron microscope, and laser Raman spectrum, confirms the formation of few-layered MoS2. The cyclic voltammetry and electrochemical impedance spectroscopy (Nyquist and Bode plots) studies of the MoS2 symmetric supercapacitor (SSC) reveals the presence of pseudocapacitive nature of charge-storage via ion-intercalation/de-intercalation process. The galvanostatic charge-discharge analysis shows that the MoS2 SSC device possesses a high specific capacitance of 14.75 F g−1 and an energy density of 18.43 Wh kg−1 (measured at a constant current density of 0.75 A g−1) with excellent cyclic stability over 5000 cycles. The experimental results suggest that the few-layered MoS2 SSC device might be the ideal choice in the development of next-generation energy devices.

Experimental (FT-IR, Laser-Raman and NMR) and theoretical comparative study on 2-benzylsulfanyl-4-pentyl-6-(phenylsulfanyl)pyrimidine-5-carbonitrile, a potential bioactive agent

In this paper, the experimental and theoretical vibrational frequencies of a potential bioactive pyrimidine derivative molecule named 2-benzylsulfanyl-4-pentyl-6-(phenylsulfanyl)pyrimidine-5-carbonitrile has been investigated. The experimental FT-IR and Laser-Raman spectra of the studied molecule are in the region (4000–400[Formula: see text]cm[Formula: see text] and (4000–100[Formula: see text]cm[Formula: see text], respectively, in gas phase. The vibrational modes and optimized ideal structure parameters(bond lengths, bond angles and selected dihedral angles) were calculated by using DFT/B3LYP, DFT/BHandHLYP and DFT/PBE1PBE methods with 6-311[Formula: see text]G(d,p) basis set. The theoretical mode assignments have been obtained by using potential energy distribution (PED) with the VEDA4 software program. Additionally, infrared and Raman intensities, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) energies and their clouds, and other related molecular properties were calculated and evaluated. The proton (1H) and carbon-13 ([Formula: see text]C) nuclear magnetic resonance (NMR) chemical shifts have been investigated for the title molecule, both experimentally (in DMSO-d[Formula: see text] and theoretically (in vacuum and DMSO). The thermodynamic properties of the tile compound have been investigated using the mentioned theoretical computational methods. The results revealed that there isgood agreement between experimental and theoretical results and these results have supported the related literature.

Nature and evolution of hydrothermal fluids in the formation of the Tuwu porphyry copper deposit in the Eastern Tianshan Mountains, NW China

The Tuwu porphyry copper deposit is located in the Eastern Tianshan Mountains, Xinjiang, China. Lentiform-like ore bodies are hosted in the Early Carboniferous Qi'eshan group, and Cu mineralization shows a close association with tonalite porphyry. Porphyry and country rocks have undergone extensive potassic, chlorite-sericite, phyllic and propylitic alteration. The mineralized veins in the Tuwu deposit can be divided into: earlier quartz–biotite ± magnetite ± chalcopyrite veins (stage I), quartz–chalcopyrite ± bornite ± pyrite veins (stage II) and quartz ± molybdenite ± chalcopyrite ± pyrite ± calcite veins (stage III), and later calcite ± quartz veins (stage IV). The Stage II and III are the main Cu mineralization stages. At the Tuwu deposit, three types of fluid inclusions have been distinguished: liquid-rich (L-type), vapor-rich (V-type) and halite-bearing (S-type), respectively. Laser Raman spectra identified magnetite, hematite, chalcopyrite, and pyrite at S-type inclusions.The quartz veins in stage I and II contain all inclusion types. L-type and V-type inclusions are recognized in stage III quartz minerals, but only L-type inclusions are present in stage IV quartz minerals. Fluid inclusions in quartz of stage I, II, III and IV are characterized by homogenization temperature vary of 275–492 °C, 232–477 °C, 199–287 °C and 133–227 °C, with corresponding NaCl equiv. salinities of 2.2–58.7 wt% NaCl equiv., 1.4–58.3 wt% NaCl equiv., 1.1–6.0 wt% NaCl equiv., and 1.1–4.2 wt% NaCl equiv., respectively. Initial ore-forming fluids of the Tuwu deposit belong to relatively oxidized H2O-NaCl system with moderate-high temperature and salinity. Sulfur isotope data from chalcopyrite and pyrite suggest a magmatic source. Two types of chlorite (type 1 and type 2) are recognized based on the relationship with metal sulfides. Electron microprobe analysis shows that chlorites are plotted in ripidolite and pycnochlorite. Decreasing Fe/(Fe + Mg) ratios of chlorites indicate that the meteoric water was involved in the magmatic water, combined with the positive correlation with AlIV, implying that the chlorite formed in a relatively reduced and acidic environment. The hydrothermal fluids in type 1 chlorite bring large quantities of reduced metallic minerals compared to the barren fluids in type 2 chlorite. The formation temperatures of chlorite are roughly coincident with the results that obtained from fluid inclusion studies, which show a decrease trend. Changes in temperature, redox, pH, and fluid-rock interaction likely play an important role in the transportation and precipitation of metal sulfides of the Tuwu deposit.

Enhanced catalytic properties of Cu-based composites for NOx reduction with coexistence and intergrowth effect

Cu-based composites were prepared by a facile preparation method and were employed as reactive catalysts for the elimination of NOx. The characterizations of XRD (X-Ray Diffraction), BET (Brunauer-Emmet-Teller), LRS (Laser Raman Spectra), H2-TPR (H2-Temperature-Program-Reduction), TGA-DSC (Thermo Gravimetric Analyzer-Differential Scanning Calorimetry), ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectroscopy), HRTEM (High Resolution Transmission Electron Microscope), O2-TPD (O2-Temperature-Program-Desorption) and in situ FT-IR (in situ Fourier Transform Infrared Spectroscopy) show the formation of CuAl2O4 spinel during the calcination process and the coexistence and intergrowth effect among three-phases CuO-CuAl2O4-CeO2, promoting the increase of the amount of surface active sites. These results further present that the composite CCA800 exhibits the best catalytic performance in the elimination of NOx, completely converting NO to N2 at only 220 °C, which exhibits more excellent catalytic properties than the same type of Cu/Ce/Al catalysts applied in the field of the elimination of NOx. The coexistence and intergrowth effect among three-phases CuO-CuAl2O4-CeO2 greatly promotes the catalytic performance in the elimination of NOx.

Spectroscopic (FT-IR, Laser-Raman and NMR) and conformational analysis on novel pyrazole β-keto ester compound

Our goal in this study is to submit a comprehensive theoretical study of novel compound. Therefore, we perused and analyzed the experimental (real form) and theoretical (gas form) vibrational frequencies for the most stable conformer of title compound. The crystallographic geometry was used for full geometry optimization, followed by a conformational analysis. The experimental FT-IR and Laser-Raman spectra of the studied molecule were taken in the region (4000-400 cm−1) and (4000-100 cm−1) in gas phase, respectively. For the most stable conformer, the vibrational modes and their assignments and optimized structure parameters (bond lengths, bond angles) were computed by using DFT/B3LYP functional and 6-311++G(d,p) basis set. Gaussian 09W software and GaussView5 interface programs were utilized for all computations. Theoretical mode assignments of the most stable conformer were obtained by using potential energy distribution (PED) with free VEDA 4 software program. The observed FT-IR and Laser-Raman spectra were compared with the calculated theoretical data. The computed vibrational frequencies of C1 conformer were also found in good agreement with the experimental results. The Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO) analysis divulge the possibility of charge transfer within the molecule. The proton (1H) and carbon-13 (13C) nuclear magnetic resonance (NMR) chemical shifts were researched for the most stable conformer C1, both experimentally in DMSO-d6 and theoretically in DMSO with integral equation formalism polarizable continuum model (IEFPCM) method.

Preparation and characterization of polyvinylidenedifluoride-co-chlorotrifluoroethylene hollow fiber membranes with high alkaline resistance

In the present work, polyvinylidenedifluoride-co-chlorotrifluoroethylene (PVDF-co-CTFE) hollow fiber membranes were prepared via non-induced phase separation (NIPS) using 1-methyl-2-pyrrolidone (NMP) or triethyl phosphate (TEP) as the solvent. The thermodynamic characterization of both systems PVDF-co-CTFE/NMP/water and PVDF-co-CTFE/TEP/water) and the rheological properties of dope solutions were first investigated. Subsequently, the effect of dope concentration and spinning conditions such as air gap on the membrane permeability and mechanical strength was discussed in detail. The rejection of polystyrene with a size of 50 nm was 85, 100 and 100% for PVDF-co-CTFE hollow fiber membranes prepared with PVDF-co-CTFE concentrations of 14,17 and 20 wt%, while the permeability was 119, 39 and 2.5 L/m2 h bar, respectively. The morphologies of hollow fiber membranes were observed using scanning electron microscopy to evaluate the effect of solvent and spinning conditions on the membrane structure. The resultant PVDF and PVDF-co-CTFE hollow fiber membranes were immersed in a strong alkaline solution (NaOH (1 M)+NaClO (4000 ppm)) to evaluate the chemical resistance of PVDF-co-CTFE hollow fiber membranes in comparison with that of PVDF membranes. The mechanical properties of PVDF and PVDF-co-CTFE hollow fiber membranes immersed in the alkaline solution for 180 days were declined 90% and 10% as compared to the original ones, respectively. Moreover, the hollow fiber membranes were characterized using laser Raman spectra, Fourier-transform infrared spectra, differential scanning calorimetry, and X-ray photoelectron spectroscopy, before and after the immersion, to hypothesize the degradation mechanism of PVDF-co-CTFE and PVDF hollow fiber membranes in the alkaline solution.

Effects of process parameters on interfacial microstructure, residual stresses, and properties of tunnel furnace brazed diamonds

Diamonds were brazed on the substrate with nickel‑chromium (NiCr) filler alloy at a certain temperature for three different mesh belt speeds in the mesh belt continuous tunnel furnace, respectively. In this study, a different perspective involving the exploration of the new processes was used that could allow for the mass production of brazed diamond tools. The interfacial microstructure between the diamonds and filler alloy was analyzed by scanning electron microscopy, energy dispersive spectrometry, and X-ray diffraction. The residual stresses and mechanical properties of the brazed diamonds were determined through the laser Raman spectrum and the compressive strength or impact toughness testing equipment for superabrasives, respectively. The results illustrated the occurrence of chemical reaction at the interface of the filler alloy-diamond followed by the formation of the CrC compound. Moreover, the thickness of the interfacial reaction layer increased with the decrease in the mesh belt speed. The brazing high temperature and development of the CrC layer were found to be responsible for the residual stresses in the diamonds. The mechanical properties of the brazed diamond grits strongly depended on the resultant thickness of the diamond surface and the residual stresses produced during brazing.

Catalytic Reduction of NO by CO over Promoted Cu3Ce0.2Al0.8 Composite Oxides Derived from Hydrotalcite-Like Compounds

Catalytic reduction of NO by CO has been studied over a battery of Cu3CexAl(1–x) composite oxide catalysts prepared by coprecipitation method. The solids were further characterized by X-ray diffraction, laser Raman spectra, N2-physisorption (Brunauer–Emmet–Teller (BET)), H2-temperature-programmed reduction, inductively coupled plasma atomic emission spectroscopy, X-ray photoelectron spectroscopy, and in situ diffuse reflectance infrared Fourier transform spectroscopy techniques. The assessment on the catalytic properties were conducted with the NO + CO model reaction. The influences of Cu and different ratios of Ce and Al on the catalytic performance have been investigated. When the ratio of Ce and Al was 1:4, this sample possessed the best catalytic properties, which was exactly derived from hydrotalcite-like compounds. The introduction of a few cerium species (Cu/Ce = 15:1) in the structure improved the activity/selectivity toward selective catalytic reduction of NO by lowering the temperature of carbon...

远程激光拉曼光谱探测系统前置光学系统设计

远程激光拉曼光谱探测系统前置光学系统设计

Growth, Laser Raman, Thermal, Edax and Photoluminescence Studies of Pure and Calcium Doped Zinc Hydrogen Phosphate Crystals Using Single Diffusion Technique

Growth aspects of pure and Calcium doped Zinc hydrogen phosphate single crystals from silica gel by the process of single diffusion technique are discussed. Crystals with different morphologies and effect on various parameters like gel pH, and gel ageing, gel density and concentration of reactants on the growth of pure and Calcium doped ZnHPO 4 crystals were studied. Laser Raman spectra of the pure and Calcium doped ZnHPO 4 crystals are recorded and the vibrational assignments have been made with possible explanations. Thermo gravimetrical analysis is undertaken to study the thermal stability of the grown crystals. The photoluminescence measurement shows that the material is suitable for photonic devices. The crystals grown were characterized by Laser Raman spectrum, TG/DTA, EDAX and Photoluminescence.

Differentiation of molecular chain entanglement structure through laser Raman spectrum measurement of High strength PET fibers under stress

The aim of this study was to investigate the mechanism for the improvement of mechanical properties of poly(ethylene terephthalate) (PET) fibers based on the concept of controlling the state of molecular entanglement. For this purpose, five different PET fibers were prepared through either the conventional melt spinning and drawing/annealing process or the high-speed melt spinning process. In both cases, the melt spinning process was designed so as to realize different Deborah number conditions. The prepared fibers were subjected to the laser Raman spectroscopy measurement and the characteristics of the scattering peak at around 1616 cm−1, which corresponds to the C-C/C=C stretching mode of the aromatic ring in the main chain, were investigated in detail. It was revealed that the fibers drawn and annealed after the melt spinning process of lower Deborah number showed higher tensile strength as well as lower value of full width at half maximum (FWHM) in the laser Raman spectrum. Narrow FWHM was considered to represent the homogeneous state of entanglement structure, which may lead to the higher strength and toughness of fibers because individual molecular chains tend to bare similar level of tensile stress when the fiber is stretched. In case of high-speed spun fibers prepared with a high Deborah number condition, the FWHM was narrow presumably because much lower tensile stress in comparison with the drawing/annealing process was applied when the fiber structure was developed, however the value increased significantly upon applying tensile load to the fibers during the laser Raman spectrum measurement. From these results, it was concluded that the Laser Raman spectroscopy could differentiate molecular chain entanglement structure of various fiber samples, in that low FWHM, which corresponds to either homogeneous state of molecular entanglement or lower level of mean residual stress, and small increase of FWTH upon applying tensile stress are considered to be the key factors for the improvement of the mechanical properties of PET fibers.

Vapor-phase cristobalite as a durable indicator of magmatic pore structure and halogen degassing: an example from White Island volcano (New Zealand)

Vesicles in volcanic rocks are physical records of magmatic degassing; however, the interpretation of their textures is complicated by resorption, coalescence, and collapse. We discuss the textural significance of vesicle-hosted vapor-phase cristobalite (high-T, low-P SiO2 polymorph), and its utility as a complement to textural assessments of magmatic degassing, using a representative dacite bomb erupted from White Island volcano (New Zealand) in 1999. Imaging in 2D (SEM) and 3D (CT) shows the bomb to have 56% bulk porosity, almost all of which is connected (~ 99%) and devoid of SiO2 phases. The remaining (~ 1%) of porosity is in isolated, sub-spherical vesicles that have corroded walls and contain small (< 30 μm across) prismatic vapor-phase cristobalite crystals (98.4 ± 0.4 wt.% SiO2 with diagnostic laser Raman spectra). Halogen degassing models show vapor-phase cristobalite to be indicative of closed-system chlorine and fluorine partitioning into H2O-rich fluid in isolated pores. At White Island, this occurred during shallow (< 100s of meters) ascent and extensive (~ 50%) groundmass crystallization associated with slow cooling in a volcanic plug. Pristine textures in this White Island bomb demonstrate the link between pore isolation and vapor-phase cristobalite deposition. We suggest that because these crystals have higher preservation potential than the bubbles in which they form, they can serve as durable, qualitative textural indicators of halogen degassing and pre-quench bubble morphologies in slowly cooled volcanic rocks (e.g., lava flows and domes), even where emplacement mechanisms have overprinted original bubble textures.

Visible light active N-doped TiO2 immobilized on polystyrene as efficient system for wastewater treatment

Abstract The photocatalytic activity of N-doped TiO2 particles supported on polystyrene (PS) surface by using a solvent-cast method at ambient temperature was evaluated on methylene blue (MB) dye decolourization. Subsequently, the effect of the new photocatalyst was evaluated in the inactivation of an antibiotic resistant (AR) Escherichia coli (E. coli) strain selected from the effluent of the biological process of an urban wastewater treatment plant. N-doped TiO2 particles supported on PS were characterized by UV–vis DRS reflectance and Laser Raman spectra measurements. The results of photocatalytic tests with MB water solutions showed that MB can be successfully degraded (83–100%) under visible light after 180 min of irradiation. The system was also effective in the phenol photocatalytic degradation. Moreover, photocatalytic process effectively inactivated AR E. coli strain which was reduced by 97% after 30 min treatment. The developed preparation method could be a promising simple and low cost procedure for preparing immobilized photocatalysts for large scale commercial applications to wastewater treatment under direct solar light.

Promotional synergistic effect of Cu and Nb doping on a novel Cu/Ti-Nb ternary oxide catalyst for the selective catalytic reduction of NOx with NH3

A series of Ti-Nb binary oxide were synthesized by co-precipitation as supports to prepare Cu/Ti-Nb mixed oxide catalysts through wetness impregnation. The novel catalyst 0.8%Cu/Ti2NbOx exhibited an excellent catalytic activity and N2 selectivity with a broad operation temperature (250–425°C) under a gas hourly space velocity (GHSV) of 177,000h−1 for the selective catalytic reduction of NOx with NH3. A series of analytical techniques including high resolution transmission electron microscopy (HRTEM), N2-physisorption, X-ray diffraction (XRD), Laser Raman spectra (LRS), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), NH3 temperature-programmed desorption (NH3-TPD), H2 temperature-programmed reduction (H2-TPR) and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) were used to investigate the correlations among catalyst structure, surface properties and catalytic performance. For the support Ti2NbOx, the specific surface area was larger than that of TiO2, promoting the high dispersion of the active component. Also, the surface acid sites were increased by addition of niobium oxide species and the redox capability of the support was enhanced by doping copper species. Moreover, the introduction of copper species effectively enhanced the catalytic performance within 225–400°C. The copper species mainly existed as isolated Cu2+ and non-isolated Cu+ and the isolated Cu2+ ions played a significant role in the high NH3-SCR performance over 0.8%Cu/Ti2NbOx catalyst. Hydrothermal aging treatment experiment demonstrated that 0.8%Cu/Ti2NbOx catalyst had an excellent hydrothermal stability. In addition, water vapor or/and SO2 had a slightly reversible inhibition influence on the catalytic performance over 0.8%Cu/Ti2NbOx, indicating that it was a promising candidate for NH3-SCR catalyst in the future practical application. The reaction pathway over 0.8%Cu/Ti2NbOx catalyst followed both Eley-Rideal mechanism and Langmuir-Hinshelwood mechanism at 225°C.

Spectroscopic investigation of 2-(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)-4H-naphto[2,3-d][1,3]oxazin-4-one molecule

In this present study, the experimental and theoretical vibrational frequencies of an important pharmacological molecule 2-(4-benzoyl-1,5-diphenyl-1[Formula: see text]-pyrazol-3-yl)-4[Formula: see text]-naphto[2,3-[Formula: see text]][1,3]oxazin-4-one have been researched. The experimental FT-IR and laser-Raman spectra of the title compound have been taken in the region (4000–400[Formula: see text]cm[Formula: see text]) and (4000–100[Formula: see text]cm[Formula: see text]), respectively. The vibrational modes and optimized structure parameters have been computed by using DFT/B3LYP methods with 6-311[Formula: see text]G(d,p) basis set. In our calculations, Gaussian 09W software program has been used. Assignments of theoretical vibrations have been obtained by potential energy distribution analysis using VEDA 4 software program. This program is important because it performs assignments with 10% precision. We have obtained a fairly good agreement between experimental and theoretically obtained results, and these results have supported the literature. Additionally, we have examined the highest occupied molecular orbital and the lowest unoccupied molecular orbital energies, the other related molecular energy values, nuclear magnetic resonance ([Formula: see text]C and1H-proton) chemical shifts, and UV–Vis wavelengths (electronic absorption wavelengths of the title compound) by using the mentioned calculation level. The nonlinear optical properties of the title compound have also been determined by using DFT/B3LYP/6-311[Formula: see text]G(d,p) level.