scholarly journals Barium Titanium Oxynitride from Ammonia-Free Nitridation of Reduced BaTiO3

Inorganics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 62
Author(s):  
Hua Guo ◽  
Aleksander Jaworski ◽  
Zheng Chen ◽  
Can Lu ◽  
Adam Slabon ◽  
...  

We investigated the nitridation of reduced BaTiO3, BaTiO2.60H0.08, corresponding to an oxyhydride with a large concentration of O defects (>10%). The material is readily nitrided under flowing N2 gas at temperatures between 400 and 450 °C to yield oxynitrides BaTiO2.6Nx (x = 0.2−0.22) with a slightly tetragonally distorted perovskite structure, a ≈ 4.01 and c ≈ 4.02 Å, and Ti partially remaining in the oxidation state III. The tetragonal structure was confirmed from Raman spectroscopy. 14N MAS NMR spectroscopy shows a single resonance at 270 ppm, which is typical for perovskite transition metal oxynitrides. However, largely different signal intensity for materials with very similar N content suggests N/O/vacancy ordering when prolonging nitridation times to hours. Diffuse reflectance UV-VIS spectroscopy shows a reduction of the intrinsic band gap to 2.4–2.45 eV compared to BaTiO3 (~3.2 eV). Mott-Schottky measurements confirm n-type conductivity and reveal a slight negative shift of the conduction band edge from –0.59 V (BaTiO3) to ~–0.65 eV.

2021 ◽  
Author(s):  
Yu-Hao Lo ◽  
Shu-Chi Li ◽  
Hirotsugu Hiramatsu

A new sampling unit design enhances the signal intensity and is available to combine Raman spectrometer with liquid chromatography.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Lu Pei ◽  
Yiqun Huang ◽  
Chunying Li ◽  
Yuanyuan Zhang ◽  
Barbara A. Rasco ◽  
...  

Silver-coated gold bimetallic nanoparticles were synthesized and used as substrates for surface-enhanced Raman spectroscopy (SERS) in detecting prohibited triphenylmethane drugs (including crystal violet and malachite green) in fish muscle. The optical properties and physical properties of bimetallic nanospheres were characterized by UV-Vis spectroscopy and transmission electron microscopy. The optimal nanospheres selected had relatively uniform size (diameter: 33 ± 3 nm) with a silver layer coated on the surface of gold seed (diameter: 18 ± 2 nm). For both crystal violet and malachite green, characteristic SERS spectral features could be identified at concentration as low as 0.1 μg/L with these bimetallic nanospheres. Crystal violet and malachite green residues in fish muscle could also be detected at levels as low as 0.1 ng/g, which could meet the most restricted regulatory requirements for the limit of detection in terms of analytical methods for crystal violet or malachite green in fish muscle. This study provides a basis for applying SERS technology with bimetallic nanoparticles to the identification of trace amounts of prohibited substances in aquatic food products, and the methodology could be extended to analyses of other hazardous chemicals in complex food matrices like vegetables and meats.


1979 ◽  
Vol 178 (1) ◽  
pp. 171-175 ◽  
Author(s):  
S. Aime ◽  
L. Milone ◽  
D. Osella ◽  
G.E. Hawkes ◽  
E.W. Randall

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Dong Uk Lee ◽  
Jin Yeong Jeong ◽  
Ji Woong Han ◽  
Gi-Chung Kwon ◽  
Pankaj Attri ◽  
...  

Conducting polymer has many applications in electronics, optical devices, sensors, and so on; however, there is still a massive scope of improvement in this area. Therefore, towards this aim, in this study, we synthesized a new thiophene-based conducting polymer, 2-heptadecyl-5-hexyl-6-(5-methylthiophen-2-yl)-4-(5-((E)-prop-1-enyl)thiophen-2-yl)-5H-pyrrolo[3,4-d]thiazole (HHMPT). Further, to increase its application, the interactions between the conducting polymer (HHMPT) and ionic liquids (ILs) were investigated by UV-Vis spectroscopy, FTIR spectroscopy, and confocal Raman spectroscopy techniques. Moreover, film roughness and conductivity of the polymer film with or without ILs were also studied. The imidazolium- and ammonium family ILs with the potential to interact with the newly synthesized conducting polymer were used. The results of the interaction studies revealed that the imidazolium family IL-polymer mixtures and ammonium family IL-polymer mixtures have almost similar conductivity at low concentration of ILs. This study provides an insight into the combined effect of a polymer and ILs and may generate many theoretical and experimental opportunities.


Author(s):  
Gleb S. Budylin ◽  
Denis A. Davydov ◽  
Nadezhda V. Zlobina ◽  
Alexey V. Baev ◽  
Vyacheslav G. Artyushenko ◽  
...  

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 405 ◽  
Author(s):  
Brett H. Pogostin ◽  
Anders Malmendal ◽  
Casey H. Londergan ◽  
Karin S. Åkerfeldt

Determining the pKa of key functional groups is critical to understanding the pH-dependent behavior of biological proteins and peptide-based biomaterials. Traditionally, 1H NMR spectroscopy has been used to determine the pKa of amino acids; however, for larger molecules and aggregating systems, this method can be practically impossible. Previous studies concluded that the C-D stretches in Raman are a useful alternative for determining the pKa of histidine residues. In this study, we report on the Raman application of the C2-D probe on histidine’s imidazole side chain to determining the pKa of histidine in a short peptide sequence. The pKa of the tripeptide was found via difference Raman spectroscopy to be 6.82, and this value was independently confirmed via 1H NMR spectroscopy on the same peptide. The C2-D probe was also compared to other Raman reporters of the protonation state of histidine and was determined to be more sensitive and reliable than other protonation-dependent signals. The C2-D Raman probe expands the tool box available to chemists interested in directly interrogating the pKa’s of histidine-containing peptide and protein systems.


2004 ◽  
Vol 69 (12) ◽  
pp. 1053-1061 ◽  
Author(s):  
Josef Husárek ◽  
Richard Pstorek ◽  
Michal Malon ◽  
Zedenek Sindalar ◽  
Marek Pavlícek

A series of new Ni(II) dithiocarbamate compounds of the composition [NiX(cetdtc)(PR3)](X = Cl, Br, I, NCS; cetdtc = cyclohexylethyldithiocarbamate; R = phenyl, n-butyl) has been synthesized. All the isolated complexes have been characterized by elemental analysis, IR and UV/VIS spectroscopy, 31P{1H}-NMR spectroscopy, thermal analysis magnetochemical and conductivity measurements. On the basis of the results of the physico-chemical study, all complexes are diamagnetic, non-electrolytes with a square-planar NiS2PX chromophore.


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