Evaluation of photocatalytic and supercapacitor potential of nickel tungstate nanoparticles synthesized by electrochemical method

2018 ◽  
Vol 42 (24) ◽  
pp. 19934-19944 ◽  
Author(s):  
Seied Mahdi Pourmortazavi ◽  
Mehdi Rahimi-Nasrabadi ◽  
Meisam Sadeghpour Karimi ◽  
Somayeh Mirsadeghi

Nickel tungstate nanoparticles (NiWO4 NPs) that were synthesized by an electrochemical method under various reaction conditions, namely, different tungstate ion concentrations, voltages, temperatures, and stirring rates, were studied here.

Synlett ◽  
2021 ◽  
Author(s):  
Kripa Subramanian ◽  
Subhash L. Yedage ◽  
Kashish Sethi ◽  
Bhalchandra M. Bhanage

An electrochemical method for the synthesis of phenanthridinones via constant potential electrolysis (CPE) mediated by <i>n</i>-Bu<sub>4</sub>NI (TBAI) has been reported. The protocol is metal and oxidant free and proceeds with 100% current efficiency. Here TBAI plays the dual role of the redox catalyst as well as supporting electrolyte. The intramolecular C-H activation proceeds under mild reaction conditions and short reaction time via electrochemically generated amidyl radicals. The reaction has been scaled up to gram level showing its practicability and the synthetic utility and applicability of the protocol has been demonstrated by the direct one-step synthesis of the bioactive compound Phenaglaydon.


2011 ◽  
Vol 399-401 ◽  
pp. 1002-1007
Author(s):  
Bin Li ◽  
Hai Jun Niu ◽  
Lin Zhang ◽  
Xu Duo Bai

POT (poly (o-toluidine)) was synthesized on ITO/glass by using electrochemical method and the effect of different reaction conditions such as scan rate, the concentrations of monomer and sulfuric acid, and cycle times on the POT was studied. The resulting POT was characterized by spectroscopy such as FT-IR, Roman, and UV-vis methods. The surface morphology of protruding island shape was recorded by scanning electronic microscope (SEM). The electrochromic properties were found that the color of the polymer can turn from green to blue reversibly by increasing the applied voltage. The anode of the solar cell was made of FTO/glass covered with nano-TiO2/POT showed good photo-electron conversion performance which indicated the potential application in electrochromic and solar cell devices.


2018 ◽  
Vol 69 (11) ◽  
pp. 3010-3012
Author(s):  
Liliana Norocel ◽  
Gheorghe Gutt

The developed biosensor is based on the electrochemical signal of the complex formed between the ligand used (glycine) and copper(II) ions. The developed electrochemical method is quick, inexpensive, easy to apply, and has shown good selectivity for copper ions. In this research, a linear response for copper ions was obtained in the concentration range of 0.2 mg to 1 mg/L, which largely covers the area of copper ion concentrations in wine. The achieved sensitivity was 11.05E-05 and the limit of detection (LOD) was 0.041 ppm. The biosensor with screen printed electrodes has been successfully used to detect copper ions in wine. A comparative study between the developed portable biosensor and ICP-MS analysis results of the same samples showed similar results.


1978 ◽  
Vol 24 (2) ◽  
pp. 261-266 ◽  
Author(s):  
S N Buhl ◽  
K Y Jackson ◽  
B Graffunder

Abstract Optimal reaction conditions for assaying human lactate dehydrogenase pyruvate-to-lactate were determined for isoenzymes 1 and 5 at 25, 30, and 37 degrees C. Three of the nine different buffers examined--imidazole, triethanolamine, and N-tris(hydroxymethyl)-methyl-2-aminoethane sulfonic acid--are satisfactory. Beta-NADH, pyruvate, and hydrogen ion concentrations were chosen to measure both isoenzymes with maximal-equal-sustainable efficiency at the lowest substrate concentrations. Approximately 95% of each isoenzyme is measured, for activities up to threefold the upper normal limit, if the measurements are made immediately after the reaction is initiated. The Arrhenius relationship for each isoenzyme is unique. Interconversion of results from one temperature to another is practical only with reservations. Results at 37 degrees C are not as reliable as those at 25 degrees C.


2013 ◽  
Vol 634-638 ◽  
pp. 2541-2544
Author(s):  
Hai Yang Zhang ◽  
Hai Jun Niu ◽  
Lin Zhang ◽  
Xu Duo Bai

Poly(m-trifluoromethylaniline) (PMTFMA) was synthesized on ITO/glass by using electrochemical method and the effect of different reaction conditions such as scan rate, the concentrations of monomer and sulfuric acid, and cycle times on the PMTFMA was studied. The resulting PMTFMA was characterized by FT-IR and UV-vis spectroscopy. The surface morphology of porous shape was recorded by scanning electronic microscope (SEM). It was found that the color of the polymer can turn from light yellow to yellow reversibly by increasing the applied voltage.


Author(s):  
James F. Hainfeld ◽  
Kyra M. Alford ◽  
Mathias Sprinzl ◽  
Valsan Mandiyan ◽  
Santa J. Tumminia ◽  
...  

The undecagold (Au11) cluster was used to covalently label tRNA molecules at two specific ribonucleotides, one at position 75, and one at position 32 near the anticodon loop. Two different Au11 derivatives were used, one with a monomaleimide and one with a monoiodacetamide to effect efficient reactions.The first tRNA labeled was yeast tRNAphe which had a 2-thiocytidine (s2C) enzymatically introduced at position 75. This was found to react with the iodoacetamide-Aun derivative (Fig. 1) but not the maleimide-Aun (Fig. 2). Reaction conditions were 37° for 16 hours. Addition of dimethylformamide (DMF) up to 70% made no improvement in the labeling yield. A high resolution scanning transmission electron micrograph (STEM) taken using the darkfield elastically scattered electrons is shown in Fig. 3.


2010 ◽  
Vol 1247 ◽  
Author(s):  
Rocío Calderón-Villajos ◽  
Carlos Zaldo ◽  
Concepción Cascales

AbstractControlled reaction conditions in simple, template-free hydrothermal processes yield Tm-Lu2O3 and Tm-GdVO4 nanocrystals with well-defined specific morphologies and sizes. In both oxide families, nanocrystals prepared at pH 7 reaction media exhibit photoluminescence in ∼1.95 μm similar to bulk single crystals. For the lowest Tm3+ concentration (0.2 % mol) in GdVO4 measured 3H4 and 3F4 fluorescence lifetimes τ are very near to τrad.


Author(s):  
Alex L. Bagdasarian ◽  
Stasik Popov ◽  
Benjamin Wigman ◽  
Wenjing Wei ◽  
woojin lee ◽  
...  

Herein we report the 3,5bistrifluoromethylphenyl urea-catalyzed functionalization of unactivated C–H bonds. In this system, the urea catalyst mediates the formation of high-energy vinyl carbocations that undergo facile C–H insertion and Friedel–Crafts reactions. We introduce a new paradigm for these privileged scaffolds where the combination of hydrogen bonding motifs and strong bases affords highly active Lewis acid catalysts capable of ionizing strong C–O bonds. Despite the highly Lewis acidic nature of these catalysts that enables triflate abstraction from sp<sup>2</sup> carbons, these newly found reaction conditions allow for the formation of heterocycles and tolerate highly Lewis basic heteroaromatic substrates. This strategy showcases the potential utility of dicoordinated vinyl carbocations in organic synthesis.<br>


2020 ◽  
Author(s):  
Alex L. Bagdasarian ◽  
Stasik Popov ◽  
Benjamin Wigman ◽  
Wenjing Wei ◽  
woojin lee ◽  
...  

Herein we report the 3,5bistrifluoromethylphenyl urea-catalyzed functionalization of unactivated C–H bonds. In this system, the urea catalyst mediates the formation of high-energy vinyl carbocations that undergo facile C–H insertion and Friedel–Crafts reactions. We introduce a new paradigm for these privileged scaffolds where the combination of hydrogen bonding motifs and strong bases affords highly active Lewis acid catalysts capable of ionizing strong C–O bonds. Despite the highly Lewis acidic nature of these catalysts that enables triflate abstraction from sp<sup>2</sup> carbons, these newly found reaction conditions allow for the formation of heterocycles and tolerate highly Lewis basic heteroaromatic substrates. This strategy showcases the potential utility of dicoordinated vinyl carbocations in organic synthesis.<br>


2019 ◽  
Author(s):  
Shiori Date ◽  
Kensei Hamasaki ◽  
Karen Sunagawa ◽  
Hiroki Koyama ◽  
Chikayoshi Sebe ◽  
...  

<div>We report here a catalytic, Markovnikov selective, and scalable synthetic method for the synthesis of saturated sulfur heterocycles, which are found in the structures of pharmaceuticals and natural products, in one step from an alkenyl thioester. Unlike a potentially labile alkenyl thiol, an alkenyl thioester is stable and easy to prepare. The powerful Co catalysis via a cobalt hydride hydrogen atom transfer and radical-polar crossover mechanism enabled simultaneous cyclization and deprotection. The substrate scope was expanded by the extensive optimization of the reaction conditions and tuning of the thioester unit.</div>


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