Choline Chloride-urea Deep Eutectic Solvent Research Articles

Synthesis of Multi-layered Spherical ZnO Micro/Nano-crystals by Hydrothermal Method from Deep Eutectic Solvent and Their Photo Catalytic Performance†

Multi-layered spherical ZnO micro/nano-crystals were synthesized by means of hydrothermal and antisolvent method from the urea-choline chloride deep eutectic solvent(UCC-DES). The effects of reaction time,amount and concentrations of antisolvents on the morphology of ZnO micro/nano-crystals were investigated,and the formation of ZnO micro/nano-crystals was discussed. Furthermore,the photocatalytic activities of the as-prepared ZnO crystals for the degradation of methyl orange were investigated. The results indicate that multi-layered spherical ZnO micro/nano-crystals exhibit a superior photocatalytic activity. The synthetic method of ZnO is facile,safe and environmentally friendly,it is in line with the requirements of green chemistry and should have widespread application in the future.

Electrochemical synthesis of copper nanoparticles using cuprous oxide as a precursor in choline chloride-urea deep eutectic solvent: nucleation and growth mechanism.

The electrochemical nucleation and growth kinetics of copper nanoparticles on a Ni electrode have been studied with cyclic voltammetry and chronoamperometry in the choline chloride (ChCl)-urea based deep eutectic solvent (DES). The copper source was introduced into the solvent by the dissolution of Cu(I) oxide (Cu2O). Cyclic voltammetry indicates that the electroreduction of Cu(I) species in the DES is a diffusion-controlled quasi-reversible process. The analysis of the chronoamperometric transient behavior during electrodeposition suggests that the deposition of copper on the Ni electrode at low temperatures follows a progressive nucleation and three-dimensional growth controlled by diffusion. The effect of temperature on the diffusion coefficient of Cu(I) species that is present in the solvent and electron transfer rate constant obeys the Arrhenius law, according to which the activation energies are estimated to be 49.20 and 21.72 kJ mol(-1), respectively. The initial stage of morphological study demonstrates that both electrode potential and temperature play important roles in controlling the nucleation and growth kinetics of the nanocrystals during the electrodeposition process. Electrode potential is observed to affect mainly the nucleation process, whereas temperature makes a major contribution to the growth process.

Effects of existence form and concentration of PbO on the conductivity of choline chloride–urea deep eutectic solvent

The effects of existence form and concentration of lead oxide (PbO) on the conductivity and viscosity of choline chloride (ChCl)-urea deep eutectic solvent (DES) were investigated. The ESI-MS and FT-IR analyses indicated that three-coordinated complexes are presented in the form of {[PbO∙CO(NH2)2]∙Cl−}−. It is deduced that the complex anions are formed through sp3 hybrid orbitals of Pb2+ ion and three sp hybrid orbitals are all filled with lone pair electrons which are donated by Cl−, O2− and O atoms of urea respectively. The raising of temperature leads to the electrical conductivity increases. With PbO concentration, however, the conductivity increases firstly and then decreases. The viscosity has an opposite change trend compared with the conductivity. These experimental phenomena can be explained by the formation of PbO-containing complexes and oligomers.

Preparation of sub-micrometer lead wires from PbO by electrodeposition in choline chloride-urea deep eutectic solvent

The sub-micrometer lead wires have been prepared by lead electrodeposition onto a stainless steel substrate from 40mM PbO+choline chloride-urea deep eutectic solvent. The electrochemical behavior of the PbO dissolved in this solvent was investigated with cyclic voltammetry. It is demonstrated that a substantial overpotential is required to initiate the lead deposition process on the stainless steel substrate because a nucleation loop is generated. Temperature and current density have obvious effect on the cathodic current efficiency, specific energy consumption, and deposits morphology during the lead electrodeposition. The highest current efficiency (96.45%) and the corresponding specific energy consumption (649.10kWht−1) were achieved at 130Am−2 and 343K. The lead wires obtained at 323K have a mean particle size of 2–4μm in length and 1μm in diameter. The XRD patterns of the deposits indicate that purified lead is obtained with face-centered cubic crystal structure and the crystallites are predominately oriented in (200) plane.

In Situ Generated Cetyltrimethylammonium Bisulphate in Choline Chloride–Urea Deep Eutectic Solvent: A Novel Catalytic System for One Pot Synthesis of 1,3,4-Oxadiazole

Cetyltrimethylammonium bisulphate ([CTA]HSO4) catalysed one pot synthesis of 2,5-disubstituted-1,3,4-oxadiazoles from carboxylic acid and acid hydrazide in biodegradable deep eutectic solvent is investigated. [CTA]HSO4 is generated in situ from cetyltrimethylammonium peroxodisulphate. Cyclization of diacylhydrazide using [CTA]HSO4 gives best alternative to traditional dehydration agents. Its remarkable features include a milder procedure, simplicity in workup and purification, good to excellent yields of products, use of inexpensive, recyclable reagents, and eco-friendly aspects by avoiding toxic catalysts/reagents and solvents. .

Synthesis of ZIF-8 in a deep eutectic solvent using cooling-induced crystallisation

We report an alternative route for the synthesis of ZIF-8 in a choline chloride–urea deep eutectic solvent (DES). Zinc nitrate hexahydrate and 2-methylimidazole were dissolved in the hot DES. The ZIF-8 sample could precipitate from the DES when the solution was cooled using rapid cooling or programmed cooling. The effect of the synthetic conditions, including the cooling rate of synthesis system and the reaction temperature, on the particle size and morphology of the ZIF-8 sample were investigated. The product was characterised using PXRD, SEM, TG, the particle size analysis and gas-sorption. When the system was chilled via rapid cooling, the product was 0.35μm in size, agglomerating to form irregular spheres. After programmed cooling, the product was 5–50μm with a rhombic dodecahedron or truncated rhombic dodecahedron morphology, depending on the cooling rate and reaction temperature. In addition, the precipitation of ZIF-8 in DES is also discussed. ZIF-8 synthesised in DES also displayed excellent thermal and chemical stability, as well as good gas adsorption and separation performances.

Electrochemical study and electrodeposition of copper(I) in ionic liquid-reline

The authors made the electrochemical studies on the electrode processes during copper electrodeposition with ionic liquids-reline as an electrolytic medium. Reline is a commercial name for a eutectic mixture of choline chloride and urea(1:2, molar ratio). This new proposed method of copper deposition is an ecological one because the ionic liquids are recyclable, non-volatile and non-toxic. Cyclic voltammetry investigations were conducted at 343 and 353 K in choline chloride-urea(Reline) deep eutectic solvent with single salt CuCl(generally in 0.05–0.38 mol/L concentration range). Electrochemical impedance spectroscopy investigations were conducted in choline chlorideurea ionic liquid with CuCl(0.05 mol/L). We investigated both cathodic and anodic processes of Cu+ ions at different sweep rates in this new electrolytic system based on choline chloride. We have proposed by this an alternative to the classical copper electrodeposition. Coefficient of diffusion, D 0, for the system Reline-CuCl is presented and the value of D 0 is 1.22×10−8 cm2/s.

An efficient four-component synthesis of dithiocarbamate derivatives

Abstract An environmentally benign, one-pot, four-component synthesis of chemically and pharmaceutically interesting dithiocarbamate derivatives is reported. The one-pot reaction of various aromatic aldehydes, ketones, aliphatic amines, and carbon disulfide, in the presence of potassium hydroxide in urea-choline chloride deep eutectic solvent or ethanol, leads to the corresponding dithiocarbamates in good to excellent yields. This method provides a convenient and time-saving strategy, with a simple work-up procedure.

Effect of Water Addition to Choline Chloride–Urea Deep Eutectic Solvent (DES) on the Removal of Post-Etch Resid ues Formed on Copper

Feasibility of dissolution of post-etch residues (PERs) formed on copper in formulations containing a mixture of urea (U)-choline chloride (CC) deep eutectic solvent (DES) and water (W) has been investigated. PER films were formed on copper surface by spin coating deep ultraviolet photoresist film, followed by CF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> /O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> plasma etching. The residue removal process was characterized using X-ray photoelectron spectroscopy and scanning electron microscopy techniques. Effective removal of PER was obtained in water-DES solutions containing as high as 90% water in the temperature range of 20-40 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C. Additionally, the etch rates of copper and siloxane-based low-k dielectric material in water-DES solutions were found to be lower than that in deaerated 250:1 [H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O: hydrofluoric acid (HF) (49%) volume ratio] dilute HF solutions.