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Metal sulfide is often utilized as a catalyzed material to form colorimetric response system for some heavy metal detection. While the aggregation effect and conventional morphology limited the catalyzed efficiency. Herein, a robust method based on morphology adjustment was proposed to improve the dispersibility and catalytic performance of CuS. The results demonstrated when the solvent ratio of ethylene glycol and dimethyl sulfoxide arrived at 3:1, it displayed an optimal structure which is like a patulous flower. Meanwhile, an optimal surface binding energy (ΔE) of 120.1 kcal/mol was obtained via theoretical calculation model. The flower-like structure caused a 2-fold increase in the catalytic level. Subsequently, the CuS was employed to make colorimetric detection of Cr(VI) in water. The assay results exhibited a linear range of the Cr(VI) from 60 to 340 nM, the limit of detection was 1.07 nM. In the practical tests for Qianhu lake water, the spiked recoveries were 93.6% and 104% with the RSD of 4.71% and 3.08%. Therefore, this CuS-based colorimetric method possesses a satisfactory application prospect for the Cr(VI) determination in water. [ABSTRACT FROM AUTHOR]

Understanding the phase regulation mechanism of BaTiO 3 synthesized by a hydrothermal method is a complicated and challenging task. Here, we successfully prepared cubic and tetragonal BaTiO 3 single nanocrystals by changing the ratio of water and ethanol in the solvent. We confirm that the BaTiO 3 phase is mainly affected by the hydroxylation process due to the reaction with solvent. In particular, ethanol can be catalytically oxidized by titanium atoms, cause BaTiO 3 hydroxylation and promote the formation of a cubic phase. In the mixed solution of ethanol and water, the hydroxylation process is suppressed, which facilitates the formation of the tetragonal phase. The relationship framework between the solvent ratio, phase structure and hydroxyl defects of BaTiO 3 is established. Tetragonal BaTiO 3 with fewer hydroxyl defects can promote charge transfer and surface reaction after polarization, thereby enhancing their photoelectric catalytic performance. This work provides references for the controllable synthesis of ferroelectric nanocrystals by hydrothermal methods and new insight for the utilization of polarization in photoelectrocatalysis applications. [Display omitted] • Cubic BaTiO 3 were prepared in pure ethanol or water solution due to the hydroxylation effect in the hydrothermal process. • In the mixed solution of ethanol and water, the hydroxylation process was suppressed and tetragonal BaTiO 3 were generated. • The polarization electric field of tetragonal BaTiO 3 has a significant imapct on their photoelectrocatalytic performance. [ABSTRACT FROM AUTHOR]

Lignin is recommended to a tempting alternative precursor of petroleum for fabricating carbon nanofibers (CNFs) due to its high carbon content, low-cost and renewable resources. However, the property of lignin-based carbon nanofibers (LCNFs) is inferior owing to the heterogeneity and 3D-network structure of lignin, which hinders its application in supercapacitors. The latest developments in fractionation technology have shown great potential for overcoming the aforementioned shortcomings. However, most of fractionation methods mainly rely on expensive chemicals and complex reaction process, such as enzymes, multiple solvents, membranes, and dialysis tubes. Herein, we proposed a controllable and effective strategy to fractionate lignin by only changing the ratio of ethanol/water (V/V) as mixture solvent. This gradient extraction method effectively removed the part of lignin with small molecular and branching structure, thus selectively getting the fractionated lignin with high molecular weight, narrow polydispersity index, and good linear structure. Fortunately, when the ratio of ethanol/water was 6:4, the corresponding LCNFs (LCNFs-L60) was obtained with large specific surface area, independent filamentous morphology networks and excellent electrochemical property. Its specific capacitance was up to 405.8 F/g. This way features controllable and sustainable for preparing high-quality LCNFs supercapacitors. [Display omitted] • The high linear structure of sugarcane bagasse lignin was obtained through different solvent ratio fractionation way. • The heterogeneity of fractionated lignin was decreased by screening large molecular weight sugarcane bagasse lignin. • L60 with more β-O-4 structural units and smaller homogeneity was more suitable for fabricating high performance LCNFs. • The LCNFs-L60 showed independent morphology, uniform diameter, large surface area and excellent power storage capacity. • This method was an effective strategy for preparing low-cost and high-quality LCNFs supercapacitors electrodes. [ABSTRACT FROM AUTHOR]

Highlights • The effect of solvent ratio on Co 2 (OH) 3 Cl was studied for the first time. • The highest capacitance of 321.79 F g−1 was got when V water :V glycol = 1:2. • No obvious capacitance decay was observed after 10,000 cycles. Abstract Co 2 (OH) 3 Cl was synthesized by a facile solvothermal method with different solvent ratios of water/glycol (V water :V glycol). The Co 2 (OH) 3 Cl prepared at the ratio of 1:2 showed uniform cubic nanostructure and provided the highest specific capacitance of 321.79 F g−1 at 0.5 A g−1. The capacitance retention and the Coulombic efficiency were both kept at 100% without obvious decay after continuous 10,000 charge-discharge cycles, demonstrating the durability and eximious stability of the Co 2 (OH) 3 Cl when utilized as the supercapacitor electrode material. [ABSTRACT FROM AUTHOR]

Two new coordination polymers (CPs), namely, [Cu(4-bptzp)(BDC)] ( 1 ) and [Cu 2 (4-bptzp) 2 (BDC)Cl 2 ] ( 2 ) (4-bptzp = 1,4-bis(5-(4-pyridyl)tetrazolyl)propane, H 2 BDC = 1,3-benzenedicarboxylic acid) were synthesized by changing the proportion of the solvents under the solvothermal conditions, and structurally characterized by single crystal X-ray diffraction, infrared spectroscopy (IR), powder X-ray diffraction (PXRD), elemental analyses and thermogravimetric analyses (TGA). The 4-bptzp was firstly introduced into the CPs. Complexes 1 and 2 show two kinds of 1D chain structures. Complex 1 contains the 1D ladder-like [Cu(BDC)] n chains and Cu 2 (4-bptzp) 2 rings, while complex 2 consists of the 1D linear [Cu 2 (BDC)Cl 2 ] n chain containing the bridging Cl − ions and Cu 2 (4-bptzp) 2 rings. The adjacent 1D chains in 1 and 2 are extended to 2D supramolecular layers by the hydrogen bonding interactions, respectively. In addition, the electrochemical properties and dye adsorption properties of complexes 1 and 2 have been investigated. The solvent ratio plays a key role in adjusting their structures and adsorption property. [ABSTRACT FROM AUTHOR]

Three groups of polypyrrole (PPy) were synthesised at different mole ratio of FeCl3 to pyrrole of 0·5∶1, 0·75∶1 and 1∶1, and were marked as N-PPy, H-PPy and M-PPy respectively. The effects of oxidant dosage on morphologies, chemical structures, conductivities and especially dielectric properties were contrastively studied, and the influences of solvent ratio (volume ratio of acetonitrile to water) on permittivity and dielectric loss of PPy were also studied for. The results indicate that the variation law and mechanism of morphology of H-PPy and M-PPy are unchanged when compared with N-PPy, as we have reported before. H-PPy shows the highest conductivity and dielectric loss among the three groups of PPy, which can be attributed to the most suitable oxidation and doping degree. As to the solvent ratio effect, we find that all the dielectric parameters decrease with the increase in the volume ratio of acetonitrile to water, which is due to the solvent effect. [ABSTRACT FROM AUTHOR]

• Control of microscopic morphology by modulation of the water-to-alcohol ratio. • The high capacitance of NCS-3 (857C/g) and the capacitance retention rate is 80% (20 A g−1). • Asymmetric supercapacitor shows high energy density 48.7 Wh kg−1 at a power density of 801 W kg−1. Because of high electrical conductivity, theoretical capacity, and numerous redox pairs, NiCo 2 S 4 has sparked a lot of interest in energy storage. In the paper, with citric acid as inductive agent, NiCo 2 S 4 mesoporous microspheres have been successfully prepared via solvothermal approach by regulating the solvent ratio (water/ethanol ratio = 1/3). It reveals that citric acid dominate in the nucleation and orientated growth of NiCo 2 S 4 and the morphology of NiCo 2 S 4 with different submicron structures can be tuned by the ratio of water/ethanol. The morphology, structure, and electrochemical properties of all NiCo 2 S 4 samples have been investigated. Among these samples, NiCo 2 S 4 mesoporous microspheres display the best electrochemical properties due to their unique mesoporous structure and high specific area. It has a high discharge capacity of 857C/g at a current density of 1 A/g, and exhibit exceptional rate capability (80 % retention even at 20 A/g). Additionally, when employed as positive of an asymmetric NiCo 2 S 4 //active carbon (AC) supercapacitor, it yields an energy density of 48.7 Wh kg−1 at 801 W kg−1 and 81 % capacity retention after 10,000 cycles at a current density of 5 A/g. The work describes a quick and easy way to increase the performance of NiCo 2 S 4 electrode materials and demonstrates its potential in practical application. [ABSTRACT FROM AUTHOR]

Chemically modified TiO 2 colloidal paste with a mixed solvent of water and t -butanol are developed for preparation of dye-sensitised photoanodes on plastic indium-tin oxide (ITO)-coated polyethylene-naphthalate (PEN) substrates. The effects of the solvent ratio on the rheological behaviour of the binder-free paste and the contact angle between the paste and the substrate for TiO 2 photoanodes are scrutinised. First, tests of the rheological behaviour revealed that the increasing content of water leads to a decrease in the viscosity of the paste. Second, the dependence of the contact angle on the content of t -butanol is attributed to the trends of surface tension. Third, both the rheological properties and the contact angle influence the microstructure and morphology of the TiO 2 coating on the ITO-PEN surface. Finally, the EIS results confirm that electron transport and recombination are significantly influenced for the mixed case. All of these results enable the optimisation of the connection in the photoanodes, achieving the highest energy conversion efficiency of 5.30%. [ABSTRACT FROM AUTHOR]

Salient results of the installation of a pulsating crystallizer on the 39/6-4 dewaxing unit at the Omsk Lubricant Plant (Omskii Zavod Smazochnykh Masel) - a subsidiary of the gas-exporting company Gazprom Oil-Lubricants (Gazpromneft'-SM) are reported. The operating principle of the pulsating crystallizer is based on multi-batch mixing of wax-containing stock with a coolant (cooled solvent, filtrates,and their mixtures, etc.). The stock stream is mixed with batches of coolant by the pulsating action of a compressed inert gas. When the distillate stock is refined, the overall solvent-to-stock ratio was reduced by 24.8-26.6%, and the solvent-to-residual-stock ratio by 10.1%. moreover, the decrease in specific consumptions (calculated per 1 ton of dewaxed oil) was: stream - up to 35%, electric power - up to 10%, and water - up to 21%. When operating in two dewaxing stages, the yield of dewaxed oil increased by 4-6 and 1-2 wt. %, respectively, for the distillate and residual stock at the required pour point of the latter. The oil content in the slack wax (petrolatum) of the second filtration stage ncreased on average by 4-4.6 times when the distillate had beentreated, and 1.4 times when the residual stock had been treated. [ABSTRACT FROM AUTHOR]

A simple approach is discussed to synthesise CdS nanoparticles using various pure alcohols and their mixtures with water as a reaction medium. The study highlights that the solvent plays an effective role not only in controlling the particle size but also the structure. The size and phase of CdS nanoparticles were controlled by thermal reaction between cadmium precursor and thiourea in alcohol and their mixtures with water. Use of pure alcohols for the synthesis produces cubic structure as revealed from X-ray diffraction (XRD), while mixture of water with alcohol gives rise to hexagonal phase. XRD showed the presence of CdS nanoparticles with size 10–13 nm in an alcohol–water mixture whereas use of alcohols alone showed size in the range 1–3 nm. The composition and structural features were also studied by Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. Thiourea, in the presence of pure alcohol seems to be responsible for reduction in particle size as compared to that in the presence of alcohol/water mixture. The possible mechanism for the structural phase transition is discussed on the basis of change in surface energy and solvent–solvent interaction. [ABSTRACT FROM AUTHOR]

Eudragit® microspheres, to float in the gastrointestinal tract, were prepared to prolong a gastrointestinal transit time. To enhance their buoyancy, non-volatile oil was added to the dispersed phase. When an oil component was not miscible with water, over 90% was entrapped within the microspheres and prolonged the floating time of the microspheres. Depending on the solvent ratio, the morphologies of the microspheres were different and the best result was obtained when the ratio of dichloromethane:ethanol:isopropanol was 5:6:4. As the isopropanol portion increased, the time to form microspheres was delayed and the amount of fibre-like substance produced was decreased, due to the slow diffusion rate of the solvent. Compared with microspheres prepared without non-volatile oil, the release rate of the drug from microspheres was faster in all cases tested, except the microspheres containing mineral oil. The solubility of the drug in the non-volatile oil affected the release profiles of the drugs. The non-volatile oil tends to decrease the glass transition temperature of prepared microspheres and change the release profile. The internal morphology of the microspheres was slightly different depending on the entrapped oil phase used. Tiny spherical objects were present at the inner surface of microspheres and the inside of the shell. [ABSTRACT FROM AUTHOR]