A novel route for the synthesis of indium nanoparticles in ionic liquid

In this paper, we report a novel preparation of indium nanoparticles by the reduction of indium chloride in ionic liquid by methanolic solution of NaBH₄. The particles are characterized by means of transmission electron microscopy (TEM), X-ray diffraction and UV-visible studies indicated that the powder consist of the cubic phase of indium. The particle size of indium nanoparticles is in the range of 20 nm mean diameter by Transmission electron microscopy (TEM). The samples display a strong surface plasma absorption band at 231 nm, which indicates that the sample is metal indium and the particle size is less than 20 nm. The thermal analysis of the sample indicate indium not indium oxide. Electrochemical studies show that indium nanoparticles have very good electrical properties.     

Electrodeposition of chalcopyrite films from ionic liquid electrolytes

An air and water stable room-temperature ionic liquid based on choline chloride/urea eutectic mixture has been investigated as a system for the electrodeposition of CuInSe₂ (CIS) and Cu(In,Ga)Se₂ (CIGS) films for photovoltaic applications. Deposition potentials and bath compositions were optimized to obtain Cu-In, Cu-In-Se and Cu-In-Ga-Se precursor films, which were selenized in a tube furnace at 500 °C for 30 min to form CIS and CI(G)S films. Photo-electrochemical measurements on these selenized films showed p-type photoconductivity with band gaps of 1.0 eV and 1.09 eV, respectively, for CIS and CIGS. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photocurrent spectroscopy and electrolyte electro-reflectance spectroscopy (EER).     

A novel green synthesis of zero valent iron nanoparticles (NZVI) using three plant extracts and their efficient application for removal of Cr(VI) from aqueous solutions

In the present study, NZVI particles were synthesized from the plant extracts including Rosa damascene (RD), Thymus vulgaris (TV), and Urtica dioica (UD). The FTIR arspectshowed that polyphenols, proteins and organic acids which serve as reducing and stabilizing agents play a significant role in the synthesis of NPs and reduce the possibility of aggregation of NPs compared to chemical techniques of NPs synthesis. The amount and type of compounds in plant extracts affect the structure and also agglomeration of NPs after adsorption process. Based on the results, the highest removal efficiency occurred at pH 2. With increase in contact time and amount of dose, the percentage removal increases. Inversely, increase of initial concentration of Cr(VI) decreases the removal efficiency of the contaminant. These nanoparticles have a high adsorption capacity. Accordingly, by applying a dose of 0.2 g/l and contact time of 10 min, the three NPs yielded >90% removal efficiency. Also, for 1 min contact time, the percentage removal was 94.87%, 83.48% and 86.8% for RD-Fe, UD-Fe and TV-Fe, respectively. By an increase to 25 min, the removal percentage reached to 100% for TV-Fe and UD-Fe. Moreover, 30 min was required to remove Cr(VI) completely by RD-F.     

Synthesis of interstratified graphene/montmorillonite composite material through organics-pillared,delamination and co-stacking and its application in hexavalent chromium removal from aqueous solution

Layers from two different delaminated dispersions of 3-aminopropyltriethoxysilane (APTES)-intercalated montmorillonite (Mts) and octylamine (OA)-intercalated graphene oxide (GO) could be co-stacked to obtain APTES-intercalated Mts (Mts-APTES)/OA-intercalated GO (GO-OA) interstratified composites (MAGO). The synthesized composites were characterized by XRD, FTIR, BET, TGA, TEM and XPS, which showed that MAGO had been prepared successfully. The optimal concentration of APTES was 8% in anhydrous toluene which avoided self-polymerization of APTES while facilitating the nucleophilic attack of APTES amine groups and the protic character of ethanol to compete with silane for the intimal hydroxyl groups by H-bonding. The MAGO demonstrated an extremely fast Cr(VI) removal from aqueous solution with a high removal efficiency at low pH. Data from batch studies of the adsorption process followed pseudo-second-order kinetics. The results fit a Langmuir model of adsorption, with maximum adsorption capacities of MAGO composites at pH 3.0 being 44.25 mg g^?1, 47.46 mg g^?1, 49.58 mg g^?1 under 30 °C, 40 °C, 50 °C, respectively, which were much higher than capacities of some conventional adsorbents. The reusability of the MAGO composite was also determined through adsorption-desorption studies, providing evidence for the potential use of MAGO composite in the removal of Cr(VI) from acidic wastewater.     

Efficient removal of Cr(VI) from aqueous solution by natural pyrite/rhodochrosite derived materials: Performance,kinetic and mechanism

In this work, pyrite/rhodochrosite (Py_xRh_y) composite synthesized from natural pyrite and rhodochrosite to remediate Cr(VI) containing wastewater was systematically investigated and evaluated. Results show that pyrite/rhodochrosite (1:1) showed the best Cr(VI) removal performance. XRD showed that emergence of MnS and pyrrhotite contributed to a significant increasing Cr(VI) reduction rate. The estimated maximum adsorption capacity was 95.58 mg/g at pH value of 6, temperature of 303.15 k, which was larger than other iron and manganese-based materials. Additionally, thermodynamic study illuminated that Cr(VI) removal by Py₁Rh₁ was a spontaneous and endothermic process. Taffel curve and EIS result presented higher corrosion current and lower electrical resistance for Py₁Rh₁, respectively, which was more favorable for the electron transfer. The surface cyclic regeneration of Fe(II) and Mn(II) provided long-term electron transfer to the Cr(VI) reduction. Our results demonstrated the great potentials of natural pyrite and rhodochrosite synthetic materials in the remediation of Cr(VI) polluted water.     

Kinetic investigation of zinc electrodeposition from sulfate electrolytes in the presence of impurities and ionic liquid additive [BMIM]HSO4

The effects of some common impurities such as copper, iron, nickel, cobalt, lead and their interaction with an ionic liquid additive 1-butyl-3-methylimidazolium hydrogen sulfate-[BMIM]HSO₄ on zinc electrodeposition from acidic sulfate electrolyte were characterized in terms of the polarization behavior and the kinetics of zinc deposition using cyclic voltammetry and potentiodynamic polarization measurements. The results showed that these metallic impurities studied exerted some different changes in cyclic and cathodic polarization voltammograms. The addition of [BMIM]HSO₄ was observed to counteract the detrimental effects of these impurities and induced a blocking effect on the zinc electrodeposition process through its cathodic adsorption on the electrode surface. The adsorption of this additive shifted the electroreduction potential of zinc ions towards more negative values, restricted impurities ions from being electroreduced, and inhibited hydrogen evolution. Moreover, the kinetics analysis of cathodic polarization suggested that the presence of these impurities alone and in combination with [BMIM]HSO₄ had no effect on the Tafel slope and transfer coefficient but affected the exchange current density for the zinc deposition.     

Removal of reactive red-120 and 4-(2-pyridylazo) resorcinol from aqueous samples by Fe3O4 magnetic nanoparticles using ionic liquid as modifier

The nanoparticles of Fe₃O₄ as well as the binary nanoparticles of ionic liquid and Fe₃O₄ (IL-Fe₃O₄) were synthesized for removal of reactive red 120 (RR-120) and 4-(2-pyridylazo) resorcinol (PAR) as model azo dyes from aqueous solutions. The mean size and the surface morphology of the nanoparticles were characterized by TEM, DLS, XRD, FTIR and TGA techniques. Adsorption of RR-120 and PAR was studied in a batch reactor at different experimental conditions such as nanoparticle dosage, dye concentration, pH of the solution, ionic strength, and contact time. Experimental results indicated that the IL-Fe₃O₄ nanoparticles had removed more than 98% of both dyes under the optimum operational conditions of a dosage of 60 mg, a pH of 2.5, and a contact time of 2 min when initial dyes concentrations of 10-200 mg L⁻¹ were used. The maximum adsorption capacity of IL-Fe₃O₄ was 166.67 and 49.26 mg g⁻¹ for RR-120 and PAR, respectively. The isotherm experiments revealed that the Langmuir model attained better fits to the equilibrium data than the Freundlich model. The Langmuir adsorption constants were 5.99 and 3.62 L mg⁻¹ for adsorptions of RR-120 and PAR, respectively. Both adsorption processes were endothermic and dyes could be desorbed from IL-Fe₃O₄ by using a mixed NaCl-acetone solution and adsorbent was reusable.     

锂离子电解液/环氧乙烯基酯树脂固态电解质的制备与性能

将具备优良化学稳定性及高电导率的双三氟甲烷磺酰亚胺锂（LiTFSI）溶于1-乙基-3-甲基咪唑双三氟甲磺酰亚胺盐（EMIM-TFSI）离子液体中制成LiTFSI-EMIM-TFSI电解液,加入环氧乙烯基酯树脂（VER）中对其进行改性。结果表明,添加了上述电解液后的锂离子电解液/环氧乙烯基酯树脂（LiTFSI-EMIM-TFSI/VER）体系可通过FTIR检测到离子液体的特征吸收峰。随着电解液含量的增加,LiTFSI-EMIM-TFSI/VER体系的孔隙率逐渐增大,沟壑与片层结构逐渐增多。这一变化有利于锂离子的传导,提高体系的电学性能,同时可在一定程度上改善树脂的塑性和韧性,提高LiTFSI-EMIM-TFSI/VER体系的力学性能。在本实验中,当电解液含量为40wt%时,LiTFSI-EMIM-TFSI/VER体系多功能性得以最好地实现。     

Time-correlated single photon counting system and light-collection system for studying fluorescence emitters under high-vacuum conditions: Use of immersion objective and ionic liquid

In this paper, we introduce a time-correlated single photon counting system and an efficient light-collection system for studying fluorescence emitters under high-vacuum conditions; the latter system has an immersion objective, and an ionic liquid is used as a refractive index matching medium. The ionic liquid is positioned in high vacuum. The time-correlated single photon counting system has modified photomultiplier tubes that act as photon detectors. The light-collection system is designed to be simple, compact, and easy to use. In order to verify the performance of these systems, the optical properties of colloidal semiconductor nanocrystals (CdSe/ZnS) and fluorescent dye molecules are studied as examples.     

1,3-二正丁基咪唑六氟磷酸盐离子液体的微波辅助合成与结构表征

以三甲基硅烷咪唑和1-溴代正丁烷作为原料,采用未经改装的家用微波炉在无溶剂条件下经季铵化反应合成了中间体溴化1,3-二正丁基咪唑([DnBIM][Br]),此步反应产率可以达到92%.再将第一步制得的中间体与六氟磷酸钾经复分解反应,得到1,3-二正丁基咪唑六氟磷酸盐离子液体([DnBIM][PF6]),收率为68%.提...