Alkylpyridinium Hydrosulfate Ionic Liquids as Novel Additives for Zinc Electrodeposition

The effects of three novel alkylpyridinium hydrosulfate ionic liquids (ILs)-EpyHSO4, BpyHSO4 and HpyHSO4 on current efficiency (CE), energy consumption (EC), catholic polarization behavior, surface morphology and crystallographic orientation during zinc electrodeposition from acidic sulphate solution were investigated. Addition of these additives was found to increase CE, decrease EC and improve the surface morphology at lower concentrations. Voltammetric studies indicated that these additives had a pronounced inhibiting effect on Zn2+ electroreduction and polarization of the electrode was in the order: HpyHSO4 > BpyHSO4 > EpyHSO4. X-ray diffraction analysis revealed that the presence of additives did not change the structure of the electrodeposited zinc but affected the crystallographic orientation of the crystal planes.

Synthesis and characterization of tenorite (CuO) nanoparticles from smelting furnace dust(SFD)

Tenorite (CuO) nanoparticles were prepared from a dilute CuSO4 solution. The solution was obtained by leaching (pH=1.5) of smelting furnace dust of Sarcheshmeh Copper Complex, Iran. The recovery of copper from the acidic sulphate solution was carried out by solvent extraction using Lix 984-N. Tenorite nanoparticles were synthesized by direct thermal decomposition of Langite [Cu4(OH)6SO4(H2O)2] as a precursor which was calcinated in air for 2 h at 750?C. The Samples were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. The average diameter of the spherical pure CuO nanoparticles and their crystallite size were estimated to be 92 nm and 40nm, respectively. The simplicity of the present method suggests its potential application at industrial scale as a cheap and convenient way to produce pure CuO nanoparticles from dilute CuSO4 solutions obtained from leaching of smelting furnace dust.

Characteristics of Potentiodynamic Polarization Curves of Aluminum Electrodeposion Coating in Acidic Sulphate Solution

The density and anodic potentiodynamic polarization (PDP) in different diluted acidic sulphate solution of the aluminum electrodeposion coating on Q235 steel substrate, obtained in the molten salt of AlCl3,NaCl and KCl and treated by diffusion treatment, have been investigated. The results indicated that with the increase of temperature of diffusion treatment, the dencity of the coatings increases first, then reduces little. At 500°C, the dencity is biggest, 2.76g/cm3, which is almost equal to that of compact pure aluminum. As-received coating displays a current oscillation behavior on the anodic potentiodynamic polarization curves in different diluted acidic sulphate solution . And with the increase of diffusion temperature, the current oscillation behaviors donated by the current oscillation domains in solution of 180g/L H2SO4 gradually disappeared. When the temperature is up to 500°C and 700°C, no current oscillation phenomena can be observed. Based on these phenomena, a mode between the porosity of the coating, which was affected by the temperature of diffusion treatment, and current oscillation behaviors was roughly established.