Abstract:The electrodeposition of lathanium on a Pt electrode was investigated in 0.01mol/L LaCl3－0.1mol/L LiCl－EMIMBF4 ionic liquid. The cyclic voltammetry, chronoamperometry and constant voltage electrolysis techniques were employed. The results of the cyclic voltammogram and the XRD spectrum of deposits after electrolysis under constant voltage have supported a one step electrodeposition mechanism of lanthanum, La3 3e-→La. The results also indicated that the reduction of La3 ion was irreversible. The transfer coefficient and the diffusion coefficient of La3 ion in 0.01mol/L LaCl3－0.1mol/L LiCl－EMIMBF4 ionic liquid were calculated as 0.0492 and (1.07-1.19)?0-6 cm2/s, respectively.

Abstract:In order to enhance the corrosion resistance of 304 stainless steel, niobium was electrodeposited on its surface in air-and-water-stable 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate ([emim]OTF) ionic liquids. The electrochemical behaviors of bare and niobium coated 304 stainless steel were evaluated by electrochemical tests in simulated PEMFC environment. The results show that deposited niobium is finely dispersed on the surface of 304 stainless steel as isolated islands and that the height of isolated island is within 100 nm. The result of X-ray photoelectron spectroscopy (XPS) and X-ray diffraction analysis (XRD) manifest that the smooth and strong chemical inertness compound film is obtained on the surface of 304 stainless steel, which is mainly composed of NbO and Nb2O5. The thin composite film acts as barrier and remarkably improves the corrosion resistance of 304 stainless steel in PEMFC environment

Abstract:The electrodeposition of lanthanum on a Pt electrode was investigated in 0.01 mol/L LaCl3-0.1 mol/L LiCl-EMIMBF4 ionic liquid. The cyclic voltammetry, chronoamperometry and constant voltage electrolysis techniques were employed. The results of the cyclic voltammogram and the XRD pattern of deposits after electrolysis under constant voltage have supported a one step electrodeposition mechanism of lanthanum, La3+ + 3e-→La. The results also indicate that the reduction of La3+ ion is irreversible. The transfer coefficient and the diffusion coefficient of La3+ ion in 0.01 mol/L LaCl3-0.1 mol/L LiCl-EMIMBF4 ionic liquid are 0.0492 and (1.07-1.19)×10-6 cm2/s, respectively

Abstract:The ionic liquid CO(NH2)2-NaBr-KBr-CH3NO-ZnCl2 was adopted for electroplating zinc on NdFeB magnet. All the pre-processing of the matrix, the solvents and power supply were authenticated through experiments and the coating was characterized by means of neutral salt spray experiment, SEM and XRD. The results show that when the current density is 1 A/dm2, the temperature 30 oC, the electroplating time 20 min and the additives 10 mL·L-1, a comparatively bright, uniform zinc coating with good corrosion resistance can be obtained by means of digital pulse plating power supply. Therefore it supplies a new idea for electroplating of zinc on NdFeB magnet.

Abstract:This work applied lanthanide ions to simulate the actinides in order to use the room temperature ionic liquids as the electrolytes as a substitute for chloride high temperature molten salt to attain the goal of reducing the actinide such as uranium or plutonium?in the nonaqueous reprocessing applications of spent nuclear fuel. The electrochemical behavior of La(III) in the ionic liquid, N-methyl-N-propylpiperidinium bis(trifluoromethylsulfonyl)imide (MPPiNTf2), has been investigated by cyclic voltammetry. The results indicate that the reduction of La(III) is irreversible. The diffusion coefficient and the energy of activation of La(III) in ionic liquid MPPiNTf2 are 2.79×10-7 cm2/s at 323 K and 99.4 kJ/mol, respectively. Controlled potential electrolysis of a solution of La(Ⅲ) in MPPiNTf2 at –2.9 V (vs.Pd) results in the deposition of metallic lanthanum.

Abstract:The electrodeposition of dysprosium on a Pt electrode from 1-ethyl-3-methyl-imidazolium tetrafluoroborate (EMIMBF4) ionic liquid was investigated. The cyclic voltammetry, chronopotentiometry and chronoamperometry were employed to examine the electrochemistry of Dy3+ in 0.01 mol/L DyCl3-0.1 mol/L LiCl-EMIMBF4 ionic liquid. The electrochemistry experiments indicate that the reduction of Dy3+ ion in 0.01 mol/L DyCl3-0.1 mol/L LiCl-EMIMBF4 ionic liquid is an irreversible process and is completed through only one step electrodeposition mechanism Dy3+ + 3e-→Dy. In 0.01 mol/L DyCl3-0.1 mol/L LiCl-EMIMBF4 ionic liquid the transfer coefficient and the diffusion coefficient of Dy3+ ion have been determined to be 0.176 and (4.87-5.04)×10-10 cm2/s, respectively. XRD pattern shows that the dysprosium deposits can be obtained, and SEM images shows that crystallites sizes of the deposits are few hundred nanometers.

Abstract:The electrodeposition of molybdenum in the binary alkali metal salts of bis[(tri-fluoromethyl)sulfony]amide LiTFSI-CsTFSI (eutectic point, 0.07: 0.93 in mole fraction; m.p., 112 oC) was investigated. Results show that MoCl3 was selected as the molybdenum ion source and electroreduced into metallic molybdenum on nickel plate in the eutectic LiTFSI-CsTFSI melt at 200 oC and 150 oC. Cyclic voltammetry measurement combined with SEM and XPS were employed. The results confirm that the electrodeposits obtained potentiostatically at 1.4 V (vs. Li+/Li) on nickel electrode are amorphous molybdenum

Abstract:1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid ([BMIM]+[BF4]-) was synthesized using N-methylimidazole and 1-bromobutane as starting materials by two-step method. The obtained ionic liquid was characterized by IR spectra. Gold nanochains were prepared through the reduction of HAuCl4 by NaBH4 in [BMIM]+[BF4]-. UV-Vis spectra and TEM images reveal that the prepared nano gold is mainly chain-like. The ionic liquid not only acts as reaction medium but also as modifier in the preparation of nano gold.

Abstract:The electroreduction of MoCl5 was performed in the binary room temperature ionic liquid, lithium bis[(tri-fluoromethyl) sulfony]amide (LiTFSI) and cesium bis[(tri-fluoromethyl)sulfony]amide (CsTFSI) (eutectic point, 0.07: 0.93 in mole fraction; m.p., 112 oC) at 150 oC for the sake of electrodeposition of molybdenum. Analyses from cyclic voltammetry complemented by SEM-EDAX and XPS show that metallic molybdenum is electrodeposited on nickel substrate in the ionic liquid LiTFSI-CsTFSI containing MoCl5 at 150 oC. Quality of the deposits is improved by using galvanostatic electrolysis and pulsed current electrolysis

Abstract:The electrochemical behaviors of iridium electrodeposited in 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid were studied. Cyclic voltammograms prepared on the gold electrode suggested that Ir(III) was reduced to iridium with an irreversible one-step process, which was controlled by the diffusion of Ir(III). The diffusion rate is 3.83×10?11 m2/s and the average transfer coefficient is 0.083. The morphology and composition of iridium coatings prepared on molybdenum substrates were characterized by scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy, respectively. The morphology of iridium coatings was dependent on the potential, time and current density of electrodeposition. Compact coatings were obtained at the reduction peak potential with a balance between the nucleation rate and the growth rate. Flat and compact coatings were formed when current density ranged from 0.5 to 1.82 mA/cm2 in the galvanostatic electrodeposition.