Ionic Liquid Electrodeposition Of Zinc And Zinc - Study Of Ti Alloy

Ionic liquids are widely used in preparation of nanostructured materials, production of clean fuel, and play an important role in electrochemical deposition of metals, especially the active metals.The characteristic of Urea-ZnCl2ionic liquids are studied, such as physicochemi-cal properties, effection of LiCl, NaCl, KCl, NH4Cl, TMAC additives on the melting points and the electrical conductivities, and sedimentary conditions to Ti metal content and SEM in Ti-Zn alloy.The results indicated that Urea-ZnCl2ionic liquid is clear and transparent, with increasing ZnCl2concentration, the melting point decrease first then increase, and the lowest is20℃when x(ZnCl2) equals to25%. The melting point can be decreased when adding additives MCl(M=Li, Na, K, NH4,(CH3)4N), and the lowest one is-4℃in Urea-NaCl-ZnCl2ionic liquid. The electrical conductivities of Urea-ZnCl2ionic liquid increase with the increase of the x(ZnCl2) when x(ZnCl2)<25%, however, they will decrease with the increase of the x(ZnCl2) while adding MCI, even though they are also much bigger than the ones of Urea-ZnCl2ionic liquid that x(ZnCl2)<22%. It can decrease the melting point and increase the electrical conductivities when adding TiCl4in the Urea-ZnCl2ionic liquid, but the electrical conductivities could be decreased in the Urea-MCl-ZnCl2ionic liquid, and the relationship of the electrical conductivities and temperature is governed by Kohlraush equation:k=k0+α(t-to)+β(t-t0)2.The electrochemical window of Urea-ZnCl2ionic liquid is determined, the electrochemical window was2.2V compared to Pt electrode, which the cathodic limit potential is-1.1V. The reduction potentials will be negative transfer with increasing the electrical conductivities in Urea-MCl-ZnCl2ionic liquid. The zinc and Zn-Ti alloy can be reduced in Urea-MCl-ZnCl2ionic liquid, and the reduction process of Ti4+is gradually reduced and quasi reversible:Ti(Ⅳ)→Ti(Ⅲ)→Ti(Ⅱ)→Ti, and ZnCl2has the effect of resistance function on the electrodeposition, and the reduction potentials will be negative transfer with increasing the ZnCl2. The process of the Zn and Zn-Ti alloys electrodeposition in Urea-MCl-ZnCl2ionic liquid is studied through changing certain parameters, such as substrates, the reduction potentials, the temperature, and the sedimentaries are analyzed by XRD, SEM, EDS and other test methods. Finally, we obtain the optimal technological condition:x(ZnCl2) is22%, temperature is80℃, concentration of Ti4+is0.82mol/L, we can attain the flat and compact deposit which the crystal size is nearly0.8μm.