| Nano-material has been paid more and more attention for its unusual optical, electrical, magnetic and thermochemical properties. In the normal condition, silver has the best electroconductibility and heat-conductivity, good ductibility and antimicrobial properties, so it has been widely used as Sensor Materials, Circuit Board Component and so on. Room Tempreature Ionic Liquids(RTILs), or named Room Temperature Molten Salts, is a new green solvent of inorganic salt and organic salt. Compared with the conventional aqueous solutions, the RTILs has more advantages in application for its unique physicochemical property, such as low vapour pressure, non-volatile, strong thermostability, good electroconductibility and wide electrochemical window. It has been experimentally put into use as solvent in the electrolysis, electroplating and electrodeposition because of its no-water condition.In this paper, we prepared silver nano-materials on an indium tin oxide (ITO)-coated glass substrate in EminBF4 solution by electrodeposition. The nucleation mechanism of Ag+ on the ITO had been discussed. MWNTs modified silver film electrode has been used as a probe to detect the SCN- in phosphate buffer solution. The main content and conclusions are under below.Using the platinum sheet as positive electrode, well, the ITO as negative electrode, the silver materials has been prepared by the direct current electrodeposition in EminBF4 room temprature ionic liquids with the change of the conditions such as current density, electrodeposition time, the placement of the electrodes and with or without the assistance of ultrasound. The surface morphology of the deposits was characterized by SEM and XDS. The deposition process of silver on ITO in RTILs follows the rules of electrocrystallization as well as that in aqueous solutions. The low current density produced large aggregates and the aggregates'growth rate is faster than that of nucleation. Well, the high current density makes small deposits and the deposits grow slowly. The large aggregates can be founded with the assistance of ultrasound too. The placement, shape and distance of the electrodes has great influence on the surface morphology of the deposits.The nucleation mechanism of Ag+ on ITO in EminBF4 solution was researched by Cyclic voltammetry and Chronoamperometry technique. The reduction current peaks are rising with the increase of the scanning speed and the silver ions'concentration, respectively. Meanwhile, the reduction current peaks were proportional to the square root of scanning speed and the silver ions concentration. The reduction process of Ag+ in RTILs is still controlled by diffusion. Under the potential of reduction peaks, the nucleation pattern of the silver ions on the ITO is followed the progressive nucleation originally, then, will be between the instantane nucleation mode and progressive nucleation mode when it reaches the limited current. If there are some silver deposits on the electrode substrate, the nucleation pattern will be inclined to the progressive nucleation.The detection of SCN- on the new born Ag/MWNTs/ITO modified electrode in the phosphate buffer solution(PBS) has been carried out by cyclic voltammetry technique. The electrode has good electrochemical activity with a pair of redox current on the CV graph. There is a new oxidation current peak be founded when SCN- is added to the PBS solution. The new current peak is increasing with the increase of thiocyanate anions concentration and the scanning speed, well the original peak decreases. The detection limit of SCN- is 3.4079×10-8 mol/L. The reaction of the detective of SCN- by the silver film electrode could be an EC process. The MWNTs/Ag combination electrode has good stability and repeatability.
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