• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.14 no.2
• /
• pp.37-46
• /
• 2004

The electrochemical adsorption of the Ag ions from aqueous solution on pelletized activated carbon monolith was investigated over wide range of operation time. The adsorption capacities of pelletized activated carbon monolith are associated with their internal porosity and are related properties such as surface area, pore size distribution. The chemical industry generates wastewater that contains toxic matters like heavy metals in small concentrations so that their economic recovery is not feasible. But, the method using activated carbon monolith can be used to withdrawal of heavy metals in waste water. After the electrochemical treatment, the quantitative properties in Ag ion solutions are also examined by pH concentration and studied elemental analysis by ICP-Atomic Emission Spectrometer and Energy Disperse X-ray (EDX) spectra. It is consider that the pH is very important factor at the reason of water pollutant with increasing acidity in industrial field. The result of quantitative analysis using Inductively Coupled Plasma-Atomic Emission Spectrometer of metal after electrochemical reaction in Ag ions solution depending on time are shown that the amount of Ag ions deposited was decreased with growth of Ag particles on the carbon surfaces as increasing electrochemically treated time. And, surface morphologies are investigated by scanning electron microscopy (SEM) to explain the changes in adsorption properties.

• Bulletin of the Korean Chemical Society
• /
• v.9 no.6
• /
• pp.338-341
• /
• 1988

Two crystal structures of fully dehydrated silver and potassium exchanged zeolite A, stoichiometries of $Ag_{9.3}K_{{2.7}^-}A$ (${\alpha}$ = 12.282(2) ${\AA}$) and $Ag_{10.7}K_{{1.3}^-}{\AA}$ (${\alpha}$ = 12.287(2) A) per unit cell, have been determined from 3-dimensional x-ray diffraction data gathered by counter methods. All structures were solved and refined in the cubic space group Pm3m at 21(1)$^{\circ}C$ . The crystals of $Ag_{9.3}K_{{2.7}^-}A$ and $Ag_{10.7}K_{{1.3}^-}A$ were prepared by flow method using exchange solutions in which mole ratios of $AgNO_3$ and $KNO_3$ were 1:10 and 1:5, respectively, with total concentration of 0.05M. The structures of the dehydrated $Ag_{9.3}K_{{2.7}^-}A$ and $Ag_{10.7}K_{{1.3}^-}A$ were refined to yield the final error indices $R_1$ = 0.037 and $R_2$ = 0.040 with 321 reflections, and $R_1$ = 0.042 and $R_2$ = 0.043 with 371 reflections, repectively, for which I > 3${\sigma}$(I). In both structures, eight $Ag^+$ ions are found nearly at 6-ring centers and each $Ag^+$ ion is nearly in the (1 1 1) plane at its O(3) ligands. The 8-ring sites are preferentially occupied by $K^+$ ions in both structures. 1.3 and 1.7 reduced silver atoms per unit cell were found inside of sodalite units of $Ag_{9.3}K_{{2.7}^-}A$ and that of $Ag_{10.7}K_{{1.3}^-}A$, respectively. These reduced silver species were presumably formed from the reduction of $Ag^+$ ions by oxide ions of residual water molecule or of the zeolite framework. These two crystals may be presented as hexasilver cluster in 21.7% and 28.3% of sodalite unit cells for $Ag_{9.3}K_{{2.7}^-}A$ and $Ag_{10.7}K_{{1.3}^-}A$, repectively.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.6
• /
• pp.1169-1174
• /
• 2011

CdTe thin-film solar cell technology is well known that it can theoretically improve its conversion efficiency and manufacturing costs compared to the conventional silicon solar cell technology, due to its optical band gap energy (about 1.45eV) for solar energy absorption, high light absorption capability and low cost requirements for producing solar cells. Although the prior studies obtained the high light absorption, CdTe thin film solar cell has not been come up to the sufficient efficiency yet. So, doping method was selected for the improvement of the electrical characteristics in CdTe solar cells. Some elements including Cu, Ag, Cd and Te were generally used for the p-dopant as substitutional acceptors in CdTe thin film. In this study, the sputtering-deposited CdTe thin film was immersed in $AgNO_3$ solution for ion exchange method to dope Ag ions. The effects of immersion temperature and Ag-concentration were investigated on the optical properties and electrical characteristics of CdTe thin film by using Auger electron spectroscopy depth-profile, UV-visible spectrophotometer, and a Hall effect measurement system. The best optical and electrical characteristics were sucessfully obtained by Ag doping at high temperature and concentration. The larger and more uniform diffusion of Ag ions made increase of the Ag ion density in CdTe thin film to decrease the series resistance as well as mede the faster diffusion of light by the metal ions to enhance the light absorption.

• Analytical Science and Technology
• /
• v.7 no.2
• /
• pp.181-186
• /
• 1994

Using poly(3-methylthiophene) conducting polymer film electrodes, feasiblity for Ag determination by stripping voltammetry has been studied. Ag ions accumulated by complexation with 18-crown-6, which are existing on the surface of the polymer film electrode, migrate inside of polymer film through potential scanning within limited potential range, and then are reduced and oxidized on the glassy carbon substrate. Therefore, the polymer film must have proper thickness and porosity for easy penetration of Ag ions. On the basis of these experimental results, $5.0{\times}10^{-6}M$ Ag(I) in aqueous solution could be determined.

• Applied Chemistry for Engineering
• /
• v.10 no.2
• /
• pp.218-224
• /
• 1999

Continuous ion exchange characteristics of the synthetic coolant contained Ni, Co and Ag ions of low concentration in acidic-oxidizing conditions have been studied to suggest the guideline for the optimum operation of mixed-bed demincralizer during the shutdown period of a pressurized water reactor (PWR). In the effect of the form of cation resins on the removal capacity of metal ions, the performance of a $H^+$-form resin was about 6% higher than that of a $Li^+$-form resin. Mixed-bed of cation and anion resins in comparison with nonmixed-bed of them, had no affected on the removal capacity of metal ions but very slightly increased the slope of breakthrough curves of metal ions. In the effect related to acidic-oxidizing conditions of the coolant, the addition of boric acid very slightly decreased the slope of breakthrough curves of metal ions, while the addition of hydrogen peroxide slightly decreased the removal capacity of metal ions.

• Bulletin of the Korean Chemical Society
• /
• v.17 no.12
• /
• pp.1109-1111
• /
• 1996

The Podand Ⅰ (Figure 1) has been studied as cation carrier in a bulk liquid membrane system. Ag+ and some other transition metal ions (M2+=Cu, Ni, Co, Zn, and Cd) have been transported using the podand as carrier in a bulk liquid membrane system. Studies on the transport of equimolar mixtures of two or three competing components have also been carried out with the same system. Ag+ exhibited a higher transport rate than the other M2+ in the competitive experiments. Ligand structure and the equilibrium constant for complex formation are important parameters in the transport of the metal ions.

• Journal of Electrochemical Science and Technology
• /
• v.8 no.3
• /
• pp.215-221
• /
• 2017

The electroless plating process largely consists of substrate cleaning, seed formation (activator formation), and electroless plating. The most widely used activator in the seed formation step is Pd, and Sn ions are used to facilitate the formation of this Pd seed layer. This is problematic because the Sn ions interfere with the reduction of Cu ions during electroless plating; thus, the Sn ions must be removed by a hydrochloric acid cleaning process. This method is also expensive due to the use of Pd. In this study, Cu electroless plating was performed by forming a seed layer using a silver nanosol instead of Pd and Sn. The effects of the Ag nanosol concentration in the pretreatment solution and the pretreatment time on the thickness and surface morphology of the Cu layer were investigated. The degrees of adhesion to the substrate were similar for the electroless-plated Cu layers formed by conventional Pd activation and those formed by the Ag nanosol.

• Bulletin of the Korean Chemical Society
• /
• v.7 no.1
• /
• pp.1-5
• /
• 1986

The influences of $LiNO_3\;and\;AgNO_3$ on the N-C(O) rotational barrier of N,N-dimethylacetamide and N,N-dimethylpropionamide have been investigated. The rotational activation free energy $({\Delta}G^{\neq})\;for\;Li^{+}$-amide complexes is found to increase with increasing salt concentration. On the other hand, that for $Ag^+$-amide complexes increases in the presence of $Ag^+$ ion up to 0.25 M ion concentration and then decreases as the concentration of $Ag^+$ ion is further increased. Such an unusual behavior of $Ag^+$-amide complexes has been interpreted in terms of ion-pairing and diluent effect on the amides. However, $^{13}C$ nmr chemical shift data for the amides have shown that both of these ions interact primarily with the carbonyl group in amides.

• Journal of the Korean Chemical Society
• /
• v.32 no.6
• /
• pp.520-527
• /
• 1988

The crystal structures of $Co^{2+}\;and\;Ag^+\;exchanged\;zeolite\; A,\; Ag_6Co_3$-A(a = 12.131(5)$\AA$) and $Ag_3Co_{4.5}$-A(a = 12.145(1)$\AA$), have been determined by single crystal X-ray diffraction techniques. Both structures were solved and refined in the cubic space group Pm3m at 21(1)$^{\circ}C$. Full-matrix leastsquares refinement converged to the final error indices of R1 = 0.045 and R2 = 0.041 for $Ag_3Co_{4.5}-A,\; and\; R1 = 0.066\; and\; R2 = 0.076\; for\; Ag_6Co_3$-A using the 258 and 189 reflections, respectively, for which I > 3$\sigma$(I). Both structures indicate that CO(Ⅱ)ions are coordinated by three framework oxygens; the Co(II) to O(3) distances are 2.118(4)$\AA$ for $Ag_3Co_{4.5}$-A and 2.106(1)$\AA$ for $Ag_6Co_3-A$, respectively. In each structure, the angle substended at Co(II), O(3)-Co(II)-O(3) is ca 120°, close to the idealized trigonalplanar value. $Co^{2+}$ ions prefer to 6-ring sites and $Ag^+$ ions prefer to 8-ring site when total number of cations is more than 8. The crystals of hydrated and dehydrated $Ag_{12-2x}Co_x-A (x > 4.5)$ had no crystalline diffraction pattern, indicating the apparent exchange limit of $Co^{2+}\; into\; Ag_{12}-A\; is\; 4.5 Co^{2+}$ ions per unit cell. $Co^{2+}$ ions hydrolyze $H_2O$ molecules and $H_3O^+$ concentraction is accumulating. These $H_3O^+$ ions destroy the zeolite structures.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.343-344
• /
• 2012

It has been known since the mid 1960s that Ag can be photodissolved in chalcogenide glasses to form materials with interesting technological properties. In the 40 years since, this effect has been used in diverse applications such as the fabrication of relief images in optical elements, micro photolithographic schemes, and for direct imaging by photoinduced Ag surface deposition. ReRAM, also known as conductive bridging RAM (CBRAM), is a resistive switching memory based on non-volatile formation and dissolution of a conductive filament in a solid electrolyte. Especially, Ag-doped chalcogenide glasses and thin films have become attractive materials for fundamental research of their structure, properties, and preparation. Ag-doped chalcogenide glasses have been used in the formation of solid electrolyte which is the active medium in ReRAM devices. In this paper, we investigated the nature of thin films formed by the photo-dissolution of Ag into Ge-Se glasses for use in ReRAM devices. These devices rely on ion transport in the film so produced to create electrically programmable resistance states. [1-3] We have demonstrated functionalities of Ag doped chalcogenide glasses based on their capabilities as solid electrolytes. Formation of such amorphous systems by the introduction of Ag+ ions photo-induced diffusion in thin chalcogenide films is considered. The influence of Ag+ ions is regarded in terms of diffusion kinetics and Ag saturation is related to the composition of the hosting material. Saturated Ag+ ions have been used in the formation of conductive filaments at the solid electrolyte which is the active medium in ReRAM devices. Following fabrication, the cell displays a metal-insulator-metal structure. We measured the I-V characteristics of a cell, similar results were obtained with different via sizes, due to the filamentary nature of resistance switching in ReRAM cell. As the voltage is swept from 0 V to a positive top electrode voltage, the device switches from a high resistive to a low resistive, or set. The low conducting, or reset, state can be restored by means of a negative voltage sweep where the switch-off of the device usually occurs.