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Electrical Equipment in a Corrosive Environment
Published in Bella H. Chudnovsky, Electrical Power Transmission and Distribution, 2017
Silver sulfide (Ag2S) is a major product of silver corrosion in atmospheres containing sulfuric gases. Silver corrosion recognized as “tarnish” is the very first step in silver sulfuric corrosion, when the corrosion layer forms a dark thin film, which can relatively easily be removed with a tarnish cleaner or scotch-bright material. As soon as a significant layer of silver is consumed, silver sulfide is formed on the surface as a heavy dark gray or black flaking deposit. The formation of silver sulfide is linear with time.
Materials, Coatings, and Platings
Published in Paul G. Slade, Electrical Contacts, 2017
Silver Sulfide (Ag2S) is a major corrosion product on silver-plated surfaces in an ambient with concentrations of a sulfuric gas such as H2S [1]. Once the Ag2S layer is in place, whiskers of silver can begin to form [1,70]. Unlike the tin whiskers that form from a surface of pure tin, the silver whiskers require a layer of Ag2S before they begin to form. Although the corrosion layer is necessary, Chudnovsky [70] has shown that the whisker is made up almost entirely of silver; see Figure 8.16. The metallic nature of this whisker means that it is highly conductive and can easily cause adjacent conductors to short and fail.
Electrical Equipment in a Corrosive Environment
Published in Bella H. Chudnovsky, Transmission, Distribution, and Renewable Energy Generation Power Equipment, 2017
Silver sulfide (Ag2S) is a major product of silver corrosion in atmospheres containing sulfuric gases. Silver “tarnish” is the very first step in silver sulfuric corrosion, when the corrosion layer forms a dark thin film, which can relatively easily be removed with a tarnish cleaner or scotch-bright material. As soon as a significant layer of silver is consumed, silver sulfide is formed on the surface as a heavy dark gray or black flaking deposit. The formation of silver sulfide is linear with time.
A comprehensive review on photocatalytic degradation of organic pollutants and microbial inactivation using Ag/AgVO3 with metal ferrites based on magnetic nanocomposites
Published in Cogent Engineering, 2023
Nuralhuda Aladdin Jasim, Shahlaa Esmail Ebrahim, Saad H. Ammar
It has recently become a huge hazard for organic pollutants and pathogenic bacteria to become a major concern in the environment, and it is seen as a problem. As a result, green technology has evolved into a viable technique capable of degrading contaminants and bacterial inactivation (Ajormal et al., 2020). Ag2S (silver sulfide), this semiconductor is deemed desirable. Despite this, the high recombination rate of photoelectron–hole couples has a substantial influence on Ag2S applications. Understanding how a Z-scheme heterojunction can enhance charge transfer and oxidative durability can help (Jamil, 2021). Adding a redox mediator to Z-scheme photocatalysts reduces charge recombination, increases electron–hole utilization efficiency, according to new research (Nguyen et al., 2022).
An Advanced Anti-Tarnish Process for Silver Coins and Silverware—Monomolecular Octadecanethiol Protective Film
Published in Tribology Transactions, 2021
Based on the above discussion, the conclusions are as follows: The reaction rate between chemicals and silver surfaces is dramatically accelerated by the 2D two-frequency ultrasonic bath. The tangential movement of the aqueous solution under the pressure generated by cavitation bubble collapse increases the entropy in the surface system. Whether the reacted products will stay on the surface or dissolve in the water is dependent on the chemical properties in the solution.When the octadecanethiol molecules are continuously coated on the surface and the silver oxide and extra octadecanethiol layer are constantly removed by the chemicals in the extra layer remover in the ultrasonic bath, a chemically reacted monomolecular octadecanethiol layer is formed on the silver surface, regardless of the surface shape, morphology, and residual thick oxide layers.With the monomolecular octadecanethiol film, the silver surfaces remained in almost their initial condition after severe sulfurization tests that equate to being exposed in the ambient atmosphere for several years. Without a protective film, the color of the silver surfaces changed to deep brown and blue, which are typical colors of silver sulfide. The closely packed film blocks the H2S or other sulfur ions from contacting the silver surface and protects it from tarnish for a very long time.The new advanced silver anti-tarnish process can be easily implemented in production. Coin collectors can also coat their coins with this “magic” film at home to protect coins from tarnishing and maintain their values.
Lamellar structure silver sulfide nanoparticles for adsorption and selective separation of zirconium, yttrium and strontium ions
Published in Journal of Dispersion Science and Technology, 2022
Hoda E. Rizk, Mohamed F. Attallah, Amal M. Ali
Silver sulfide (Ag2S) nanocrystalline was prepared by the wet chemical precipitation method. Firstly 0.1 M of silver nitrate solution is heated with stirring until it starts to boil. Then, 0.05 M of sodium sulfide dropwise is added to the prepared solution. Finally, the prepared precipitated powder was collected, washed, and dried. The structure and morphology of the prepared sample were examined as follows: The FTIR spectrum was measured using a Perkin Elmer 1600 FT-IR spectrometer. The sample was scanned in the region of (400-4000) cm−1. The morphological study was done using a scanning electron microscope (SEM, JSM-6510 LA; JEOL, Japan) in high vacuum mode using an accelerating voltage of 20 kV, the working distance of 11 mm, and magnifications of X 500, 1000, and 2000. TEM is performed to analyze the crystal size and surface, and textural morphology of silver sulfide using (JEM 100 CX microscope, JEOL Japan) after dispersing in methanol and dropping on the copper grid. The surface properties of the studied sample were measured. Before the measurement, the sample was pre-evacuated at 300 °C/2h. Specific surface area (SSA) and pore size distribution were achieved using (Nova 3000 series, Quantachrome, USA). The surface properties that were measured using (Nova 3000 series, Quantachrome, USA) are: specific surface area (SBET); total pore volume (Vp), and average pore radius (rp) (are calculated from a t-plot that is derived from nitrogen-adsorption isotherm), and pore size distribution measurements are calculated using Barret-Joyna-Halenda (BJH) method,[28] and density functional theory (DFT). At room temperature, the X-ray diffraction (XRD) pattern of the prepared silver sulfide was recorded to study the crystallographic structure of this sorbent by a Shimadzu X-ray diffractometer (XRD-6000 model, 40 kV, 30 mA, Japan) using X-ray tube (Cu target) for equipped. The pH at the point of zero charge (pHpzc) was determined using the pH drift method. 0.2 g samples of Ag2S were added to a series of 0.01 M NaCl solutions (50 mL) prepared at different initial pHs between 2 to 11. The pH of the solution was adjusted using a dilute solution of NaOH and HCL. The samples were shaken for 48 h. The final pH of the solutions was measured and plotted with the initial pH. The point at which the initial and final pH curves intersect is the pHPZC.