Ag Content Research Articles

Effect of large deformation on microstructure and properties of copper alloy wire

Cu–Ag alloy wire with different deformations and Ag contents of 1%, 2%, and 4% are prepared using vacuum continuous casting technology combined with cold drawing and intermediate annealing processes. The evolution of microstructure, electrical properties, and mechanical properties of the Cu–Ag alloy wire is investigated, and a relationship model between wire diameter, Ag content, and alloy wire properties is established. The results showed that the directionally solidified billets exhibited good elongation and are suitable for drawing fine wire. As the Ag content increased, the twinning content inside the Cu–Ag alloy wire also increased significantly. It is found through Strain++ characterization that there is non-uniform deformation within the wire, and the tensile and compressive strains that exist interactively tend to aggregate within the twins. The properties of the Cu–Ag alloy wire with different diameters varied significantly at different stages of deformation, showing a pronounced size effect below 1 mm. With decreasing wire diameter or increasing Ag content, the DC resistance, resistivity, and tensile strength of the Cu–Ag alloy wire gradually increased, while the conductivity decreased. The effect of Ag content on elongation is not significant. Statistical analysis revealed that the established performance model had high predictive accuracy and could provide references for the optimization of production processes for Cu–Ag alloy wire.

Characterization of deep ore-forming fluid in the Zhaoxian gold deposit within the Jiaodong gold province: insights from quartz vein fluid inclusion, in-situ trace element analysis, and S isotopic composition in pyrite

The Jiaodong gold province, situated in the southeastern margin of the North China Craton, is globally renowned for its substantial gold reserves exceeding 5,000 tonnes. The Zhaoxian gold deposit is part of the significant Jiaojia gold belt within the Jiaodong gold province. Fieldwork has identified four distinct stages of ore formation in this study: an early barren quartz vein stage (Stage 1) containing fine-grained pyrite; a gold-bearing stage (Stage 2) consisting of quartz, pyrite, and native gold; a polymetallic sulfide-rich stage (Stage 3) comprising quartz, polymetallic sulfides, and native gold; and a late-stage (Stage 4) primarily composed of quartz and calcite with minimal pyrite content. We conducted fluid inclusion analysis using microthermometry and Raman spectroscopy techniques to examine the fluid characteristics. In-situ analysis of trace elements in pyrite was performed to investigate the fluid composition and evolution. Additionally, we determined the sulfur isotope composition in pyrite to analyze the source of sulfur. Our findings indicate that the ore-forming fluid in the Zhaoxian gold deposit belongs to a medium-to-low-salinity H₂O-NaCl-CO₂-CH₄ system. Fluctuations in Au and As concentrations observed along with oscillating zones and sulfide inclusions during Stage 2 suggest potential fluid boiling processes occurring during mineralization. High concentrations of Ag, Cu, Zn, Cd, In, Pb, and Bi without oscillating zones during Stage 3 imply precipitation of polymetallic sulfides under stable fluid conditions. The δ34S values observed in the Zhaoxian gold deposit are slightly higher than those found in granitoids from other areas within Jiaodong but similar to those seen in other deposits within the Jiaojia gold belt region. In conclusion, magmatic-hydrothermal ore-forming fluids were involved along with significant fluid-rock interaction during metallogenic processes of the Zhaoxian gold deposit.

Experimental and Theoretical Studies on Ag Nanoparticles with Enhanced Plasmonic Response, Formed Within Al2O3 Thin Films Deposited by Magnetron Sputtering

AbstractReactive magnetron sputtering was employed to prepare nanocomposite thin films of Ag/Al2O3, on a glass substrate. The films are characterized by the formation of Ag nanoparticles embedded in the Al2O3 matrix, after thermal treatment at 600 °C, which are responsible for the appearance of an outstanding pronounced and narrow localized surface plasmon resonance (LSPR) band. Electron microscopy analysis also revealed the presence of larger Ag fractal aggregates at the film’s surface, responsible for a broad band absorption. Noteworthily, the LSPR band maximum remains at the same position (about 412 nm) for Ag concentrations ranging from 23 to 34 at.%, despite some discernible alterations in both LSPR band intensity and width. An optimized thin film is characterized by full transparency in non-resonant wavelengths due to suppression of Ag aggregates at the film’s surface, while maintaining the LSPR behavior. To better explain the plasmonic behavior of the Ag/Al2O3 films, discrete dipole approximation was used to determine the extinction, scattering, and absorption efficiencies of Ag spheres surrounded by an Al2O3 cap layer. This allowed to ascertain some nanostructural features of the films, pointing to the formation of Ag nanoparticles with average sizes in the order of 40 nm.

Interdiffusion and atomic mobility in FCC Ag–Cu–Ni alloys

In the present work, the diffusion behavior of the Ag–Cu–Ni alloys was comprehensively studied for the first time. Twelve solid-solid diffusion couples were prepared and annealed at 1023, 1123, and 1223K, respectively. Based on the measured composition-distance profiles, the interdiffusion coefficients in FCC Ag–Cu–Ni alloys at different temperatures were then calculated by both the Matano-Kirkaldy (MK) and numerical inversion (NI) methods. The atomic mobilities of the Ag–Cu–Ni alloys were also optimized. The results indicate that the model-predicted diffusion behavior shows reasonable agreement with the experimental data, validating the reliability of the two versions of atomic mobility obtained in this work and demonstrating the accuracy and efficiency of the NI method. Ag diffuses faster than Ni in the Cu matrix alloy. The pre-exponential factor D0Ag and the activation energy QAgAgCu show a slight change with the Ag, but significantly increase with the Ni. The variation of the pre-exponential factor D0Ni and the activation energy QNiNiCu with the concentration of Ag and Ni were presented with a 3-D planes and discussed in detail. The accurate diffusivities and atomic mobilities of FCC Ag–Cu–Ni alloys obtained in this work will provide crucial input for the development and design of multi-component low-Ag brazing filler metals.

Ag/α-Fe2O3/g-C3N4 nanocomposites as Z-scheme heterojunction photocatalysts for degradation of RhB

In this study, Ag/α-Fe2O3/g-C3N4 composites with varying α-Fe2O3 and Ag contents were synthesized by loading α-Fe2O3 and Ag nanoparticles onto the g-C3N4 with a high specific surface area via acid annealing. These composites were then utilized for the photocatalytic degradation of RhB under the irradiation of visible light. For α-Fe2O3/g-C3N4 composites with 5 wt% content of α-Fe2O3, the degradation efficiency reached a peak of 97.57% within 55 min, which was much higher than that of α-Fe2O3 and acid-annealed g-C3N4 with 45.92% and 83.61%, respectively. Furthermore, the photocatalytic degradation efficiency of Ag/α-Fe2O3/g-C3N4 composites reached its maximum of 99.61% with 1% content of Ag. It was demonstrated that the ternary Z-scheme heterojunction construction leaded to a significant enhancement of carrier separation and transfer effects, while the incorporation of Ag serves as electron reservoirs and photoinduced electrons capturers, thereby significantly enhancing the Fenton reaction and photocatalytic performance. This work is significant to drive the widespread application of g-C3N4 based heterojunctions in photocatalytic water purification.

Effect of Gas Flowrate on the Properties and Photocatalytic Activity of ZnO-Ag Nanocomposite Materials Prepared by Flame Pyrolysis

It is well known that adding the appropriate amount of Ag to semiconductor materials can enhance photocatalytic performance. In our previous study, the addition of Ag nanoparticles to ZnO enhanced the photocatalytic activity. The best photocatalytic performance was obtained when Ag content was 5 wt%. However, the effect of a carrier gas flow rate has not been investigated. The objective of this study is to investigate the effect of carrier gas flow rate on the morphology of the ZnO-Ag nanocomposites as well as the photocatalytic activity of the produced nanocomposites. ZnO-Ag nanocomposite was fabricated by a one-step process using flame pyrolysis and the produced nanocomposites were characterized by a scanning electron microscope (SEM) and X-Ray Diffraction (XRD) analysis. The photocatalytic performance was evaluated by measuring the degradation of methylene blue under UV light irradiation. SEM images indicated that the morphology of ZnO-Ag nanocomposites has a spherical shape with a particle diameter of around 65 nm. Moreover, increasing the flow rate will increase the particle size of the produced nanocomposites. The photocatalytic test was determined based on the rate constant of MB degradation efficiency under UV light irradiation, where the photocatalytic activity decreased when the carrier gas increased. Finally, the produced nanocomposites were also tested several times (recycling test), where photocatalytic performance showed that the degradation value of methylene blue for each recycle did not vary much with the variable before being recycled.

Silver Nanoparticles Embedded ZnO Foam and its Surface Photoinduced Charge Transfer Behaviors

AbstractZinc oxide (ZnO) has been widely acknowledged as a highly effective photocatalyst for the degradation of organic pollutants. In this study, we presented silver nanoparticles (AgNPs) embedded ZnO foam photocatalyst (Ag−ZnO) on glass substrates by the chemical bath in‐situ co‐deposition method. Our findings demonstrat that at low Ag‐loading content, metallic Ag0 NPs are embedded within the ZnO foam, while at high Ag‐loading content, they accumulates increasingly from inside to the surface of the foam. With the increase of AgNPs loading from 0.1 mM to 1.5 mM, the absorption of Ag−ZnO foams in the visible light region gradually enhances. The photocatalytic degradation efficiency of rhodamine B (RhB) is the highest in Ag−ZnO foams when the Ag loading concentration reaches 0.8 mM, suggesting an optimal content of Ag for enhanced performance. This trend is attributed to the photo‐induced charge transfer behavior of Ag−ZnO samples. The AgNPs embedded inside the ZnO foam enhance the separation of photo‐induced charges and prevent their recombination. As a result, Ag−ZnO(0.8 mM) foam with more photo‐induced holes participate in the photocatalytic reaction, leading to a remarkably high photocatalytic activity.

Modification of SmMn2O5 Catalyst with Silver for Soot Oxidation: Ag Loading and Metal–Support Interactions

A series of Ag-modified manganese-mullite (SmMn2O5) catalysts with different Ag contents (1, 3, and 6 wt.%) were prepared via a citric acid sol–gel method for catalytic soot oxidation. The catalysts were characterized by powder X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Raman spectroscopy, transmission electron microscopy (TEM), high-resolution transmission electron microscopy analysis (HRTEM), X-ray photoelectron spectroscopy (XPS), and H2 temperature-programmed reduction (H2-TPR). The soot oxidation activity of the mullite was significantly promoted by the addition of silver and affected by the loading amount of the metal. Herein, the influences of silver loading on the metal size distribution and its interactions with the mullite were studied. Based on these characterizations, a possible soot oxidation reaction mechanism was proposed for silver-modified SmMn2O5.

Copper skarn mineralization related to reduced monzodioritic magma at the Huanren deposit, northeastern China

Most known copper (Cu) skarns are associated with oxidized intrusions. In this contribution, we report a Cu skarn associated with a reduced monzodioritic intrusion at Huanren, northeastern China, which contains 0.41 Mt of Cu accompanied by economic concentrations of Zn, Pb, Fe, Mo, and Ag. Copper-polymetallic mineralization in the Huanren deposit is concentrated in skarns located between the contacts of the monzodiorite (SiO2 = 52−55 wt%) and the Cambrian carbonate rocks, with minor molybdenite-bearing veinlets/veins and dissimilated chalcopyrite mineralization hosted within the monzodiorite. Laser ablation−inductively coupled plasma−mass spectrometry (LA-ICP-MS) U-Pb zircon geochronology indicates the monzodiorite crystallized at 125.4 ± 0.6 Ma (2σ). Isotope dilution (ID)-ICP-MS Re-Os molybdenite geochronology indicates mineralization at Huanren occurred at 125.3 ± 0.8 Ma (2σ). Whole-rock major- and trace-element and zircon Hf isotopic compositions suggest enriched (subduction metasomatized) lithospheric mantle−derived sources for the parental magma of the monzodiorite without significant crustal assimilation. Zircon trace-element and magmatic apatite major-element compositions indicate the reduced nature of the monzodiorite, as evidenced by low magmatic oxygen fugacity (fayalite-magnetite-quartz [FMQ] buffer = −1.09 ± 0.19) and negligible apatite SO3 contents (<0.05 wt%). A reduced magmatic-hydrothermal system at Huanren is also supported by the predominance of magmatic ilmenite over magnetite in the monzodiorite and by the presence of pyrrhotite and the absence of anhydrite and hematite in the ore. Chalcopyrite from the Huanren deposit has an average δ34S value of 4.34‰ ± 0.88‰ (1σ), which is clearly higher than values from most porphyry-skarn Cu ± Mo ± Au deposits. Accordingly, we suggest that interaction between (1) external oxidized fluids equilibrated with evaporites and (2) reduced Cl-bearing magmas and related exsolved fluids may have played a critical role in the formation of the Huanren Cu skarn by increasing the ability of fluids to scavenge Cu from the reduced magma and subsequently precipitate Cu in the carbonate rocks. This study defines a new type of Cu skarn and thereby opens new potential for Cu skarn exploration proximal to intrusive units previously deemed too reduced to be Cu fertile, especially in non-arc settings. Moreover, we conclude that the availability of Cl and S in magmatic-hydrothermal systems may be as critical as fO2 in facilitating the actual ore-forming event in Cu skarn systems.

Development and evaluation of CrAlAgN self-lubricating coatings for high temperature metal forming dies

Conventional lubricants are widely used for die release as well as for cooling assistance on the die surface. However, lubrication is difficult at high temperatures. Oxidation and scaling occur on the work pieces that lead to poor surface finish and a possible warping of the material during cooling. The aim of this research is to develop self-lubricating CrAlAgN nanocomposite coatings for metal forming dies and evaluate their thermal fatigue resistance and wear behavior at elevated temperatures. The CrAlAgN coatings with different Ag contents have been deposited by plasma-enhanced magnetron sputtering. The structure and properties of the coatings were systematically studied to determine the optimal Ag content for achieving a combination of good adhesion, thermal fatigue resistance, and surface lubricity at elevated temperatures. The thermal fatigue resistance of the coatings was evaluated using thermal cyclic testing by cycling the coatings from room temperature to 800 °C up to 1200 cycles. The high temperature wear behavior of the coatings was evaluated using a tribometer up to 900 °C. Good thermal fatigue resistance and low coefficient of friction (COF) were observed in the CrAlAgN coatings with an Ag content in the range of 5–10 at. % at 800 °C. The CrAlAgN coating with 10 at. % Ag exhibited the lowest average COF of 0.05 at 800 °C. The COF of thick CrAlAgN coatings (8 at. % Ag) decreased from 0.5 to 0.2 from 500 to 900 °C, accompanied by an increase in the wear rate under more aggressive wear test conditions. The lubricity of the CrAlAgN coatings at high temperatures was attributed to the lubrication effects from the mixed oxides and encapsulated Ag diffused toward the surface. To further evaluate the coating performance, a hydraulic hot forging punch was coated with a thick CrAlAgN (8 at. % Ag) coating and evaluated in the industrial forging process. The preliminary in-plant trials demonstrated that the coating significantly reduced the dimensional distortion and wear for the forging punch.

Effect of Ag-doping process into the yttrium iron garnet (Y3Fe5O12) thin films on the structural, magnetic and optical properties

In this work, the effect of Ag doping process (directly and as a nanoparticle) into the Y3Fe5O12 (YIG) thin films on the structural, morphological, optical and magnetic properties was studied in detail. Ag-doped YIG thin films were grown on thermally oxidized Si substrates by following sol–gel and spin-coating methods. All films were crystallized without cracks by two-stages heat treatment process. The XRD patterns confirm the formation of YIG peaks, and metallic Ag peaks which settled into the structure without bonding with the YIG components. In both Ag doping processes, the coercive field (Hc) and saturation magnetization (Ms) values of the samples containing 3% Ag are significantly lower than the other samples. The Ms values of 5% Ag doped samples were found the highest in both series. The Ms values of the films between in-plane and out-of-plane measurement increased with the Ag concentration. The optical measurements indicate an absorption peak in the range of 0–4 eV in both sample series and the optical band gap of the films decreased with the Ag doping due to its metallic characteristic. The ferromagnetic resonance measurements indicate that the lowest FMR linewidth as 92 Oe is seen in the 1% Ag-doped YIG sample. The relatively cheap and easy production of the used method and additive material may enable the widespread the usage of Ag-doped YIG thin films in magneto-optical devices.

Silver nanoparticles and silver/silica nanocomposites: Impacts on Z. mays L. growth, nutrient uptake and soil health

Although silver nanoparticles (Ag NPs) are widely employed in diverse industries, including agriculture, concerns about their adverse effects on plants at higher concentrations prompt exploration of alternatives, such as Ag/SiO2 NCs. Adding nano SiO2 is anticipated to create a complex with Ag+ ions, potentially decreasing their release into the environment and mitigating toxicity. The potential of Ag/SiO2 NCs as plant growth stimulants remains understudied to date. In this context, the study evaluates the impact of Ag/SiO2 NCs on 30-day-old Z. mays plants compared to Ag NPs at 100 and 200 ppm concentrations and on soil health. Soil health analysis revealed that both Ag NPs and Ag/SiO2 NCs supported the proliferation of P-solubilizing and N-fixing bacteria. Bioaccumulation analysis reveals higher Ag content in plants treated with Ag/SiO2 NCs, attributed to reduced agglomeration. Ag NPs exhibited concentration-dependent toxicity as 200 ppm hindered Z. mays growth, chlorophyll levels and absorption of P, Mg and K, whereas 100 ppm was found to be stimulatory. In stark contrast, Ag/SiO2 NCs demonstrated a remarkable capacity to mitigate Ag toxicity. The beneficial impact of Ag/SiO2 NCs on growth metrics, chlorophyll levels, lipid peroxidation, antioxidant enzyme activity and nutrient absorption was observed at both 100 and 200 ppm. However, it was more pronounced at 100 ppm concentration. This suggests that incorporating SiO2 in NCs may counteract the toxic effects of Ag, possibly through the complexation of Ag+ and a slower release mechanism.

Tuning the response trend of anaerobic ambience used Pd-based hydrogen sensor by engineering electronic band

Pd-based constituents have been widely used for sensing H2 due to the incredible selectivity, however, the sensitivity and measuring range in anaerobic ambience are largely limited for these using electronic signals. The variations between Pd and coincided hydride would typically increase resistance upon absorbing H2, whereas the intrinsic α-β phase transition alters the regularity of response features. Surprisingly, an inverse response has been detected by alloying Ag into Pd lattice, and this negative trend could be resulting from a new mechanism based on the experimental investigation and first-principles calculations. It is the contribution of modified Pd/Ag ratio, which optimizes the electronic band structure and density of states (DOS), thus a trade-off between free electron concentration and coincided scattering strength, would tune the response trend and make a switch. Consequently, the resistance of films with proper Ag contents, would be decreased at low H2 concentrations (10 ppm-4 vt.%), and the detection range can be widened as the trend reverses to be positive at high concentrations. These, combined with the ultralow detection limit of 10 ppm, and proportional sensor response values from − 0.5% of 10 ppm H2 to − 3.8% of 4 vt.% at 1 atm, confirm the promising virtues of anaerobic ambience used Pd-based sensors configuring inverse response. Furthermore, our study elucidates that alloying proper elements into Pd to modify the electronic band structure and DOS on Fermi energy, may be an effective strategy for promoting H2 sensing features.

Emerald eco-synthesis: harnessing oleander for green silver nanoparticle production and advancing photocatalytic MB degradation with TiO2&CuO nanocomposite

The tertiary composite of TiO2/CuO @ Ag (TCA) were synthesized by the solid state method using different ratios of TiO2/CuO NCs and Ag NPs. The structural, morphological, and optical properties of nanocomposites were analyzed by scanning electron microscope, Transmission electron microscope, X-ray diffraction, Fourier transform infrared spectra, UV–Vis diffuse reflectance spectra (UV–Vis/DRS) and photoluminescence spectrophotometry. The results showed enhanced activity of TCA hybrid nano crystals in oxidizing MB in water under visible light irradiation compared to pure TiO2. The photocatalytic performance TCA samples increased with suitable Ag content. The results show that the photo degradation efficiency of the TiO2 compound improved from 13 to 85% in the presence of TiO2–CuO and to 98.87% in the presence of Ag containing TiO2–CuO, which is 7.6 times higher than that of TiO2. Optical characterization results show enhanced nanocomposite absorption in the visible region with long lifetimes between e/h+ at optimal TiO2–CuO/Ag (TCA2) ratio. Reusable experiments indicated that the prepared TCA NC photo catalysts were stable during MB photo degradation and had practical applications for environmental remediation.

Morphology dependent EMI shielding performance of Ag-Ni core-shell nanowires

The proposed work reports a facile chemical reduction method for synthesizing the hierarchical silver-nickel core-shell nanowire structures with controllable morphologies by varying the Ag concentration. The growth of Ni shells around the Ag core to make thorny and smooth Ag-Ni core-shell nanowires is studied for addressing electromagnetic interference (EMI). The synthesized Ag-Ni nanowires show better EMI shielding effectiveness (SE) than Ni nanowires with much-improved absorption loss (SEA). Due to high electrical conductivity (8630 S cm−1), magnetic permeability (44.1 emu/g), and heterojunction core-shell interfaces, the bimetallic nanowires flakes exhibit exceptional average EMI SE of 90.5 dB in the X-band frequency range (8–12 GHz) with a thickness of 0.11 mm, taking specific EMI SE to 822.72 dB/mm. In addition, the EMI shielding performance of the smooth Ag-Ni nanowires showed a 45% enhancement in SEA with marginal change in reflection loss (SER) compared to the thorny ones, indicating high absorption of EM waves. The unique core-shell nanowires with high aspect ratio with tunable physical properties can be ideal candidates for futuristic applications in microwave absorption and electromagnetic interference shielding.

Neoproterozoic-Early Cambrian Northern Chah-Farsakh Cu-Zn VMS-type deposit, Iran: Constraints from geology, geochemistry, fluid inclusions and geodynamic

Northern Chah-Farsakh is the first seafloor VMS described in the Torud-Chahshirin metallogenic belt of Iran. The deposit is hosted by Neoproterozoic-Early Cambrian mafic (basaltic andesitic)-siliciclastic rocks in volcano-sedimentary basin. The evolution of the ore-bearing basin is governed by the Proto-Tethys Oceanic crust subduction beneath the Central Iranian microcontinent. Three ore facies can be distinguished based on the ore textures studies: stringer zone ore facies, massive-replacement ore facies, bedded ore and distal facies. Pyrite, chalcopyrite, magnetite and sphalerite are the main minerals, together with minor amounts of pyrrhotite, bornite, tetrahedrite and tennantite. Textures include laminated, banded, replacement, massive, and vein-veinlet texture. There is a distinct metal zonation in the massive sulfide orebody; Gold, Ag, and Zn contents increase vertically from the stringer to the bedded ore facies; Cu and Co increase in the massive ore facies, and Pb is highest in the stringer zone. Ore mineralization in the Northern Chah-Farsakh deposit has emplaced in two stages. The fine-grained ore bands (stage 1) which are intricately interlayered with host rock beds, exhibit sedimentary structure such as laminae and bedding are consistent with a syn-sedimentary origin. Coarser-grained stage 2 ores have massive and vein-veinlet textures that are considered to form by replacement during sub-seafloor fluid flow. Based on SEM-EDS analysis, significant compositional variations were observed in the Py-1b grains. Py-1b is enriched in Pb compared to Py-1a. The elemental distribution map shows that the chalcopyrite (Cpy-2) minerals in Northern Chah-Farsakh deposit do not have variable composition and are homogeneous. Fluid inclusions in quartz minerals rom the footwall stringer zone have trapping temperatures between 203 and 500 °C with salinities (3.39–16 wt% NaCl equiv.) higher than modern seawater. Fluid inclusion studies suggest that the ore-forming fluids were derived from seawater. High level of Se in the massive ore facies of the Northern Chah-Farsakh supports the formation of mineralization from a high-temperature hydrothermal fluid. The Northern Chah-Farsakh Cu-Zn VMS deposit typify the mafic-siliciclastic type (Besshi-type), where the majority of the host stratigraphy is composed of a mafic flow-volcaniclastics and sedimentary rocks.

Superior visible-light absorbing Ag@ZnO nanorods hybrid photocatalyst for efficient decomposition of commercial pharmaceuticals tetracycline and amoxicillin

This work assesses the role of the noble metal silver in the visible-light sensitization of UV-active ZnO by introducing a localized plasmonic resonance effect and enhancing the spatial charge carrier separation. We herein synthesize ZnO nanorods via a solvothermal approach, yielding nanorods of length and diameter 1.356 ± 0.619 μm and 120.56 ± 25.09 nm, respectively. Silver nanoparticles are reduced on the surface of ZnO nanorods via the photodeposition route. XRD spectra reveal a high crystallinity and wurtzite-type structure for ZnO with new peaks for cubic phase Ag upon Ag-loading. The diffraction peaks shift upon Ag modification, indicating partial incorporation of Ag into the ZnO lattice. Further, upon Ag-decoration, a slight increase in dislocation density and micro strain is obtained, which could suppress the recombination rate of charge carriers. The DRS spectra reveal a band gap contraction of materials from 3.19 to 2.98 eV with increasing Ag density. The PL spectra confirmed that the optimum Ag concentration of 3 wt% is proficient in harvesting visible light towards high photocatalytic degradation efficiencies of tetracycline (92.1 %) and amoxicillin (76.4 %) in 90 min as compared to 49.4 % and 38 % over pristine ZnO nanorods. TOC studies reveal only partial mineralization of ∼42.7 % (tetracycline) and ∼31.3 % (amoxicillin) due to the formation of reaction intermediates identified by HR-MS chromatograms. In addition, degradation pathways are proposed through the fragments at different m/z ratios.

Effect of Ag incorporation on the microstructure and properties of ZnS thin films

In this study, ZnS thin films doped with different content of Ag were deposited on quartz glass substrates by RF magnetron sputtering technique and were annealed at 600 °C in sulfur vapor. The crystal structure, grain size, surface morphology, composition, optical properties and defects of the doped ZnS thin films were analyzed by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), UV–Vis spectroscopy and positron annihilation doppler broadening spectroscopy (DBS). The results showed that all films exhibited the cubic sphalerite structure with a preferred orientation along the (111) crystal plane, and the composition of the doped films were more consistent with the stoichiometric ratio compared to the undoped film. The grain size gradually increased as the Ag content grew, indicating the improvement of crystallinity of the ZnS thin films. Besides, the bandgap values of these ZnS films with good optical transparency in the visible region were decreased from 3.87eV to 3.53eV as the Ag content grew. DBS results also showed that the defect concentration of ZnS films gradually decreased from the surface to the inner layer, and the film defects decreased with the increase of Ag content. However, the types of defects changed when the Ag content increased. Furthermore, the results showed Ag also has an effect on the porosity of ZnS thin films.

Genesis of Caoziwa Pb–Zn Deposit in Tengchong Block, SW China: Constraints from Sulfur Isotopic and Trace Elemental Compositions of Sulfides

The Caoziwa Pb–Zn deposit is one of the typical vein-type Pb–Zn deposits in the western part of the Tengchong block. Due to limited research, the genesis of these deposits is unknown. In this study, the sulfur isotopic and trace elemental compositions of sulfides from the Caoziwa Pb–Zn deposit were analyzed to trace the sources of ore-forming materials, and to reveal the genetic type of this deposit. The results show that abundant Co, Ni, As, and Se, and less Cu, Zn, Ag, Cd, Sn, Sb, Te, Pb, and Bi could enter pyrite by isomorphic substitution. Elemental Mn, Fe, Cd, Co, and Ni could substitute Zn to enter sphalerite, while the contents of Ag, Sn, and Sb are mainly controlled by the Pb-rich inclusions in sphalerite. Elemental Bi, Sb, Cd, Sn, Ag, and Tl mainly enter the galena grains via an isomorphic substitution mechanism of (Bi, Sb)3+ + (Cd, Sn)2+ + (Ag, Tl)+ ↔ 2Pb2+. Both sulfur isotopic compositions and trace elemental compositions indicate that the ore-forming materials and fluids of the Caoziwa Pb–Zn deposit mainly originate from magmatic hydrothermal fluid related to Paleocene granitic magmatism. Combined with the geological facts that some skarnizations developed in the northern part of the ore field near the Paleocene granite, the Caoziwa Pb–Zn deposit is suggested to be a magmatic hydrothermal vein-type deposit that probably belongs to a distal part of a skarn mineralization system developed by the intrusion of Paleocene granitic magmatism in the western part of the Tengchong block.

Green synthesis of AgNPs from leaves extract of Saliva Sclarea, their characterization, antibacterial activity, and catalytic reduction ability

Abstract Several technologies are employed for the synthesis of silver nanoparticles, each synthesis technique has advantages and disadvantages, and the best technique relies on the application at hand, the required qualities of the nanoparticles, and the size of the product. But in this article green synthesis were followed. In this research, AgNPs were synthesized using Salvia Sclarea leaf extract in green synthetic routes. The synthesized nanoparticles were examined using UV–vis spectroscopy, powder XRD, SEM, and FT-IR. Here three different type of silver nanoparticles were biosynthesized, AgNPs-1, AgNPs-2, and AgNPs-3 (where composition of AgNO3 and extract were 6:1, 10:1 and 14:1 respectively). The catalytic ability of AgNPs 1–3 was determine in the reduction of nitro-compounds into corresponding amines, where AgNPs-2 was found efficient reductive catalyst. Moreover, antibacterial activities were checked against both gram-positive (Bacillus Suntilis) and gram-negative bacteria (Klebsiella pneumoniae). Upon increasing Ag contents antibacterial activities were found in increasing mode. Which open new era of knowledge for further consideration.