Ag Nanopowders Research Articles

Fabrication of Air Conditioning Antimicrobial Filter for Electrically Powered Port Tractors via Electrospinning Coating

With the stricter emission regulations for internal combustion engines, electric vehicles, including electrically powered port tractors, have received increasing attention. However, currently, most of the filters used in electric vehicles are conventional membranes that only have the function of filtering particles and foreign objects. Therefore, in order to improve the above issues, the surface of commercial non-woven filter membranes was coated with Ag nanopowder nanofibers and AgNO3 nanofibers via electrospinning. At present, the comparative research on the antibacterial ability of Ag nanopowder and AgNO3 is still blank in the same research system, especially with the use of electrospun coating technology. The morphologies and structures of non-woven fabrics and electrospinning coated samples were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The characterization results indicate that both pure PVA and PVA composite fibers can be successfully coated on the surface of non-woven fabrics. The average diameter of all electrospun PVA composite fibers is distributed in the range of 470–700 nm. The PVA nanofibers with a low content of 1 wt% AgNO3 have good antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with clearance clear zones of inhibition of 26.00 mm and 17.30 mm, respectively.

Controlling the Sensitivity of Pentaerythritol Tetranitrate to Visible Laser Radiation by the Addition of ZnO:Ag Nanopowder

Controlling the Sensitivity of Pentaerythritol Tetranitrate to Visible Laser Radiation by the Addition of ZnO:Ag Nanopowder

A new strategy to improve the mechanical properties of CoCrNi medium-entropy alloys based self-lubricating composite in a wide temperature range

The fact that metal matrix is incompatible with hexagonal boron nitride (h-BN) seriously aggravates the mechanical and tribological properties of solid-lubricating composites. This study successfully introduces a solid-lubricant h-BN@Ag (Ag nano powders generated in-situ on h-BN surface). Adding h-BN@Ag to CoCrNi medium entropy alloys significantly improve the fracture toughness of the CoCrNi/h-BN (increased by 40.1%), which is resulted from decreasing porosity of the composite. In comparison with the CoCrNi/h-BN composite, obvious plasticity characteristics are found in CoCrNi/h-BN@Ag composite. Moreover, the composite containing h-BN@Ag exhibits a low, stable coefficient of friction (COF) in a wide temperature range (RT—600°C). Obviously, the COF of CoCrNi/h-BN@Ag composite is more stable than CoCrNi/Ag composite. Our findings show that adding h-BN@Ag is an effective way to enhance the fracture toughness and tribologicial behaviors of the CoCrNi matrix composites.

Graphene–Silver Hybrid Nanoparticle based Organic Phase Change Materials for Enhanced Thermal Energy Storage

Due to the intermittent nature of solar energy, researchers and scientists are working to develop thermal energy storage (TES) systems for effective utilization of solar energy. Phase change materials (PCMs) are considered to be promising materials for TES. In this study, organic paraffin RT50 and graphene silver (Gr:Ag) nanopowder are adopted as TES material and thermal property enhancers. Microstructure and morphological behavior as well as chemical, optical, and thermal stability of the prepared composite PCM are visually investigated using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy, thermal conductivity analyzer, differential scanning calorimeter (DSC). and thermogravimetric analyzer (TGA). Furthermore, based on the outstanding thermal performance of the composite, an extended investigation on the thermal and chemical properties are evaluated for 500 thermal cycles to ensure their reliability. Results show the thermal conductivity of RT50 improved by 53.85% when Gr:Ag nanopowder is dispersed at a weight percent of 0.8 (RT50-0.8Gr:Ag). The change in latent heat value of the composite sample is less than 3%, which is significant for effective thermal energy storage. The thermal decomposition of RT50 is slightly improved from 300 °C to 330 °C. To ensure a reliable and passive technique for thermal energy storage within solar thermal application devices, such as solar air heaters and solar photovoltaic thermal systems, using nanoparticle enhanced PCMs at the range of a 50 °C melting point are a current research hotspot.

Molluscicidal and antioxidant activities of silver nanoparticles on the multi-species of snail intermediate hosts of schistosomiasis.

BackgroundSchistosomiasis, also known as bilharzia, is the second important parasitic disease after malaria. The present study aimed to evaluate the molluscicidal effects of silver nanoparticles on Biomphalaria alexandrina, B. glabrata, Oncomelania hupensis, snail intermediate hosts of intestinal schistosomes (i.e. Schistosoma mansoni and S. japonicum), along with the changes their antioxidant enzymes.MethodsSilver (Ag) nano powder (Ag-NPs) was selected to test the molluscicidal effects on three species of freshwater snails. Exposure to Ag-NPs induced snail mortality and the LC50 and LC90 values of Ag-NPs for each snail species were calculated by probit analysis. Control snails were maintained under the same experimental conditions in dechlorinated water. Snail hemolymph was collected to measure the levels of antioxidant enzymes, such as total antioxidants capacity (TCA), glutathione (GSH), catalase (CAT) and nitric oxide (NO). In addition, the non-target organism, Daphnia magna, was exposed to a series of Ag-NPs concentration, similar to the group of experimental snails, in order to evaluate the LC50 and LC90 and compare these values to those obtained for the targeted snails.ResultsThe results indicated that Ag-NPs had a molluscicidal effect on tested snails with the variation in lethal concentration. The LC50 values of Ag-NPs for B. alexandrina snails exposed for 24, 48, 72 hrs and 7 days were 7.91, 5.69, 3.83 and 1.91 parts per million (ppm), respectively. The LC50 values for B. glabrata snails exposed for 24, 48, 72 hrs and 7 days were 16.55, 10.44, 6.91 and 4.13 ppm, respectively, while the LC50 values for O. hupensis snails exposed for 24, 48, 72 hrs and 7 days were 46.5, 29.85, 24.49 and 9.62 ppm, respectively. Moreover, there is no mortality detected on D. magna when exposed to more than double and half concentration (50 ppm) of Ag-NPs during a continuous period of 3 hrs, whereas the LC90 value for B. alexandrina snails was 18 ppm. The molluscicidal effect of the synthesized Ag-NPs seems to be linked to a potential reduction of the antioxidant activity in the snail’s hemolymph.ConclusionsSynthesized Ag-NPs have a clear molluscicidal effect against various snail intermediate hosts of intestinal schistosome parasites and could potentially serve as next generation molluscicides.

Influence of Different Nanometals Implemented in PMMA Bone Cement on Biological and Mechanical Properties.

Cemented arthroplasty is a common process to fix prostheses when a patient becomes older and his/her bone quality deteriorates. The applied cements are biocompatible, can transfer loads, and dampen vibrations, but do not provide antibacterial protection. The present work is aimed at the development of cement with antibacterial effectivity achieved with the implementation of nanoparticles of different metals. The powders of Ag, Cu with particles size in a range of 10–30 nm (Cu10) and 70–100 nm (Cu70), AgCu, and Ni were added to PMMA cement. Their influence on compression strength, wettability, and antibacterial properties of cement was assessed. The surface topography of samples was examined with biological and scanning electron microscopy. The mechanical properties were determined by compression tests. A contact angle was observed with a goniometer. The biological tests included an assessment of cytotoxicity (XTT test on human cells Saos-2 line) and bacteria viability exposure (6 months). The cements with Ag and Cu nanopowders were free of bacteria. For AgCu and Ni nanoparticles, the bacterial solution became denser over time and, after 6 months, the bacteria clustered into conglomerates, creating a biofilm. All metal powders in their native form in direct contact reduce the number of eukaryotic cells. Cell viability is the least limited by Ag and Cu particles of smaller size. All samples demonstrated hydrophobic nature in the wettability test. The mechanical strength was not significantly affected by the additions of metal powders. The nanometal particles incorporated in PMMA-based bone cement can introduce long-term resistance against bacteria, not resulting in any serious deterioration of compression strength.

High virucidal potential of novel ceramic-metal composites fabricated via hybrid selective laser melting and spark plasma sintering routes.

In this work, we combine selective laser melting (SLM) and spark plasma sintering (SPS) to fabricate new materials with high virucidal potential. Various bioactive disc-shaped ceramics, metal alloys, and composites were fabricated and tested against bacteriophage Phi6—a model system for RNA-enveloped viruses. We prepared silver-doped titanium dioxide (TiO2 + 2.5‒10% Ag), copper-doped titanium dioxide (TiO2 + 2.5‒10% Cu), Cu2NiSiCr, and Cu15Ni8Sn composite materials (metal lattices filled with ceramics). The virucidal tests of the ceramic and metal powders were performed in buffered suspensions, while the surfaces of the discs were tested by swabbing. The results show that the virus titer on the TiO2 + 10% Ag ceramic and CuNi2SiCr metal discs decreased by 4 logs after 15 min of exposure to the surfaces compared to the control ceramic and steel discs. We show that SLM 3D printed pre-alloyed CuNi2SiCr filled with bioactive TiO2 + 10% Ag nanopowders and sintered by the SPS process combines the simplicity of printing with the strength and virucidal properties of Ag and Cu materials. The proposed new virucidal materials were also used for the fabrication of prototype elevator buttons.

Adsorption and Photocatalytic Activity of the Porous Glass–ZnO–Ag Composite and ZnO–Ag Nanopowder

Adsorption and Photocatalytic Activity of the Porous Glass–ZnO–Ag Composite and ZnO–Ag Nanopowder

Polymer-Salt Synthesis of Photoactive Bactericide ZnO–Ag and ZnO–SnO2–Ag Nanopowders and a Study of Their Structure and Properties

Polymer-Salt Synthesis of Photoactive Bactericide ZnO–Ag and ZnO–SnO2–Ag Nanopowders and a Study of Their Structure and Properties

Comparative assessment of the fate and toxicity of chemically and biologically synthesized silver nanoparticles to juvenile clams

Nanoparticles (NPs) can be produced via physical, chemical, or biological approaches. Yet, the impact of the synthesis approaches on the environmental fate and effects of NPs is poorly understood. Here, we synthesized AgNPs through chemical and biological approaches (cit-AgNPs and bio-AgNPs), characterized their properties, and toxicities relative to commercially available Ag nanopowder (np-AgNPs) to the clam Mercenaria mercenaria. The chemical synthesis is based on the reduction of ionic silver using sodium borohydride as a reducing agent and trisodium citrate as a capping agent. The biological synthesis is based on the reduction of ionic silver using biomolecules extracted from an atoxigenic strain of a filamentous fungus Aspergillus parasiticus. The properties of AgNPs were determined using UV–vis, dynamic light scattering, laser Doppler electrophoresis, (single particle)-inductively coupled plasma-mass spectroscopy, transmission electron microscopy, and asymmetric flow-field flow fractionation. Both chemical and biological synthesis approaches generated spherical AgNPs. The chemical synthesis produced AgNPs with narrower size distributions than those generated through biological synthesis. The polydispersity of bio-AgNPs decreased with increases in cell free extract (CFE):Ag ratios. The magnitude of the zeta potential of the cit-AgNPs was higher than those of bio-AgNPs. All AgNPs formed aggregates in the test media i.e., natural seawater. Based on the same total Ag concentrations, all AgNPs were less toxic than AgNO3. The toxicity of AgNPs toward the juvenile clam, Mercenaria mercenaria, decreased following the order np-AgNPs > cit-AgNPs > bio-AgNPs. Expressed as a function of dissolved Ag concentrations, the toxicity of Ag decreased following the order cit-AgNPs > bio-AgNPs > AgNO3 ~ np-AgNPs. Therefore, the toxicity of AgNP suspensions can be attributed to a combined effect of dissolved and particulate Ag forms. These results indicate that AgNP synthesis methods determine their environmental and biological behaviors and should be considered for a more comprehensive environmental risk assessment of AgNPs.

Synthesis and comparative study on the structural and optical properties of ZnO doped with Ni and Ag nanopowders fabricated by sol gel technique

In this work we have tried to prepare Ni and Ag doped ZnO nanopowders using the sol gel technique. The influence of Ni and Ag (1, 3 and 5 mol.%) on the crystalline structure and optical properties of ZnO was investigated. The samples were characterized by XRD, FTIR and UV–visible spectrophotometer. XRD patterns confirmed the wurtzite formation of doped and undoped ZnO nanopowders. The average crystallite sizes of the prepared samples found from XRD were 19 nm for undoped ZnO, from 17 to 22 nm for Ni-ZnO and from 19 to 26 nm for Ag-ZnO. The average crystallite size of Ag-ZnO increased with increasing Ag contents. Different optical properties of Ni-ZnO and Ag-ZnO nanopowders were observed for different Ni and Ag content. The band gaps of Ni-ZnO and Ag-ZnO nanopowders were lower than that of the undoped ZnO (3.1 eV). The band gaps of Ag-ZnO were lower than that of Ni-ZnO. The optical properties of ZnO were enhanced by Ni (mol.%) in the UV region and by Ag (3 and 5 mol.%) in the visible region.

Effects of silver nanoparticles added into polyurea coating on sulfate-reducing bacteria activity and electrochemical properties; an environmental nano-biotechnology investigation

In the present work, Ag nanoparticles were added to polyurea coating in order to improve its antibacterial and electrochemical properties in sulfide-reducing bacteria-containing media. To this end, Ag nano-powder was mixed with two component polyuria, and then the antibacterial behavior of the nanocomposite coating was studied in sulfate-reducing bacteria (SRB)-containing medium. The results revealed the inhibitory effects of nanocomposite coating on the formation of SRB biofilms on the samples. Moreover, the SRB population decreased in contact with the Ag nanoparticles-mixed coating over 7 days. Investigation of the growth and activity of the bacteria represented the effective antibacterial properties of Ag nanoparticles in the polyurea matrix. Furthermore, EIS (electrochemical impedance spectroscopy) measurements indicated that the corrosion properties of the nanocomposite coating improved considerably over 7 days. The coating resistance increased 2 times by adding Ag nanoparticles after 1 day and 3.3 times after 7 days. In accordance with the same results, the charge transfer resistance increased 1.5 times and 1.1 times by adding Ag nanoparticles after 1 day and 7 days, respectively. The improvement in the protective properties of the nanocomposite coating are reflected in the increase in both film and charge transfer resistance.

Electrochemical Sensor and luminescence applications of Chonemorpha fragrans leaf extract mediated ZnO/Ag nanostructures

ZnO: Ag (0–20 mol%) hexagonal nanostructures were prepared via the phyto-synthesis route using Chonemorpha fragrans leaf extract. The structure, morphology, and compositions of the as-formed product were characterized by powder X-ray diffraction (PXRD), Field Emission Scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), Surface-enhanced area diffraction (SEAD), and Raman spectroscopy. Further, prepared nanostructures were subjected to sensor and luminescence studies. PXRD pattern shows the formation of the hexagonal wurtzite system. The Rietveld refinement analysis is used to refine structural parameters. FESEM micrographs show the agglomeration of the nanoparticles. The TEM pictures reveal the hexagonal shaped nanoparticles. The average 30 - 35 nm ranged crystallite sizes were determined using Scherrer's method which is in good agreement with the TEM. An economical and naturally responsive strategy can be the use of plant extract in the synthesis of nanostructured products. Also, studies related to sensing of paracetamol were performed using ZnO: Ag (20 mol%) indicating that it is a promising electrode material for paracetamol sensing. The identified PL emission bands indicate favorable luminescence applications for ZnO: Ag nanopowders.

In English

n-TiO2 and n-TiO2:Ag nanopowders were synthesized by the method of electric explosion of wires (EEW). The doping of nanopowders took place during the explosion of titanium wire, on the surface of which an Ag2O layer of the appropriate mass was applied. The energy of the explosion was equal to Е = 3.1·Еs, where Es is the energy of sublimation of the metal. Based on the synthesized nanopowders, mesoporous n-TiO2 and n-TiO2:Ag films were formed. The phase composition of the surface of several series of n-TiO2 and n-TiO2:Ag samples under different annealing conditions was studied by X-ray photoelectron spectroscopy. The XPS spectra of the Ti2p- and Ag3d- levels were decomposed by the Gauss-Newton method into interconnected components 2p3/2/2p1/2 and 3d5/2/3d3/2 with parameters DЕ = 5.76 eV; I1/I2 = 0.5 and DЕ = 6.0 eV; I1/I2 = 0.66 to take into account the spin-orbit splitting of the pair respectively. The paper presents histograms of the contributions of the components to the Ti2p- and Ag3d- spectra, which vary depending on the degree of doping and annealing conditions for 4 series of samples. According to XPS data, on the surface of EEW nanopowders TiO2 and TiO2:Ag titanium is represented by Ti3+- and Ti4+- states, silver by Ag0-, Ag1+- and Ag2+- states. In all series of samples, the contribution of the Ti3+- state simultaneously increases with an increase in the absolute Ag content, which is a consequence of the lattice distortion through the formation of a surface phase with Ti–O–Ag bonds. Annealing at 300 °C in air leads to an increase in the contribution to the spectra of Ti4+- states of ЕbTi2p3/2 = 458.3 eV and Ag1+ - states. Pretreatment of the samples with hydrogen peroxide before annealing leads to an increase in the contribution of oxide-hydroxide phases of titanium and Ag0- states. Annealing of the samples at 300 °С in argon with pretreatment with hydrogen peroxide leads to an increase in the contribution to the spectra of Ti4+- states with ЕbTi2p3/2 = 458.8 eV, oxide-hydroxide phases of titanium and Ag0. It has been found that the direction of redox processes on the surface of n-TiO2 after the action of H2O2 and subsequent annealing in air depends on the state of hydration of the original nanopowders.

(Invited) Interactions of Block Co-Polymer Ionomers on Metal Surfaces for Tuned Electrocatalysis

In acidic fuel cells, the ionomer and catalyst layer were developed empirically, and only recently studies have begun investigating the success of the heterogeneous microstructure and triple-phase boundary. Currently, the catalyst layer is not well understood due to its complexity; however, model interfaces between ionomers and catalyst particles have been used to provide valuable insight on ionomer-catalyst interfacial interactions. It is known from studies with Nafion® that restructuring of the polymer morphology can occur when it exists as an ionomer thin film at a catalyst interface. The behavior of the thin film ionomer changes compared to its bulk characteristics, which ultimately affects electrode kinetics by altering ionic and water transport networks. In the field of alkaline fuel cells, there is limited research published on ionomer developments in general or on specific interactions between ionomers and catalysts. The few fuel cell studies that compare the effects of ionomer chemistry have conflicting conclusions, which likely arise because the ionomer chemistries interact with Pt in different ways. Overall, this provides the motivation for our work to study idealized structures in the electrode, specifically to elucidate and modify interactions occurring at the interface between ionomers and non-PGM catalysts. This insight will enable the rational and systematic development of ionomer chemistry with the ultimate goal of improving electrode kinetics for a variety of important electrochemical reactions.We have synthesized a large number of model cationic block co-polymers, diblocks, triblocks and pentablocks (AB, ABA, ABABA). Where the hydrophobic block is either polyisoprene or polycyclooctadiene, or their hydrogenated analogues, polymethylbutylene or polyethylene. The other block is polychloromethylstyrene that can be quaternized with a variety of amines to vary the interaction with the surface, inmost of work we use the relatively simple benzyltrimethylammonium (TMA) cation or the reportedly more stable and more bulky benzylmethylpyrolidinium (MPRD) cation. Our initial studies using commercial Ag nano powders showed that the olefinic groups of the polymers interacted wit the Ag and that the interaction of the cations with the Ag surface could completely remove the crystallinity from the entire sample in the case of the polyethylene block. Probing the effects of these interactions on electrocatalysis of the oxen reduction reaction is on going and we will report our progress in this paper.To further constrain the polymers we have also studied them as thin films on flat Si wafers and the same substrate coated with thin metallic films and studied by GISAXS. When block co-polymers are spin coated on plain silicon wafers we almost always see no scattering as there is no alignment of the polymer on the silicon surface. When a thin layer of silver is coated onto the silicon, discrete alignment of features perpendicular to the surface are observed for many of the polymers we have synthesized on the nanoscale. The size of these features in the thin films is not always correlated with the block sizes observed in the bulk films by SAXS. AFM imaging of the polymer air interface suggests that these vertically aligned features persist throughout the film, a property presumably needed for transport, but that the size can vary. The data shown below is typical of aligned vertical triblock ABA polymers on Ag. We have also investigated these thin films as a function of temperature and hummidity and observed transients of the changes in the morphology of these materials. In this paper we will show how these interactions can be utilized for the beneficial development of electrocatalysts. Figure 1

Customized physical and structural features of phosphate-based glass-ceramics: role of Ag nanoparticles and Ho3+ impurities

The effects of silver nanoparticles (Ag NPs) embedment on the physical and structural characteristics of the holmium ions (Ho3+) activated phosphate-based glass-ceramics were assessed. Two series of such glass-ceramics were prepared using the melt-quenching and characterized. In the first series, the Ag NPs were nucleated from the incorporated AgCl via the redox process. In the second series, the pure Ag nanopowder was directly added. The overall properties of these glass-ceramics were strongly sensitive to the cooling procedure and NPs addition strategies, leading to different density and refractive index modifications in the two series. The recorded O1s XPS peaks were exploited to determine the bridging to non-bridging oxygen ratios in the studied glass-ceramics network that enabled to unfold the differences in the observed inferences. A compelling correlation among various attributes in the achieved glass-ceramics was established. Briefly, the overall traits of the proposed glass-ceramics were tailored by regulating the preparation conditions.

Flame-synthesized nickel-silver nanoparticle inks provide high conductivity without sintering

A new concept for the synthesis of conductive metal nanoparticle inks (nano-inks) is introduced using a one-step continuous flame-based process. Bimetallic nickel (Ni)-silver (Ag) nanopowders are simultaneously produced and functionalized in a High Temperature Reducing Jet (HTRJ) reactor. The HTRJ process allows rapid aerosol (gas phase) formation of multicomponent metal nanoparticles with relatively high production rates from low-cost metal precursors. Octylamine, a volatile aliphatic amine, is sprayed into the reactor effluent after the particle formation zone to cap nanoparticles as they form. Ni-Ag Functionalized Nano Powders (FNPs) were characterized and compared with Bare Nano Powders (BNPs) to verify that in situ ligand attachment was successful. Nano-inks were prepared by dispersing FNPs in an organic solvent. Conductive films were fabricated using different nano-ink compositions starting from pure Ni to 50 wt% Ni. With the use of a small capping agent, films containing 50 wt% (65 at%) Ni provide an electrical conductivity of 5.14 × 104 S m−1 without any post-processing. Conductivity increased to 4.22 × 105 S m−1 after thermal annealing in an inert environment. These sintering-free bimetallic conductive nanoparticles can be used as a lower cost replacement for current silver inks for single-step printing of conductive traces without post-processing.

Synthesis and Characterization of Ag Nano Particle by Solution Combustion Method and their Biological Studies

In this paper we reported a facile, novel and low temperature method for the synthesis of Ag Nano powder. The Catharanthus roseus plant leaf extract was used as bio fuel and Ag(NO3)2.6H2O used as oxidizer at low temperature 400 ±10 °C. Various analytical methods were used to characterize the powder such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), Fourier transformer infers red spectroscopy (FTIR). The phase formation studies were evaluated using PXRD graph and all the diffraction peaks are well matched with cubic structure of Silver NPS Card No. JCPDS 65-2871.The average crystallite size estimated from the Debye-Scherer equation is found to be 28 nm. SEM micrographs show the formation porous and agglomerated ZnO Nano powder. The FTIR spectrum confirms the M-O bond formation and purity of the product. An eco-friendly and simple method of solution combustion method by using bio-fuel synthesis of Silver nanoparticles is suggested so forth to apply for numerous applications like photocatalytic activities, biological activities and catalytic activities can be studied here The IC50 were found to be 183.53µg and 2.12 mg for DPPH and FRAP respectively. The anti-fungal activity ZnO NPs shows the maximum zone of inhibition against A. Niger (5 ± 0.5 mm) and P. aeruginosa (4± 0.4mm) at 30µg concentration.

Synthesis of submicron silver powder from scrap low-temperature co-fired ceramic an e-waste: Understanding the leaching kinetics and wet chemistry

The current study focuses on the understanding of leaching kinetics of metal in the LTCC in general and silver leaching in particular along with wet chemical reduction involving silver nanoparticle synthesis. Followed by metal leaching, the silver was selectively precipitated using HCl as AgCl. The precipitated AgCl was dissolved in ammonium hydroxide and reduced to pure silver metal nanopowder (NPs) using hydrazine as a reductant. Polyvinylpyrrolidone (PVP) used as a stabilizer and Polyethylene glycol (PEG) used as reducing reagent as well as stabilizing reagent to control size and shape of the Ag NPs. An in-depth investigation indicated a first-order kinetics model fits well with high accuracy among all possible models. Activation energy required for the first order reaction was 21.242 kJ mol−1 for Silver. PVP and PEG 1% each together provide better size control over silver nanoparticle synthesis using 0.4 M hydrazine as reductant, which provides relatively regular morphology in comparison to their individual application. The investigation revealed that the waste LTCC (an industrial e-waste) can be recycled through the reported process even in industrial scale. The novelty of reported recycling process is simplicity, versatile and eco-efficiency through which waste LTCC recycling can address various issues like; (i) industrial waste disposal (ii) synthesis of silver nanoparticles from waste LTCC (iii) circulate metal economy within a closed loop cycle in the industrial economies where resources are scarce, altogether.

Enhanced photocatalytic and antifungal properties of PbS nanopowder doped with Ag+ ions

PbS nanopowder doped with Ag+ ions was synthesized by a cost effective chemical method using lead nitrate, thiourea and silver nitrate as the precursor salts. Thermogravimetric-differential thermal analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy, Fourier transform infrared (FT-IR) spectroscopy, photoluminescence were used to characterize the samples. XRD studies reveal that all the samples exhibit cubic crystal structure with a strong preferential growth along the (2 0 0) plane. Cauliflower shaped nanostructures are visible from the SEM images. FTIR studies confirm the presence of peaks related to heteropolar diatomic molecule of lead sulfide for all the samples. The photocatalytic activity of pure PbS got enhanced with silver doping and PbS:Ag nanopowders could be used as an efficient photocatalyst for the degradation of methyl orange. Ag+ ions seem to dominate the antifungal efficiency of pure PbS. The results obtained confirm that PbS:Ag nanopowders are well suited for biomedical applications.