Ag Nanocomposites Research Articles

Construction of Cu2O−Ag Nanocomposites for the Selective and Efficient Electrochemical Detection of Catechol

AbstractHighly sensitive and selective electrochemical sensors are essential for human health, especially for monitoring the state of environmental pollutant content. Here, Cu2O nanocubes uniformly decorated with Ag nanoparticles were synthesized by a tractable wet‐chemical method. The electrochemical studies confirm that the Cu2O‐Ag‐16 composite shows increased electrochemical activity for catechol determination compared with either the bare Cu2O or the other two as‐proposed Cu2O−Ag catalysts (Cu2O−Ag‐8, Cu2O−Ag‐24). More specifically, the Cu2O−Ag‐16 presents excellent electrochemical responses towards catechol detection over wide linear ranges of 0.05 μM – 1 mM and 1 mM – 5 mM, with high sensitivity and low detection limits (50 nM). Furthermore, the as‐proposed sensor also displays good reproducibility, with a relative standard deviation of 2.3 % (n=3). Satisfactory recoveries in the range of 98.3 % to 101.2 % or 98 % to 100.7 % for lake water and/or tap water indicate the reliability of the sensor for catechol detection in practical applications. Constructing such composite structures to manipulate the local charge distribution for outstanding electrochemical sensing properties would provide us with an innovative strategy to explore other highly efficient electrode materials.

A facile synthesis of Bi2O3/SnS2 and Ag@Bi2O3/SnS2 nanostructures and their enhanced photodegradation application toward RhB

In this study, the binary Bi2O3/SnS2 (2 & 4 wt%) and ternary Ag (2, 4 & 6 wt%)@Bi2O3/SnS2 (2 wt%) nanostructures were prepared by the facile precipitation and deposition method. The synthesized materials were characterized by using several analytical methods such as X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray, ultraviolet visible diffuse reflectance specctroscopy, photoluminescence, and X-ray photoelectron spectroscopy. The organic pollutant Rhodamine B (RhB) was used to determine the photocatalytic efficiency of prepared nanocomposites. Bi2O3/SnS2 and Ag@Bi2O3/SnS2 nanocomposites showed the maximum photocatalytic activity in acidic medium. As photocatalyst, ternary nanocomposite Ag (4 wt%)@Bi2O3/SnS2 (2 wt%) exhibited admirable performance (99.85% degradation in 40 min) in comparison to binary Bi2O3/SnS2 (2 wt%) nanocomposite for the degradation of RhB (98.95% degradation in 40 min). The enhanced activity was ascribed to the fabrication of Z-type heterojunctions which are beneficial for the effective separation of photoinduced charged species and decrease the recombination rate of charge carrier species. Also, the Ag (4 wt%) @ Bi2O3/SnS2 (2 wt%) photocatalyst showed magnificent stability after five cycles, in which the efficiency dropped by 5.31% only. The role of scavengers involved during the degradation reaction was conducted, and from this experimentation, the superoxide anion radicals and holes are found responsible dominant active species for the RhB degradation. This research work highlights the enhanced photocatalytic abilities and performance ofAg@Bi2O3/SnS2 for the elimination of organic pollutants such as RhB dye and it would exhibit the potential application in wastewater treatment.

A facile synthesis of Ag incorporated Bi2O3/CuS nanocomposites as photocatalyst for degradation of environmental contaminants

Binary Bi2O3/CuS (2, 3 & 5 wt%) and ternary Bi2O3/CuS (3 %)/Ag (3, 10 & 15 wt%) nanocomposites were successfully prepared by a facile precipitation and deposition methods. The prepared materials were characterized for different features by using various techniques in a matter of structure (XRD), constitutional elements (EDX), morphology characteristics (FESEM and HRTEM), optical (PL and UV-DRS) and photocatalytic properties. The photocatalytic performance of the prepared nanocomposites was tested on the organic pollutant, RhB dye. Bi2O3/CuS/Ag nanocomposites resulted the maximum activity in the acidic medium (99.3 % in 60 min) as compared to basic (10.9 % in 60 min) and neutral (1.22 % in 60 min) medium. As photocatalysts, ternary nanocomposite Bi2O3/CuS (3 wt%) /Ag (10 wt%) showed highest performance in degradation (99.3 % degradation in 60 min) than binary Bi2O3/CuS (3 wt%) sample (97.2 % degradation in 60 min). The increased photocatalytic efficiencies due to the refinement in the absorbance and obtained band gap in visible region (2.14 eV) and formation of heterojunctions due to which lifetime of the photo-induced electron-hole species is intensified by the decrement in recombination. Active species involved in the degradation reaction were also examined by scavenger studies and follows the order: holes > superoxide anion radical > hydroxyl radical.

Development of a novel flexible thin PWO(Er)/ZnO(Ag) nanocomposite for ionizing radiation sensing

Radiation dosimetry is an essential aspect of modern radiotherapy. Optically stimulated luminescence (OSL) dosimetry is a promising technique that uses materials to measure radiation doses. However, current OSL dosimeters are limited in their ability to provide comprehensive validation of spatial dose distributions, particularly in flexibility radiation sensitivity. In this regard, a novel flexible PWO(Er)/ZnO(Ag) nanocomposite sensor has been developed by a solvothermal procedure and its ionization radiation responses were investigated under UV, proton, laser 980 nm, and 241Am sources. The calculated alpha detection efficiency showed that the prepared PWO(Er)/ZnO(Ag) sensor is highly sensitive to alpha radiation (99.6 %) with good stability/repeatability and linear response. According to the Photo/Ionoluminescence study, the doped dual nanocomposite sample showed the strongest blue, green, and yellow emissions at room temperature compared with pure and single doped samples with an exciton lifetime of τ = 143.30 ±0.07 μs. The XRD, FTIR, Raman, and EDX results indicated that the prepared pure and doped nanocomposites have two-phase compositions of PWO and ZnO and related chemical compounds/elements in the nanocomposite structure. The morphologies of the PWO and PWO(Er) nanoparticles (NPs) were mostly cubic and heterogeneous with average particle sizes of 125 and 82 nm. ZnO and ZnO(Ag) had hexagonal, spherical, and rod-shaped particles with typical particle diameters of 130 and 90 nm, respectively. Our results indicate the prepared luminescent nanocomposites are transparent, flexible, highly stable, highly sensitive to ionizing radiation, and have the potential for practical use in optoelectronics and medical imaging in the future.

Fabrication, surface characterization and electrical properties of hydrogen-irradiated nanocomposite materials

Flexible poly(vinyl alcohol) (PVA)/polyaniline (PANI)/silver (Ag) nanocomposites consisting of PANI and silver nanoparticles (AgNPs) with PVA were successfully fabricated using the casting method for application in energy-storage devices. The surface characteristics of the composite films were analyzed using X-ray diffraction, differential scanning calorimetry and Fourier transform infrared spectroscopy techniques. The estimated crystallite size of AgNPs was 11.7 nm, which increased to 15.3 nm by increasing silver from 2 to 4%. In addition, the morphology of the films was investigated utilizing scanning electron microscopy. The conductivity σ DC improved from 4.8 × 10−11 S/cm for PVA to 1.3 × 10−10 S/cm for PVA/PANI and to 1.2 × 10−9 S/cm for PVA/PANI/silver. Furthermore, with an increasing temperature value, the electrical resistance was reduced. Moreover, the activation energy was modified with the addition of PANI and silver into the PVA matrix. PVA/PANI/silver was irradiated with hydrogen fluences of 0.4 × 1018, 0.8 × 1018 and 1.2 × 1018 ions/cm2. σ AC was enhanced from 2.67 × 10−9 S/cm for PVA/PANI/silver to 2.02 × 10−8 S/cm for 0.4 × 1018 ions/cm2 and to 3.95 × 10−6 S/cm for 1.2 × 1018 ions/cm2. Moreover, the dielectric constant increased from 0.43 for PVA/PANI/silver to 0.56, 1.23 and 4.18 with exposure to 0.4 × 1018, 0.8 × 1018 and 1.2 × 1018 ions/cm2, respectively. The results showed modifications in the electrical characteristics of the irradiated composites, which opened the way for applying these samples in a wide range of dielectric applications.

Flower-like nanocomposite of carbon quantum dots, MoS2, and dendritic Ag-based Z-scheme type photocatalysts for effective tartrazine degradation

Nanocomposites of carbon quantum dots, molybdenum disulfide, and dendritic silver (MoS2/CQD/dendritic Ag) were synthesized via a facile and inexpensive procedure and utilized to investigate photocatalytic degradation of tartrazine (TZN) in aqueous medium. The nanocomposites and their individual components were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive spectrometry (EDS), mapping, X-ray photoelectron spectroscopy (XPS), and ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS). The optimum conditions for TZN degradation obtained were TZN concentration of 20 mg/L and a solution pH of 6.5. Electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) analysis were employed to evaluate the TZN degradation by the prepared MoS2/CQD/dendritic Ag nanocomposites. XRD of CQDs, MoS2 and Ag NPs showed amorphous, hexagonal phase and face-centered cubic structures, respectively. Band gaps of 3.3 and 1.9 eV for CQDs and MoS2, respectively as obtained from UV–Vis DRS.The enhanced photo-degradation of TZN was achieved due to the synergistic effects between the nanocomposite constituents. Complete degradation of TZN occurred within 30 min with a rate constant value of 0.172 min−1, wherein oxygen radicals played a significant role compared to other species during the process of degradation.

In Situ Formation of Silver Nanoparticles Induced by Cl-Doped Carbon Quantum Dots for Enhanced Separation and Antibacterial Performance of Nanofiltration Membrane.

Polyamide (PA) nanofiltration (NF) membranes suffer from biofouling, which will deteriorate their separation performance. In this study, we proposed a strategy to incorporate silver nanoparticles (Ag NPs) into PA NF membranes in situ, in order to simultaneously enhance water permeability and antibacterial performance. The chloride-doped carbon quantum dots (Cl-CQDs) with photocatalytic performance were pre-embedded in the PA selective layer. Under visible light irradiation, the photogenerated charge carriers generated by Cl-CQDs rapidly transported to silver ions (Ag+ ions), resulting in the in situ formation of Ag NPs. The proposed strategy avoided the problem of aggregating Ag NPs, and the amount of Ag NPs on the membrane surfaces could be easily tuned by changing silver nitrate (AgNO3) concentrations and immersion times. These uniformly dispersed Ag NPs increased membrane hydrophilicity. Thus, the obtained thin film nanocomposite Ag NPs (TFN-Ag) membrane exhibited an improved water flux (31.74 L m-2 h-1), which was ~2.98 times that of the pristine PA membrane; meanwhile, the sodium sulfate (Na2SO4) rejection rate was 96.11%. The sterilization rates of the TFN-Ag membrane against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were 99.55% and 99.52%, respectively. Thus, this facile strategy simultaneously improved the permeability and antibacterial property of PA NF membranes.

Fabrication of silver nanoparticles immobilized on magnetic lignosulfonate: Evaluation of its catalytic activity in the N-acetylation reactions and investigation of its anti-cutaneous squamous cell carcinoma effects

Due to the non-optimal response of most types of cancer to various treatment methods and their rapid progress, research continues in the field of producing drugs with less toxicity and greater efficiency. There are many nanocomposites with diverse biological activities that include part of anticancer drugs in new pharmacological science. The present investigation describes a green procedure for the in situ support of Ag nanoparticles (NPs) over sodium lignosulfonate (NaLS) modified magnetic nanoparticles (Fe3O4@NaLS/Ag) and its subsequent biological and chemical performance. FT-IR, TEM, FE-SEM, EDS, ICP, VSM and XRD techniques were used to characterize the synthesized Fe3O4@NaLS/Ag. The catalytic efficacy of the desired composite was applied in the N-acetylation of various amines in the presence of Ac2O under solvent-free conditions. The Fe3O4@NaLS/Ag catalyst was recovered by an external magnet and reused for nine runs without a significant decrease in the activity. The cytotoxic and anti-cutaneous squamous cell carcinoma potentials of biologically synthesized Fe3O4@NaLS/Ag nanocomposite against PM1 and MET1 cells were determined. The anti-cutaneous squamous cell carcinoma properties of the Fe3O4@NaLS/Ag nanocomposite could significantly remove PM1 and MET1 cells. The IC50 of Fe3O4@NaLS/Ag nanocomposite was 288 and 270 μg/mL against PM1 and MET1 cells, respectively. Also, Fe3O4@NaLS/Ag nanocomposite presented a high antioxidant potential according to the IC50 value. According to the above results, the recent nanocomposite can be used in treating cutaneous squamous cell carcinoma after doing clinical trial studies.

Bifunctional quaternary magnetic composite as efficient heterojunctions photocatalyst for simultaneous photocatalytic visible light degradation of dye and herbicide pollutants from water and bacterial disinfection

In the present study, the magnetic Fe3O4/Ag2C2O4/Ag3PO4/Ag nanocomposite were prepared through a simple co-precipitation method by using calendula officinalis seed extract as a stabilizer. The fabricated quaternary photocatalyst was applied for to degrade food dye Brilliant Blue FCF (BB) and herbicide Paraquat (PQ) as contaminants at binary mixture in a batch and continuous flow-loop photoreactor under visible light irradiation and also the antibacterial properties was investigated. The fabricated nanocomposite was determined by XRD, FESEM, EDX, BET&BJH, UV-DRS, FT-IR and VSM methods to gain insight about structure, morphology, purity, surface area, optical, functional group and magnetic properties. The photoelectrochemical experiments, PL and DRS indicate the successful coupling of the active semiconductors. The degradation efficiency of BB and PQ was announced to be 88.9% and 92.72% under optimal conditions with a high reaction rate constant value (0.03 and 0.0326 min−1), respectively. The quaternary photocatalyst exhibited superior photocatalytic performance compared with Ag3PO4/Ag2C2O4 and Ag2C2O4. Various scavengers were used to explore the mechanism of photocatalytic performance and supports that O2−. and OH. is main active species in the degradation process of BB and PQ, respectively. Furthermore, the Fe3O4/Ag2C2O4/Ag3PO4/Ag also demonstrated bactericidal activity against Staphylococcus aureus (S. aureus) as gram-positive bacteria and Escherichia coli (E. coli) as gram-negative bacteria.

Optical properties of ZnO nanorods for reduced graphene oxide

The preparation and characterization of innovative nanocomposites based on zinc oxide nanorods (ZNR) encapsulated by graphene (Gr) nanosheets and decorated with silver (Ag), and copper (Cu) nanoparticles (NP) were studied. The prepared nanocomposites (ZNR@Gr/Cu Ag) were examined by different techniques including Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), UV-Vis spectrophotometry and fluorescence spectroscopy. The results showed that the ZNR had a good cover of five layers of graphene and decorated with Ag and Cu NPs with particles size of about (10-15) nm. In comparison with ZNR, the ZNR@Gr/Cu Ag nanocomposites revealed superior absorption in the entire region of 300–1000 nm. Moreover, the band gap decreased from 3.2 eV of ZNR to 1.2 eV for ZNR@Gr/Cu Ag nanocomposites. Taking into account the superiority of ZNR@Gr/Cu Ag nanocomposites in terms of easy fabrication, low-cost method, and environmental friendliness, which made it favorable for huge-scale preparation in many applications such as water splitting, sensor, solar

Optical properties of ZnO nanorods for reduced graphene oxide

The preparation and characterization of innovative nanocomposites based on zinc oxide nanorods (ZNR) encapsulated by graphene (Gr) nanosheets and decorated with silver (Ag), and copper (Cu) nanoparticles (NP) were studied. The prepared nanocomposites (ZNR@Gr/Cu Ag) were examined by different techniques including Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), UV-Vis spectrophotometry and fluorescence spectroscopy. The results showed that the ZNR had a good cover of five layers of graphene and decorated with Ag and Cu NPs with particles size of about (10-15) nm. In comparison with ZNR, the ZNR@Gr/Cu Ag nanocomposites revealed superior absorption in the entire region of 300–1000 nm. Moreover, the band gap decreased from 3.2 eV of ZNR to 1.2 eV for ZNR@Gr/Cu Ag nanocomposites. Taking into account the superiority of ZNR@Gr/Cu Ag nanocomposites in terms of easy fabrication, low-cost method, and environmental friendliness, which made it favorable for huge-scale preparation in many applications such as water splitting, sensor, solar cell, antibacterial and optoelectronic devices.

Graphene-silver nano-ink for inkjet printing of paper electrode for electrochemical sensing of 4-nitrophenol

Here, an inkjet printed paper electrode (PPE) decorated with graphene (Gr)-silver (Ag) nanocomposite was exploited as an electrochemical sensing probe for analysis of 4-nitrophenol (4-NP) in environmental water samples. In this work, 4% Gr-Ag nanocomposite ink (NI) was prepared in ethanol, ethylene glycol, and glycerol in the ratio of 50:45:5, which possess surface tension and viscosity of 36 mN m−1 and 11 mPa s, respectively. The office inkjet printer was employed to print formulated Gr-Ag NI on digital photo paper, followed by sintered at 200 °C for 30 min to make effective conducting tracks for the sensing of 4-NP. Gr-Ag NI-based PPE was used as a working electrode in cyclic voltammetry. The working principle of detection is based on the electrocatalytic reduction process of 4-NP on the electrode surface. A good linearity range of 3.125–100 μM was observed, achieving a detection limit of 2.7 μM to measure 4-NP. Thus, the developed PPE holds considerable potential and offers an economical, biodegradable, and user-friendly sensor for future applications in the monitoring of 4-NP in environmental water samples.

Single-Step Synthesis of Ag Hexagonal Nanoplate-Decorated Reduced Graphene Oxide and Its Cytotoxicity Studies.

Graphene-based Ag nanocomposites are of specific interest because of their unique properties and applications, especially in the field of cytotoxicity. However, developing a simple method to synthesize reduced graphene oxide (rGO)/silver hexagonal nanoplate (Ag HNPT) (rGO-Ag HNPT) nanocomposites with well-defined morphology has been believed to be a major challenge. In this work, a facile, robust, and single-step synthesis method was developed to prepare silver-graphene (rGO-Ag HNPT) nanocomposites with hexagonal-structured silver nanoplates without any templates. The primary characterizations of the synthesized nanocomposite were done using a UV-visible spectrophotometer, X-ray diffraction (XRD), and Raman spectroscopy. The formation of uniformed hexagonal-shaped Ag nanoplates was confirmed by high-resolution transmission electron microscopy (HR-TEM), and the elemental composition was confirmed using energy dispersive X-ray analysis (EDX). With SiHa cervical cancer cells, the short-term in vitro cytotoxicity of the as-synthesized rGO-Ag HNPTs was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The anticancer response of the rGO-Ag HNPTs was investigated using an MTT assay.

Catalytic and antimicrobial properties of Ag and polyacrylic acid doped SrO nanocomposites; molecular docking analysis

This study investigates the co-precipitation synthesis of (2 and 4 wt%) Ag and polyacrylic acid-doped SrO nanocomposites for bactericidal activities and catalytic Rhodamine B (RhB) decolorization. The objective of the investigation was to minimize the rate of electron-hole recombination of SrO to enhance charge transfer. The influence of Ag and PAA on the crystal structure, morphology, absorbance wavelength, and exciton recombination rate of SrO was studied using a systematic characterization. The binary dopants were added into SrO to reduce the crystallite size, which produces the new active sites (reduces the recombination rate) and may generate reactive oxygen species (ROS). In a neutral medium with sodium borohydride (NaBH4), the synthesized nanocomposites demonstrated reasonable results for catalytic reduction of RhB dye (74.3 %). The bactericidal efficiency (96.6 %) of prepared samples was measured for Escherichia coli (E. coli) at various concentrations. Molecular docking studies were performed to rationale the antibacterial activity of PAA-SrO and Ag/PAA-SrO nanocomposites against DHFRE. coli, DHPSE. coli, and FabIE.coli suggested their role as inhibitors.

The Influence of Ag+/Ti4+ Ratio on Structural, Optical and Photocatalytic Properties of MWCNT–TiO2–Ag Nanocomposites

In this paper, we propose a simple procedure to obtain multi-walled carbon nanotubes (MWCNTs) decorated with TiO2–Ag nanoparticles (MWCNT–TiO2–Ag). The MWCNTs were decorated with TiO2–Ag via combined functionalization with –OH and –COOH groups and a polymer-wrapping technique using poly(allylamine)hydrochloride (PAH). TiO2-modified Ag nanoparticles were synthesized via the Pechini method using a mixture of acetylacetonate-modified titanium (IV) isopropoxide with silver nitrate (with Ag+/Ti4+ atomic ratios of 0.5%, 1.0%, 1.5%, 2.0%, and 2.5%) and L(+)-ascorbic acid as reducing agents. XRD analysis revealed the formation of nanocomposites containing CNT, anatase TiO2, and Ag. The presence of nanoparticles on the MWCNT surfaces was determined using TEM. The morphology of the TiO2–Ag nanoparticles on the MWCNT surfaces was also determined using TEM. UV–Vis investigations revealed that an increase in the ratio between Ag+ and Ti4+ decreased the band gap energy of the samples. The characteristic vibrations of the TiO2, Ag, and C atoms of the graphite were identified using Raman spectroscopy. The photocatalytic activity of the MWCNT–TiO2–Ag nanocomposite was assessed by examining the degradation of Allura Red (E129) aqueous solution under UV irradiation. The dye photodegradation process followed a pseudo-first-order kinetic with respect to the Langmuir–Hinshelwood reaction mechanism. The spin-trapping technique evidenced that •O2− was the main species generated responsible for the Allura Red degradation.

Bio-Fabrication of Cu/Ag/Zn Nanoparticles and Their Antioxidant and Dye Degradation Activities

The biological synthesis of nanoparticles with copper, silver, and zinc (Cu, Ag, Zn) is reported in this study, adopting a greener, safe, reliable, and eco-friendly approach by using an aqueous leaf extract of Catharanthus roseus. The synthesised trimetallic nanoparticles were characterised using different characterisation techniques. The UV–visible spectroscopic technique was initially used to assess nanoparticle formation, in which absorption bands were observed at 220, 270, and 370 nm for Cu, Zn, and Ag nanocomposites, respectively. XRD revealed that the average crystalline size of the nanocomposites was 34.67 nm. The roles of reducing and capping/stabilising agents in the synthesis of Cu/Ag/Zn nanoparticles were confirmed by FTIR analysis, and the successful biosynthesis of the same was also confirmed by X-ray energy-dispersive spectroscopy (EDX) analysis. Potential applications of these synthesised trimetallic nanoparticles were evaluated by assessing their antioxidant and catalytic dye degradation activities. The antioxidant activity of the synthesised nanomaterial was studied using the DPPH assay. The catalytic breakdown of the harmful dyes phenol red and eosin yellow was examined using NaBH4 as a reducing agent. The results showed that the nanomaterial’s radical scavenging capacity at 1000 ug/mL was 75.76% and the degradation of these dyes was up to 78% in the presence of NaBH4. Furthermore, the biogenic trimetallic nanomaterial exhibited effective catalytic degradation activity against methyl red and phenol red dyes.

Facile preparation of porphyrin@g-C3N4/Ag nanocomposite for improved photocatalytic degradation of organic dyes in aqueous solution

In the quest of improving the photocatalytic efficiency of photocatalysts, the combination of two and more semiconductors recently has garnered significant attention among scientists in the field. The doping of conductive metals is also an effective pathway to improve photocatalytic performance by avoiding electron/hole pair recombination and enhancing photon energy absorption. This work presented a design and fabrication of porphyrin@g-C3N4/Ag nanocomposite using acid-base neutralization-induced self-assembly approach from monomeric porphyrin and g-C3N4/Ag material. g-C3N4/Ag material was synthesized by a green reductant of Cleistocalyx operculatus leaf extract. Electron scanning microscopy (SEM), X-ray diffraction (XRD), FT-IR spectroscopy, and UV–vis spectrometer were utilized to analyse the properties of the prepared materials. The prepared porphyrin@g-C3N4/Ag nanocomposite showed well integration of porphyrin nanostructures on the g-C3N4/Ag's surface, in which porphyrin nanofiber was of the diameter in nanoscales and the length of several micrometers, and Ag NPs had an average particle size of less than 20 nm. The photocatalytic behavior of the resultant nanocomposite was tested for the degradation of Rhodamine B dye, which exhibited a remarkable RhB photodegrading percentage. The possible mechanism for photocatalysis of the porphyrin@g-C3N4/Ag nanocomposite toward Rhodamine B dye was also proposed and discussed.

Realization of Al:ZnO (AZO)-Ag nanocomposite as a novel photocatalyst capable of broadband photon harnessing driven by near-infrared plasmonics

The rising level of environmental pollution is a global concern and towards its mitigation, infrared photocatalysis emerges as a new concept, as the solar radiation at the earth’s surface has over 50% energy distribution in the near infrared (NIR) region. Al-doped ZnO (AZO) is a non-toxic congener of indium tin oxide (ITO) as transparent conducting oxide (TCO). A TCO-metal framework is developed as AZO-Ag@AZO nanocomposite by pulsed DC/DC magnetron sputtering. The consequences of diverse process conditions, viz, doping level, sputtering pressure, deposition time, and Ag/AZO co-sputtering time are noteworthy as the morphological, compositional, optical, and electrical properties are critically dependent on the process conditions. The structural and compositional analyses confirm wurtzite AZO and f.c.c. Ag with nanosized crystalline domains. A series of photocatalysis experiments reveal the significance of NIR plasmonics of AZO, realized by nanostructuring and generating optimum electron density (∼1020 cm−3). Notably, the optimal degradation rate (95%) of R6G is attained with tailored AZO-Ag@AZO nanocomposite. The gravity of visible surface plasmon resonance (SPR) due to Ag nanocrystallites and electron-hole pair creation in AZO cannot be undermined due to the remarkable participation of energetic electrons, and holes in redox reactions in harmony with actions of NIR SPR driven lower energy electrons.

Optical characteristics of silver-based nano-composites fabricated by an environmentally friendly method

This work presents a simple and environmentally friendly method of synthesis of chitosan and Ag nanocomposites. The structure of the obtained organic matrix was determined by Fourier-transform infrared spectroscopy (FTIR). Formation of chitosan- chitin copolymer was discovered. Nanocomposite films with silver content of 9–71 wt.% were prepared. The microstructure and elemental composition of the obtained films were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The prepared films are characterized by uniform distribution of silver nanoparticles in the organic matrix. Optical properties were studied by diffuse reflectance spectroscopy. The diffuse reflectance spectra of the films have maxima. The increase of the Ag 0 concentration in the nanocomposite films was found to lead to the maximum shift of the diffuse reflectance spectra to longer wavelengths. The optical transitions energies were estimated using the Kubelka–Munk function in combination with the Tauc method.

Single-step laser ablation synthesis of ZnO–Ag nanocomposites for broad-spectrum dye photodegradation and bacterial photoinactivation

We present the single-step production of zinc oxide (ZnO)–silver (Ag) nanocomposites using a second harmonic nanosecond laser. The Ag concentration was controlled using various concentration of AgNO3 solution as the medium. The evaluation of the structural and optical characteristics indicated the formation of ZnO–Ag nanocomposites. The resulting nanocomposites exhibited photocatalytic activity in broad-spectrum light, both UV and visible light, for the degradation of rhodamine 6G. Furthermore, the nanocomposites were assessed as antibacterial agents, and the addition of Ag improved the antibacterial activity of pure ZnO against Escherichia coli and Staphylococcus aureus. Under light exposure, Ag greatly increased S. aureus degradation through a simultaneous antibacterial process. Eventually, the nanocomposites could be anticipated as photoactivation antibacterial agent and water purification nanocatalyst applications.