Silver Doping Research Articles

Investigation of Silver and Copper Doping on Antimony Sulfide Thin Films Obtained by Electrophoretic Deposition

Investigation of Silver and Copper Doping on Antimony Sulfide Thin Films Obtained by Electrophoretic Deposition

Impact of Silver Incorporation and Flash-Lamp-Annealing on the Photocatalytic Response of Sputtered ZnO Films.

Thin films of silver-doped zinc oxide (SZO) were deposited at room temperature using a DC reactive magnetron co-sputtering technique using two independent Zn and Ag targets. The crystallographic structure, chemical composition and surface morphology of SZO films with different silver concentrations were correlated with the photocatalytic (PC) properties. The crystallization of the SZO films was made using millisecond range flash-lamp-annealing (FLA) treatments. FLA induces significant structural ordering of the wurtzite structure and an in-depth redistribution of silver, resulting in the formation of silver agglomerates. The wurtzite ZnO structure is observed for silver contents below 10 at.% where Ag is partially incorporated into the oxide matrix, inducing a decrease in the optical band-gap. Regardless of the silver content, all the as-grown SZO films do not exhibit any significant PC activity. The best PC response is achieved for samples with a relatively low Ag content (2-5 at.%) after FLA treatment. The enhanced PC activity of SZO upon FLA can be attributed to structural ordering and the effective band-gap narrowing through the combination of silver doping and the plasmonic effect caused by the formation of Ag clusters.

Enhancement of antimicrobial properties and cytocompatibility through silver and magnesium doping strategies on copper oxide nanocomposites

In the present study, silver (Ag), magnesium (Mg), and the various molar ratios of Ag:Mg-doped copper oxide nanocomposites (CuO NCs) were synthesized by the co-precipitation method. The CuO NC samples calcined at 500 °C were further analyzed for their morphological, structural, functional, and optical properties. Adding single and dual doping increased the pristine CuO band gap from 1.28 to 1.50 eV. The Ag and Mg metal peaks were revealed in the Fourier transform infrared (FTIR) analysis, while an elevated Mg band was observed in all Mg-doped samples in the Raman results. All CuO NCs showed a monoclinic crystalline structure, flake, and rod-like morphologies. Microbes of Bacillus subtilis, Shigella dysenteriae, and Candida albicans were tested against different concentrations of CuO NCs. Better results for all tested microbes were observed with the 2 mg concentration. The high cytotoxicity effect was observed in the pristine and Cu:Ag (94:6) sample, and other CuO NCs, which demonstrated over 80 % viability in RAW 246.7 cells at a concentration of 0.5 µg/ml. Remarkably, over 94 % cell viability at 0.5 µg/ml was achieved with the Cu:Ag:Mg (94:3:3) NCs ratio, owing to the synergistic effect of the ion-releasing ability of Cu2+, Ag2+, and Mg2+ ions. It possesses a distinctive high aspect ratio shape, is ion-releasing, and has excellent cytocompatibility. The suitability of the Cu:Ag:Mg (94:3:3) NCs ratio for addressing microbial challenges in healthcare is suggested by their distinct characteristics, indicating the promising potential for future biomedical applications.

Trace silver doping improved the efficiency of copper-based Fenton-like catalysts cathode for wastewater treatment

The treatment of highly concentrated and recalcitrant organic pollutants in industrial wastewater has garnered significant attention, with Fenton oxidation emerging as a promising approach. However, traditional iron-based Fenton reagents present certain limitations, and copper-based Fenton systems are often less efficient. Thus, it is necessary to develop innovative copper-based Fenton catalytic materials. In this study, Cu₂O and Ag-modified activated carbon fibers (Cu₂O-Ag@ACF) were synthesized via liquid-phase reduction. The composition, structure, and morphology of Cu₂O-Ag@ACF were systematically characterized. The Cu₂O-Ag@ACF was employed as a functionalized cathode in the electro-Fenton process to degrade a highly concentrated organic pollutant solution, with methylene blue serving as a model contaminant. The loading of Cu₂O and Ag not only enhances the electrochemical performance of ACF but also improves its Fenton oxidation efficiency. Cu₂O-Ag@ACF exhibited less than 1 % performance degradation after five cycles of use, highlighting its potential for industrial applications under simulated realistic conditions. Moreover, the electro-Fenton system parameters, including current density, pH, electrode spacing, and solution temperature, were optimized. Under the optimal conditions, the degradation rate of methylene blue by Cu₂O-Ag@ACF reached 92.8 % within 120 minutes. Kinetic analysis indicated that the reaction followed a first-order kinetic model, with a rate constant of 0.253 min⁻¹. Furthermore, this study revealed that trace silver doping significantly accelerated the generation of reactive oxygen species, thereby enhancing the efficiency of the Cu-based Fenton-like catalysts. In conclusion, this work presents a convenient strategy for the sustainable and efficient purification of industrial wastewater, contributing to the improvement of human life quality.

Biocompatibility and antimicrobial efficacy of silver-doped borosilicate bioactive glass for tissue engineering application

Borate bioactive glasses are an auspicious material for tissue engineering applications due to their enhanced dissolution rate, bioactivity, and capacity to integrate therapeutic ions. In this study, borate-based S49B4 bioactive glass doped with silver at mass fraction of 0.5, 1, and 3 wt% were studied for bioactivity, degradation, antibacterial, and cytocompatibility. Thermogravimetric analysis revealed that the bioactive glasses were thermally stable between 600 and 700 °C. Fourier transform infrared spectroscopy and X-ray diffraction confirmed the successful synthesis of an amorphous phase of the doped borosilicate bioactive glasses and the incorporation of silver ion crystals within the structure, as well as associated contributions from borate and silicate network formers in the borosilicate bioactive glass. Morphological evaluation revealed that the borosilicate bioactive glasses exhibit a uniform and spherical shape across all formulations, with the mean particle size varying from 65 to 76 nm. An in-vitro acellular bioactivity in simulated body fluid medium showed that increasing the silver content increased the degradation rate and pH. Besides, scanning electron microscopy and Energy dispersive X-ray spectroscopy analysis revealed an upsurge in apatite production on the BBGs' surfaces as well as incremental Calcium-Phosphate ratio values of 1.50, 1.65 and 1.70 as the silver content increases. The antibacterial effect was tested against Escherichia coli and Staphylococcus aureus, while cytocompatibility was tested against human gingival epithelial cells. Silver integration at 1 wt percent yielded the most promising outcomes, which were particularly bactericidal at 79.8 % for Escherichia coli and 93.41 % for Staphylococcus aureus. Similarly, its Lactate Dehydrogenase percentage is significantly similar to the negative control employed in the study, indicating its biocompatibility. In contrast, 3 wt% silver exhibited the maximum bactericidal activity while also exhibiting mild cytotoxicity. In summary, our research indicates that elevated silver concentration enhances the bioactivity and antimicrobial characteristics of borosilicate bioactive glasses; nevertheless, a higher silver weight percent in this study also increases the possibility of cytotoxicity. It is therefore essential to carefully regulate the amount of silver doping at lower concentrations in order to maximize antibacterial action and minimize toxicity to human cells. The results presented here contribute to our understanding of the prospective use of silver doped borosilicate bioactive glasses as a possible material for tissue engineering applications.

EFFECT OF SILVER DOPING ON IRON OXIDE ELECTRICAL PROPERTIES

Iron silver oxide (Agx[Formula: see text]O3; [Formula: see text]) structure for photoelectrochemical (PEC) water splitting was grown by RF–DC co-sputtering of an iron–silver target in argon/oxygen plasma mixtures at 300°C, followed by thermal annealing at 560°C. The chemical composition and structure of the deposited film can be tuned by controlling the metal doping and the annealing temperature. The thermal treatment extensively improves the PEC water-splitting performances of the films. XRD patterns of AgxFe[Formula: see text]O3 shown in the figure can be indexed to the hexagonal structure of silver oxide and the rhombohedral structure of hematite and new X-ray Diffraction (XRD) peaks of AgxFe[Formula: see text]O3 structure. The annealing and doping process seems to cause a serious change in the crystal structure of the thin film, it showed a serious change in its electrical properties. The electrical parameters of resistance for thin films were measured using the Hall measurement method at room temperature. With Hall measurements, the n-type carrier concentration of the Fe2O3 structure was calculated, and it was observed that its resistance was 1[Formula: see text]M[Formula: see text]. Likewise, it was observed that AgxFe[Formula: see text]O3 exhibited an n-type carrier concentration, and its resistance was calculated to be 0.5[Formula: see text]M[Formula: see text]. The conductivity change is based on silver doping. The doping process seems to cause a change in the bandgap of the thin film, it showed a change in its optical properties. The film’s optical absorption was measured by UV–Vis photo spectroscopy. Subsequently, the structural and topographic properties of AgxFe[Formula: see text]O3 structures were investigated by high-precision characterization devices.

Bio activity testing of SnO2-TiO2 nanocomposite synthesis by chemical methods

In this work, SnO2:TiO2 nano composite with silver dopant have been prepared by chemical route method at preparation temperature 100 ℃ , with 6% Ag ratio. Titanium chloride (TiCl3) has been used as the precursors of TiO2 and tin chloride (SnCl2) were taken as the precursors of SnO2 in the laboratory. The prepared samples were described by FESEM, X-Ray diffraction and uv-visible spectrophotometer. Results show that compared to pure SnO2 and pure TiO2 ,SnO2:TiO2 nano composite calcined 400℃ shows a large surface area. The average crystalline size was estimated from XRD analysis by using Debye-Scherrer’s formula and the result shows that the crystalline size increases from (27.78) nm to (29.2354)nm after adding Ag. Bio activity application of the prepared composite has been tested after immersion SnO2:TiO2 nano composite in the simulated body fluid SBF, the morphology and particle size of the prepared immersed samples have been estimated after 20 days by FESEM images.

Silver-doped ZrO2-TiO2 nanocomposite coatings on 316L stainless steel for enhanced corrosion resistance and bio applications

The demand for ceramic based nanocomposite coatings has increased because they play a significant role in orthopedic implants and medical devices. Ceramic nanocomposites are inert and highly biocompatible, which improve corrosion resistance under physiological fluids. The ceramic nanocomposites were deposited (silver-doped ZrO2/TiO2) on SS 316L, and their biocompatibility, strength of adhesiveness, and corrosion resistance properties were studied. A detailed investigation of corrosion resistance, wettability, and biocompatibility concerning microstructures and the inclusion of silver as a dopant was conducted. The deposited films annealed at 600 °C display crystallinity with the coexistence of TiO2 rutile and ZrO2 monoclinic phases. The surface morphology shows the average particle size on thin film is around 40 to 45 nm. The deposited films show a decreased corrosion current density (ICorr) in potentiodynamic polarization curves, confirming the adequate protection against corrosion using simulated body fluid and phosphate buffer saline at 37±1 °C. The surface wettability of coatings is hydrophilic, and it improves in-vitro compatibility. The apatite growth in SBF solution on the implant surface predicts a favorable condition for bone regeneration in the patient's body. The effect of silver dopant on improving apatite growth on implant surface is also discussed. From electrochemical impedance spectroscopy, the diameter of the semicircle in the Nyquist plot shows more than bare metal; the higher the diameter indicates the more resistive behavior of deposited films, which shows the effective corrosion resistance in the electrolytic solution. It is found that the biocompatibility and corrosion resistance are improved compared with bare SS 316L. Hence, ceramic nanocomposite coatings show great potential in the orthopedic implant industry.

Aftermath of Ag embedding on structural, optical, and supercapacitor electrode attributes of USP-grown CuO thin films

Here, ultrasonic spray pyrolysis method (USP) was utilized to produce pure and silver doped copper oxide nanostructures on glass substrates. Thereafter, several characterization techniques were conducted on the grown samples to delve into their morphological, structural, electrochemical, and optical aspects. The mentioned analyses were carried out by performing x-ray photoelectron spectroscopy, scanning electron microscope, X-ray diffraction, electrochemical impedance spectroscopy, galvostatic charge-discharge, cyclic voltammetry, and UV–visible spectroscopy measurements. Thus, the impact of silver impurity doping on the relevant aspects of host material were recorded as well as the features of unspoiled copper oxide films. Accordingly, the samples, as indicated by X-ray diffraction results, possessed (002) preferential plane orientation of copper oxide material along with the crystallite sizes ranging from 52.52 nm to 75.02 nm due to the imperfections caused by the silver doping. The scanning electron microscope images exhibited that the silver doping did not form significant modifications in the host material morphology where nanowire-like structures observed. The presence of the suggested materials in the films was verified by the x-ray photoelectron spectroscopy. Also, the UV–visible spectroscopy measurements detected that optical absorbance edge and bandgap energy values red shifted as a result of the impurity doping. The electrochemical supercapacitors performances of the silver doped copper oxide nanostructured thin films were inspected by using the GCD, EIS, and CV. The silver doped copper oxide films demonstrated a specific capacitance value of 66 F/g at a current density of 1 A/g in 1 M KOH electrolyte. From Nyquist plot, Rs, Rcor, Rpo, Ccor and Cc were obtained as 2.327 × 103 Ω.cm2, 43.63 × 103 Ω.cm2, 4.580 × 103 Ω.cm2, 111.5 × 10-6 S*s^a. cm-2 and 101.1 × 10-6 S*s^a. cm-2, respectively. The results indicated that the electrochemically synthesized the silver doped copper oxide electrodes can be obtained and developed as an alternative electrode material for supercapacitors (SCs).

Silver-doped cadmium aluminate and its MXene based composite for visible-light driven photocatalytic degradation of organic pollutants

Visible-light-driven photocatalysis has attracted enormous prominence as a sustainable approach to address escalating environmental pollution. Consequently, it is paramount to develop photocatalysts featuring absorption in visible light with enhanced charge separation to perform well under solar light irradiation. Herein, we have fabricated pure (CdAl2O4) and silver-doped cadmium aluminate (Ag–CdAl2O4) by following the facile coprecipitation route while the MXene-based composite of doped material (Ag–CdAl2O4/MXene) by ultrasonication. The photocatalytic activity of the as-prepared photocatalysts was estimated by degrading crystal violet and phenol as sample pollutants. The composite material displayed substantially enhanced photocatalytic performance and degraded ∼95 % (0.0204 min−1) and ∼84.6 % (0.0130 min−1) of crystal violet and phenol, respectively. This enhanced catalytic performance corresponds to the synergism of silver doping and composite fabrication, enhancing the visible-light-response and efficient decoupling of the photo-generated charge carriers. Additionally, active species generated during the photocatalytic process and their role in the breakdown of the targeted pollutants were determined by the scavenging investigation. The kinetics study revealed the first-order kinetics model for the degradation reaction of the targeted pollutants. The present findings unveil the significant catalytic potential of the as-fabricated composite (Ag–CdAl2O4/MXene) for the degradation of organic pollutants.

Exploring Enhanced Structural and Dielectric Properties in Ag-Doped Sr(NiNb)0.5O3 Perovskite Ceramic for Advanced Energy Storage

The ceramic Sr(NiNb)0.5O3, incorporating silver doping in the A site, was synthesized using a sol–gel route and subjected to comprehensive analysis through various experimental techniques. X-ray diffraction data analysis indicates a rhombohedral crystal structure. Scanning electron microscopy (SEM) examination reveals densely packed grains with minimal surface porosity. A thorough investigation of electrical properties, encompassing dielectric constant, loss tangent, electrical impedance, modulus, conductivity, etc., was conducted across a wide frequency range (103–106 Hz) and temperature range (260–340 K). This analysis provided valuable insights into structure–property relationships and conduction mechanisms. The discussion highlights the significance of interface effects, space charge polarization, and Maxwell–Wagner dielectric relaxation in achieving the material’s high dielectric constant at low frequencies and elevated temperatures. Examination of temperature dependence through Nyquist plots elucidates the contributions of grain behavior to the material’s resistive and capacitive properties. The dielectric permittivity, dissipation of energy, and electrical characteristics like impedance, modulus and conductivity are notably influenced by the frequency of the applied electric field and temperature. Overall, the material exhibits promising potential for industrial applications such as energy storage, given its intriguing properties.

Facile synthesis of silver doped manganese oxide nanocomposite with superior photocatalytic and antimicrobial activity under visible spectrum

Water pollution and antimicrobial resistance (AMR) have become two global threats; 80% of diseases and 50% of child deaths are due to poor water quality. In this study, hydrothermal processing was employed to manufacture manganese oxide nanorods. Silver dopant was deposited on the surface of manganese oxide. XRD diffractogram confirmed the facile synthesis of Ag/Mn2O3 nanocomposite. XPS survey analysis demonstrated silver content of 9.43 atom %. Photocatalytic measurements demonstrated the outstanding efficiency of the Ag-Mn2O3 compared to virgin oxide particles under visible radiation. Degradation efficiencies Mn2O3 and Ag/Mn2O3 on methyl orange (MO) dye was found to be 53% and 85% under visible spectrum. Silver dopant was found to decrease the binding energy of valence electrons; this action could support electron–hole pair generation under visible spectrum and could promote catalytic performance. Ag/Mn2O3 NPs demonstrated most effective performance (95% removal efficiency) at pH 3; this could be ascribed to the electrostatic attraction between positively charged catalyst and the negatively charged MO. Ag/Mn2O3 demonstrated enhanced antibacterial activity against Gram-positive Staphylococcus aureus (S. aureus) (19 mm ZOI), and Gram-negative Escherichiacoli (E. coli) (22 mm ZOI) respectively; the developed nanocomposite demonstrated advanced anti-film activity with inhibition percentage of 95.5% against E. coli followed by 89.5% against S. aureus.

Porous Ag-ZnO/Ag heterostructure: Microscopic and electrochemical investigation

Porous Ag-ZnO/Ag heterostructures have been synthesized by the combustion approach. The independent silver crystal formation was confirmed by the appearance of an independent peak on the XRD pattern and HRTEM image d-spacing analysis. The low-angle shift on the XRD pattern also confirms the inclusion of silver in the ZnO lattice. Thus, the XRD and HRTEM analyses confirm the formation of the Ag-ZnO/Ag (za) heterostructure. Silver inclusion in the ZnO lattice was also confirmed by the DRS-UV–vis indirect bandgap change from 3.03 to 2.86 eV. The porous nature of the materials is confirmed by the FESEM image. The PL spectra intensity reduction for za indicates the presence of charger transfer. Silver dopant surface distribution and composition were confirmed from the EDS-elemental mapping analysis. The porous ZnO heterostructure also showed better lead detection capacity compared to ZnO. Thus, porous materials have future outlooks for pollutant detection and removal applications.

Computational study of the structural, electronic, optical, and thermoelectric properties of (Ag, B, I) doped Cs2PdBr6 compound

This investigation explores the properties of pure lead-free Cesium Hexabromopalladate (IV), Cs2PdBr6, and Cs2PdBr6-xYx (Y = Ag, B, I) (x = 0.2496) compounds using the Density Functional Theory (DFT) method. The study examines the compounds’ structural, electronic, optical, and thermoelectric attributes, establishing their negative formation energies and relative stability, indicating their potential for synthesis. The research reveals a decrease in indirect band gap with the incorporation of Iodine, Boron, and Silver dopants. Additionally, the optical properties, including the absorption coefficient and optical band gap, demonstrate pronounced absorbance and efficacy in the visible region. The transport properties are modelled, with the Seebeck coefficient indicating a transition from p-type to n-type conductive demeanor for B and Ag-doped Cs2PdBr6. The study concludes that pure Cs2PdBr6 and B, Ag, I-doped Cs2PdBr6 are superlative contenders for optoelectronic and solar cell applications. Overall, this research proffers valuable insights into the prospective applications of these compounds and their attributes.

Synthesis of silver‐doped TiO2 nanoparticles with highly efficient adsorption of Congo red

AbstractTiO2 nanoparticles (NPs) doped with Ag were produced through a solvothermal method, with varying amounts of silver doping ranging from 0.5% to 1.5%. The samples were analyzed for crystallite sizes, structure, and metallic bondings using XRD, SEM, EDXS, and FTIR techniques. The BET surface areas were determined through nitrogen adsorption isotherms. The efficiency of the silver‐doped TiO2 NPs for removing Congo red (CR) was tested through adsorption experiments. The results showed that the synthesized TiO2 NPs doped with Ag were uniformly spherical in shape, with tiny average sizes ranging from 7.97 to 12.74 nm and large BET surface areas (98.41–166.1 m2 g−1). The silver‐doped TiO2 samples with a 0.5% Ag doping amount exhibited the highest adsorption capacity in CR removal, with a maximum adsorption capacity of 454.55 mg of dye per gram of adsorbent and a lower contact time of 20 min than other metal oxide NPs. The CR adsorption onto 0.5% Ag‐TiO2 obeyed the Langmuir isotherm model (R2 = 0.989), and the adsorption followed a pseudo‐second‐order kinetic equation. The adsorbent could be efficiently reused for five consecutive cycles to remove CR.

Silver-Doped Titanium Oxide Layers for Improved Photocatalytic Activity and Antibacterial Properties of Titanium Implants.

Titanium has a long history of clinical use, but the naturally forming oxide is not ideal for bacterial resistance. Anodization processes can modify the crystallinity, surface topography, and surface chemistry of titanium oxides. Anatase, rutile, and mixed phase oxides are known to exhibit photocatalytic activity (PCA)-driven bacterial resistance under UVA irradiation. Silver additions are reported to enhance PCA and reduce bacterial attachment. This study investigated the effects of silver-doping additions to three established anodization processes. Silver doping showed no significant influence on oxide crystallinity, surface topography, or surface wettability. Oxides from a sulfuric acid anodization process exhibited significantly enhanced PCA after silver doping, but silver-doped oxides produced from phosphoric-acid-containing electrolytes did not. Staphylococcus aureus attachment was also assessed under dark and UVA-irradiated conditions on each oxide. Each oxide exhibited a photocatalytic antimicrobial effect as indicated by significantly decreased bacterial attachment under UVA irradiation compared to dark conditions. However, only the phosphorus-doped mixed anatase and rutile phase oxide exhibited an additional significant reduction in bacteria attachment under UVA irradiation as a result of silver doping. The antimicrobial success of this oxide was attributed to the combination of the mixed phase oxide and higher silver-doping uptake levels.

Ionic liquid-mediated TiO2/Ag/CA photocatalyst for enhanced water remediation

The effect of an environmentally friendly green solvent template, ionic liquid (IL) - 1-butylimidazolium acetate on the surface area of TiO2 and its further combination with silver (Ag) dopant and cellulose acetate (CA) support were evaluated together. In this study, the TiO2/Ag/CA photocatalyst was synthesized and systematically investigated for the degradation of dyes. The incorporation of IL during synthesis led to a notable increase in the surface area of TiO2 (174.8 m2/g) and TiO2/Ag/CA (186.5 m2/g) photocatalyst, as evidenced by Brunauer Emmett Teller (BET) surface analysis. The findings revealed that TiO2/Ag/CA photocatalyst (IL: 3 mL, Ag: 2 wt%, CA: 0.5%) exhibited great efficiency in removing both individual and mixed dyes (MB, MO and RhB) under UV irradiation (λ = 365 nm) and visible light (λ = 440 nm) after 120 min. The antibacterial activity of TiO2-1/Ag 2%/CA 0.5% investigated via disc diffusion method against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria demonstrated inhibition zones, indicating the antibacterial effectiveness of the photocatalyst. With the imperative goal of eliminating chemical pollutants and undesired biological constituents from wastewater, the TiO2/Ag/CA photocatalyst investigated in this study exhibits the capability to effectively tackle both challenges with a high degree of efficiency.

Evaluation of Antimicrobial and Antifungal Effects of Ag and Mg Dual-Doped Zinc Oxide Nanoparticles against Staphylococcus Epidermidis, Pseudomonas Aeruginosa, and Candida Albicans

Background: Microbial infectious diseases are one of the serious health problems that have attracted the attention of the public as a threat to human health all over the world. Zinc oxide nanoparticles due to their various properties such as antibacterial, antifungal, and anticancer are of great interest. Methods: The antimicrobial activity of synthesized un-doped and silver and magnesium-doped zinc oxide nanoparticles with Salvadora persica extract against different strains of Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans was investigated through two methods of broth diffusion and the minimum microbial inhibitory concentration (MIC). Results: According to results, MIC of un-doped and silver and magnesium-doped zinc oxide nanoparticles showed 160, 80, 40, and 40 µg/mL on Staphylococcus epidermidis, and 80, 40, 40, and 40 µg/mL on Staphylococcus aureus. These values on Pseudomonas aeruginosa were obtained ˃5120, 640, 320, and 320 µg/mL. Conclusion: The results of the broth dilution method on Staphylococcus epidermidis and Staphylococcus aureus showed the presence of silver has a very good inhibition effect on these bacteria. In Pseudomonas aeruginosa and Candida albicans fungus, it has been observed that by increasing the amount of silver and magnesium doping, the inhibitory rate of nanoparticles on Gram-negative bacteria and fungi has increased.

Silver-Doped CsPbI2Br Perovskite Semiconductor Thin Films

All-inorganic perovskite semiconductors have received significant interest for their potential stability over heat and humidity. However, the typical CsPbI3 displays phase instability despite its desirable bandgap of ~1.73 eV. Herein, we studied the mixed halide perovskite CsPbI2Br by varying the silver doping concentration. For this purpose, we examined its bandgap tunability as a function of the silver doping by using density functional theory. Then, we studied the effect of silver on the structural and optical properties of CsPbI2Br. Resultantly, we found that ‘silver doping’ allowed for partial bandgap tunability from 1.91 eV to 2.05 eV, increasing the photoluminescence (PL) lifetime from 0.990 ns to 1.187 ns, and, finally, contributing to the structural stability when examining the aging effect via X-ray diffraction. Then, through the analysis of the intermolecular interactions based on the solubility parameter, we explain the solvent engineering process in relation to the solvent trapping phenomena in CsPbI2Br thin films. However, silver doping may induce a defect morphology (e.g., a pinhole) during the formation of the thin films.

Silver and silicon doped βTCP scaffolds with gentamicin or ceftazidime loaded P(3HB) coatings as multifunctional biomaterials for bone regeneration

The risk of bacterial infections is a significant challenge faced frequently in the use of implants or scaffolds for bone regeneration. Therefore, this study focusses on the development and characterisation of novel β tricalcium phosphate (βTCP) scaffolds co-doped with silver and silicon, along with composites coated with antibiotic-loaded poly(3-hydroxybutyrate) (P(3HB)) layers. The successful incorporation of silver and silicon dopants while maintaining the formation of βTCP phase was confirmed using X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS) analysis. The developed materials demonstrated comparable total and open porosity (∼64–70 vol%), suggesting high interconnectivity between pores conducive to nutrient transport and tissue repair. The increase in compressive strength was achieved for both doped (4.73 ± 0.79 MPa) and P(3HB) coated (5.79 ± 0.92 MPa) scaffolds due to the fine bioceramic microstructure and polymeric coating. Silver and silicon-modified βTCP demonstrated enhanced growth inhibition of Gram-negative (Pseudomonas aeruginosa, Escherichia coli) and Gram-positive (Staphylococcus aureus) bacterial strains in vitro compared to the pure βTCP. P(3HB) coatings, enriched with gentamicin or ceftazidime, exhibited burst and sustained release of the antibiotics from the scaffolds up to 120 h further intensifying the bacteria-killing capability, with evident inhibition zones observed in vitro. Moreover, the composites exhibited apatite-forming ability, suggesting their bioactive potential. In vivo evaluation using Caenorhabditis elegans demonstrated the lack of toxicity of the tested materials. The simultaneous incorporation of the dopants and antibiotic-loaded P(3HB) coatings not only offer a dual antibacterial approach but may also facilitate bone regeneration. However, further in vitro and in vivo investigations are needed to assess their potential in clinical application.