Search Results (932)

Sol–gel-processed zinc oxide (ZnO) and magnesium-doped zinc oxide (ZnMgO) are widely used in quantum dot light-emitting diodes (QLEDs) due to their excellent charge transport properties, ease of fabrication, and tunable film characteristics. In particular, the ZnMgO/ZnO bilayer structure has attracted considerable attention for its dual functionality: defect passivation by ZnMgO and efficient charge transport by ZnO. However, while the effects of resistive switching (RS) in individual ZnO and ZnMgO layers on the aging behavior of QLEDs have been studied, the RS characteristics of sol–gel-processed ZnMgO/ZnO bilayers remain largely unexplored. In this study, we systematically analyzed RS properties of an indium tin oxide (ITO)/ZnMgO/ZnO/aluminum (Al) device, demonstrating superior performance compared to devices with single layers of either ZnMgO or ZnO. We also investigated the shelf-aging characteristics of RS devices with single and bilayer structures, finding that the bilayer structure exhibited the least variation over time, thereby confirming its enhanced uniformity and reliability. Furthermore, based on basic current–voltage measurements, we estimated accuracy variations in MNIST pattern recognition using a two-layer perceptron model. These results not only identify a promising RS device architecture based on the sol–gel process but also offer valuable insights into the aging behavior of QLEDs incorporating ZnMgO/ZnO bilayers, ITO, and Al electrodes. Full article

This research introduces a synergistic photoelectrocatalytic (PEC) system designed for the effective degradation of tetracycline (TC), integrating a PO₄³⁻-grafted Mo-doped BiVO₄ (PO₄³⁻-Mo:BiVO₄) photoanode with a Pd-loaded ordered mesoporous carbon (Pd/CMK-3) cathode. The incorporation of Mo doping and PO₄³⁻ modification significantly improved the photoanode’s charge separation efficiency, achieving a photocurrent density of 2.9 mA cm⁻², and fine-tuned its band structure to enhance hydroxyl radical (·OH) generation. Meanwhile, the Pd/CMK-3 cathode promoted a two-electron oxygen reduction reaction pathway, producing hydrogen peroxide (H₂O₂) and facilitating molecular oxygen activation via atomic hydrogen (H*) intermediates. Under optimized conditions—1.0 V vs. Ag/AgCl of anodic potential, pH 6.58, and oxygen saturation—the combined system accomplished 80% TC degradation within 60 min, markedly surpassing the performance of the photoanode (72%) or cathode (71%) alone. Notably, this synergistic approach also reduced energy consumption to 0.0065 kWh m⁻³, outperforming individual components. Radical quenching experiments and liquid chromatography–mass spectrometry (LC-MS) analysis revealed that the photogenerated holes (h⁺) and ·OH were the key reactive species responsible for TC mineralization. The system demonstrated remarkable stability, with only a 2.96% decline in activity, and effectively degraded other contaminants, such as phenol, 4-chlorophenol, and ciprofloxacin. This study highlights an energy-efficient PEC strategy that harnesses the combined strengths of anodic oxidation and cathodic molecular oxygen activation to significantly enhance the removal of organic pollutants. Full article

This investigation addresses the enhancement of ammonia fuel cell performance using Pd (palladium)- and Co (cobalt)-doped cathode catalysts. Initially, the performance of the Ag/C cathode catalyst in ammonia fuel cells yielded a baseline power density of only 38 mW/cm². To improve efficiency, Pd and Co were introduced, resulting in the synthesis of a new 15 wt% PdAgCo/C (15 wt% PdAgCo and 85 wt% C) cathode catalyst, which increased the power density to 74 mW/cm². Further performance enhancement was achieved by using a highly efficient 40 wt% PtIr/C anode catalyst, as reported in the literature, and applying a cathode catalyst loading of 0.5 mg/cm², raising the power density to 172 mW/cm². This investigation addresses the successful synthesis of a 15 wt% PdAgCo/C cathode catalyst, which has proven to be a better choice over conventional catalysts, along with the significance of doping Pd and Co with Ag/C in the augmentation of catalytic activity and fuel cell performance. Thus, a series of physicochemical and electrochemical characterizations, the approach for optimization of the working parameters, and the impact analysis of catalyst loading have all resulted in the achievement of an impeccable power density of 332 mW/cm². Full article

The growing challenge of biofilm-associated infections in dentistry necessitates advanced solutions. This review highlights the potential of smart bioactive and antibacterial materials—bioactive glass ceramics (BGCs), silver nanoparticle (AgNP)-doped polymers, and pH-responsive chitosan coatings—in transforming restorative dentistry. BGCs reduce biofilms by >90% while promoting bone integration. AgNP-polymers effectively combat S. mutans and C. albicans but require controlled dosing (<0.3 wt% in PMMA) to avoid cytotoxicity. Chitosan coatings enable pH-triggered drug release, disrupting acidic biofilms. Emerging innovations like quaternary ammonium compounds, graphene oxide hybrids, and 4D-printed hydrogels offer on-demand antimicrobial and regenerative functions. However, clinical translation depends on addressing cytotoxicity, standardizing antibiofilm testing (≥3-log CFU/mL reduction), and ensuring long-term efficacy. These smart materials pave the way for self-defending restorations, merging infection control with tissue regeneration. Future advancements may integrate AI-driven design for multifunctional, immunomodulatory dental solutions. Full article

Photopolymer PQ/PMMA, as a pivotal material in the field of holographic storage, demonstrates significant application potential owing to its advantages, such as straightforward preparation processes, cost-effectiveness, and tunable thickness. However, its practical application is still constrained by the need for further enhancement in key performance indicators, including diffraction efficiency, photosensitivity, and anti-aging properties. In this study, N-vinylpyrrolidone (NVP) is employed as a comonomer. By precisely controlling the doping ratio, we systematically investigate the influence mechanism of different NVP doping concentrations on the holographic performance of NVP-PQ/PMMA materials. Research indicates that the introduction of NVP effectively increases the vinyl concentration in the PQ/PMMA matrix, thereby directly generating photoproducts with PQ during the photoreaction process and further enhancing the photopolymerization process. Consequently, the holographic performance of the novel NVP-PQ/PMMA material is improved in a multi-faceted manner compared to ordinary PQ/PMMA. Specifically, the diffraction efficiency is enhanced by 1.93 times, the photosensitivity is increased by 1.64 times, the material uniformity is improved by 38%, and the light-induced shrinkage rate is reduced by 39%. Additionally, NVP-PQ/PMMA materials exhibit excellent stability and aging resistance in high-temperature accelerated aging experiments. Doping with a monomer of specific structure enhances the optical properties, providing broad adaptability for further research on PQ/PMMA photopolymer materials. Full article

A natural deep eutectic solvent (NADES)-based electropolymerization strategy was developed to deposit polypyrrole (PPy) and Naproxen-doped PPy films onto a biomedical Ti–20Zr–5Ta–2Ag high-entropy alloy. Using cyclic voltammetry, chronoamperometry, and chronopotentiometry, coatings were grown potentiostatically (1.2–1.6 V) or galvanostatically (0.5–1 mA) to fixed charge values (1.6–2.2 C). Surface morphology and composition were assessed by optical microscopy, SEM and FTIR, while wettability was quantified via static contact-angle measurements in simulated body fluid (SBF). Electrochemical performance in SBF was evaluated through open-circuit potential monitoring, potentiodynamic polarization, and electrochemical impedance spectroscopy. Drug-release kinetics were determined by UV–Vis spectrophotometry and analyzed using mathematical modelling. Compared to uncoated alloy, PPy and PPy–Naproxen coatings increased hydrophilicity (contact angles reduced from ~31° to <10°), and reduced corrosion current densities from 754 µA/cm² to below 5.5 µA/cm², with polarization resistances rising from 0.06 to up to 37.8 kΩ·cm². Naproxen incorporation further enhanced barrier integrity (R_coat up to 1.4 × 10¹¹ Ω·cm²) and enabled sustained drug release (>90% over 8 days), with diffusion exponents indicating Fickian (n ≈ 0.51) and anomalous (n ≈ 0.67) transport for potentiostatic and galvanostatic coatings, respectively. These multifunctional PPy–Naproxen films combine robust corrosion protection with controlled therapeutic delivery, supporting their potential biomimetic role as smart coatings for next-generation implantable devices. Full article

This review examines the emerging role of manganese-based nanoparticles (Mn-NPs) in detecting heavy metal pollutants in environmental matrices. Heavy metals such as cadmium, lead, zinc, and copper pose serious environmental and health concerns due to their tendency to persist in ecosystems and accumulate in living organisms. As a result, there is a growing need for reliable methods to detect and remove these pollutants. Manganese nanoparticles offer unique advantages that scientists could consider as replacing other metal nanoparticles, which may be more expensive or more toxic. The physicochemical properties of Mn-NPs—including their multiple oxidation states, magnetic susceptibility, catalytic capabilities, and semiconductor conductivity—enable the development of multi-modal sensing platforms with exceptional sensitivity and selectivity. While Mn-NPs exhibit inherently low electrical conductivity, strategies such as transition metal doping and the formation of composites with conductive materials have successfully addressed this limitation. Compared to noble metal nanoparticles (Au, Ag, Pd) and other base metal nanoparticles (Bi, Fe₃O₄), Mn-NPs demonstrate competitive performance without the drawbacks of high cost, complex synthesis, poor distribution control, or significant aggregation. Preliminary studies retrieved from the Scopus database highlight promising applications of manganese-based nanomaterials in electrochemical sensing of heavy metals, with recent developments showing detection limits in the sub-ppb range. Future research directions should focus on addressing challenges related to scalability, cost-effectiveness, and integration with existing water treatment infrastructure to accelerate the transition from laboratory findings to practical environmental applications. Full article

Due to its unique layered structure that facilitates ion intercalation and deintercalation, δ-MnO₂ has emerged as a promising cathode material for aqueous zinc-ion batteries (ZIBs). However, its structural collapse and Mn dissolution during prolonged cycling significantly limit its practical application. In this study, we demonstrate that metal ion doping, particularly with Fe³⁺, can effectively stabilize the δ-MnO₂ structure and enhance its electrochemical performance. Through a hydrothermal synthesis approach, δ-MnO₂ materials with varying Fe³⁺ doping ratios are prepared and systematically investigated. Among them, the sample with a Mn:Fe molar ratio of 20:1 exhibits the best performance, maintaining the layered δ-MnO₂ phase while significantly increasing Mn³⁺ content and promoting the formation of oxygen vacancies. At a current density of 0.5 A·g⁻¹, the iron-doped sample exhibited an initial specific capacity of 116.24 mAh·g⁻¹, with a capacity retention rate of 41.7% after 200 cycles. In contrast, the undoped δ-MnO₂ showed an initial specific capacity of only 85.15 mAh·g⁻¹, with a capacity retention rate of merely 19.9% after 200 cycles. The results suggest that Fe³⁺ doping not only suppresses Mn dissolution but also improves structural stability and Zn²⁺ transport kinetics. This work provides new insights into the development of durable Mn-based cathode materials for aqueous ZIBs. Full article

Nb₂O₅ (niobia) coatings were prepared by spin coating of niobium sol, synthesized using niobium chloride as the precursor and ethanol and water as solvents, followed by high-temperature annealing. Doping of the films was achieved by incorporating commercially available SiO₂ (Ludox) and noble metal nanoparticles (NPs) into the sol prior to its deposition. Various sizes of Pt (5 and 30 nm), Ag (10, 20, and 40 nm), and Au (5, 10, and 20 nm) NPs were used to enhance sensing behavior of coatings. After annealing, films were subjected to chemical etching to remove the silica phase. This process generated porosity within the films, which in turn enabled the tailoring of both their optical and sensing properties. It was demonstrated that both the type and size of the incorporated nanoparticles significantly influenced the sensing behavior. The most effective enhancement was observed with the addition of 10 nm AuNPs. Optical characterization indicated that 10 nm AuNPs had a minimal effect on the optical properties. In contrast, doping with 20 nm AuNPs led to a reduction in the refractive index and an increase in Urbach energy. No significant alteration in the optical band gap due to doping was observed. Full article

The treatment of organic waste from dyes or other industry processes is a crucial issue that requires urgent attention. Photocatalysis is a promising method for tackling this problem, with ZnO being a commonly used photocatalyst material. This study compared the degrading efficiency of ZnO particles and ZnO-Ag composites by utilizing flame and spray pyrolysis techniques. Under UV light, methylene blue (MB) was used as a model organic waste. The generated particles were characterized using Brunauer–Emmett–Teller (BET) surface area, scanning electron microscopy (SEM), X-Ray diffraction (XRD), and a UV-Vis spectrometer. The findings showed that the ZnO and ZnO-Ag obtained using both methods exhibited hexagonal Wurtzite crystal structures, and there was no significant difference in the crystal sizes produced. SEM analysis indicated that the morphology of the resulting particles differed significantly, with flame-synthesized particles being remarkably smaller in size (one-thirtieth the size following spray synthesis) and having smoother surfaces. Furthermore, the addition of Ag particles to ZnO enhanced the MB degradation efficiency by two to three times, achieving a maximum of 64% at 75 min. The BET analysis showed that the surface area of ZnO doped with Ag was larger compared to that of pristine ZnO. On the other hand, the ZnO-Ag particles produced via spray pyrolysis exhibited a total pore volume (determined through nitrogen adsorption–desorption analysis) three times larger than that of the particles produced via the flame method. The particles produced via spray pyrolysis also had better MB degradation performance compared to those synthesized using flame pyrolysis. Full article

Background: Occlusion of plastic biliary stents is a common complication in biliary drainage, often requiring exchange procedures every 2–4 months due to microbial colonization and sludge formation. This study aimed to evaluate diamond-like carbon (DLC) coatings, with and without silver nanoparticle additives, for preventing stent occlusion. Methods: Polyethylene (PE) stents were coated with DLC using PlasmaImpax for DLC-1 and pulsed laser deposition for DLC-2. Silver ions (Ag) were incorporated into the DLC-2 coatings. To simulate in vivo conditions, a co-culture of Enterococcus faecalis (E. faecalis), Escherichia coli (E. coli), and Candida albicans (C. albicans) was used for microbial colonization. Standardized human bile simulated physiological conditions. Adhesion tests, weight measurements, and scanning electron microscopy (SEM) quantified bacterial adherence to stents. Results: DLC-1 coatings demonstrated higher bacterial growth than uncoated PE stents with E. faecalis (adhesion assay difference: 0.6 log [p = 0.19] and 0.1 log [p = 0.75] in rounds 1 and 2, respectively). In the bile incubation model, DLC-1 did not significantly reduce bacterial counts at 5 days (0.4 log [p = 0.06]) or 14 days (0.2 log [p = 0.44]). DLC-2 showed no significant reduction either. DLC-2-Ag significantly reduced bacterial adhesion (5 days: −0.3 log [p = 0.00]; 14 days: −0.4 log [p = 0.16]) and exhibited inhibition zones against E. faecalis (2.3 mm), E. coli (2.1 mm), and C. albicans (0.6 mm). SEM revealed cracks and flaking in the coating. Conclusions: DLC coatings alone did not prevent microbial adhesion. Tendencies of anti-adhesive properties were seen with Ag-doped DLC coatings, which were attributed to the antibacterial effects of Ag. Optimization of the DLC-coating process is needed to improve stent performance. Future studies with larger samples sizes are needed to confirm the observed trends. Full article

Inorganic halide perovskites have garnered significant attention as promising candidates for photovoltaic and optoelectronic applications, owing to their enhanced thermal and chemical stability relative to hybrid perovskite materials. This review synthesizes recent progress in vapor-phase deposition methodologies, such as co-evaporation, close space sublimation (CSS), continuous flash sublimation (CFS), and chemical vapor deposition (CVD), which enable the precise modulation of film composition and morphology. Advances in material systems, including the stabilization of CsPbI₂Br, the introduction of tin-doped phases, and the investigation of lead-free double perovskites like Cs₂AgSbI₆ and Cs₂AgBiCl₆, are critically evaluated with respect to their impact on device performance. The incorporation of these materials into photovoltaic devices and tandem configurations is explored, with particular emphasis on improvements in power conversion efficiency and operational durability. Furthermore, interface engineering approaches tailored to vacuum-deposited films—such as defect passivation and energy-level alignment—are examined in detail. The potential for scalable manufacturing is assessed through simulation analyses, throughput modeling, and pilot-scale demonstrations, underscoring the feasibility of industrial-scale production. By offering a comprehensive overview of these advancements, this review provides valuable perspectives on the current landscape and prospective trajectories of vapor-deposited inorganic perovskite technologies. Full article

We report the development of highly luminescent, bovine serum albumin (BSA)-stabilized gold–silver bimetallic nanoclusters (Au-AgNCs@BSA) as a novel platform for high-sensitivity, ratiometric intracellular temperature sensing. Precise and non-invasive temperature sensing at the nanoscale is crucial for applications ranging from intracellular thermogenesis monitoring to localized hyperthermia therapies. Traditional luminescent thermometric platforms often suffer from limitations such as high cytotoxicity and low photostability. Here, we synthesized Au-AgNCs@BSA via a one-pot aqueous reaction, achieving significantly enhanced photoluminescence quantum yields (PL QYs, up to 18%) and superior thermal responsiveness compared to monometallic counterparts. The dual-emissive Au-AgNCs@BSA exhibit a linear ratiometric fluorescence response to temperature fluctuations within the physiological range (20–50 °C), enabling accurate and concentration-independent thermometry in live cells. Time-resolved PL and Arrhenius analyses reveal two distinct emissive states and a high thermal activation energy (E_a = 199 meV), indicating strong temperature dependence. Silver doping increases radiative decay rates while maintaining low non-radiative losses, thus amplifying fluorescence intensity and thermal sensitivity. Owing to their small size, excellent photostability, and low cytotoxicity, these nanoclusters were applied to non-invasive intracellular temperature mapping, presenting a promising luminescent nanothermometer for real-time cellular thermogenesis monitoring and advanced bioimaging applications. Full article

The inferior electrical conductivity and elevated hardness of AgSnO₂ electrical contact materials have impeded their development. To investigate the effects of Co, Bi, and La doping on the stability and electrical properties of AgSnO₂, this study established interfacial models of doped AgSnO₂ based on first-principles calculations initiated from the atomic structures of constituent materials, subsequently computing electronic structure parameters. The results indicate that doping effectively enhances the interfacial stability and bonding strength of AgSnO₂ and thereby predicted improved electrical contact performance. Doped SnO₂ powders were prepared experimentally using the sol–gel method, and AgSnO₂ contacts were fabricated using high-energy ball milling and powder metallurgy. Testing of wettability and electrical contact properties revealed reductions in arc energy, arcing time, contact resistance, and welding force post-doping. Three-dimensional profilometry and scanning electron microscopy (SEM) were employed to characterize electrical contact surfaces, elucidating the arc erosion mechanism of AgSnO₂ contact materials. Among the doped variants, La-doped electrical contact materials exhibited optimal performance (the lowest interfacial energy was 1.383 eV/Ų and wetting angle was 75.6°). The mutual validation of experiments and simulations confirms the feasibility of the theoretical calculation method. This study provides a novel theoretical method for enhancing the performance of AgSnO₂ electrical contact materials. Full article

Al/AgO seawater-activated batteries with high specific energy and high specific power are widely used at present. The AgO electrode determines the performance of the battery, with its active material utilization rate having a significant impact on the specific capacity, energy density and discharge capacity of the battery. Therefore, this study briefly introduces the structure and working principle of Al/AgO seawater-activated batteries. Starting from the AgO material itself, common preparation methods for such positive electrode materials—including sintered silver oxide electrodes, pressed silver oxide electrodes and thin-film silver oxide electrodes—are introduced, and the factors influencing their electrochemical performance are analyzed in depth. We elaborate on the relevant research progress regarding AgO electrodes in terms of improving battery performance, detailing the effects of the silver powder’s morphology, porosity, purity, ordered structure, surface treatment and doping modification methods on silver oxide electrodes. Finally, various methods for improving the electrochemical performance of silver oxide electrodes are detailed. Current challenges and possible future research directions are analyzed, and prospects for the future development of high-specific-energy batteries based on AgO electrode materials are discussed. Overall, this review highlights the characteristics of Al/AgO batteries, providing a theoretical basis for the development of high-performance Al/AgO batteries. Full article