Search

Co/B co‐doped ZnO nanoparticles, denoted as Zn0.95‐xBxCo0.05O, are synthesized using the sol–gel method to explore the effects of the defects on optical properties. The stoichiometry is adjusted by varying the doping levels (x = 0.00, 0.01, 0.02, 0.03, 0.04, and 0.05). X‐ray diffraction is employed to analyze the structural characteristics of all Co/B co‐doped ZnO nanoparticles, confirming the presence of a hexagonal Wurtzite structure by assessing the c/a ratios. To investigate structural defects, photoluminescence properties are measured using the Fluorescence Spectrophotometer, revealing violet, blue, green, and red emissions. With the doped of boron (B), a shift from green emission to blue emission occurs, indicating a transformation of singly charged oxygen vacancies (VO+) to VZn vacancies. Fourier Transform Infrared (FTIR) spectra (4000–400 cm−1) are acquired using the Perkin Elmer Spectrum Two FTIR‐ATR spectrophotometer. The surface morphology, crystallite size, and nanoparticle shapes are characterized through Transmission Electron Microscope (TEM) analysis. Elemental compositions are determined using Electron Dispersive Spectroscopy (EDAX). The Shimadzu 2600 UV‐Spectrophotometer is used to examine optical characteristics. The samples' energy band gaps are calculated, and the impact of dopant elements on these optical characteristics is examined. Five different models are used to compute the refractive index. [ABSTRACT FROM AUTHOR]

Purpose: Wound healing disorders caused by bacterial infections in dental surgery, especially where membranes are used, are a common issue in oral surgery. Cold atmospheric plasma (CAP) offers a non-invasive solution for surface decontamination, including dental implants. The aim of this study was to evaluate the antibacterial effectiveness of CAP on various clinically applied membranes made of collagen and polytetrafluoroethylene (PTFE)., Materials and Methods: To assess the antibacterial properties of CAP, enterococcus faecalis were seeded on different membranes: Memlock (collagen), Memlock Pliable (collagen), Agronaut (collagen), and PermaPro (PTFE); n = 4. After in vitro cultivation for 6 days, CAP using a kINPen ® MED with an output of 5 W was applied 5 min and 10 min. Bacterial colony-forming units (CFU) were quantified to detect decontamination effectiveness. In addition, live and dead staining as well as scanning electron microscopy (SEM) of membranes was performed for validation and surface texture analysis., Results: Bacterial colonization was highest on collagen-based membranes (CFU Memlock: 14.38 ± 8.91). The results showed that CAP significantly reduced bacterial colonization on all membrane types after 10 min application of CAP; Memlock (CFU after 10 min 0.22 ± 0.16^10 6 ; p = 0.0256), Argonaut (CFU after 10 min 0.02 ± 0.01^10 6 ; p = 0.0129) and PermaPro (complete bacterial decontamination; p = 0.0058). This was paralleled by fluorescence and scanning electron microscopy. CAP was most effective on smooth membrane surfaces as SEM revealed., Conclusion: CAP thus offers a non-invasive, cost-effective method to reduce bacterial infections in guided bone regeneration using membranes., Competing Interests: Declarations Ethics approval and consent to participate Not applicable. Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Titanium dioxide is well-known for its excellent photocatalytic properties. UV-controlled photodeposition of gold on TiO 2 is achieved by photocatalytic reduction of precursor ions from a tetrachloroauric solution. During the growth process on the surface, clusters grow from nucleation centers and coalescence is observed for sufficiently long UV illumination times, resulting in gold structures with complex shapes. Here, we hypothesize and demonstrate that the growth process is altered by employing an ITO sublayer below the TiO 2 layer. Photocatalytic gold growth experiments on a microstructured thin film stack of 6 nm ITO and 70 nm TiO 2 lead to strongly localized gold growth along the edge of the patterned area. A conductive gold line with a height of 3.8 μm is achieved along the edge of the TiO 2 -coated region, while gold growth on the surface of TiO 2 is effectively suppressed. For substrates coated only with ITO or TiO 2 , no edge growth is observed. Furthermore, for an 845 nm thick TiO 2 layer, either with or without ITO sublayer, gold growth on the TiO 2 surface is dominant. Thus, for the effective steering of electrons to the edge, both the ITO sublayer and a sufficiently thin TiO 2 layer are necessary. This modified method of photocatalytic deposition─electrons photogeneration in a thin layer, collection in a dedicated conductive sublayer, and growth by reduction at a different position─opens opportunities for localized material deposition. We are in particular aiming at extending the toolbox of neuromorphic engineering by providing a technical implementation of stimulus-controlled dynamic formation of directional conductive interlinks.

In recent years, defective TiO 2 has caught considerable research attention because of its potential to overcome the limits of low visible light absorption and fast charge recombination present in pristine TiO 2 photocatalysts. Among the different synthesis conditions for defective TiO 2 , ambient pressure hydrogenation with the addition of Ar as inert gas for safety purposes has been established as an easy method to realize the process. Whether the Ar gas might still influence the resulting photocatalytic properties and defective surface layer remains an open question. Here, we reveal that the gas flow ratio between H 2 and Ar has a crucial impact on the defective structure as well as the photocatalyic activity of TiO 2 . In particular, transmission electron microscopy (TEM) in combination with electron energy loss spectroscopy (EELS) revealed a larger width of the defective surface layer when using a H 2 /Ar (50 %-50 %) gas mixture over pure H 2 . A possible reason could be the increase in dynamic viscosity of the gas mixture when Ar is added. Additionally, photoinduced enhanced Raman spectroscopy (PIERS) is implemented as a complementary approach to investigate the dynamics of the defective structures under ambient conditions which cannot be effortlessly realized by vacuum techniques like TEM., (© 2024 The Authors. ChemSusChem published by Wiley-VCH GmbH.)

Designing an efficient, durable, and inexpensive bifunctional electrocatalyst toward oxygen evolution reactions (OER) and oxygen reduction reactions (ORR) remains a significant challenge for the development of rechargeable zinc-air batteries (ZABs). The generation of oxygen vacancies plays a vital role in modifying the surface properties of transition-metal-oxides (TMOs) and thus optimizing their electrocatalytic performances. Herein, a H 2 /Ar plasma is employed to generate abundant oxygen vacancies at the surfaces of NiCo 2 O 4 nanowires. Compared with the Ar plasma, the H 2 /Ar plasma generated more oxygen vacancies at the catalyst surface owing to the synergic effect of the Ar-related ions and H-radicals in the plasma. As a result, the NiCo 2 O 4 catalyst treated for 7.5 min in H 2 /Ar plasma exhibited the best bifunctional electrocatalytic activities and its gap potential between E j = 10 for OER and E 1/2 for ORR is even smaller than that of the noble-metal-based catalyst. In situ electrochemical experiments are also conducted to reveal the proposed mechanisms for the enhanced electrocatalytic performance. The rechargeable ZABs, when equipped with cathodes utilizing the aforementioned catalyst, achieved an outstanding charge-discharge gap, as well as superior cycling stability, outperforming batteries employing noble-metal catalyst counterparts., (© 2024 The Authors. Small published by Wiley‐VCH GmbH.)

Noble metal/semiconductor nanocomposites have been synthesized using various methods, including precipitation and hydrothermal and electrochemical processes. Among these, the photodeposition method stands out for its simplicity, without the need for high temperatures, redox agents, or complex steps. This method facilitates the control over noble metal nanoparticle size by adjusting parameters such as metal precursor concentration, irradiation time, and power. However, understanding the interaction between solid and liquid interfaces, particularly the role of solution viscosity in the growth process, remains a challenge. This knowledge is crucial for precise control over nanoparticle size and distribution. Our study highlights the influence of viscosity, manipulated through different alcohols, on the formation of Ag nanostructures on TiO 2 thin films via photodeposition, offering insights into optimizing nanocomposite synthesis., Competing Interests: The author declares no conflicts of interest.

The reconstruction of bony defects in the alveolar crest poses challenges in dental practice. Guided tissue regeneration (GTR) and guided bone regeneration (GBR) procedures utilize barriers to promote bone regeneration and prevent epithelial growth. This study focuses on evaluating the antibacterial properties of marine algae-polylactic acid (PLA) composite membranes compared to commercially available collagen membranes. Marine algae (Corallina elongata, Galaxaura oblongata, Cystoseira compressa, Saragassum vulgare, and Stypopodium schimperi) were processed into powders and blended with PLA to fabricate composite membranes. Cytocompatibility assays using human periodontal ligament fibroblasts (n = 3) were performed to evaluate biocompatibility. Antibacterial effects were assessed through colony-forming units (CFU) and scanning electron microscopy (SEM) analysis of bacterial colonization on the membranes. The cytocompatibility assays demonstrated suitable biocompatibility of all marine algae-PLA composite membranes with human periodontal ligament fibroblasts. Antibacterial assessment revealed that Sargassum vulgare-PLA membranes exhibited the highest resistance to bacterial colonization, followed by Galaxaura oblongata-PLA and Cystoseira compressa-PLA membranes. SEM analysis confirmed these findings and revealed smooth surface textures for the marine algae-PLA membranes compared to the fibrous and porous structures of collagen membranes. Marine algae-PLA composite membranes show promising antibacterial properties and cytocompatibility for guided bone and tissue regeneration applications. Sargassum vulgare-PLA membranes demonstrated the highest resistance against bacterial colonization. These findings suggest that marine algae-PLA composite membranes could serve as effective biomaterials for infection control and tissue regeneration. Further in vivo validation and investigation of biodegradation properties are necessary to explore their clinical potential., (© 2024. The Author(s).)

Background cold atmospheric plasma (CAP) is known to be a surface-friendly yet antimicrobial and activating process for surfaces such as titanium. The aim of the present study was to describe the decontaminating effects of CAP on contaminated collagen membranes and their influence on the properties of this biomaterial in vitro. Material and Methods: A total of n = 18 Bio-Gide ® (Geistlich Biomaterials, Baden-Baden, Germany) membranes were examined. The intervention group was divided as follows: n = 6 membranes were treated for one minute, and n = 6 membranes were treated for five minutes with CAP using kINPen ® MED (neoplas tools GmbH, Greifswald, Germany) with an output of 5 W, respectively. A non-CAP-treated group ( n = 6) served as the control. The topographic alterations were evaluated via X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Afterward, the samples were contaminated with E. faecalis for 6 days, and colony-forming unit (CFU) counts and additional SEM analyses were performed. The CFUs increased with CAP treatment time in our analyses, but SEM showed that the surface of the membranes was essentially free from bacteria. However, the deeper layers showed remaining microbial conglomerates. Furthermore, we showed, via XPS analysis, that increasing the CAP time significantly enhances the carbon (carbonyl group) concentration, which also correlates negatively with the decontaminating effects of CAP. Conclusions: Reactive carbonyl groups offer a potential mechanism for inhibiting the growth of E. faecalis on collagen membranes after cold atmospheric plasma treatment.

Here, a 4N-in-1 hybrid substrate concept (nanocolumnar structures, nanocrack network, nanoscale mixed oxide phases, and nanometallic structures) for ultra-sensitive and reliable photo-induced-enhanced Raman spectroscopy (PIERS), is proposed. The use of the 4N-in-1 hybrid substrate leads to an ≈50-fold enhancement over the normal surface-enhanced Raman spectroscopy, which is recorded as the highest PIERS enhancement to date. In addition to an improved Raman signal, the 4N-in-1 hybrid substrate provides a high detection sensitivity which may be attributed to the activation possibility at extremely low UV irradiation dosage and prolonged relaxation time (long measurement time). Moreover, the 4N-in-1 hybrid substrate exhibits a superior photocatalytic degradation performance of analytes, allowing its reuse at least 18 times without any loss of PIERS activity. The use of the 4N-in-1 concept can be adapted to biomedicine, forensic, and security fields easily., (© 2022 The Authors. Small published by Wiley-VCH GmbH.)

Biodegradable collagen-based materials have been preferred as scaffolds and grafts for diverse clinical applications in density and orthopedy. Besides the advantages of using such bio-originated materials, the use of collagen matrices increases the risk of infection transmission through the cells or the tissues of the graft/scaffold. In addition, such collagen-based solutions are not counted as economically feasible approaches due to their high production cost. In recent years, incorporation of marine algae in synthetic polymers has been considered as an alternative method for preparation grafts/scaffolds since they represent abundant and cheap source of potential biopolymers. Current work aims to propose a novel composite patch prepared by blending Sargassum vulgare powders (SVP) to polylactide (PLA) as an alternative to the porcine-derived membranes. SVP-PLA composite patches were produced by using a modified solvent casting method. Following detailed material characterization to assess the cytocompatibility, human osteoblasts (HOBs) and osteosarcoma cells (SaOS-2) were seeded on neat PLA and SVP-PLA patches. MTT and BrdU assays indicated a greater cytocompatibility and higher proliferation for HOBs cultured on SVP-PLA composite than for those cultured on neat PLA. SaOS-2 cells cultured on SVP-PLA exhibited a significant decrease in cell proliferation. The composite patch described herein exhibits an antiproliferative effect against SaOS-2 cells without impairing HOBs' adhesion and proliferation.

The current study aimed to describe the fabrication of a composite patch by incorporating marine algae powders (MAPs) into poly-lactic acid (PLA) for bone tissue engineering. The prepared composite patch was functionalized with the co-polymer, poly (2-hydroxyethyl methacrylate-co-ethylene glycol dimethacrylate) (p(HEMA-co-EGDMA)) via initiated chemical vapor deposition (iCVD) to improve its wettability and overall biocompatibility. The iCVD functionalized MAP-PLA composite patch showed superior cell interaction of human osteoblasts. Following the surface functionalization by p(HEMA-co-EGDMA) via the iCVD technique, a highly hydrophilic patch was achieved without tailoring any morphological and structural properties. Moreover, the iCVD modified composite patch exhibited ideal cell adhesion for human osteoblasts, thus making the proposed patch suitable for potential biomedical applications including bone tissue engineering, especially in the fields of dentistry and orthopedy.

Titanium alloys are the most commonly used dental and orthopedic implant materials due to their proven biocompatibility and mechanical properties. The native oxide layer (TiO 2 layer) formed on such Ti-based implants acts as the self-protecting layer against possible ion release. Increasing the oxide layer thickness further on such TiO 2 implants even opens the triggering of the osseointegration process if the oxide layer is having a certain degree of roughness, preferably higher. This work reports a novel photocatalytic patterning of sputter deposited TiO 2 layers with flower-like Au structures to enhance the early osteoblastic activity. The prepared hierarchical Au structures, composed of micro- and nanoscale features on the top, lead to improved number of filopodia formation. This suggest that proposed Au-TiO 2 surface may foster the cell attachment and as well as cell proliferation., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Au nanoparticle (NP) decorated heterogeneous TiO 2 catalysts are known to be effective in the degradation of various organic pollutants. The photocatalytic performance of such Au-TiO 2 structures remarkably depends on the size, morphology, and surface coverage of the Au NPs decorating TiO 2 . Here we propose an effective way of preparing a highly active Au nanocluster (NC) decorated TiO 2 thin film by a novel photodeposition method. By altering the solvent type as well as the illumination time, we achieved well-controlled surface coverage of TiO 2 by Au NCs, which directly influences the photocatalytic performance. Here the Au NCs coverage affects both the electron store capacity and the optical absorption of the hybrid Au-TiO 2 system. At low surface coverage, 19.2-29.5%, the Au NCs seem to enhance significantly the optical adsorption of TiO 2 at UV wavelengths which therefore leads to a higher photocatalytic performance.

Thrombosis and bacterial infection are major problems in cardiovascular implants. Here we demonstrated that a superhydrophobic surface composed of poly(bis(2,2,2-trifluoroethoxy)phosphazene) (PTFEP)-Al 2 O 3 hybrid nanowires (NWs) is effective to reduce both platelet adhesion/activation and bacterial adherence/colonization. The proposed approach allows surface modification of cardiovascular implants which have 3D complex geometries., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

TiO 2 thin films are used extensively for a broad range of applications including environmental remediation, self-cleaning technologies (windows, building exteriors, and textiles), water splitting, antibacterial, and biomedical surfaces. While a broad range of methods such as wet-chemical synthesis techniques, chemical vapor deposition (CVD), and physical vapor deposition (PVD) have been developed for preparation of TiO 2 thin films, PVD techniques allow a good control of the homogeneity and thickness as well as provide a good film adhesion. On the other hand, the choice of the PVD technique enormously influences the photocatalytic performance of the TiO 2 layer to be deposited. Three important parameters play an important role on the photocatalytic performance of TiO 2 thin films: first, the different pathways in crystallization (nucleation and growth); second, anatase/rutile formation; and third, surface area at the interface to the reactants. This study aims to provide a review regarding some strategies developed by our research group in recent years to improve the photocatalytic performance of TiO 2 thin films. An innovative approach, which uses thermally induced nanocrack networks as an effective tool to enhance the photocatalytic performance of sputter deposited TiO 2 thin films, is presented. Plasmonic and non-plasmonic enhancement of photocatalytic performance by decorating TiO 2 thin films with metallic nanostructures are also briefly discussed by case studies. In addition to remediation applications, a new approach, which utilizes highly active photocatalytic TiO 2 thin film for micro- and nanostructuring, is also presented.

Morphology is a critical parameter for various thin film applications, influencing properties like wetting, catalytic performance and sensing efficiency. In this work, we report on the impact of oxygen partial flow on the morphology of ceramic thin films deposited by pulsed DC reactive magnetron sputtering. The influence of O 2 /Ar ratio was studied on three different model systems, namely Al 2 O 3 , CuO and TiO 2 . The availability of oxygen during reactive sputtering is a key parameter for a versatile tailoring of thin film morphology over a broad range of nanostructures. TiO 2 thin films with high photocatalytic performance (up to 95% conversion in 7 h) were prepared, exhibiting a network of nanoscopic cracks between columnar anatase structures. In contrast, amorphous thin films without such crack networks and with high resiliency to crystallization even up to 950 °C were obtained for Al 2 O 3 . Finally, we report on CuO thin films with well aligned crystalline nanocolumns and outstanding gas sensing performance for volatile organic compounds as well as hydrogen gas, showing gas responses up to 35% and fast response in the range of a few seconds.

In recent years, heterogeneous photocatalysis has gained enormous interest due to increasing concerns about environmental pollution. Here we propose a facile approach to synthesize cauliflower-like CeO 2 -TiO 2 hybrid structures by magnetron reactive sputtering, exhibiting an extremely high photocatalytic activity. While heating and air-quenching of the sputter deposited TiO 2 thin film (first layer) triggered the formation of a nanocrack network, the second heat-treatment led to transformation of the CeO 2 film (second layer) into CeO 2 nanoclusters (NCs). We attribute the resulting high photocatalytic activity to the confined structure of the CeO 2 NCs and the CeO 2 -TiO 2 interface, which allows Ce 3+ /Ce 4+ dynamic shifting. In addition to high photocatalytic activity in an aqueous medium, the prepared CeO 2 -TiO 2 hybrid structures exhibited significant self-cleaning properties in air (non-aqueous).