Applied Surface Science Advances最新文献

Electrochemical oxidation is a low-toxicity, fast-reacting technology that is easy to employ. This technology has great promise for improving the sustainability and efficiency of wastewater treatment by eliminating dyes and other organic contaminants. In this study, a cathodic electrodeposition technique was used to effectively synthesize pure Cu-MOF on a Pt electrode. Fourier-Transform Infrared Spectroscopy (FTIR), Ultraviolet -Visible Spectroscopy (UV-Vis), Scanning Electron Microscopy (SEM), Energy-Dispersive X-Ray (EDX), and X-Ray Diffraction (XRD) were used to evaluate the synthesized Copper-Metal Organic Framework (Cu-MOF). The electrochemical degradation of tartrazine dye in an aqueous KCl solution under various conditions was used to evaluate the electrochemical efficiency of the Cu-MOF/Pt electrode. Tartrazine (Tz) degradation as a function of time has been adjusted for the influence of operational parameters such as the type of supporting electrolyte, pH of the solution, accumulation time, and applied potential. Based on the results, the acid medium (pH=3) was the most beneficial medium for the active degradation of Tz dye at optimal operating conditions. It was found that 99 % of the dye had disappeared following 20 min of electrolysis. The optimal potential for the degradation of Tz was 1.4 V of the applied potential since it has no negative impacts on the energy consumption or stability and durability of the electrodes. The Tz degradation was fitted to pseudo-first-order kinetics with a rate constant of 0.124 min^-1. The findings demonstrated that Cu-MOF/Pt has a good electrochemical efficiency of 99 %, and the electrode recovery, reproducibility, and reusability have all been researched. A computational investigation used the Lee/Yang/Parr (B3LYP) level, 6-311++ G(d,p), as the basis for function set calculation to demonstrate the electrochemical destruction of Tz by the HClO radical. The results showed that the experimentally predicted mechanism and the theoretically determined mechanism agreed remarkably well. According to the proposed mechanism, Cu-MOF functions as a catalyst in the degradation of Tz, where it discharges water to produce HO^• radicals, which are physically adsorbed on the Cu-MOF/Pt surface. Cu-MOF(HO^•) combines with Cl⁻ ions presence in water to form Cu-MOF(HClO) which attacks Tz dye in the azo bond (–N=N–) and degrades it into CO₂ and H₂O.

Aluminium alloy 6063 was subjected to two different surface treatments: anodizing in sulphuric acid (SA) and the deposition of cerium conversion coatings (CeCC), in order to evaluate the antibacterial properties of the new surfaces. The microstructure and composition of the anodized samples and the cerium conversion coatings were characterized by scanning electron microscopy, energy dispersive spectrometry (SEM/EDS) and X-ray Photoemission Spectroscopy (XPS). Roughness and wettability were measured for all new surfaces. Bacterial adherence studies were carried out using Pseudomonas aeruginosa, with promising results for the anodized samples.

Molybdenum nitride-based composites, specifically the two-dimensional MoN/Mo₂N variants, emerge as promising electrode materials for next-generation energy storage devices. This research presents a facile synthesis approach involving a mechanochemical method followed by heat treatment at 900 ֯C in a nitrogen atmosphere to produce the MoN/Mo₂N composite material. Crystallographic analysis using X-ray diffraction (XRD) and morphological characterization via high-resolution scanning electron microscopy (HRSEM) were conducted. The electrochemical evaluation demonstrated remarkable supercapacitor performance, with a specific capacitance of 306.7 F/g at 1 A/g, highlighting exceptional charge storage capacity. Even at a higher current density of 2 A/g, the composite maintained substantial reversible capacity (198.6 F/g), higher capacitance retention (95.7 %), and Coulombic efficiency (86.2 %) over 6000 cycles, showcasing its robust stability. At a challenging current density of 10 A/g, the specific capacitance remained high at 85.4 F/g. Detailed charge storage mechanism analysis, employing the Dunn method, revealed a complex interplay of capacitive and diffusive processes. Particularly noteworthy was the predominance of capacitive behavior, constituting 78.4 % at an accelerated scan rate of 100 mV/s. This observation underscores the material's advantageous propensity for a higher proportion of capacitive behavior in the charge storage mechanism at elevated scan rates, making it well-suited for applications requiring rapid energy storage and release.

Modification of the structural features of activated charcoal by KOH-mediated heat treatment is reported. Improved adsorption of rhodamine B (RhB) and methyl orange (MO) is observed, which is dependent on the KOH/precursor ratio. At the optimum ratio of 2:1, the removal of RhB is (92 ± 2)% and that of MO is (82 ± 1)% in 15 min. The influence of contact time, adsorbent dose, adsorbate concentration and temperature on the adsorption are analyzed. The kinetics and equilibrium studies are also carried out. The process follows pseudo-second-order kinetics for both the dyes. The Langmuir isotherm results in the best linear fit with a monolayer adsorption capacity of 312.5 mg g^-1 in the case of RhB adsorption and 188.7 mg g^-1 for MO adsorption. Thermodynamic studies reveal the predominance of chemisorption in the removal of RhB, whereas in the case of MO, physisorption is favoured. The versatility in removing various organic dyes is evident from the ∼100% removal of methylene blue (MB), malachite green (MG), crystal violet (CV) dyes as well as a 1:1 mixture of RhB and MO. The structure and chemical composition before and after activation is analyzed. The activation results in a significant improvement in specific surface area from 787.9 to 975.4 m² g^-1 and an enhancement in the number of nanopores. The mechanism of adsorption is discussed in terms of the improved specific surface area, surface functionalization and the resultant adsorbent-adsorbate interactions.

Creatinine is the by-product of creatine phosphate within the muscle, supplying energy to the muscle tissues. It is imperative to clinically assess creatinine levels in both urine and blood as it serves as an indicator of renal, muscle, and thyroid functionality. The point-of-care medical diagnostic research and development is the most innovative form of exploratory research. The determination of creatinine can be achieved through several traditional methods such as colorimetric, spectrophotometric and chromatographic techniques. Although these method offers high sensitivity and selectivity, they are accompanied by drawback such as long analysis time, the need for sample pre-treatment, expensive instruments and skilled personnel. In contrast, sensors and biosensors present a favourable solution to these limitations as they offer rapid, user-friendly, cost effective and highly sensitive alternatives. This review article describe recent trends in creatinine detection by using electrochemical and optical biosensors, advantages and disadvantages of biosensors. This review highlights the wide detection range of creatinine and explore the commercialization aspects of biosensors with in home monitoring system.

This study explores the optimization of deposition parameters for CuI thin films, and investigates their potential application as photocatalysts. γ-CuI thin films were grown on glass substrate using the nebulized spray method at different substrate temperatures. Structural, morphological, and optical studies of the films were carried out. The substrate temperature was found to have a profound influence in determining the aforesaid properties of the films. As seen from scanning electron micrographs, the morphology of the films varied from discontinuous to uniform, and then to being agglomerated, when substrate temperature was increased from 50 °C to 175 °C. At the same time, it was observed from x-ray diffraction studies that films with better crystallite size was formed at lower temperatures. To obtain films with good crystallinity as well as continuous morphology, multiple spraying was carried out which involve repeating the deposition process manifold on the same substrate. Systematic characterization showed that multiple spraying at low temperatures resulted in uniform films with good crystallinity. The photocatalytic activity of single, double and triple sprayed CuI thin films prepared by nebulized spray method under visible light irradiation was also investigated. All of the films exhibited photocatalytic activity in the visible spectral region, with the triple-sprayed CuI thin film exhibiting the greatest efficiency in the photocatalytic degradation of Methylene blue.

In this study, phase-transited lysozyme (PTL) induced Ca₁₀(PO₄)₆(OH)₂ (PTL-HA) coating was applied to the 3D-printed titanium surface for improving bioactivity. The morphology and phase of the coating were analyzed by EDS, SEM, XRD, and XPS, while biocompatibility was investigated in vitro. The observation from SEM showed that a uniform coating with the presence of spheric-like and plate-shaped crystals was covered on the titanium. The main composition of the coating was Ca₁₀(PO₄)₆(OH)₂. More importantly, the in vitro results showed the PTL-HA coating could upregulate the expression of osteogenic-related genes. Therefore, it is considered that the phase-transited lysozyme-induced hydroxyapatite film was a promising, rapid, low-cost, and green route to improve the bioactivity of a bone implant.

Despite numerous tutorials and standards written to the technical community on X-ray photoelectron spectroscopy (XPS), difficulties with data acquisition, analysis, and reporting persist. This work focuses on common errors in XPS that are frequently observed in the scientific literature and their sources. Indeed, this work covers: (i) XPS data collection, initial data analysis, and data presentation, (ii) Handling XPS backgrounds, (iii) Common errors in XPS peak fitting, and (iv) XPS data presentation and reporting. Graphical examples of errors and appropriate ways of handling data and correcting errors are provided. Additional readings are listed for greater in-depth exploration of the subjects discussed.

In this study, we aimed to evaluate the characteristic changes in polyvinyl alcohol-based nanofibers after being stored with black sea salmon fillets. For this purpose, electrospun nanofibers were produced as control (PVA), black carrot extract-incorporated (PVAB), and extract+SnO₂ incorporated (PVASN), and their properties were compared. Morphological results showed the formation of regular ultrafine nanostructures, and differences between nanofiber samples were evaluated by measuring fiber diameters. Nanofiber sizes increased with the addition of black carrot and SnO₂. Elemental analysis was performed to obtain information about the concentration in the nanofibers. Different O and Sn concentrations indicated that important constituents of anthocyanins and SnO₂ were attached to the samples. The location of C, O, Sn atoms was determined by Energy Spectrum Analysis (EDS) color mapping, which confirmed the attachment of Sn in the PVASN sample. To elucidate the relationship between spoilage and the absorption of volatiles from smoked salmon fillets, nanofibers and fillets were kept together in a petri dish at room temperature. After being stored with salmon meat, the PVASN sample showed fewer entanglements without any defects. Upon exposure to volatiles, molecular structures changed, and water contact angle values decreased. X-Ray Diffraction (XRD) results indicated the state of the polymer matrix and SnO₂. Chemical bond interactions with released volatiles effected the peak parameters of nanofibers. 3D and 2D surface topographical images of PVASN were also compared before and after storage using a profilometer. This study's results showed that functionalized nanofibers with extract-SnO₂ could be applied as an intelligent food packaging layer, providing valuable data about the potential usage of electrohydrodynamic processing.

In this study, the corrosion response of the Al-Mg-Sc-Zr alloy produced by selective laser-melting in marine atmospheric environments with different Cl⁻ concentrations was studied by electrochemical and immersion. Microstructural observations showed the microstructural of Al-Mg- Sc -Zr alloy featured a double grain microstructure, making up a coarse and fine grain area. TEM showed that some white precipitates enriched with Zr and Sc were dispersed in the samples. The potentiodynamic polarization test indicated increasing the Cl⁻ concentration led to a negative shift of corrosion potential and narrowed the potential range of the passive zone, which also caused the increase of corrosion current density value. The electrochemical impedance spectroscopy showed that higher Cl⁻ concentration was greatly detrimental to generating a compact and dense oxide film on the Al-Mg-Sc-Zr alloys, as indicated by decreasing the resistance of the corrosion product layer and charge transfer resistance. The immersion test demonstrated that the samples suffered serious pit corrosion when the Cl⁻ content increased to 1.5 and 3.5 wt%, showing a larger size and more depth of corrosion pits. This study is expected to provide data to determine the reliability of the SLM-manufactured Al-Mg-Sc-Zr alloy in marine atmospheric conditions.