Applied Surface Science Advances最新文献

In this study, laser surface structuring (LSS) of Ti6Al4V was carried out using an Nd:YLF laser with a second harmonic wavelength of 527 nm and a pulse duration of 100 ns at varied laser fluence, scan speed, and line spacing. A detailed study of the effect of process parameters on surface topography, microstructure, composition, phase, contact angle, electrochemical behavior, and bioactivity was undertaken. Nanosecond pulsed laser irradiation with overlapping resulted in the formation of linear continuous grooves on the surface due to ablation/evaporation of materials. There is the formation of oxides of titanium (TiO₂ and Ti₂O₃) whose mass fractions varied with process parameters. The average microhardness of the laser-structured region was improved (393 VHN - 535 VHN) as compared to the as-received Ti6Al4V (303 VHN). The contact angle of simulated body fluid (SBF) against the structured surface (58°- 123°) showed increased contact angle as compared to as-received samples (50°). The laser surface structuring exhibited a superior corrosion resistance property (in SBF) as compared to as-received Ti6Al4V. The mechanism of corrosion behavior was established by electrochemical impedance spectroscopic study (in SBF). The optimum process parameter for the LSS of Ti6Al4V with enhanced hardness and corrosion resistance was derived. The LSS surface processed under the optimum parameters measured by immersing in SBF revealed a higher deposition of calcium phosphate as compared to the as-received Ti6Al4V.

Accessing the electromagnetic spectrum is the essence of modern warfare, which is determined by the detection direction, the airframe structure, and the material. Modern aviation equipment with a long strike range, penetration, and strong sensing and rapid decision-making capabilities is the key to capturing spectrum access. The development of penetration detection can promote the application of stealth materials/structures in next-generation aviation equipment, though the design of component-level stealth structures is constrained by aerodynamic efficiency, maneuverability, and preparation processes. Panel-level stealth material/structure design provides new avenues for the development of next-generation aviation equipment. This paper reviews the key advances and future challenges for stealth materials/structures. The main content focuses on the detection technology and application of stealth materials/structures in aviation equipment and the challenges posed by stealth materials/structures in terms of aviation equipment maintenance. Furthermore, this study addresses the opportunities and development tendencies of stealth materials/structures.

In this work, morphology-tuned tungsten oxide (m-tuned WO₃) thin films are deposited on a glass substrate by a simple and cost-effective chemical bath deposition (CBD) method. The deposition pH is varied to tune the physicochemical properties of m-tuned WO₃ thin films. The m-tuned WO₃ thin films show an orthorhombic crystal structure with a preferred orientation along the (020) plane. The morphological study demonstrated the conversion of ‘rice hull’ to ‘interlocked nanosheets’ to ‘reticulated nanosheets composed of nanorods’ upon changing pH, highlighting the significant role of pH in m-tuned WO₃ thin film synthesis. The m-tuned WO₃ thin films show good absorption in the visible-light region (390–780 nm) of the solar spectrum. The m-tuned WO₃ thin films are used for the visible light active photocatalytic degradation of organic molecules such as methylene blue (MB), rhodamine B (Rh B), and tetracycline hydrochloride (TC). The optimized m-tuned WO₃ thin film shows maximum photocatalytic performance of 95, 94, and 86 % in 180 min for MB, Rh B, and TC, respectively. The present study demonstrates the usefulness of the CBD method for the deposition of m-tuned WO₃ and improved photocatalytic performance.

Developing a photocatalyst for environmental remediation with extortionate visible light absorption capability and low reunion of photogenerated charge carriers is of tremendous interest. Considering this, the present work reports the fabrication of a low-cost and eco-friendly Fe-doped WO₃/BiVO₄ photocatalyst prepared by the facile one-step hydrothermal technique. The photocatalyst outperformed in the removal of rhodamine B dye than the pristine samples. The XRD and Raman spectroscopy analysis affirms the successful doping of the Fe cations within the WO₃ crystal structure. The absorption studies reveal the redshift to higher wavelengths which elucidates the enhancement of oxygen vacancy, and the band gap value changes are also apparent due to the heterojunction scheme of the photocatalyst. The time-resolved photoluminescence studies substantiate the effective reduction in the recombination rate with an average lifetime of 364 ns proving it to be an effective photocatalyst for the removal of rhodamine B dye. The catalyst revealed outstanding performance with 94.3 % removal of rhodamine B dye within 6 h. However, the removal efficiency was higher at pH 14 with a degradation of 92.6 % (100 min) corroborating that the influence of hydroxyl radical greatly facilitates a Fenton-like reaction that provokes the degradation process faster. It was further confirmed from the scavenging analysis that, with the addition of an H₂O₂ scavenger the degradation rate is fast due to the formation of hydroxyl radicals that emerged from the fusion of H₂O₂ with superoxide radicals. This outperformance validates the competency of the photocatalyst in the removal of organic pollutants.

The anti-corrosion effectiveness of novel 1‑butyl‑3-methylimidazolium tetrachloroindate ionic liquid ([C₄MIM][InCl₄] (IL)) for aluminum-silicon-titanium (Al-Si-Ti) based aluminum alloy in 1mole (M) potassium hydroxide (KOH) electrolyte at 303–343 K was explored in the current study. To realize this, standard methods such as weight loss, electrochemical investigation, density functional theory (DFT)/molecular dynamics simulation (MD-simulation), scanning electron microscope (SEM), and scanning force microscopy (SFM), were employed to scrutinize the anti-corrosion successfulness of [C₄MIM][InCl₄] for aluminum alloy in KOH solution. From our findings, the ionic liquid mitigated the corrosion of Al-Si-Ti aluminum alloy, and the inhibition efficiency (IE%) is enhanced with improved ionic liquid concentration. The inhibition efficiencies obtained at 0.8 g/L [C₄MIM][InCl₄] concentration were 88.46%, 82%, and 82.35%, for gravimetric, potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) procedures, respectively. PDP result disclosed [C₄MIM][InCl₄] performed like a mixed-type inhibitor of a cathodic predominance. The SEM/SFM examination proved that the ionic liquid developed a shield coat on the metal alloy surface. The thermodynamic probe disclosed [C₄MIM][InCl₄] molecules fastened onto Al-Si-Ti aluminum alloy surface by physisorption mechanism and best fitted the Frumkin adsorption isotherm model. The DFT/MD-simulation procedure confirmed the adsorption configuration and orientation of [C₄MIM][InCl₄] molecules in gas and aqueous phase which is in harmony with the experimental discovering. Simulated neural network (SNN), and the adaptive neuro-fuzzy inference system (ANFIS) were deployed for a robust training, forecast and modeling of the interactive effects of the input parameters and the expected feedback, Herein, training via the ANN and ANFIS designs without (GA), as well as computing the statistical indices such as the mean squared error (MSE), hybrid fractional error function (HYBRID%), absolute average relative error (AARE), Marquardt's percentage standard deviation (MPSED%) and r-squared (R²) were employed to appraise the models capability. The optimal IE% forecasted was 88.4842% and 89.0643%, for the ANN and ANFIS, respectively. Based on the numerical values of the ANN and ANFIS parameters calculated much acceptance was accorded to the ANFIS model over the ANN due its high degree of precision and robustness. The aftermath of this study furnishes additional information on systematic plan of corrosion mitigation, and proffer useful instructions for the logical use of [C₄MIM][InCl₄] as anti-corrosion additive for Al-Si-Ti aluminum alloy threatened by alkaline solution.

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.