Applied Surface Science Advances最新文献

Gallic acid (GA), an important phenolic component, is gaining popularity due to its biological and industrial applications. However, its rapid expansion can be hazardous, causing cancer and gene damage, making the design of a low-cost and fast GA sensor difficult. We used a single-step hydrothermal approach to synthesize MoS₂ nanoparticles for colorimetric detection of GA. The nanoparticles were analyzed using techniques like; UV–Vis spectroscopy, FT-IR spectroscopy, SEM, EDX and XRD. The optimization of key parameters such as MoS₂ concentration (2.0 mg), temperature (30 °C), and pH (7) resulted in a limit of detection (LOD) of 0.125 × 10⁻⁶ M with a dynamic range of 0.5 to 36 × 10⁻⁶ M. MoS₂ nanoflowers performed as nanozymes in the filter paper-based sensor, catalyzing 3, 3′, 5, 5′-tetramethylbenzidine (TMB) oxidation, while GA acted as an inhibitor to prevent further reaction progression. The detection was made feasible through capturing an image support by an ordinary smartphone and the steady-state kinetic study validated MoS₂ nanoflowers' affinity for sensing H₂O₂. The sensor performed well in real-world samples such as diet tea, green tea, water, blood serum, and urine, with recovery rates ranging from 93.2 % to 102.1 %. Density functional theory calculations were applied to provide an insight into GA-MoS₂ binding interactions and changes in electronic properties. With all of these merits, we believe MoS₂ nanoparticles can provide low-cost and portable filter paper-based strips as a sensing platform for visual assessment of GA.

The aim of this work was the preparation of an environmentally friendly protective coating on the AZ31B alloy using Flash plasma electrolytic oxidation (F-PEO) process. It was developed with different electrolyte compositions, that determine the morphology and properties of the coatings, this being crucial to understand the anti-corrosion properties. The incorporation of carbonate ions to the electrolyte proved to enhance the electrical response of the F-PEO process, resulting in a more efficient process with an energy reduced consumption of 1.1 kW h m⁻²μm⁻¹. Surface and cross-sectional morphology analysis of the coatings revealed the presence of isolated pores structure with small pore size (less than 1 µm) that delays the infiltration of aggressive ions towards the substrate. The characterisation by XRD, EDX and Raman spectroscopy showed the presence of amorphous carbonate and phosphate phases in the FPEO-CO layer, that provide a self-restauration effect through a dissolution/reprecipitation mechanism. The lowest value of the corrosion current density was obtained for FPEO-CO coating, 4.60 × 10⁻⁷ A·cm⁻², together with the highest impedance modulus (f<0.1 Hz), ⁓10⁴ Ω·cm², two orders of magnitude higher than the AZ31B Mg alloy. Furthermore, the corrosion protection properties of FPEO-CO coating were also analysed through an immersion test in 3.5 wt.% NaCl, confirming the excellent response of the coating for long times up to 336 h (2 weeks). The synergy between a more compact coating and the self-repairing ability of carbonate amorphous species plays a critical role in improving the corrosion resistance properties of the AZ31B Mg alloy, offering an eco-friendly alternative to chromate conversion coatings.

The continuous emergence of food additives and contaminants in edibles, especially confectioneries, demands advanced detection methods to ensure public health and safety. Vanillin (VAL) and sulfadiazine (SD) are of paramount concern due to their extensive application in various products. While VAL is favored for its flavoring attributes, SD, a common antibiotic, can inadvertently contaminate food items. For accurate and swift detection of these compounds, we introduced an innovative electrochemical sensor using cobalt oxide nanostructures. Notably, synthesizing these nanostructures through a green approach using glucose and starch is a significant advancement, offering both environmental benefits and enhanced material properties. The novelty of the material lies in its eco-friendly synthesis route and superior electrocatalytic performance. Preliminary results indicate a promising limit of detection (LOD) VAL= 0.003 µM & SD= 0.0055 µM and a broad linear range 0.02–209 µM emphasizing its potential for real-world food quality monitoring. This work, therefore, provides a crucial intersection of sustainable material synthesis and effective food contaminant detection, heralding a new era in food safety evaluation.

Exploration of blend polymer membrane with desire performances is a highly essential research topic because it makes them as key component of the battery technologies. However, the blend membrane cannot simultaneously meet out the high electrical insulation and ion conductivity. Here, we report porous PVdF-HFP based polymer membrane blended with P123 polymer which is prepared by phase inversion technique and along with solution casting technique for comparison. Especially, the major improvements can be claimed with porous PVdF-HFP blend with P123 matrix by phase inversion process that could be mainly due to increasing the disorganize crystallinity of the PVdF-HFP, thereby enhancing the ionic conductivity of PVdF-HFP/P123 than the same prepared by traditional solution casting. More importantly, our studies reveals that, besides having an effect of crystallinity and high ionic conduction PVdF-HFP/P123 blend matrix yield homogeneous pores with higher pore density when prepared by phase inversion approach. We attribute this to remarkable enhancement in higher electrolyte uptake and higher cation transport in the blend membrane. This facilitates high ionic conductivity of 7.06 × 10⁻⁵ S/cm and electrochemical stability of 2.8 V,while the solution casting approach display low ionic conductivity of 1.63 × 10⁻⁶ S/cm and electrochemical stability of 2.2 V, respectively. A symmetric supercapacitor device is fabricated with the membrane prepared by phase inversion process, resulting in a high specific capacitance of 80 F/g at the current density of 0.25 A/g with 90.51% specific capacitance retention at 0.5 A/g. The energy density of 90.9 W/kg can be achieved at the power density of 0.375 W/kg.

Recently there has been a growing fascination with two-dimensional (2D) materials, driven by their remarkable and distinctive characteristics. This paper introduces a straightforward, efficient, and affordable approach for producing Mo₂C@CNF nanocomposite electrodes by using the Electrospinning (E-Spun) technique and subsequent calcination process. The Mo₂C@CNF-1 and Mo₂C@CNF-2 are E-spun, iodized, and notably Mo₂C@CNF-2 is carried out by the ageing process. The purpose of the iodization and ageing process before carbonization is to create a stronger C=C backbone and to reduce carbon loss during the formation of carbon nanofiber. The physical properties of the sample were characterized using XRD, HRSEM, EDAX, HRTEM, XPS, and BET. Further, their electrochemical performance is comparatively studied for supercapacitor applications in three-electrode setups. The Mo₂C@CNF-2 exhibits a high specific capacitance of 873 F g⁻¹ with a coulombic efficiency of 88.4 % at 1 A g^-1 current density. Further studies on the electrochemical performance of symmetric Mo₂C@CNF-2 devices show 126 F g⁻¹ capacitance indicating its good electrochemical performance at 0.1 A g⁻¹. Furthermore, the charge storage kinetics studied for the Mo₂C@CNF-2 device, shed light on the insertion/de-insertion process of electrolytic ions being responsible for its excellent performance.

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.