Applied Surface Science Advances最新文献

Magnetic nanomaterials (MNMs) with metallic and semiconducting properties are useful in energy conversion, energy storage, environmental, biomedical, agricultural applications thanks to their large surface area, charge carrier mobility, optical band structure, non-toxic nature, and ability to recover and recycle. However, their poor stability, agglomeration, lack of biocompatibility, fast electron-hole recombination, and leaching in acidic environments restrict bare MNMs for real-time applications. There are several approaches employed to overcome these issues, such as elemental doping, defect formation, nanocomposites, and surface functionalization. Among them, functionalization is one of the promising techniques to alter various properties of MNMs such as specific morphology, size, facet, crystalline phase, and electron mobility. Functionalized MNMs have been explored for various areas of research, including biomedical and environmental applications such as MRI, drug delivery, catalysis, solar hydrogen production, sensors, water and air purification. In this short perspective, promising advances in various functionalization strategies such as surface modification, amino functionalization, polymer functionalization, and biomolecule functionalization, techniques were consolidated, reviewed and their various applications are discussed in detail.

In this work the interface between a Pt film and a Bi₂Se₃ (0001) surface is investigated using electron microscopy and microanalysis, in order to characterize the structure of the interface and verify if it is chemically stable or an interaction occurs. At room temperature, the Pt film is composed of small clusters (∼10 nm) and the interface is stable. However, already upon mild annealing (200 °C) the interface displays instability and forms an interfacial phase. The interfacial phase, not previously reported in literature, is a long-range ordered ternary Pt:Bi:Se phase aligned with the Bi₂Se₃ crystal, most probably an intermetallic compound. The presence of a new phase at Pt/Bi₂Se₃ interface, together with the possible effects on the topological surface states, has to be considered in all the applied studies where this interface is present, as well as in the models for theoretical studies.

In the present work, the corrosion inhibition of AA2024 by lithium salts (nitrate, oxalate and carbonate) is investigated by using both global and local electrochemical techniques. With LiNO₃ (0.1 M), the anodic and cathodic current densities are lower and the impedance values higher by comparison with the results obtained in the presence of 0.1 M Li₂C₂O₄ or 0.1 M Li₂CO₃. After 20 h of immersion in the electrolyte, SEM observations reveal the formation of thick films on the AA2024 surface in the presence of carbonate or oxalate, whereas a thin and denser film is formed in the presence of nitrate. Specifically, the Li₂C₂O₄ addition, by increasing the pH of the electrolyte, induces significant alloy dissolution from the very beginning of immersion which contributes to the growth of a protective layer on the alloy surface, combining lithium, carbonate species and metal cations.

A self-healing effect by Li₂C₂O₄ or Li₂CO₃ is shown by local impedance measurements on artificial scratches made on a water-based epoxy coating deposited on AA2024 plates, confirming their potential use, as inhibitive species, in organic coatings.

The development of electrocatalysts with high catalytic performance and low costs for oxygen reduction reaction (ORR) is still challenging. Herein, an overall solution for ORR in alkaline media, from the catalyst synthesis to catalyst regeneration and to the development of a rapid, reliable and easy approach for electrode surface evaluation, is presented. We focused on the development and characterization of an efficient material for ORR in alkaline media, α-Fe₂O₃ N-doped graphene (Fe-N-Gr). The associative pathway for the four electron transfer ORR mechanism is sustained by the Raman spectra recorded from the electrode surface. We highlighted the possibility of catalyst regeneration by a simple electrochemical method. After two regeneration rounds and 1500 cycles in O₂-saturated 1 M NaOH, the catalyst still retains 40.8 % catalytic activity. Finally, as a part of the overall solution, we demonstrated that a methodology based on Raman spectroscopic measurements and machine learning algorithms can be applied for graphene-based catalysts lifetime investigation.

Mg-based alloys are used in various industrial sectors due to the unique combination of mechanical and biomedical behaviors. However, they are challenging in terms of corrosion protection and do not produce a protective oxide layer on their surface. The unregulated corrosion rate of these alloys restricts their application. One of the strategies that can provide a protective coating that prevents the direct contact of corrosive media with the substrates is coating on magnesium and its alloys. In recent years, MOF‒MOF-containing coatings have been investigated as a means of protecting various metal alloys against corrosion. The results show that these inhibitors have significantly reduced the rate of metal dissolution by affecting the kinetics of electrochemical reactions and greatly increasing corrosion resistance. So, these coatings are useful for increasing the corrosion resistance of magnesium alloys. Also, the anti-corrosion mechanisms and performance of MOFs in the coating matrix are discussed accordingly. This review article attempts to highlight the importance of MOFs for coating applications and enhancing corrosion resistance.

The article discusses the function of green nanoparticles in preventing corrosion of different alloys such as copper, zinc, steel, and aluminium alloys. Green nanoparticles are characterized by their environmentally friendly and sustainable production methods, which emphasize using natural materials. Environmental issues have long been linked to traditional corrosion inhibitors, which has led to a shift towards more environmentally friendly alternatives. A potential remedy for these issues is the use of green nanoparticles, which are derived from renewable and biodegradable resources. Green nanoparticles support sustainability goals and have strong corrosion inhibition properties. Their combined role makes them essential players in a future where environmental awareness and material safety coexist. The review envisages a significant paradigm shift in critical industrial contexts, which calls for a robust and ecologically friendly approach to corrosion prevention. Green nanoparticles can potentially transform the field of materials protection entirely, and their investigation as corrosion inhibitors opens up new directions for study and development. In conclusion, this review highlights the crucial role of these nanoparticles in creating a sustainable future where creative solutions will enhance industrial productivity and environmental well-being. Finally, the prospects and difficulties of sustainably applying green nanoparticles to corrosion inhibition have also been explored.

Electropolishing or electrochemical polishing (EP) is an ultrafinishing process that improves esthetic, technical and functional properties of metallic surfaces by reducing their roughness. This process is based on anodic dissolution of the workpiece through an oxidation reaction. For many years, cyanide-based electrolytes were used to electropolish precious metals like gold and its alloys. The need for safer working conditions encouraged the replacement of cyanide by other complexing agents, mainly thiourea. However, the latter is also harmful. Therefore, the aim of this work is to electropolish pure gold and 18k jewelry gold alloys (yellow, rose, red and gray) in a cyanide-free electrolyte, to evaluate the electrochemical behavior and the influence of different parameters. For this purpose, a previously reported solution based on hydrochloric acid and glycerol was used. In the first part of the study, the influence of chloride concentration on pure gold EP was determined by electrochemical techniques and surface properties analysis. The effects of adding ethanol to electrolyte composition and of variating rotation speed were also evaluated. The best results were obtained for a HCl 50% vol. - Glycerol 25 % vol. - Ethanol 25 % vol. electrolyte at a rotation speed of 1000 rpm. In the second part of the study, this solution was used to electropolish 18 K gold alloys. Silver-containing alloys were not uniformly polished due to the formation of an AgCl film on the surface that partially masks the substrates.

Breast cancer poses a significant health concern due to its increasing prevalence and mortality rates. Hence, prompt action is needed to develop innovative therapeutic interventions, as conventional treatments exhibit severe adverse effects and have limited efficacy. This study aims to develop an innovative therapeutic intervention for breast cancer using biosynthesized nanoceria. Nanoceria has gained significant importance in the medicinal field due to its biocompatibility, dual capabilities as both antioxidant and prooxidant, and specific cytotoxicity towards cancer cells. Herein, nanoceria was biosynthesized using Echinochloa frumentaceae grain extract (EFNC) due to its eco-friendly and cost-efficient nature, and it was systematically investigated using standard characterization techniques. Furthermore, their anticancer efficacy against MCF-7 breast cancer cell lines was studied using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) cell viability assay, and the occurrence of apoptosis was determined using acridine orange/ethidium bromide (AO/EtBr) staining. Significantly, EFNC exhibited superior anticancer efficacy even at lower concentrations (10 µg/mL), and the IC₅₀ value was found at 47.32 µg/mL. In addition, the observed bright green and orange-red fluorescence, along with fragmented/condensed chromatin features in AO/EtBr staining clearly indicated that the EFNC caused cell death through the apoptotic route. One potential factor contributing to the observed anticancer effectiveness of EFNC could be its prooxidant properties within cancer cells. These properties ultimately enhanced oxidative stress, induced the accumulation of reactive oxygen species (ROS), and led to apoptosis. Hence, the in vitro analysis substantiated the significant anticancer efficacy of EFNC, suggesting its potential utility as a promising therapeutic agent in anticancer treatment. These findings pave the way for further exploration and development of EFNC as a valuable candidate for addressing cancer-related challenges.

This study presents a novel methodology for the rapid on-site detection of tannic acid (TA), a prevalent organic contaminant in various natural environments, notably in plant-derived sources. The proposed approach involves the development of a compact integrated electrochemical sensor incorporating a nanozyme system. Specifically, this system comprises Fe₂O₃ nanoparticles (NPs) embedded within a chitosan (CS) matrix, immobilized onto a sulfur-doped graphene (S-Gr) substrate deposited on a gold electrode (AuE). The Fe₂O₃NPs exhibit peroxidase-like artificial enzyme activity, contributing to exceptional stability and catalytic efficiency in TA oxidation processes. Additionally, the CS matrix acts as a stabilizing agent, enhancing the performance and recyclability of the nanozyme. Furthermore, the S-Gr nanomaterial facilitates rapid electron transfer, leading to heightened sensitivity and prompt response times. The integration of these advanced nanomaterials with a microfabricated electrode presents an economically feasible, reliable, and effective solution for TA detection, with promising prospects for large-scale deployment and environmental monitoring. The Fe₂O₃CS-S-Gr/AuE sensing system demonstrates a calculated limit of detection (LOD) of 3.6 × 10⁻³ µM and an increased sensitivity of 0.2 µA×µM⁻¹, with a wide linear concentration range spanning from 0.01 to 1000 µM for TA detection. Notably, the recovery values obtained for surface water samples fall within the range of 97.7 % to 99.5 %, indicating strong agreement with results derived from the standard method, UHPLC-MS/MS.

Wastewater remediation is a prominent concern that should be addressed, as it is a critical problem that damages natural resources and has a negative impact on living organisms. In this study, the synthesis of copper ferrite and silver doped-copper ferrite nanoparticles named CuFe₂O₄ and Ag_XCuFe₂O₄ using Monsonia burkeana (M. burkeana) as a fuel and their photocatalytic performance against the textile pollutant, Methylene blue (MB) and the pharmaceutical pollutant, sulfisoxazole (SSX) was reported. The physical, optical, spectroscopic, and surface analyses of the as-prepared nanoparticles were characterized using various techniques. XRD confirmed the crystalline structure of Ag-CuFe₂O₄ and the incorporation of silver on the surface of the nanoferrites. FTIR analysis indicated the formation of a single-phase spinel crystalline structure with two sub-lattices (T_d and O_h). UV–Vis absorption spectra of silver-substituted copper ferrite revealed that the band gap energy (E_g) decreased with increasing crystallite size. Upon testing their degradation efficiency, at pH 12, the highest degradation of 99 % after 60 min for the 7 % AgCuFe₂O₄ was reported, and the rate of the reaction was found to be 0.09769 min⁻¹. The 7 % Ag-CuFe₂O₄ catalyst could be reused more than 4 times with a minimal loss in photostability and the e⁻ and •O^2- were the primary species responsible for MB degradation. The photocatalyst 7 %Ag-CuFe₂O_4, showed a 60 % decomposition for the antibiotic after 120 min of UV-radiation. The 7 % Ag-CuFe₂O₄ photocatalyst displayed superior magnetic recovery capability under the action of the external magnetic field. These developments in this study offer wide promising applications in water environmental remediation.