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In this experimental study, diamond-reinforced Ni-P coatings were developed by flame and high-velocity air fuel (HVAF) spraying techniques using Ni-P capped diamond powder. Further, effect of heat-treatment on microstructure, structural, hardness and high temperature wear characteristics of the above coatings was investigated. After heat-treatment, high hardness was observed in HVAF coating compared to flame sprayed which is attributed to the high porosity of the latter as evident from the microstructure. Extensive diamond particle fragmentation was observed in the HVAF sprayed coating, providing motivation for including the lower velocity flame spraying in this work. It is interesting to note from the wear tests that coatings deposited by flame spraying exhibited superior wear resistance and low friction coefficient at high temperature, i.e., under dominated oxidative wear conditions, which is attributed to the soft matrix leading to diamond particles' exposure and graphitization. However, hard and dense heat-treated HVAF sprayed coatings exhibited highest wear resistance in room temperature tests dominated by abrasive wear mechanism as evident from the wear track morphology. Raman spectroscopy and energy dispersive spectroscopy analysis (EDS) confirmed the graphitization for the flame sprayed coatings and formation of oxides in the wear tracks. [ABSTRACT FROM AUTHOR]

The study explores innovative crosslinking processes for biopolymer gel materials using amino acids and ion-redox initiators to significantly enhance their structural and functional properties. Advanced analytical techniques, including FTIR, Raman spectroscopy, XRD, TEM, TGA, DSC, ToF-SIMS, SEM/EDS, GPC/SEC, and elemental analysis, were employed for comprehensive material characterization. The synthesized materials show potential applications in packaging and medicine, particularly for single-use products with short life cycles. Two crosslinking strategies were developed. The first combines gelatin with polyvinyl alcohol (PVA); keratin hydrolysate; and amino acids such as cysteine, hydroxyproline, proline, and histidine. The second employs endogenous cysteine, activated by ion-redox initiators, leveraging its trans-sulfuration ability to form highly stable polymer networks with optimized mechanical and thermal properties. Notably, the synergy between cysteine and potassium persulfate redox initiators proved particularly effective, making this approach attractive for industrial applications. This study introduces novel crosslinking methods and highlights the potential of amino acid-based strategies for designing advanced biopolymer gels with enhanced properties. [ABSTRACT FROM AUTHOR]

This investigation aimed to explore the characteristics of reduced graphene oxide (rGO) through a comprehensive approach. The synthesis of graphene oxide (GO) began with a customized adaptation of the modified Hummer's method, followed by subsequent chemical and thermal reduction processes. Chemical reduction involved the use of ascorbic acid, hydrazine hydrate, and sodium borohydride, while thermal reduction occurred at various temperatures in the presence of hydrogen. The study employed a diverse array of analytical techniques to unravel the structural and chemical intricacies of the material. X-ray diffraction (XRD) revealed significant changes indicative of structural transformations. Raman spectroscopy meticulously examined defects and layer formations. Scanning Electron Microscopy (SEM) visualized the evolutionary aspects of the material's structure. UV–VIS spectroscopy is employed to analyze the optical bandgap of the sample, and the primary importance of this study lies in its application potential for solar cells. [ABSTRACT FROM AUTHOR]

Background and Objectives Microplastics, which originate from the breakdown of larger plastic fragments or are intentionally produced for industrial applications, pose significant human and ecological risks through inhalation, ingestion, and dermal contact. Our study examined the release of microplastics during the preparation of homemade saline solutions, specifically when tearing open powder packets and mixing the powder with water. Methods We used commercially available polypropylene nasal irrigation bottles from the Korean market and collected six samples of nasal irrigation fluids. The samples were categorized into two groups: the control group comprised three samples, without sodium chloride powder, while the powder-added group consisted of three experimental samples, where a sachet of sodium chloride powder was mixed into the water to achieve a 0.9% sodium chloride concentration. The preparation involved cooling boiled water before mixing in the powder sachet. A Raman XploRA Plus confocal microscope was used for the detection and analysis of microplastics. Results We observed 17, 56, and 26 microplastic particles in the control group samples, with a mean of 33.00±20.42, and 7, 6, and 34 microplastic particles in the powder-added group, with a mean of 15.66±15.88. There was no significant difference in microplastic content between the groups. Analysis revealed that the control samples contained 66 fragments (67%) and 33 fibers (33%), while the powder-added samples contained 45 fragments (96%) and two fibers (4%). We identified three types of polymers: polypropylene (control: 96, powder-added: 41), polyethylene (control: 2, powder-added: 3), and polyethylene terephthalate (control: 1, powder-added: 3). Conclusion Our findings indicate that adding sodium chloride powder to nasal irrigation fluids does not significantly alter microplastic release, highlighting the importance of considering potential microplastic pollution from common medical devices.

The sensitive nonenzymatic sensing of glucose has been made feasible for the first time using a nonthermal plasma (NTP)-synthesized ZnO nanostructure. This work presents an interesting and novel method for surface modification. The effects of flow gas of Argon/Oxygen (20, 30 and 40 l/min) on the Zn foil surface and various properties were investigated. Optical emission spectroscopy OES has been used to characterize transmissions for positive and negative systems of Ar/O plasma. X-ray diffraction showed close adjacent tops and the strongest peak at Zn (101). EDX displays the constants (Ok_ α) , (Znk_ α) and (Znk_ β) and change in (ZnL_ α). Photoluminescence (PL) Analysis shows a shift at the vertex toward the left and then toward the right confirming the reaction of all PL spectra within a strong UV emission peak. Raman spectroscopy analysis demonstrates two clear peaks gradually shifting to the right with an increase in the percentage of gas flowing compared to the blank metal, and scanning electron microscopy (FE-SEM) images show changes in the shape of nanoparticles due to increasing gas flow, the surface of zinc metal is affected by cold plasma and forms particles with very small diameters ranging from 10.8 nm to 123 nm. Also altered the surface morphology where the nano shape changed from flower-like particles to sheets with diameters ranging 282.7–643.5 nm and the sheets grew with the increase of gas flow to diameters ranging 132–710 nm. ZnO nanostructures are employed as biosensor electrodes (nonenzymatic) glucose as the increase in current is proportional to the flowing gas (2.06E-03 mA, 2.09E-03 mA and 4.34E-03 mA). [ABSTRACT FROM AUTHOR]

As stacking technologies, such as 2.5D and 3D packages, continue to accelerate in advanced semiconductor components, the singulation and thinning of Si wafers are becoming increasingly critical. Despite their importance in producing thinner and more reliable Si chips, achieving high reliability remains a challenge, and comprehensive research on the effects of these processing techniques on Si chip integrity is lacking. In this study, the impacts of wafer thinning and singulation on the fracture strength of Si wafers were systematically compared. Three different grinding processes, namely fine grinding, poly-grinding, and polishing, were used for thinning, and the resulting surface morphology and roughness were analyzed using scanning electron microscopy and an interferometer. In addition, the residual mechanical stress on the wafer surface was measured using Raman spectroscopy. The fracture strength of Si wafers and chips was assessed through three-point bending tests. Singulation, including blade dicing, laser dicing, and stealth dicing, was evaluated for its impact on fracture strength. Among these processes, polishing for wafer thinning exhibited the lowest full-width half maximum and intensity ratio of Raman shifts (I480/I520), indicating minimal residual stress and surface defects. Consequently, Si wafers and chips processed through polishing demonstrated the highest fracture strength. Moreover, the 60 µm thick Si wafers and chips showed the highest fracture strength compared with those with thicknesses of 90 and 120 µm, possibly because of the increased flexibility, which mitigates stress. Among the singulation methods, stealth dicing yielded the highest fracture strength, outperforming blade and laser dicing. The combination of wafer thinning via polishing and singulation via stealth dicing presents an optimal solution for producing highly reliable Si chips for 2.5D and 3D packaging. These findings may be valuable in selecting optimal processing technologies for high-reliability Si chip production in industrial settings. [ABSTRACT FROM AUTHOR]

This work focuses on the study of the microstructure and magnetic properties of nanocrystalline powders of Sm4ZrFe33, prepared by high‐energy ball milling. The Sm4ZrFe33 compound adopts a monoclinic structure (space group Cm). Upon annealing, these Sm4ZrFe33 samples exhibit notable variations in their extrinsic magnetic properties, closely linked to temperature fluctuations. The investigation delves into the correlation between morphology, grain size and magnetic characteristics. A significant enhancement in coercivity (Hc), remanent magnetization (Mr), and maximum energy product ((BH)max) is observed, primarily attributed to the finer grain structure present in the samples. Particularly noteworthy, among all annealed specimens, the nanocrystalline Sm4ZrFe33 compound annealed at a temperature of Ta = 973 K demonstrates the most promising magnetic properties. This specimen exhibits a coercivity Hc of 18 500 Oe, remanent magnetization (Mr) of 58 emu g−1, maximum energy product ((BH)max) of 5.18 MGOe, Curie temperature (TC) of ≈804 K, and magnetic anisotropy field (Ha) of 115 980 Oe. These research findings pave the way for future investigations and applications in the realm of permanent magnets, spintronic devices, and magnetic recording, utilizing nanocrystalline alloys based on the Sm4ZrFe33 compound. [ABSTRACT FROM AUTHOR]

Copper (Cu) is highly sought for its excellent electrical and thermal conductivity. However, its limited mechanical strength hinders its wider application in demanding fields. This work explores the potential of graphene nanoplatelets (GNPs) as a strengthening agent for Cu. Cu-GNP composites with varying GNP content (0.1–1.5 wt%) were fabricated using a combined ball milling and powder metallurgy approach. The microstructure and mechanical properties of the composites were comprehensively analyzed using field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Raman spectroscopy. Compared to pure Cu, the Cu-GNP composites showcased significantly improved mechanical performance. Notably, the Cu-1.0 wt% GNP composite exhibited a remarkable ∼27% and ∼53% enhancement in compressive strength and micro-hardness, respectively. This improvement is attributed to the effective load transfer between Cu and well-dispersed GNPs, which act as reinforcement elements and inhibit dislocation movement. These findings demonstrate the promising potential of Cu-GNP composites for applications requiring high strength.

Carbon nanotube-based nanocomposites are most encouraging materials in the field of gas sensing. The nanocomposites with transition metals boost various properties of functionalized multiwalled carbon nanotubes (FMWCNTs), thus making them more appropriate for sensing applications. In this work, copper sulfide (CuS) nanoparticles prepared via a hydrothermal route were mixed with FMWCNTs by using a facile sonication method. The effect of CuS content in FMWCNTs/CuS nanocomposites was investigated using various characterization techniques. X-ray diffraction elucidated the formation of CuS nanoparticles along with the decrease in crystallite size of the nanocomposite. The optical behavior of the synthesized nanocomposite was studied using photoluminescence spectroscopy, which revealed an increase in the lifetime of the nanocomposite with the increase in CuS content. The absorption analysis shows an increase in the value of the bandgap with an increase in wt% of CuS in the nanocomposites. Electrical studies examined by I–V analysis confirmed the conducting nature of all three samples. The results reveal that FWMCNTs/CuS could be a potential material for sensing applications. [ABSTRACT FROM AUTHOR]

Triple-layer heterostructure of ZnO/Ge/Si was considered for establishing photodetector devices by utilizing thermal evaporation and pulse laser deposition. The structural and optical properties were obtained using XRD, SEM, Raman spectroscopic and UV–visible spectroscopy. The XRD showed patterns of the Ge layer a closed-oriented crystalline structure and results showed that zinc oxide is polycrystalline in nature, with a cubic crystalline phase. The Raman spectroscopic investigation of Ge film the figure shows three separate peaks, In particulars are corresponded to Ge phase, E(TO + LO), A1(TO), E(TO)respectively and the Raman spectra of ZnO films showed E (LO), A (TO), E (LO) + TO, and B1 vibration modes. The optical bandgaps of Ge and ZnO nanostructures were found to be 2.8 for Ge and 3.3, 3.2, and 3.1 eV for ZNO thin film as laser pulses of 400, 500, 600 pulses respectively. The current–voltage characteristics of the ZnO/Ge/Si heterojunction deposited over 400, 500, and 600 pulses were examined in dark and illumination condition. Using more pulse lasers improved the photodetector performance and the figure of merit. When the deposition pulse was increased from 400 to 600 pulses, the responsivity increased from 8.867 to 13.229 µA/W. When the photodetector was produced at the ideal pulse count of 600 pulses, the detectivity (D*) and external quantum efficiency (EQE) were 5.77 × 1014 Jones and 40.505%, respectively, at 405 nm. [ABSTRACT FROM AUTHOR]

We report a two-step growth process of MoS2 nanoflakes using a low-pressure chemical vapor deposition technique. In the first step, a MoS2 layer was synthesized on a c-plane sapphire substrate. This layer was subsequently re-evaporated at a higher temperature to form mono- or few-layer MoS2 flakes. As a result, the close proximity re-evaporation enabled the growth of pristine MoS2 nanoflakes. Atomic force microscopy analysis confirmed the synthesis of nanoclusters/nanoflakes with lateral dimensions of over 10 μm and a flake height of approximately 1.3 nm, demonstrating bi-layer MoS2, whereas transmission electron microscopy analysis revealed triangular MoS2 nanoflakes, with a diffraction pattern proving the presence of single crystalline hexagonal MoS2. Raman data revealed the typical modes of high-quality MoS2 nanoflakes. Finally, we presented the photocurrent dependence of a MoS2-based photoresist under illumination with light-emitting diode of 405 nm wavelength. The measured current–voltage dependence across various luminous flux outlined the sensitivity of MoS2 to polarized light and thus opens further opportunities for applications in high-performance photodetectors with polarization sensitivity. [ABSTRACT FROM AUTHOR]

Water contamination resulting from the presence of organic dye pollutants in the ecosystem is a significant issue in the 21st century, that requires urgent resolution. Utilizing an effective nanocatalyst for the removal of dyes from water is a viable solution to address this problem. In this study, we proposed two distinct approaches for synthesizing δ-MnO2 nanostructures: an environmentally friendly, “green” method (MG) and a “cost-effective” hydrothermal method (MH). The leaf extract of Clinacanthus nutans was used for the preparation of MG, while MnSO4 was used for MH as a reducing agent, along with KMnO4, with the reaction time fixed at 90 °C. X-ray diffraction analysis confirmed that both approaches yielded δ-MnO2 nanostructures with a monoclinic Birnessite phase. The MG sample displayed a coagulated nanoflake-like morphology, as observed in FESEM images. On the other hand, the MH sample exhibited a distinct nanoflower morphology. The materials' optical properties were investigated using UV–visible spectra analysis, revealing direct bandgap energies of 2.2 eV and 2.58 eV for the MG and MH, respectively. The surface area of the MG sample was found to be higher as compared to the MH nanoflower, showcasing a mesoporous structure. XPS analysis was employed to determine the oxidation states of the elements. The effect of varying pH levels on the degradation of Methyl Orange dye by the two nanocatalysts was investigated. The results demonstrated that acidic pH led to higher decolouration efficiency, particularly notable for the MG nanocatalyst. Consequently, this study illustrates that the green δ-MnO2 nanocatalyst effectively degrades methyl orange dye under acidic conditions through photocatalysis.

The nature of structural changes of nanosecond laser modification inside silicon is investigated. Raman spectroscopy and transmission electron microscopy measurements of cross sections of the modified channels reveal highly localized crystal deformation. Raman spectroscopy measurements prove the existence of amorphous silicon inside nanosecond laser induced modifications, and the percentage of amorphous silicon is calculated based on the Raman spectrum. For the first time, the high-resolution transmission electron microscopy images directly show the appearance of amorphous silicon inside nanosecond laser induced modifications, which corroborates the indirect measurements from Raman spectroscopy. The laser modified channel consists of a small amount of amorphous silicon embedded in a disturbed crystal structure accompanied by strain. This finding may explain the origin of the positive refractive index change associated with the written channels that may serve as optical waveguides. [ABSTRACT FROM AUTHOR]

Surface structuring by ultrafast lasers is a promising technique to modify surface-related properties of materials to tailor them for specific applications. In the present study, we experimentally investigated the laser structuring of commercially pure titanium (CP Ti) using ultrafast pulses to understand the role of the laser input parameters on the development of surface morphology, optical properties, surface chemistry, and wettability behaviour. The processed surfaces were characterized by a scanning electron microscope, energy-dispersive X-ray spectroscopy (EDX), Raman microscope, optical microscope, and sessile drop method. Laser-induced periodic surface structures decorated with nanodroplets were noted to be formed on the surface of the laser-structured CP Ti. The surface roughness measurements showed that the laser-structured surfaces had nanoscale roughness values. The EDX and the Raman analyses show that laser-structured surfaces of CP Ti have a thin oxide film. Different colours on different surfaces processed by different laser parameters were observed. The wettability assessment shows that CP Ti can transition from hydrophilic–hydrophobic and vice versa depending on the environmental conditions. This study shows that laser structuring can be utilized to modify CP Ti surfaces to obtain desirable surface properties that can find potential applications in different fields. [ABSTRACT FROM AUTHOR]

The presence of microplastics in tidal sediments is a growing ecotoxicological concern for sea and benthic health. This investigation was designed to record and characterize the vertical prevalence of microplastics (MPs) in intertidal sediments of the Persian Gulf (around Bushehr city, Iran). Sediments of three depths (0-10 cm, 10-20 cm, and 20-30 cm) were sampled during low tide in six sites along the coastal zone of Bushehr, Iran. MP particles were found in all evaluated areas and sediment depths. The average abundance of MPs in all of the sediment samples was 117.96 ± 97.75 particles kg−1 dry sediment. No differences were found in the MPs number among the sites. The most dominant microplastics in surface sediments were 2-5 mm in size. In all areas, fibers and fragments were more abundant. Particles in higher depths (0-10 cm) were often colorless (white, and transparent). Raman spectroscopy indicated the presence of polystyrene, polyethylene, polyvinyl chloride, polyethylene terephthalate, and polypropylene in the samples. Further research is required to evaluate the possible interaction between MPs and layers of sediments. Waste management and proper wastewater disposal are critical to control MPs pollution in intertidal ecosystems around coastal cities.

Microbial diseases are believed to be a global health challenge. The evolution of carbon-based nanocomposites with antimicrobial properties has played a crucial feature in controlling the growth of microorganisms. By the way, the present investigation emphasizes a sustainable, harmless, cost-effective fabrication of CuO–MgO@rGO (CMG) nanocomposite. The phase structure, morphology, and stability of the fabricated CMG nanocomposite are implemented via precise standard systematic techniques like XRD, SEM, HR-TEM, and TG analyses. The crystallite size value of the prepared nanocomposite is enumerated to be about 18.82 nm. Electron microscopy evaluation corroborates that the CMG nanocomposite divulges the formation of wrinkled nanosheet-supported nanosphere-like morphology. The cytocompatibility of the CMG nanocomposite is assessed using RAW 264.7 cells. The nanocomposite exhibits over 80 % cell viability at a concentration of 10 μg/mL. [Display omitted] • CuO–MgO@rGO (CMG) nanocomposite prepared via co-precipitation method. • CMG exhibits rGO nanosheet-supported nanosphere-like morphology. • CMG displays a crystallite size value of 18.82 nm. • CMG exposes a cell viability value of >80 % at 10 μg/mL. [ABSTRACT FROM AUTHOR]

Surface enhanced Raman spectroscopy (SERS) is a powerful non-invasive technique to detect and identify molecule traces. The accurate identification of molecules is based on the detection of distinctive vibrational modes characteristic of a molecule adsorbed onto the surface. We investigated the detection performances of three commercial SERS substrates: nanostructured Au supports from Hamamatsu, Premium Ag–Au supports from SERSitive, and RAM–SERS–Au from Ocean Insight, which were tested with solutions of thiophenol (C6H6S) at 10–6 M and 10–8 M concentration. SERS measurements were performed systematically with 633 and 785 nm excitation wavelengths and Raman mappings were recorded randomly on the surfaces. The spectral quality (baseline intensity and signal-to-noise ratio), the thermal stability under laser illumination, and the Raman intensity distribution of the Hamamatsu substrate and our own fabricated gold substrate were discussed for the detection of 10–8 M thiophenol molecules. The detection of crystal violet (CV), a toxic dye, is demonstrated at 5.10–9 M. [ABSTRACT FROM AUTHOR]

Plant diseases pose a significant threat to plant and crop health, leading to reduced yields and economic losses. The traditional methods for diagnosing plant diseases are often invasive and time-consuming and may not always provide accurate results. In recent years, there has been growing interest in utilizing Raman microscopy as a non-invasive and label-free technique for plant disease diagnosis. Raman microscopy is a powerful analytical tool that can provide detailed molecular information about samples by analyzing the scattered light from a laser beam. This technique has the potential to revolutionize plant disease diagnosis by offering rapid and accurate detection of various plant pathogens, including bacteria and fungi. One of the key advantages of Raman microscopy/spectroscopy is its ability to provide real-time and in situ analyses of plant samples. By analyzing the unique spectral fingerprints of different pathogens, researchers can quickly identify the presence of specific diseases without the need for complex sample preparation or invasive procedures. This article discusses the development of a Raman microspectroscopy system for disease diagnosis that can accurately detect and identify various plant pathogens, such as bacteria and fungi.

Controlling the growth and selection of chiral inducers is crucial for the generation of chiral inorganic structures as observed in nature. Herein, the plasmonic chirality evolution from the Au cube seed under the presence of L‐ or D‐amino acid as a chiral inducer is reported. The 432 Helicoid I structure is obtained using tryptophan (Trp), identical to the result with cysteine (Cys). The use of tyrosine (Tyr) produced a Helicoid IV‐type structure. However, no distinctive chiral structures can be obtained using phenylalanine (Phe), valine (Val) and leucine (Leu), which indicates the critical role of amino acids in chirality evolution. In particular, Trp‐Helicoid I nanoparticles (NPs) showed excellent enantioselective response toward L‐ or D‐Cys in the colorimetric assay and Raman analysis in the presence of Trp. Furthermore, the chiroptical property with a nanogap of 23.78 ± 0.82 nm in the Helicoid I structure further expands its applications for highly sensitive and quantitative chiral analysis for small molecules such as R/S‐epichlorohydrin (ECH), R/S‐limonene (LM), and R/S‐2‐butanol (BuOH) using a non‐polarized light source. The finding of amino acid‐dependent chirality evolution can widen the current understanding of chirality evolution in nature, and the use of helicoid structures with nanogaps incorporated with surface‐enhanced Raman scattering (SERS) can open a new avenue for chiral spectroscopic analysis. [ABSTRACT FROM AUTHOR]

In the case of a two‐part container for spent nuclear fuel, consisting of an iron‐based inner structure with a copper coating, the potential perforation of copper through minor damage may result in intensive galvanic corrosion between copper and steel. The present work focuses on the corrosion of steel galvanically coupled to copper and exposed to a slightly saline environment under oxic conditions. The electrochemical processes on individual electrodes were monitored by coupled multielectrode arrays (CMEAs). The CMEAs were either in contact with groundwater saturated with bentonite or immersed in groundwater only. Very high galvanic corrosion currents were detected between carbon steel and pure copper in the early oxic phase. Additionally, the use of CMEAs further made it possible to monitor the distribution of cathodic currents around the steel electrode, which behaved anodically. Various microscopy and spectroscopy techniques were applied to identify the modes of corrosion and the type of corrosion products present at the end of the period of exposure. [ABSTRACT FROM AUTHOR]

The paper presents an analysis of SEM, EDX, Raman scattering, and FTIR of Gadolinium-doped multi-walled carbon nanotubes obtained by hydrothermal method. The morphological characteristics of the materials were studied and their compositions were analyzed. Hydrothermal doping of MWCNs with Gd causes the formation of 3D network architecture and sharply increases the content of oxygen surface functionality. An unidentified intense broad peak for Gd-doped material at 2940 cm-1 was observed. The defect state of Gd-doped MWCNTs was studied by Raman spectroscopy.

The iron-based ceramic GdFeAsO has been prepared by the solid-state reaction method. To identify the ceramic and its multiple applications we have performed structural, micro structural and electrical characterizations of the sample. The crystalline size and structure are calculated at room temperature using the X-ray Diffraction (XRD) technique. Tetragonal structure has been ensured from XRD. The lattice strain of the crystal is obtained using W.H. Plot, which ensured the structural stability of the crystal. The field emission scanning electron microscopy (FESEM) technique is used to study the surface morphology of the sample. Polycrystalline grains having spherical and cylindrical sizes of ranges 1-3 micrometer are obtained. The observed prominent peaks at 107.1cm−1,150.4cm−1,216.6cm−1,296.6cm−1,344.6cm−1 and 440.37cm−1 in the Raman spectra of the sample, are for the cubic phase of the Gd2O3 in the GdFeAsO compound material. The peak at 623.0cm−1 corresponds to α-Fe2O3 in the spectra reveals the presence of impurity oxide phases. The broad peaks in the Differential Scanning Calorimetry (DSC) graph at about (290°C) and (600°C) reveals the initiation of slow crystallization of the sample within the given temperature range. The dielectric properties such as the dielectric constant (εr) and loss tangent (tanδ) of the sample have been studied at different temperatures and frequencies with LCR meter. The high value of dielectric constants is seen to exist in the materials. There are two dielectric anomalies that are observed at lower and higher temperature region. The magnetic measurement has been performed by using Vibrating Sample Magnetometer (VSM) at room temperature and showed the non linearity in the magnetization versus field curve.

A high-quality, bulk synthesis of graphene that is inexpensive, and environmentally safe is highly desired because of the broad range of applications. In comparison to the chemical vapor deposition (CVD) method, epitaxial growth on silicon carbide, etc., the electrochemical approach is thought to be the most straightforward and eco-friendly way for the cost-effective bulk production of graphene from graphite. Moreover, the thermal reduction method appears to be a particularly cost-effective way to eliminate oxygen-containing functional groups when compared to chemical reduction. The yield of graphene is also impacted by the choice of cathode low-cost, which is extremely important and played a critical role during the synthesis process. In this work, we demonstrate a green, eco-friendly, and cost-effective electrochemical method for the synthesis of reduced graphene oxide (RGO) followed by thermal reduction. To accomplish electrochemical exfoliation for the graphene synthesis, a constant DC power of 65 W (voltage = ∼ 2 0 V and current = ∼ 3. 2 5 amp) has been supplied within an electrolytic cell that contains 2 M of sulphuric acid as an electrolytic solution. The aluminium has been utilized as a cathode in place of the platinum, carbon cathode, etc. Moreover, to prepare the electrolytic solution and for the sonication process, sterilized water has been used in place of DI (deionized water). Thereafter, previously oxidized graphite oxide has been thermally reduced at a temperature of 8 0 0 ∘ C. The phase, crystallinity, and interatomic distance were investigated using X-Ray diffraction (XRD) analysis. X-Ray data show that the RGO crystal structure has been recovered following high-temperature annealing. The diffraction peak seems to be at 2 6. 4 ∘ with an interplaner distance of 3.48 Å. The intensity of the defect, as measured by the I D ∕ I G ratio (intensity ratio), was analyzed using Raman spectra, and the result of that investigation was found to be 0.196. The findings of the Raman study unambiguously reveal that the severity of the defects is judged to be on the lower end of the spectrum. The surface texture, microstructure, and elemental analysis were performed using atomic force microscopy (AFM), Field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), and EDX analysis. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to determine the number of oxygen-containing functional groups that existed in the RGO sample and their thermostability. The results of FTIR and TGA analysis clearly demonstrate that the reduction temperature has a major role in determining the proportion of oxygen that is present in the graphene. This study presents a large-scale, cost-effective, and eco-friendly graphene synthesis method for industrial applications. [ABSTRACT FROM AUTHOR]

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Analysis of oxide abrasive slurry chemical species used for chemical mechanical planarization (CMP) have attracted tremendous interests because it is one of the most considerable factors for determining the polishing performance including material removal rate, static etching rate and the roughness of surface. In this study, we investigate the distribution of Al2O3 particle size in slurry and shear time effects through the particle size analysis before and after CMP process of TiN wafer. Furthermore, a novel method for determination of particle size distribution of alumina abrasives is developed by means of Raman spectra. Matching with Raman peaks of polished slurry, the Al2O3 particle size trend increased during the particle size of abrasives (alumina oxide) mixed in CMP slurries increased. Raman spectroscopy is a novel method for assuming the TiN wafer particle size in oxide abrasive slurries when the CMP process completed. It has little research for analyzing the compositions changes during the polishing time progressing. We obtained the Raman peak intensity trend to increase due to the abrasive particle size increase at the polishing time is 150 s. [ABSTRACT FROM AUTHOR]

Surface structuring by ultrafast lasers is a promising technique to modify surface-related properties of materials to tailor them for specific applications. In the present study, we experimentally investigated the laser structuring of commercially pure titanium (CP Ti) using ultrafast pulses to understand the role of the laser input parameters on the development of surface morphology, optical properties, surface chemistry, and wettability behaviour. The processed surfaces were characterized by a scanning electron microscope, energy-dispersive X-ray spectroscopy (EDX), Raman microscope, optical microscope, and sessile drop method. Laser-induced periodic surface structures decorated with nanodroplets were noted to be formed on the surface of the laser-structured CP Ti. The surface roughness measurements showed that the laser-structured surfaces had nanoscale roughness values. The EDX and the Raman analyses show that laser-structured surfaces of CP Ti have a thin oxide film. Different colours on different surfaces processed by different laser parameters were observed. The wettability assessment shows that CP Ti can transition from hydrophilic–hydrophobic and vice versa depending on the environmental conditions. This study shows that laser structuring can be utilized to modify CP Ti surfaces to obtain desirable surface properties that can find potential applications in different fields.

The most difficult aspect in electrochemical synthesis of graphene oxide (GO) is preventing graphite from disintegrating on the surface of the anode, which affects microstructural characteristics and yield. In this study, the effect of applied potential, electrolytic temperature, and types of electrolytic solution on yield, anode surface disintegration and microstructural properties of electrochemically synthesized GO has been investigated. The GO has been synthesized in an aqueous solution of 1 M piranha solution and sulfuric acid ( H 2 SO 4 ) via electrochemical method by applying 24 V DC power source. After that, the GO was thermally reduced at around 650 ∘ C in a muffle furnace, and cooled down inside the muffle furnace. The yield, pH of the electrolytic solution, and anode surface disintegration all looked to be affected by the applied voltage and electrolyte temperature. Between the temperatures of 50 ∘ C and 70 ∘ C, the maximum yield was observed. During UV–Vis and XRD investigation, the absorbance, crystal structure, and interplanar distance appear to be unaffected by the reduction temperature, high voltage, electrolyte temperature and hydrogen peroxide addition. As demonstrated by Raman spectra, TEM, FE-SEM, AFM, and TGA analysis, high voltage, electrolyte temperature, and hydrogen peroxide addition have an important effect on the degree of defect, microstructure, and oxygen percentage, surface roughness and thermal stability of thermally reduced graphene oxide (TRGO). [ABSTRACT FROM AUTHOR]

In this paper, we used micro-Raman spectroscopy in cross-section to investigate the effect of different doping on the distribution of stress in the silicon substrate and the grown 3C-SiC film. The 3C-SiC films with a thickness up to 10 μm were grown on Si (100) substrates in a horizontal hot-wall chemical vapor deposition (CVD) reactor. To quantify the influence of doping on the stress distribution, samples were non-intentionally doped (NID, dopant incorporation below 1016 cm−3), strongly n-type doped ([N] > 1019 cm−3), or strongly p-type doped ([Al] > 1019 cm−3). Sample NID was also grown on Si (111). In silicon (100), we observed that the stress at the interface is always compressive. In 3C-SiC, instead, we observed that the stress at the interface is always tensile and remains so in the first 4 µm. In the remaining 6 µm, the type of stress varies according to the doping. In particular, for 10 μm thick samples, the presence of an n-doped layer at the interface maximizes the stress in the silicon (~700 MPa) and in the 3C-SiC film (~250 MPa). In the presence of films grown on Si(111), 3C-SiC shows a compressive stress at the interface and then immediately becomes tensile following an oscillating trend with an average value of 412 MPa. [ABSTRACT FROM AUTHOR]

Thin films of SnS were deposited chemically, and they are annealed at four different temperatures: 100 °C, 150 °C, 200 °C, and 250 °C. X-ray diffraction, Raman analysis, UV-visible spectroscopy, field emission scanning electron microscopy, and energy dispersive spectroscopy were used to investigate the impact of annealing temperature on the structural, optical, morphological, and chemical properties of thin films. As the annealing temperature rose, it was seen from the XRD patterns that the crystallinity of SnS films improved. At 250 °C, the film was almost evaporated, and the XRD pattern showed no peaks at all. The lattice strain and crystallite size were computed from the Williamson-Hall plots. The crystallite size increased and the lattice strain decreased with the increase in the annealing temperature. According to optical investigations, the samples' optical bandgap shrank as the annealing temperature rose. Morphological studies showed the formation of well-adhered films, and as the annealing temperature increased, the film became denser and more continuous with larger grains. The atomic weight percentage of sulphur decreased as the annealing temperature increased, according to the EDS analysis. Photovoltaic structures with the configuration ITO/SnS/CdS/Ag were fabricated. From the I-V characteristics, it was observed that the cell structure formed with SnS annealed at 200 °C showed better cell performance. [ABSTRACT FROM AUTHOR]

The SnS and CdS thin films were chemically prepared from the bath solutions with different pH values of 9.8, 9.9, and 10, and 11.3, 11.4, and 11.5 respectively. The X-ray diffraction confirmed the formation of orthorhombic SnS with a preferred orientation along the 013 plane and cubic CdS along the 311 planes. Crystallite size and lattice strain were calculated from the Williamson-Hall plot, and it was found that the crystallite size increased as pH increased. Raman spectra showed the prominent peaks of SnS and CdS thin films. Optical studies revealed a decrease in the optical band gap of both samples with increasing pH values. SnS films showed needle-like morphology with agglomerates and CdS flake-like interconnected structures. From the EDS analysis, it was noticed that both the SnS and CdS thin films shifted to a metal-rich composition with the increase in the pH of the bath solution. Finally, a solar cell (ITO/SnS/CdS/Ag) was made, and it was found that cell structures formed with SnS and CdS that were deposited with pH values of 10 and 11.3 showed better performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ultrafast laser ablation of alloy 699 XA under various parameters is investigated. • The finding shows that the ablation rate increases as the laser fluences increase. • LIPSS are present on the bottom of fully ablated cavities. • The elemental percentage composition of the 699 XA reduced slightly after ablation. • The oxide layer on the laser-ablated surfaces is made up of NiCr 2 O 4 and Cr 2 O 3. Ultrafast pulsed laser ablation is utilised to modify the surface of a nickel-based alloy by changing its surface chemistry and structure. This study subjected a VDM® alloy 699 XA to ultrafast pulsed laser ablation under different laser parameters. The processed surfaces were characterised by a scanning electron microscope, energy-dispersive X-ray spectroscopy, mechanical profilometer, Raman microscopy, and X-ray spectroscopy. The surface roughness at the bottom of the ablated cavities was lower than 0.3 µm. The calculated ablated depth per pulse was 2.34 × 10 - 6 and 7.81 × 10 - 6 µm per pulse for laser fluence of 1 and 10 J/cm2, respectively. Laser-induced periodic surface structures covered the bottoms of the fully ablated cavities. EDX showed that the elemental distribution of alloy 699 XA was slightly reduced after laser surface ablation. The Raman analysis shows that peaks associated with NiCr 2 O 4 , NiO, and Cr 2 O 3 were present on the ablated surfaces. The XPS analysis shows that the amount of Ni and Cr increases as laser fluences increase. It also indicates that surface oxides such as Cr 2 O 3 and NiCr 2 0 4 are formed. The study's findings provide insights into the surface morphologies, ablation efficiency, and surface chemistry of the laser-ablated alloy 699 XA, offering important information about its potential for various industrial applications. [ABSTRACT FROM AUTHOR]

• Undoped and Na doped CdO NPs (Cd 1 -x Na x O, 0 ≤ x ≤ 0.10) were prepared using the coprecipitation method. • The widening of bandgap in CdO via Na doping is observed due to quantum confinement effect and shows Burstein–Moss effect. • The functional groups and vibrational bands of Cd 1 -x Na x O have been investigated by FTIR. • CIE chromaticity color diagram revealed intense bright blue emission. • Cd 1 -x Na x O NPs presented superior antibacterial as well as antifungal activities. A series of cubic structured pristine and sodium doped CdO nanoparticles (Cd 1- x Na x O NPs) with varying dopant concentrations have been synthesized using simple Co-precipitation process. Crystal structure and the connection between various structural parameters are evidenced using powder XRD diffractograms. The crystallite size is evaluated with different models and the mean crystallite size was reduced with Na ions doping concentration due to severe lattice distortion. The existence of various vibrational modes and functional groups were demonstrated through FTIR characterization. The signature of Cd–O and Na–O stretching modes were confirmed with FTIR. Raman spectra also confirmed the formation of metal–oxygen bond and the second order vibration features. The direct bandgap of the CdO material increased from 2.132 to 2.40 eV with an increase in the Na dopant content which presents the appearance of a blue shift as probed through UV–Vis spectroscopy. The surface morphology and microstructure of the samples were studied using FESEM and HRTEM images, respectively. EDAX measurements revealed the presence of Cd, and O in the host lattice and Cd, O and Na in the doped CdO constructions. The SAED concentric ring pattern of Cd 1- x Na x O nanoparticles demonstrated the polycrystalline nature of the samples. PL study revealed the impression of intrinsic defects and the photoluminescence colour emission of the Cd 1- x Na x O materials shifted more towards bright blue region as the Na doping concentration increased. CIE color coordinates of Na-doped CdO NPs shows intense bluish color and extending its applications in commercial UV lighting, blue LEDs and Fluorescent biological labelling and tagging. Cd 1- x Na x O nanoparticles exhibited enhanced antibacterial activity with increasing Na doping content towards gram-positive, and gram-negative bacteria. Further, the antifungal analysis against C. albicans, and A. niger authenticate that Na+ substituted CdO nanoparticles shows excellent antifungal activity. The mechanism of the above observed results is examined in detail in this article. [Display omitted] [ABSTRACT FROM AUTHOR]

This work reports, improved photo catalytic performance of ZnO by band gap engineering via Eu doping (0.5–2.0 %). Single phase wurtzite structure of sol gel derived ZnO and Eu (0.5–2.0 %) doped ZnO are confirmed by XRD, FTIR and Raman spectra. Slight variation in structural parameter, FTIR stretching mode at 677 cm−1 and Raman E 2 peak position indicate substitution of Eu+3 in ZnO. Calculated band gap decreases [3.05-2.89] with Eu concentration due to generation of charge trap level. Dye degradation of MO improved in Eu doped ZnO as compare to ZnO. The catalytic effectiveness is clearly shown by significant breakdown of a commonly used MO dye (at a concentration of 120 mg l−1). ZnO: Eu 2 % has a remarkable clearance rate of 99.37 %, which is explained by pseudo-first-order kinetics. The increase in oxygen radical ion concentration due to presence of Eu 2 O 3 impurity phase in Eu 2 % doped ZnO supports MO degradation mechanism. [ABSTRACT FROM AUTHOR]

The presence and distribution of microplastics (MPs, <5 mm) has been reported worldwide in the aquatic ecosystem and is identified as emerging pollutant that can adversely affect the health of aquatic environment. The production and consumption of plastics has increased tremendously worldwide because of their properties including pliability, low cost, versatility, durability, and lightweight. Currently, the global production of plastics exceeds 320 million tonnes (Mt) per year, with single‐use plastic accounting for more than 40% of this total. Because plastic is non‐biodegradable, the majority of its annual production accumulates and finally enters the aquatic systems. Aquatic biota may suffer physical damages, fatigue, reduced appetite, blockage of metabolic channels, and altered feeding behavior due to consumption of MPs. Occurrence of MPs in air and food samples has been documented across the world. Thus, the MPs may also pose a great risk to the health of human beings, because of the human exposure to MPs and their concerned harmful contaminants through food chain or ingestion through the air. Due to the vast abundance and deleterious effects of MPs, more studies are focusing on MPs to estimate their dispersion, fate, quantity, and transport in the global aquatic systems. Through this work we have reviewed various analytical techniques of MPs including the collection of samples from surface water and sediments, identification, and quantification. One of the most prevalent techniques for recognizing MPs is visual categorization, which can be improved by combining it with other techniques viz. spectrometry and thermal methods. This review provides an insight about the following objectives: (1) the global occurrence and distribution of MPs, (2) the extensive analysis of effects of MPs on aquatic biota, and (3) the assessment of the current methods for MP sampling and analysis. [ABSTRACT FROM AUTHOR]

Graphene/metal oxide composites have generated interest for a variety of applications, such as energy storage, catalysts, and electronics, etc. However, one of the primary technical barriers to real applications has been the lack of practical and environmentally benign synthesis methods for producing homogenous graphene/metal oxide nanocomposites on a wide scale. Therefore, a simple, efficient, and environmentally friendly approach to the synthesis of graphene (reduced graphene oxide: rGO)/metal oxide (MO) nanocomposites was developed with the chemical reaction of graphene oxide (GO) and various metal oxide powders under mild temperature conditions. In this study, the GO was synthesized from graphite powder using modified Hummer’s technique initially. Later, using ascorbic acid (AA) as a reducing agent, various binary nanocomposites such as rGO/ZnO, rGO/CuO, rGO/TiO2, and rGO/Ag2O were synthesized by in situ approach. The structural and surface properties of the synthesized binary nanocomposites were extensively examined by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy dispersive spectroscopy (EDX), and Raman spectroscopy techniques. The XRD analysis of the synthesized binary rGO/MO nanocomposites confirmed the nanocrystalline nature. However, the FESEM and EDX analysis substantiated the MO nanoparticles were uniformly distributed onto the rGO layers anchoring of MO onto rGO particles and interacted with the rGO residual functional groups. Raman spectroscopy analysis indicated the increased number of defects because of the interfacial interaction between rGO and MO and the formation of binary rGO/MO nanocomposites.

In this study, the influence of boron doping on structural and surface properties of carbon material synthesized by a hydrothermal method was investigated, and the obtained results were compared with the previously published influence that boron has on characteristics of carbonized boron-doped hydrothermal carbons (CHTCB). Hydrothermal carbons doped with boron (HTCB) were obtained by the hydrothermal synthesis of glucose solutions with different nominal concentrations of boric acid. It was found that glucose based hydrothermal carbon does not have developed porosity, and the presence of boron in their structure has insignificant influence on it. On the contrary, additional carbonization increases the specific surface area of the undoped sample, while an increase in boron content drastically decreases the specific surface area. Boron doping leads to a decrease in the amount of surface oxygen groups, for both, hydrothermally synthesized and additionally carbonized materials. Raman analysis showed that the boron content does not affect a structural arrangement of the HTCB samples, and Raman structural parameters show a higher degree of disorder, compared to the CHTCB samples. Comparison of structural and surface characteristics of hydrothermal carbons and carbonized materials contributes to the study of the so far, insufficiently clarified influence that boron incorporation has on the material characteristics.

The growing process of a spinel-like oxide film can be obtained through different atmospheres; in this sense Air, O2, steam, and nitrogen atmospheres were used in different steps during the aging heat treatment at 490ºC of maraging 300 and 350 alloys. The oxidation layer produced under different atmospheres was chemically, microstructurally and mechanically characterized by means of advanced techniques. The results showed (in both alloys) a non-homogeneous mix oxide formed by magnetite, nickel and cobalt ferrites and MoO3 heterogeneously distributed along the oxide thickness. It was also founded TiO2 in the innermost areas and a particularly important quantify of hematite on the external surface. A nickel-rich austenite phase was produced at the interphase due to the combination of nickel stability and the preference of cobalt, molybdenum, and iron diffuses through the film as ions. The highest thickness values were found in the oxides produced in maraging 300 steels which could indicate greater susceptibility to oxidation comparing with grade 350 maraging steel. The oxide films produced in both maraging alloys using air atmosphere presents excellent adherence, and the results show the capability for being used for tribological applications under sliding contact tests.

Agricultural wastes are presently being used as animal feed or incinerated, yet they have the potential to become eco-friendly, value-added products. Converting agricultural waste into biocarbon material is one of the current advancements in their valorization. Biocarbons exhibit a wide range of application potential. The physical and chemical properties of biocarbons produced from agricultural feedstock differ based on pyrolysis conditions, in which the pyrolysis temperature plays a vital role. In this study, almond shell biomass was carbonized at three different temperatures: 300, 500, and 700 °C. The resulting biocarbons were analyzed to understand the influence of pyrolysis temperature on physicochemical characteristics. The carbon content in almond shells rose from 47% in the raw biomass to 75% in the biocarbon obtained at 700 °C. TGA-FTIR spectra indicated the release of volatiles such as CO2, hydrocarbons, carbonyl groups, and ethers, the release of which increased with increasing temperature. Further, the increased pyrolysis temperature improved the thermal stability of almond shell derived biocarbons. The deconvoluted ID/IG ratios of Raman peaks were calculated to 1.274 and 1.012 for the biocarbons obtained at 500 and 700 °C, respectively, indicating a trend of increasing trubostratic carbons with increasing pyrolysis temperature. The biocarbon produced at 700 °C was 53 times more electrically conductive than biocarbon produced at 500 °C, likely due to the high carbon content and increased structural ordering of the carbons.

We have synthesized large scale, thin, transparent graphene oxide (GO) flakes by Hummer’s method and investigated their suitability for fabrication of transparent nanocomposites. The GO flakes were comprehensively characterized by X-ray diffraction, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX), Raman spectroscopy and Differential Scanning Calorimetry (DSC). X-ray diffraction displayed the peak of graphene oxide at 9°degree, which is characteristic peak of GO in agreement with the literature results. Scanning Electron Microscopy images revealed that thin, transparent, flake form GO with 14,8 µm lateral size and 0,31µm thickness were synthesized. The comparison with literature results show that for the first time, our group could synthesize large scale, thin and more transparent GO flakes by simple Hummer’s method using simple dispersed graphite. EDX measurements indicate the formation of layered structure with oxygen containing functional groups. The intensity ratio between D and G peaks in the Raman spectra proves that less defective GO flakes have been synthesized. The solution ability of the synthesized material indicate that high quality GO flakes were synthesized, which make them effective soluble material due to oxygen containing groups formed on the graphene plane during synthesis process.DSC results shows that these flakes are thermally stable till 200°C. Due to high solubility properties, large scale and transparency they can be very useful in fabrication of high optical transparent nanocompoties for replacement indium tin oxide transparent conductors in solar panels, biomedical applications and microwave absorbers for electromagnetic interference (EMI) environmental protection.

• Glasses of composition xZnO–20Cs 2 O–(32–0.4x) Fe 2 O 3 –(48–0.6x) P 2 O 5 were prepared. • Glass stability and glass forming ability gradually decreased up to 10 mol% ZnO. • Raman and FTIR studies showed depolymerization of Q1 above 5 mol% ZnO. • PCT-B studies of glasses indicated low Cs leach rate in the order of 10–6 g/cm2day. The effect of doping of zinc oxide on the structural and thermal properties of cesium loaded iron phosphate glass has been studied. The composition of glasses prepared for the present study is xZnO–20Cs 2 O–(32–0.4x) Fe 2 O 3 –(48–0.6x) P 2 O 5 with x = 0–15 (mol%) wherein Fe/P ratio remains 0.67. Glasses were synthesized using conventional melt quenching technique and were characterized by XRD, DTA, Raman and FTIR spectroscopy. All the glasses showed X-ray amorphous except x = 15 mol% ZnO. Chemical durability of the glasses was studied by PCT-B. The addition of cesium in pristine IPG decreased the thermal stability. Doping of 2.5 mol% ZnO marginally increased the thermal stability and chemical durability compared to 20 mol% Cs loaded IPG. Further addition of ZnO in cesium loaded IPG resulted in slow depolymerization of pyrophosphate network. All the glasses exhibited a low Cs leach rate in the order of 10–6 g/cm2.day. [ABSTRACT FROM AUTHOR]