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The formation of nickel oxide (NiO) nanostructures using controlled thermal oxidation of thin nickel (Ni) films and their successive use as gas‐sensing materials for selective detection of low‐concentration formaldehyde vapor are discussed here. High‐purity Ni were deposited on glass/quartz substrates using a vacuum assisted electron beam (E‐beam) evaporation technique. Afterwards, thermal oxidation of these Ni thin films was conducted at various temperatures in air ambient condition. Different surface characterization techniques are employed to investigate the structure, chemistry, and electronic properties of these as‐grown oxide nanostructures. X‐ray diffraction analysis revealed that the thermal oxidation starts above 400 °C. Presence of metallic nickel peak even after oxidation at 500 °C for 5 h confirms its oxidation resistance. Increase in oxidation temperature improves the crystalline quality. Scanning electron microscopy imaging depicts an increase in particle size with oxidation temperature and a highly porous surface morphology above 800 °C. Raman spectroscopy identified the characteristic modes of NiO. UV‐Visible data exhibits a redshift in optical bandgap whereas X‐ray photoemission spectroscopy analysis reveals a gradual increase in oxygen content within the oxide layer. Finally, these NiO films show a high sensitivity and selectivity toward formaldehyde vapor sensing against a few other volatile organic compounds. [ABSTRACT FROM AUTHOR]

Metastable stannous oxide (SnO) phase of p‐type semiconductor and all tin oxides p–n junctions of SnO–SnO2 nanostructures are formed by controlled thermal oxidation of thin tin films. High purity Sn is deposited on quartz substrates using a vacuum‐assisted thermal evaporation technique. Afterwards, controlled thermal oxidation at different temperatures is performed in air ambient condition (150–800 °C). Various surface characterization techniques have been employed to analyze the structure, morphology, chemistry, optical, and electronic properties of these SnOx films. P‐type SnO phase is found to be thermodynamically stable at lower oxidation temperatures (250–400 °C), while n‐type SnO2 phase starts to appear above 500 °C. Highly uniform and dense SnO nanospheres along with few 1D nanorods are observed after oxidation at 400 °C. Mixed oxide phases of p–n junctions with a sudden decrease in electrical conductivity is observed for 500 °C film. Significantly lower surface conductivity of mixed oxide phase indicates the formation of depletion layers between p‐type SnO and n‐type SnO2 nanograins. A transition from SnO layer to SnO2 layer is also observed above 600 °C. Overall, SnOx‐based nanostructures would be a potential candidate for solar cells, p‐channel thin film transistors, p–n junction diodes and gas sensors. [ABSTRACT FROM AUTHOR]

Aiming at the demand for improving the heat release performance of solid propellants for high energy and complex practical application scenarios, the B–Mg–Al ternary alloy is proposed as a metal fuel additive. Based on the unique phase distribution of B–Mg–Al ternary metal alloy and the existing theory of ignition and combustion of metal particles, the kinetic simulation of ignition and combustion of B–Mg–Al ternary metal alloy particles in complex alternating atmosphere is carried out by combining with the virtual alternating atmosphere environment. The model calculates the combustion time tc of 10 μm B–Mg–Al alloy particles in H2O(g), H2O(g)/Air alternating mode, and Air to be 3.50 ms, 3.98 ms, and 4.60 ms, respectively, and the comparative errors with the experimental measurement of combustion time are kept around 5%, which verifies the reliability of the model results. The simulation study shows that the order of thermal oxidation reaction and the order of combustion of the monomolecular group elements of B–Mg–Al ternary alloy particles are Mg, Al, and B, which to some extent indicates that the addition of Mg and Al has the potential to improve the ignition and combustion performance of B. In addition, there are obvious differences in the ignition and combustion performance and heat transfer performance of the alloy particles under H2O(g) and that of Air with the same concentration, which leads to significant instability in both ignition and combustion processes at variable medium. [ABSTRACT FROM AUTHOR]

Polyurethane (PUR) soft foams release malodorous and potentially toxic compounds when exposed to oxidative conditions. Current chamber test methods cannot distinguish between pre-existing volatiles and those formed during oxidation, nor can they assess the formation rates of oxidation products. We subjected PUR soft foam to oxidative treatment in a continuous air flow at 120 °C. Emissions were convectively transferred from the foam to an exhaust port and analyzed using a thermodesorption–gas chromatography–mass spectrometry (TD-GC-MS) system, with external calibration employed for the quantification of selected analytes. The study identified hydroperoxide formation and degradation as key mechanisms in the breakdown of the polyether soft segments. This process predominantly produces volatiles, such as carboxylic acids, formates, acetates, alpha-hydroxy-ketones, (unsaturated) aldehydes, substituted dioxolanes and dioxanes, glycols, and allyl ethers. Volatiles associated with the degradation of the hard segments include aniline, benzoxazole, 2-methylbenzoxazole, and benzaldehyde. This experimental setup enables reproducible qualitative and quantitative analysis of volatiles formed during the oxidative degradation of PUR soft foams, providing new insights into the segment-dependent chemical pathways of the polymer's molecular breakdown. [ABSTRACT FROM AUTHOR]

To prevent infection in dental implants using photocatalytic activity under visible-light irradiation, the fabrication of Au-added TiO2 layers on Ti substrates and their antibacterial properties were studied. Pure Au and Ti-(60, 40) mol%Au alloy films with thicknesses of 10-47 nm were sputtered onto Ti, followed by thermal oxidation in air at 873K for 1.8 ks to form TiO2 layers. The antibacterial properties against Escherichia coli, cytotoxicity, and bonding strength to Ti substrates were evaluated. The highest antibacterial activity under visible-light irradiation was obtained when the sputtered film was pure Au and its thickness was 38 nm. Compared with as-polished commercially pure Ti, the number of viable mouse osteoblast-like cells and human gingival fibroblasts on Au-added TiO2 layers increased after placement in the dark but decreased after visible-light irradiation. The best antibacterial property-bonding strength balance was achieved when the Ti-40 mol%Au sputtered film with a thickness of 42 nm was formed on Ti. To the best of our knowledge, this study is the first to report the formation of TiO2 layers with antibacterial activity under visible-light irradiation by combining Au-sputtering and thermal oxidation of Ti. [ABSTRACT FROM AUTHOR]

Multilayer plastic (MP) commonly used in food and beverage packaging is difficult to recycle due to its layered structure, resulting in its accumulation over time; the consequent environmental harm is further exacerbated by its short lifespan. This study investigates recycled low-value MP as a modifier for polymer-modified bitumen (PMB). However, the difference in polarity between MP and PMB mixtures is a challenge, resulting in their poor compatibility and reduced mechanical properties. To overcome this, low-value MP was treated with atmospheric cold plasma and thermal oxidation to enhance its compatibility with PMB. The results indicate that plasma and thermal treatments increase the hydrophilicity of low-value MP through the formation of low-molecular-weight oxidized molecules containing hydrophilic hydroxyl (-OH) and carbonyl (C = O) groups that act as an intermediary boundary layer between the low-value MP and asphaltene-rich bitumen. Further, the optimal oxidation conditions for MP are revealed as 60 s of plasma treatment followed by heating at 150 °C for 60 min. Mixtures of PMB and optimally oxidized MP have optimal compositions of 1 wt.%, with ductility and penetration values of 87.7 cm and 57.4 mm, respectively. [ABSTRACT FROM AUTHOR]

In this study, we explore the fabrication and optimization of ZnO/Si heterojunction solar cells to enhance their performance through precise control of electron affinity and bandgap properties. ZnO thin films were synthesized using thermal oxidation in a high-vacuum chamber, followed by annealing to improve crystallinity and electrical characteristics. The photovoltaic performance of the ZnO/Si heterojunction solar cells was systematically characterized, and Quantum ESPRESSO simulations were employed to refine the electronic properties of ZnO. Our results show significant improvements in open-circuit voltage, short-circuit current density, and overall conversion efficiency. The optimization of ZnO/Si heterojunction solar cells involves enhancing the electronic properties of ZnO thin films. Quantum ESPRESSO simulations were utilized to optimize the ZnO structure, calculate the band structure and density of states (DOS), and study the effects of Ga and Mg doping on the electronic properties of ZnO. The initial step in our study involved the structural optimization of ZnO to determine its lowest energy configuration. The optimization of the band offset engineering to improve the efficiency of n-ZnO/p-Si photovoltaic cells was found to be critical. Doping ZnO with Ga and Mg improved the band alignment with Si, reduced recombination losses, and enhanced charge carrier mobility. Our findings underscore the potential of optimized ZnO/Si heterojunction solar cells for high-efficiency solar energy conversion, demonstrating their viability as cost-effective and efficient solutions for renewable energy applications. This study highlights the importance of precise material engineering and simulation-driven optimization in developing advanced photovoltaic devices.

The catalytic activity of metal cations exchanged with heteropoly acids (HPA) and the selectivity towards precursor composite materials can be tailored by adjusting the reaction mechanism. A structural defect engineering strategy was developed for the metallic phase of O-MoS2, doped with a Keggin-type HPA to serve as a double gyroid layer (O-MoS2@HPA). This was achieved through thermal oxidation treatment to enable a high surface area by depositing abundant catalytically active sites on the graphite felt. Optimization strategies involving MoO3−x (MoO3−x@K3PW12O40) species have been crafted, anchoring active sites in a spherical nanomorphology through the self-assembly of acid. This development introduces a new approach for enhancing electrocatalysts, aiming for superior performance in VRFB. The electrochemical results show remarkable enhancement in electrocatalytic behavior with abundant heteroatom active sites, promoting oxidation at a high current density of 150 mA/cm2, achieving an outstanding 84.62% high energy efficiency. This result is 14% higher than pristine graphite felt and exhibits extraordinary stability after 1350 cycles, overcoming the sluggish kinetic mechanism that limits redox active materials. This study creates new avenues for the design of hybrid micro/nanostructured materials on cathodes and anodes to achieve excellent performance as electrocatalysts for VRFB. [ABSTRACT FROM AUTHOR]

Cobalt ferrite (CFO) nanoparticles (NPs) are highly promising for data storage, energy conversion, permanent magnets, and biomedical applications owing to their exceptional magnetic properties. However, the presence of phase impurities (particularly FeO and CoO) can severely degrade their magnetic properties, hindering their practical use. Here, we present a simple post‐synthesis oxidation approach to address this challenge. Our method involves the thermal decomposition of Fe−Co oleate followed by oxidation using trimethylamine N‐oxide. The results reveal the effective elimination of FeO and CoO impurities and the formation of spinel ferrite crystal structures post‐oxidation with no change in morphology or size. Magnetic measurements demonstrate a significant enhancement in magnetic properties (e. g., magnetic saturation, coercivity, and blocking temperature) in oxidized CFO NPs compared to the non‐oxidized counterparts, indicative of the recovered ferrimagnetic structure upon post‐synthesis oxidation. As expected, the restoration of the ferrimagnetic structure, resulting in improved magnetic anisotropy, led to decreased SAR values as the nanoparticles moved away from the optimal anisotropy range. The study underscores the necessity of post‐synthesis oxidation for ensuring phase purity and enhancing the magnetic properties of CFO NPs, irrespective of the synthesis method. This approach offers a promising route for producing highly functional magnetic nanoparticles for practical applications. [ABSTRACT FROM AUTHOR]

As a typical hard but brittle material, Si tends to fracture abruptly at a stress well below its theoretical strength, even if the tested volume goes down to submicron scale, at which materials are usually nearly free of flaws or extended defects. Here, via the thermal–oxidation–mediated healing of the surface that is the preferred site for cracks or dislocations initiation, the premature fracture can be effectively inhibited and the over 50% homogeneous plastic strain with the near‐theoretical strength (twice the value of the unhealed counterpart) are united in submicron‐sized Si particles. In situ transmission electron microscope observations and atomistic simulations elucidate the confinement effect from the passivated and smoothened thermal oxide, which retards the dislocation nucleation and transforms the dominant deformation mechanism from partial dislocation to the more mobile full dislocation. This work demonstrates an effective and feasible surface engineering pathway to optimize the mechanical properties of Si at small scales. [ABSTRACT FROM AUTHOR]

The ambient stability of copper oxide layers produced through thermal oxidation is a critical factor for their application in advanced photovoltaic devices. This study investigates the long-term stability of thermally grown sodium-doped copper oxides fabricated at 300 °C, 500 °C, and 700 °C. The structural, optical, and electronic properties of these oxide layers were examined after a 30-day period to understand how thermal oxidation temperature and sodium doping influence the durability and properties of copper oxide films. The results indicate that the stability of thermal copper oxide increases with oxidation temperature. The film produced at 700 °C maintained consistent optical properties, work function value, and structural integrity over time, demonstrating their robustness against environmental degradation. In contrast, the layers produced at lower temperatures (300 °C and 500 °C) showed more significant changes due to continued oxidation and adsorption from ambient. [ABSTRACT FROM AUTHOR]

The oxidative stability index is one of the most used and reliable parameters to determine the quality of vegetable oil, biodiesel, and various foods. However, the leading commercially available equipment has a considerably high cost. Nevertheless, block digesters are more financially accessible and are present in most food analysis laboratories. Thus, the proposal of this study allowed us to obtain results very similar to those provided by Rancimat, based on the association between a digester block and a conductivity sensor, assisted by a low-cost and high-efficiency microcontroller, added to a simple graphical interface. Comparing the results between both techniques, it was possible to determine the oxidative stability index with reasonable equivalence and its variation as a function of temperature with a deviation of less than 10% for olive oil. This work helps disseminate oxidative stability analysis and contributes to institutions, researchers, and teachers with limited access to financial resources. [ABSTRACT FROM AUTHOR]

The roasting process of sesame oil is expected to alter its internal composition and stability under oxidation condition. Presumably, the effect of roasting may differ with oxidation conditions (i.e., thermal and photo-oxidation), but such studies have not been undertaken. To further evaluate this notion, several type of sesame oils (raw and refined as unroasted oil, and roasted oil) and rapeseed oils as comparison were subjected to thermal oxidation (120°C) and photo-oxidation (50,000 lx) for 5 and 10 hours. The result revealed that the roasting sesame oil exhibited good stability under thermal oxidation, possibly due to the change on antioxidant agents such as sesamol and Maillard products during the roasting process. In contrast, the refined sesame oil (unroasted) demonstrated high stability under photo-oxidation, indicating that the refining process has a more significant impact on the oxidative stability in sesame oil compared to the alterations in its components caused by the roasting process. Taken together, this study is the first to show that the roasting and refining processes of sesame oil alter its internal composition and show different variations in sesame oils' oxidative stability under thermal and photo-oxidation, which holds significance considering its global consumption. [ABSTRACT FROM AUTHOR]

Accurate measurement of the infrared spectral emissivity of nickel-based alloys is significant for applications in aerospace. The low thermal conductivity of these alloys limits the accuracy of direct emissivity measurement, especially during the oxidation process. To improve measurement accuracy, a surface temperature correction method based on two thermocouples was proposed to eliminate the effect of thermal conductivity changes on emissivity measurement. By using this method, the infrared spectral emissivity of Inconel 601, Inconel 625, and Inconel 718 alloys was accurately measured during the oxidation process, with a temperature range of 673–873 K, a wavelength range of 3–20 μm, and a zenith angle range of 0–80°. The results show that the emissivity of the three alloys is similar in value and variation law; the emissivity of Inconel 718 is slightly less than that of Inconel 601 and Inconel 625; and the spectral emissivity of the three alloys strongly increases in the first hour, whereafter it grows gradually with the increase in oxidation time. Finally, Inconel 601 has a lower emissivity growth rate, which illustrates that it possesses stronger oxidation resistance and thermal stability. The maximum relative uncertainty of the emissivity measurement of the three alloys does not exceed 2.6%, except for the atmospheric absorption wavebands. [ABSTRACT FROM AUTHOR]

Resistive switching memories have garnered significant attention due to their high‐density integration and rapid in‐memory computing beyond von Neumann's architecture. However, significant challenges are posed in practical applications with respect to their manufacturing process complexity, a leakage current of high resistance state (HRS), and the sneak‐path current problem that limits their scalability. Here, a mild‐temperature thermal oxidation technique for the fabrication of low‐power and ultra‐steep memristor based on Ag/TiOx/SnOx/SnSe2/Au architecture is developed. Benefiting from a self‐assembled oxidation layer and the formation/rupture of oxygen vacancy conductive filaments, the device exhibits an exceptional threshold switching behavior with high switch ratio exceeding 106, low threshold voltage of ≈1 V, long‐term retention of >104 s, an ultra‐small subthreshold swing of 2.5 mV decade−1 and high air‐stability surpassing 4 months. By decreasing temperature, the device undergoes a transition from unipolar volatile to bipolar nonvolatile characteristics, elucidating the role of oxygen vacancies migration on the resistive switching process. Further, the 1T1R structure is established between a memristor and a 2H‐MoTe2 transistor by the van der Waals (vdW) stacking approach, achieving the functionality of selector and multi‐value memory with lower power consumption. This work provides a mild‐thermal oxidation technology for the low‐cost production of high‐performance memristors toward future in‐memory computing applications. [ABSTRACT FROM AUTHOR]

This work is the first study of the Mn and Co dopants effect on the physical properties of ZnO thin films electrodeposited on aluminum substrate. In order to synthesize these samples, electroplated Zn thin layers were thermally oxidized in atmospheric air for 2 h at 500 °C. The elaborated films were analyzedby X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (FEG-SEM) equipped with energy dispersive X-ray analysis (EDX). The contact angle between the surface of the films and a deposited water drop (WCA) is measured to evaluate the wettability properties of the synthesized films. Mn and Co-doped ZnO thin films were studied and compared in order to better understand the effects of the dopant element on the physical properties of the host crystal, and to improve their hydrophobic properties.XRD analyses of a prepared mico/nanostructured material confirm the incorporation of substitutional transition metal ions on cation sites, and no secondary phase linked to Mnor Co is detected. This result was checked with EDX analysis. However, with increasing Mnor Co concentration, new modes appear in the Raman spectroscopy. The FEG-SEM images show that the surface morphologies change with dopant nature. The Mn-doped sample shows flower-like microstructures with an average size of 9µm, which are covered with spherical ZnO nanostructures with a size around 28 nm. This can lead to an improvement of the hydrophobicity of the ZnO coating compared to Co-doped films. [ABSTRACT FROM AUTHOR]

Nano- and micro-structuring of transparent glass for IR or visible spectrum applications is challenging due to low yield and slow processes, especially while maintaining high surface quality. The method proposed in this work involves the structuring and subsequent thermal oxidation of a thin metallic layer on a glass substrate. Annealing of the structured metal layer produces a transparent fully inorganic oxide surface with periodic patterns, avoiding the subtleties of glass structuring. A new method for the formation of sub-micrometer non-absorbing gratings with 750 nm periodicity is presented by direct laser interference patterning (DLIP) of thin tantalum layers on fused silica substrates followed by thermal oxidation by annealing. This method aims to improve the field of laser optics by providing a scalable and efficient method for the creation of precise metal-oxide photonic structures.

Although hydrofluoric acid (HF) surface treatment is known to enhance the joining of metals with polymers, there is limited information on its effect on the joining of AZ31 alloy and carbon-fiber-reinforced plastics (CFRPs) through laser-assisted metal and plastic direct joining (LAMP). This study uses the LAMP technique to produce AZ31-CFRP joints. The joining process involves as-received AZ31, HF-pretreated AZ31, and thermally oxidized HF-pretreated AZ31 alloy sheets. Furthermore, the bonding strength of joints prepared with thermally oxidized AZ31 alloy sheets is examined to ascertain the combined effect of HF treatment and thermal oxidation on bonding strength. The microstructures, surface chemical interactions, and mechanical performances of joints are investigated under tensile shear loading. Various factors, such as bubble formation, CFRP resin decomposition, and mechanical interlocking considerably affect joint strength. Additionally, surface chemical interactions between the active species on metal parts and the polar amide along with carbonyl groups of polymer play a significant role in improving joint strength. Joints prepared with surface-pretreated AZ31 alloy sheets show significant improvements in bonding strength.

In this paper, the morphological, micromechanical and tribological characteristics of the Ti-6Al-4V ELI alloy after thermal oxidation (TO) were identified. TO was carried out at temperatures of 848 K, 898 K and 948 K over a period of 50 h. Microscopic examination revealed that an increase in temperature resulted in an improved uniformity of coverage and an increased oxide grain size. Micromechanical tests showed that TO of the Ti-6Al-4V ELI alloy led to an increase in hardness and deformation resistance. Following oxidation, a decrease (by approximately 10–22%) was observed in the total mechanical work of indentation, Wtotal, compared to the as-received material. The formation of protective oxide films on the Ti-6Al-4V ELI alloy also led to the improvement of tribological characteristics, both when tested under dry friction conditions and in Ringer's solution. The sliding wear resistance increased with an increase in the oxidation temperature. However, a greater degree of wear reduction (by approximately 30–50%) was found for the lubricated contact in comparison with the dry friction tests. Surface roughness also increased with the increase in temperature. [ABSTRACT FROM AUTHOR]

Surfactant-based wet spinning is a promising route toward the eco-friendly production of carbon nanotube fibers (CNTFs). However, currently, the properties of surfactant-based wet-spun CNTFs lag behind those produced by other methods, indicating the need for further understanding and research. Here, we explored the surface characteristics of carbon nanotubes (CNTs) that are advantageous for the properties of CNTFs produced by wet spinning, using sodium cholate as a surfactant. Our finding indicates that appropriate thermal oxidation of CNTs enhances the fiber properties, while excessive oxidation undermines them. This implies that the bonding mechanism between CNTs and sodium cholate involves hydrophobic interaction and π-π interaction. Therefore, it is crucial to preserve a clean surface of CNTs in wet spinning using sodium cholate. We believe our research will contribute to the advancement of surfactant-based wet spinning of CNTFs. [ABSTRACT FROM AUTHOR]

• AZ31 alloy/CFRP joints were produced by laser joining with/without HF treatment. • NEXAFS technique demonstrated that HF treatment imparted reactive sites on the alloy surface for chemical bonding. • H-F bond through the interaction of MgF 2 and polar amide group of polymer resulted in high adhesion strength. Although hydrofluoric acid (HF) surface treatment is known to enhance the joining of metals with polymers, there is limited information on its effect on the joining of AZ31 alloy and carbon-fiber-reinforced plastics (CFRPs) through laser-assisted metal and plastic direct joining (LAMP). This study uses the LAMP technique to produce AZ31-CFRP joints. The joining process involves as-received AZ31, HF-pretreated AZ31, and thermally oxidized HF-pretreated AZ31 alloy sheets. Furthermore, the bonding strength of joints prepared with thermally oxidized AZ31 alloy sheets is examined to ascertain the combined effect of HF treatment and thermal oxidation on bonding strength. The microstructures, surface chemical interactions, and mechanical performances of joints are investigated under tensile shear loading. Various factors, such as bubble formation, CFRP resin decomposition, and mechanical interlocking considerably affect joint strength. Additionally, surface chemical interactions between the active species on metal parts and the polar amide along with carbonyl groups of polymer play a significant role in improving joint strength. Joints prepared with surface-pretreated AZ31 alloy sheets show significant improvements in bonding strength. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, we explore the fabrication and optimization of ZnO/Si heterojunction solar cells to enhance their performance through precise control of electron affinity and bandgap properties. ZnO thin films were synthesized using thermal oxidation in a high-vacuum chamber, followed by annealing to improve crystallinity and electrical characteristics. The photovoltaic performance of the ZnO/Si heterojunction solar cells was systematically characterized, and Quantum ESPRESSO simulations were employed to refine the electronic properties of ZnO. Our results show significant improvements in open-circuit voltage, short-circuit current density, and overall conversion efficiency. The optimization of ZnO/Si heterojunction solar cells involves enhancing the electronic properties of ZnO thin films. Quantum ESPRESSO simulations were utilized to optimize the ZnO structure, calculate the band structure and density of states (DOS), and study the effects of Ga and Mg doping on the electronic properties of ZnO. The initial step in our study involved the structural optimization of ZnO to determine its lowest energy configuration. The optimization of the band offset engineering to improve the efficiency of n-ZnO/p-Si photovoltaic cells was found to be critical. Doping ZnO with Ga and Mg improved the band alignment with Si, reduced recombination losses, and enhanced charge carrier mobility. Our findings underscore the potential of optimized ZnO/Si heterojunction solar cells for high-efficiency solar energy conversion, demonstrating their viability as cost-effective and efficient solutions for renewable energy applications. This study highlights the importance of precise material engineering and simulation-driven optimization in developing advanced photovoltaic devices. [ABSTRACT FROM AUTHOR]

This study focuses on the growth of Cu2O/CuO nanowires by one-step thermal oxidation using a flexible copper mesh at oxidation temperatures in the range of 300 to 600 °C in a controlled atmosphere of mixed-flow Ar and O2 gases. Thermal oxidation is one of the simplest used methods to obtain nanowires on a metal surface, offering advantages such as low production costs and the ability to produce metal oxides on a large scale without the use of hazardous chemical compounds. The growth of metal oxides on a conductive substrate, forming metal/oxide structures, has proven to be an effective method for enhancing charge-transfer efficiency. The as-synthesized Cu/Cu2O/CuO (Nw) electrodes were structurally and morphologically characterized using techniques such as XRD and SEM/EDX analysis to investigate the structure modification and morphologies of the materials. The supercapacitor properties of the as-developed Cu/Cu2O/CuO (Nw) electrodes were then examined using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) measurements, and electrochemical impedance spectroscopy (EIS). The CV curves show that the Cu/Cu2O/CuO (Nw) structure acts as a positive electrode, and, at a scan rate of 5 mV s −1, the highest capacitance values reached 26.158 mF cm−2 for the electrode oxidized at a temperature of 300 °C. The assessment of the flexibility of the electrodes was performed at various bending angles, including 0°, 45°, 90°, 135°, and 180°. The GCD analysis revealed a maximum specific capacitance of 21.198 mF cm−2 at a low power density of 0.5 mA cm−2 for the oxidation temperature of 300 °C. The cycle life assessment of the all of the as-obtained Cu/Cu2O/CuO (Nw) electrodes over 500 cycles was performed by GCD analysis, which confirmed their electrochemical stability. [ABSTRACT FROM AUTHOR]

The square root autocatalytic equation used to describe the initial process of lipid oxidation was investigated from the viewpoint of the kinetic theory of radical polymerization. The oxidation processes of linoleic acid were investigated from 5 °C to 40 °C, and the oxidation rate constants of the equation were estimated. The Arrhenius plot of the oxidation rate constants of linoleic acid was compared with that of glyceryl trilinoleate, and these were parallel within the investigated concentration and temperature ranges. It showed that the rate constant of oxidation of linoleic acid was faster than that of glyceryl trilinoleate and suggested that the difference was mainly ascribed to the frequency factor. [ABSTRACT FROM AUTHOR]

Due to their interesting physical and structural characteristics, zinc oxide nanostructures are one of the most commonly used materials to elaborate hydrophobic or superhydrophobic surfaces. In this work, undoped and Mn-doped ZnO thin films are prepared by the thermal oxidation of electrodeposited zinc thin layers on aluminum substrates. Structural analysis by X-ray powder diffraction and Raman spectroscopy shows the formation of ZnO mico-nanostructures, and no secondary phase linked to Mn is detected. Energy dispersive X-ray spectroscopy analysis confirms the presence of zinc and oxygen, with no Mn element detected in the doped samples. However, at high Mn concentrations, Raman spectroscopy shows the main ZnO modes with a decrease in their intensities and the appearance of new modes with increasing Mn concentration, indicating that the structural quality is slightly degraded. The formation of the deformed flower-shaped structures covered with spherical ZnO nanostructures leads to the hydrophobicity of the ZnO coating, and doping with a small Mn concentration improves this last property. [ABSTRACT FROM AUTHOR]

Heterojunctions based on p-CuO/n-ZnO, prepared by simple methods such as spin coating, normally exhibit low photoconversion efficiency and require modification. Doping the ZnO layer with ions such as Sn4+ could be a solution. In this work, heterojunctions were prepared by two simple methods. In method 1, to prepare the CuO@ZnO junction, the n-ZnO layer was spin-coated on tin-doped indium oxide/glass substrates (ITO/glass) followed by spin coating of the p-CuO layer. In method 2, to prepare the ZnO@CuO/Cu sheet junction, the p-CuO layer was prepared by thermal oxidation of the Cu metal sheet, followed by spin coating of ZnO. In both cases, the ZnO film was doped with Sn4+ ions at 1.5% concentration by mole. The effects of Sn-doping on the structural and morphological properties of the junction were comparatively studied by X-ray diffraction and atomic force microscopy. In both preparations, doping affected the optical, electrical and photovoltaic (PV) properties. The preparation method also affected junction characteristics, as preparation method 2 showed heterojunctions with higher PV characteristics. The results show inroads to improving PV characteristics for the heterojunction based on the proper preparation method and Sn doping. [ABSTRACT FROM AUTHOR]

This research highlights the importance of addressing bioplastic contamination in recycling processes to ensure the quality of recycled material and move towards a more sustainable circular economy. Polyethylene (PE) is a conventional plastic commonly used in packaging for which large amounts of waste are produced; therefore, PE is generally recycled and has an established recycling process. However, the contamination of biodegradable polymers in the PE waste stream could impact recycling. This study, therefore, focuses on polyethylene (PE) that has been polluted with a commercial thermoplastic starch polymer (TPS), as both materials are used to produce plastic films and bags, so cross-contamination is very likely to occur in waste separation. To achieve this, recycled PE was blended with small quantities of the commercial TPS and processed through melt extrusion and injection molding, and it was further characterized. The results indicate that the PE-TPS blend lacks miscibility, evidenced by deteriorated microstructure and mechanical properties. In addition, the presence of the commercial TPS affects the thermal stability, oxidation, and color of the recycled PE. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of oxidation temperature on the physical properties of β-Ga2O3 grown by thermal oxidation of GaN in the O2 ambient at high oxidation temperatures from 900 to 1400 °C. Notably, the analysis of the oxidation temperatures ranging from 1100 to 1400 °C remains unexplored in the other studies. The effects of the oxidation temperature on the physical properties were investigated via X-ray diffraction, X-ray photoelectron spectroscopy, and field-emission scanning electron microscopy (FESEM). At all oxidation temperatures, XPS results revealed oxygen deficiency. The top FESEM images indicated disordered nanocolumn structures on the surface of the oxide layer, which increased in abundance with oxidation temperatures exceeding 1100 °C. Energy-filtered high-resolution transmission electron microscopy images and the selected area electron diffraction patterns revealed that the top nanocolumns and the oxidized layer comprised polycrystalline β-Ga2O3. Additionally, the cross-sectional lamellae prepared through focused ion beam milling revealed an increase in the thickness of the β-Ga2O3 layer with oxidation temperature. To account for the variations in the oxide layer thickness, the oxidation temperatures were classified into two ranges of 900–1100 °C and 1100–1400 °C for calculating the activation energy. Moreover, this study assumed that the activation energy required for the oxidation process remained constant within each temperature interval. According to Arrhenius's model, the activation energy from 900 to 1100 °C was calculated to be 286.15 kJ/mol (2.97 eV). Furthermore, the activation energy from 1100 to 1400 °C was determined to be 111.33 kJ/mol (1.15 eV).