Materials Letters: X最新文献

In this study, a method was developed for the management of marine plastic waste via the production of activated carbon. The specific surface area, micropore volume, and mesopore volume of marine-plastic-based activated carbon prepared at selected temperatures and using selected activator weight ratios were measured, and the specific capacitance and supercapacitor electrode performance were evaluated. At an activation temperature of 800 °C and a raw material to 8 M KOH weight ratio of 1:7, a specific capacitance of 201F/g and a high surface area of 2389 m²/g were obtained. Therefore, marine plastic waste-based activated carbon can be used as the electrode material in supercapacitors.

Mn₃O₄@CC electrodes were synthesized via a fast one-step molten salt method for flexible quasi-solid symmetric supercapacitors. Mn₃O₄ grows rapidly in a high polarity molten salt system and strongly anchors to carbon cloth. The molten salt method can realize sodion embedded in Mn₃O₄ and then improve the conductivity and capacitance. The results show that the Na-0.9-based supercapacitor exhibits a high capacitance of 1225.7 mF cm⁻² at 5 mA cm⁻². The preparation method, design strategy on structure of composition in this work will provide a novel route to realize high-performance flexible supercapacitors.

Carbon nanodots (CDs) synthesized via the microwave pyrolysis approach are monodisperse with the nano-size distribution. The CDs show color tunability simply by changing the excitation wavelength. Also, the emission intensity varies with varying different microwave response times. Detail characterizations indicate that the carbon defects that lead to heterogeneous emission levels are responsible for the emission properties of the CDs.

Pure and Eu³⁺ doped La₂O₃ nanophosphor was synthesized by sol gel process. PL spectra of undoped La₂O₃ samples shows broad emission peaks between 400 and 600 nm and Eu³⁺ doped samples show PL emission peaks at 510, 515, 531, 537, 553, 578, 585, 594, 612 and 624 nm. These peaks are attributed to ⁵D₁ → ⁷F₂, ⁵D₁ → ⁷F₂, ⁵D₀ → ⁷F₀, ⁵D₀ → ⁷F₁,⁵D₀ → ⁷F₂ transitions of Eu^{3 +} ions. The electronic dipole transition corresponding to⁵D₀ → ⁷F₂ (624, 612 nm) is stronger than the magnetic dipole transition of ⁵D₀ → ⁷F₁ (585, 594 nm) of Eu³⁺ ions. Luminescence behavior of Eu³⁺ in La₂O₃ is analyzed by Judd–Ofelt intensity parameters.

CdSe and CdSe:Te thin films were grown on Si p-type substrates by RF magnetron sputtering method. The doping percentage of Tellurium (Te) in CdSe was 7% for the CdSe:Te thin film. The results show that after the doping of Te in the CdSe thin film, the conductivity changes from n-type to p-type and the mobility of the CdSe thin film increased. The conductivity of Te doped CdSe was found to be in order of 10⁻⁶ Ω⁻¹ cm⁻¹, while without doping it was 10⁻⁵ Ω⁻¹ cm⁻¹. X-ray diffraction (XRD) confirmed the presence of CdSe, Te and Si.

Core@shell nanomaterials are a class of materials containing a core and a shell, both at the nanometer scale, as they have become a consequential research interest owing to their optical, electrical, and magnetic properties. Moreover, various core@shell nanomaterials have also emerged in many other fields, such as catalysis, pharmaceuticals, and biomedical due to their less toxicity, surface area, good biocompatibility, adequate penetration power for biological tissue, and selectivity for target molecules. Hence, this review covers the optical properties of core@shell nanomaterials and biosensors based on various core@shell nanomaterials, for example, inorganic@inorganic (Au@Ag), organic@inorganic (polyurethane@Au), inorganic@organic (CeO₂@polyaniline), and organic@organic (poly(vinylidene difluoride)@dopamine) for biomedical applications; along with this, it also discusses the advantage and disadvantage of core@shell nanomaterials.

In the present work, ²⁴¹Am incorporated in SrBPO₅ (SBP) host matrix was investigated by various spectroscopic techniques to understand the trap level spectroscopic properties of the system. Photoluminescence (PL) depicted stabilization of Am in +3 oxidation state with low local symmetry. Thermoluminescence (TL) on the other hand suggested that creation of self irradiated defects in SBP:²⁴¹Am leads to a glow curve around 463 K. Electron spin resonance (ESR) further confirmed the creation of borate radical in axial symmetry on doping ‘Am’ in SBP with hyperfine splitting. We could further propose the mechanism of TL glow curve on doping Am in the SBP lattice.

In the present work, the effect of deposition time (10 min, 20 min, and 30 min) on the structural, morphological, and electrical properties of Al/Ta thin films has been investigated. The XRD and microscopy results revealed that the thin films exhibit a bcc structure, with a strong (1 1 0) preferred orientation and followed a columnar growth with grain sizes lower than 100 nm. Thin film with 20-min deposition time exhibits less average roughness and better morphology than 10-min and 30-min. Further, the average resistance was smallest for thin films with 20-min of deposition time along with the optical reflectance between 50 and 85% in wavelength region of 400–1000 nm. The Al/Ta thin film can be employed as an excellent back-contact material for thinfilm solar cells due to its improved crystallinity, reflectance, and lower resistivity.

FeCrAl alloys are among the most promising candidates for accident-tolerant fuel cladding material in light water nuclear reactors. Despite their high-temperature oxidation resistance in corrosive environments coupled with their hydrothermal corrosion resistance, a key challenge remains in optimizing the composition of the alloy that can be achieved through statistical analysis. However, the current literature on FeCrAl alloy design lack studies for designing alloys based on oxidation resistance. This study addresses that gap by developing a predictive model for the oxidation of FeCrAl alloys based on an experimental dataset, which lays the groundwork for model-based optimization for alloy composition.