Vol. 4 No. 2 (2026): July

ZrO₂:Eu phosphor materials were synthesized using a solid-state reaction method in order to investigate their structural and luminescent properties. The obtained powder samples were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) spectroscopy. XRD patterns of all Eu-doped samples reveal the coexistence of monoclinic and cubic phases of ZrO₂, indicating that phase transformation occurs during the high-temperature solid-state synthesis process. The results further suggest that the samples undergo crystallization in a dense solid form. SEM observations confirm the formation of aggregated crystalline particles with relatively uniform morphology. At room temperature, the PL spectra of all investigated samples exhibit a broad emission band attributed to host-related luminescence, along with distinct sharp emission peaks corresponding to the characteristic radiative transitions of Eu³⁺ ions under optical excitation. Notably, the overall luminescence intensity of Eu³⁺ increases by at least six times with increasing fluorine content, demonstrating the strong influence of fluorine incorporation on the optical performance of the phosphor. Possible mechanisms responsible for the enhanced luminescence behavior, including changes in local crystal field symmetry and defect-related energy transfer processes, are discussed. These findings highlight the potential of ZrO₂:Eu materials for photonic and luminescent applications.

In this study, a Ni/Al layered double hydroxide (LDH) coupled with Spirulina-derived hydrochar was successfully synthesizedvia a microwave-assisted hydrothermal method for the photodegradation of methylene blue (MB) under visible light irradiation.The incorporation of hydrochar significantly modified the structural, surface, and optical properties of Ni/Al-LDH, resultingin enhanced photocatalytic performance. Characterization results confirmed the successful formation of the compositewith improved surface area and extended light absorption. Photodegradation experiments revealed that the Ni/Al-Spirulinacomposite exhibited superior performance compared to pristine Ni/Al-LDH, achieving higher degradation efficiency undervarious conditions. The enhanced activity was influenced by operational parameters such as pH, catalyst dosage, and initial dyeconcentration, with optimal performance observed under near-neutral conditions. The improved performance is attributed tothe synergistic effect between adsorption and photocatalysis, where hydrochar facilitates charge separation and promotes thegeneration of reactive oxygen species. Overall, this study demonstrates an effective strategy for developing biomass-based LDHcomposites as efficient and sustainable photocatalysts for wastewater treatment

Phosphor-transmuted white illuminating diode units (ptWLEDs) prove to be an essential illumination means for universal illumination. For balancing the photometrical attributes for ptWLED apparatuses, significant endeavors are still aiming at regulating the thermic abatement for LED colorants. The thermic issues for phosphor components, being a profound dependability trouble in ptWLED apparatuses, continue to be a significant subject for research. The study herein concerns a reliable method capable of assessing phosphor heat within functioning ptWLED via a non-proximity, immediate tracking technique for distantly tracking the discharge spectrum. Usually, infrared cameras or thermocouples would be employed for assessing heat. IR cameras need decent calibrating for discharge and would be typically obstructed via lenses or disparate modules covering phosphor samples. Furthermore, thermocouples need a period for achieving thermic anology among the tracker as well as samples subject to experiment. Said method would be detrimental if employed in intrinsic tracking. The method herein offers benefits surpassing ordinary techniques for non-intrusiveness, non-proximity, immediate as well as intrinsic tracking. Said technique would not be influenced by apex wavelength for pump illumination, the dosage as well as breadth for phosphors as well as correlated chroma heat (CCT).

Layered double hydroxide (LDH) is a promising material; however, its application is still limited by agglomeration and suboptimal physicochemical properties. In this study, Ni–Al LDH was modified with Uncaria gambir leaf extract via coprecipitation to improve its properties. Characterization using FT-IR, XRD, BET, SEM/TEM, XPS, and UV–DRS showed that the layered structure of LDH was retained after modification, while significant changes in surface chemistry resulted from the introduction of phenolic groups. Interaction between the extract and LDH occurs primarily at the surface via hydrogen bonding and π–π interactions. Optical analysis revealed a decrease in the bandgap energy from 2.32 eV to 1.32 eV, indicating increased visible-light absorption. Textural properties revealed a decrease in surface area due to pore closure and increased agglomeration. Nevertheless, the presence of active groups from the extract enhances the material’s reactivity and interaction potential. These results demonstrate that gambier extract effectively modifies the physicochemical properties of LDH, providing a strategy for developing sustainable biomass-based hybrid materials.

We report the growth and fabrication of high-quality GaSe single crystals tailored for uses of nonlinear optics in the mid-infrared spectral range. To improve crystal uniformity and nonlinear performance, the temperature distribution of the crystal-growth furnace was optimized using a computational model based on the finite-volume method, enabling precise control of thermal gradients during solidification. Vertical crystal development was subsequently carried out using the liquid-encapsulated Bridgman technique, which minimizes melt oxidation and promotes stable crystallization. GaSe crystals produced under the optimized furnace temperature profile exhibited significantly enhanced nonlinear optical behavior, with a higher second-harmonic conversion coefficient (d) compared with conventionally grown, undoped GaSe crystals. These results demonstrate that furnace-design optimization is an effective strategy for improving the nonlinear optical efficiency of GaSe, making the material more suitable for advanced mid-IR frequency-conversion devices.

This study investigates the selective adsorption behavior of freshwater macroalgae Cladophora sp. for the removal of mixed dye systems containing cationic (rhodamine B (RB), malachite green (MG), and methylene blue (MB)) and anionic dyes (congo red (CR) and remazol red (RR)). The biomass was characterized using Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) analysis, and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDX), confirming the presence of abundant functional groups and a porous surface structure suitable for adsorption. The point of zero charge (pHpzc) was determined to be 6.5, indicating that the adsorbent surface becomes negatively charged under near-neutral conditions. Selective adsorption was evaluated using UV–Visible spectrophotometry combined with Gaussian peak deconvolution to distinguish individual dye contributions in mixed systems. The results showed a significantly higher adsorption efficiency for cationic dyes, with methylene blue exhibiting the highest removal efficiency (93.56%), followed by malachite green (91.48%) and rhodamine B (51.09%). In contrast, anionic dyes showed considerably lower adsorption, with congo red (33.99%) and remazol red (32.68%). The enhanced selectivity toward cationic dyes is primarily attributed to electrostatic attraction between the negatively charged adsorbent surface and positively charged dye molecules, supported by additional interactions such as π–π stacking and hydrogen bonding. These findings demonstrate that Cladophora sp. is a promising low-cost and sustainable bioadsorbent with selective adsorption capability, making it suitable for the treatment of complex dye-contaminated wastewater.

For supplanting traditional illuminating diode units (LED) made of silicone, non-organic chroma transmuters featuring significant thermic consistency as well as translucency, including phosphor-within-glass (PWG), are examined in the form of encasers applied to high-powered LED apparatuses. The study herein concerns the influence from disparate phosphor forms featuring different chromas (LuAG, silicate, CASN as well as oxynitride) upon the dependability as well as degeneration for separate PWG encasers in the case of high-powered LED apparatuses. Regarding said goal, one glass constitution was individually blended into every phosphor form before undergoing a sintering process under proper heat levels, creating respective PWGs. The dependability in said PWGs underwent examination via conventional quickened aging experiments. Brightness penalties as well as variances for chroma coordinate results from the PWGs underwent assessment prior as well as posterior to aging. Thermic as well as dampness-generated abatement mechanism underwent assessment as well. The exterior for PWGs with disparate phosphor samples degenerated disparately, likely caused by formational inconsistencies among the glass latticework as well as phosphor form. As such, identifying the consistency for the glass constitution alongside the employed phosphor form proves paramount for guaranteeing prolonged consistencies for encasers applied to LED apparatuses in the market.