This study investigates the surface area, optical characteristics, adsorption behavior, and photocatalytic performance
of graphite (G), copper oxide (CuO), iron oxide (Fe₂O3), and CuO/Fe₂O3 nanoparticles (NPs), as well as
their modified nanocomposites (NCs): CuO/G (denoted as Cu/G), Fe₂O3/G (Fe/G), and CuO/Fe₂O3/G (CuFe/G).
The co-precipitation method was used for NPs synthesis, whereas NPs/G are synthesized via the hydrothermal
method. The samples are characterized using XRD, SEM, and BET analyzers, and tested using optical, adsorption,
and photocatalytic measurements. The structural analysis confirmed hexagonal, monoclinic, and rhombohedral
structures for G and NPs along with mixed phases for NCs. Graphite (G) exhibits the highest porosity (PS) among
all tested materials, while incorporating G enhanced the PS of the NCs. The G structure was confirmed by wellstacked
graphene sheets. The NPs adopted a regular or irregular spherical shape, whereas the NCs formed larger
aggregates consisting of multiple NPs. The G exhibited the highest surface area (SA) at all, whereas the NPs
exhibited the lower values. However, incorporating G into NPs enhanced the SA, with the highest value for Cu/G
among NCs. Notably, pure NPs exhibited two distinct electronic transitions and corresponding energy gaps (Eg1
and Eg2), whereas the other samples displayed only a single transition with a unique Eg. Regardless of the Eg2
for NPs, the Eg is 2.2 eV for G, whereas the NPs and NCs generally demonstrated reduced Eg, spanning
1.45–2.45 eV. Graphite demonstrated the highest photocatalytic efficiency (η) of 68.78 % after 300 min, but it
decreased to 41.90 and 39.67 % for NPs and then increased for all NCs, with Cu/G reaching 61.02 %. The CuFe/G
NCs showed the highest removal efficiency of 53.69 % after 420 min, followed by Cu/G NCs (51.87 %), which
are better than those of G and NPs. The proper model for CuFe/G NCs is pseudo-2nd-order, but it changed to
pseudo-1nd-order for the other samples. These outcomes collectively demonstrate that graphite modification
provides a versatile approach to engineering composite materials with simultaneously enhanced properties
convenient for optoelectronic and water treatment applications.

This study investigates how transition metal selection influences the multifunctional properties of
T0.40Mn0.60Fe2O3 nanocomposites (NCs), where T represents Cu, Sn, Co, or Ni. Using hydrothermal method, we
prepared four NC variants and systematically characterized their structural, mechanical, magnetic, and dielectric
properties through XRD, FTIR, VSM, and BDS. X-ray diffraction revealed distinct phase compositions: Cu and Co
NCs contained monoclinic T2Mn3O8, rhombohedral Fe2O3, and cubic Fe3O4 phases, while Sn and Ni NCs formed
cubic TMn2O4 instead of the monoclinic phase. Mechanical properties varied significantly, with Cu/Sn NCs
showing larger crystallites but lower porosity compared to Co/Ni NCs. All compositions exhibited roomtemperature
ferromagnetism, with Co/Ni NCs demonstrating superior saturation magnetization (47.13 and
39.27 emu/g versus 7.45 and 30.54 emu/g for Cu/Sn) but lower coercivity (372–13.2-G versus 1.33×
103–55.99 G). Dielectric measurements showed frequency-dependent behavior, with relaxation peaks appearing
only in Sn/Co/Ni NCs. The AC conductivity followed the order Cd > Sn > Cu > Ni > Co, while impedance
analysis revealed grain boundary effects dominating in Ni/Co NCs. These property variations stem from the
interplay between magnetic moments (Co/Ni) and non-magnetic ions (Cu/Sn), enabling tailored applications:
high-Ms Co/Ni NCs for spintronics, and high-Hc Cu NCs for permanent magnets, while Sn NCs show promise for
high-frequency dielectric applications.

Aluminum-doped hematite nanoferrites (α-Fe2¡xAlxO3, x = 0.3 and 0.6) were synthesized via a hydrothermal
method and annealed at 180 ◦C for varying durations (8–16 h) to investigate their structural, magnetic, optical
band gap, and photocatalytic properties. The key innovation lies in achieving simultaneous optimization of
structural, magnetic, optical, and photocatalytic properties in a single material system - a significant advancement
over conventional hematite nanomaterials. The α-Fe2􀀀 xAlxO3 has a rhombohedral (R3c) structure, with
increasing Al content (x) reducing unit cell volume, crystallite/grain sizes, and effective mass, while increasing
bond length and Debye temperature. Annealing up to 12 h minimized crystallite size and effective mass, but
further annealing to 16 h reversed this trend. FTIR analysis revealed hydroxyl radical bands associated with
antibacterial activity at x = 0.3, which disappeared at x = 0.6. Magnetic studies showed that saturation
magnetization, retentivity, and coercivity increased with higher x, with coercivity peaking at 12 h of annealing.
Also, Al-doping reduced the switching field distribution and influenced magnetization behavior. Tauc analysis of
UV–visible spectra confirmed direct optical transitions with band gaps of 4.86–5.29 eV, demonstrating Al-doping
effects on hematite’s electronic structure. The photocatalytic performance was assessed by degrading methylene
blue (10⁻5 M) under UV–visible irradiation for 3 h. The optimal photocatalytic efficiency (66.01 %) was achieved
at x = 0.6 after annealing at 180 ◦C for 8 h, corresponding to an apparent kinetic rate of 4.6 × 10􀀀 3 min􀀀 1. These
findings demonstrate that Al-doped hematite nanoferrites, particularly when annealed at 180 ◦C for 12 h, exhibit
tunable properties suitable for advanced applications in memory devices, spintronics, and water treatment
technologies.

Fano resonance with asymmetric and sharp spectral features has recently been intriguing for refractive index sensing. In this study, we demonstrate a Fano resonance sensor that employs the coupling between a metal-insulator-metal (MIM) waveguide and a semi-ring resonator. The MIM waveguide has a three-ring resonator built in the center, and high-field confinement is observed due to the coupling of the two structures. The coupled structure's transmission spectrum exhibits three Fano resonance modes that are influenced by structure geometry and the surrounding medium's refractive index. The high-quality factor ( ) of mode 3 indicates that this sensor is suitable for use in optical sensing applications. To achieve maximum sensing performance, the parameters of the proposed structure are manipulated and different sensing parameters are computed. The sensor's estimated sensitivity of 3164.97 nm/RIU is equivalent to that of other Fano resonance sensors. Additionally, for plasmonic MIM sensors, the developed sensor achieves high values of and of 5420.99 and 5641.57 , respectively. The proposed high-sensitivity sensor could be an attractive choice for sensing applications because of its straightforward design and ease of fabrication. Also, the combination of very high sensitivity and FOM in a tiny and compact configuration is ideal for on-chip plasmonic nanosensors

We propose and analyze a novel plasmonic multi-resonator perfect absorber based entirely on an all-metal Cu grating structure for high-performance optical sensing applications. The design features a continuous Cu substrate with two identical grating exhibiting seven distinct narrowband resonances spanning the near-infrared region (1270–1990 nm) with absorption efficiencies exceeding 90%. With an ultra-narrow linewidth (FWHM = 0.0188 nm) and an outstanding Q-factor (≈ 10⁵), the highest-order resonance (P7) exhibits a perfect absorption value at 1991.312 nm, guaranteeing remarkable spectrum selectivity and sensing resolution. To enable tailored sensing capabilities, systematic studies reveal that adjusting geometric features such as the grating height and the spacing between gratings can precisely tune the resonance wavelength while maintaining strong absorption and narrow linewidths. Sensitivity analysis against refractive index variations in the surrounding medium indicates a high sensitivity (S ≈ 1991.311 nm/RIU), an outstanding figure of merit (FOM ≈ 1.06 × 10⁵), and a low detection limit on the order of 10⁻⁶ RIU. The absorber’s strong sensitivity to small changes in refractive index, including those caused by gas analytes such as air, helium, nitrogen, and carbon dioxide, highlights its promising potential for use in multiplexed and selective biochemical and gas sensing applications. The use of an all-metal configuration supporting multiple high-Q resonances is unique among current absorber designs. This structure combines simplicity, tunability, and multi-wavelength operation in a single material platform, o​f​f​e​r​i​n

Metamaterial perfect absorbers operating at resonance wavelengths have emerged as a promising platform for next-generation optical sensing technologies. In this study, we propose and investigate a high-performance plasmonic absorber designed for refractive index sensing in the infrared region, based on a Fabry–Perot resonance cavity. The structure consists of a thick gold layer acting as a reflective mirror and absorber, while carefully selected dielectric silicon strips are used to achieve optimal resonance coupling. The main innovation lies in integrating a Fabry–Perot resonance cavity with a plasmonic absorber to achieve near-perfect absorption and precise wavelength tunability. This approach improves the sensing accuracy and efficiency compared to traditional absorbers by leveraging strong resonance coupling and optimized material configuration. By varying the refractive index of the dielectric spacer material between the Fabry–Perot mirrors, the sensor demonstrates a clear and measurable shift in resonance wavelength. The proposed design achieves a high sensitivity of 993.03 nm/RIU, an exceptional quality factor of 1581.96, a figure of merit of 958.49 , and near-perfect absorption reaching 99.5 %. These results highlight a significant improvement in sensing performance compared to conventional designs and suggest strong potential for applications in highly sensitive metamaterial-based optical sensors. The proposed structure significantly enhances sensing performance by achieving a higher sensitivity, quality factor, and figure of merit compared to conventional plasmonic absorbers. These advancements make the design well-suited for real-world applications in optical biosensing, environmental monitoring, and infrared detection technologies.

Fluids are major fractionation agents in granitic systems because they partly control the behaviour and partitioning of elements, including rare metal, during the magmatic-hydrothermal transition and their subsequent redistribution during the later subsolidus stage. The exsolution of magmatic fluids from a volatile-saturated magma and their subsequent circulation commonly result in important textural and geochemical changes with primary magmatic features being entirely overprinted and earlier minerals chemically re-equilibrated. The changes documented herein serve as a basis for tracking the equilibration of a rare-metal granite with interacting fluids. The Mueilha F-Nb-Ta-REE-Y granitic system (Eastern Desert of Egypt) is composed of different facies such as the “red granite”, representing the main volume of the intrusion, and the “border facies”, occurring along the red granite south-western margin

A high resonance peak in the spectral response enables a highly sensitive mechanism for refractive index monitoring, enabling accurate detection of environmental changes. In this work, a new plasmonic structure that incorporates two periodic silver nanorods into a metal–insulator-metal (MIM) waveguide are proposed. Dual periodic silver nanorods in MIM waveguide form the basis of the innovative and straightforward plasmonic structure introduced by the suggested design, which has never been described before. Due to the periodic manipulation of silver nanorods, this arrangement offers a high-quality factor resonance and remarkable sensing capability, all while being tiny and straightforward to fabricate. A high-transmission resonance mode that is highly sensitive to the surrounding medium’s refractive index is supported by the cavity produced between these nanorods. The performance of this design using finite element method ($\text{FEM}$) simulations was examined, showing plasmon-induced transparency ($\text{PIT}$) effects and notable improvements in refractive index sensitivity. The sensor is comparable to the most sophisticated plasmonic sensors on the literature with a sensitivity of $1780\text{nm}\mathrm{/}\text{RIU}$. Additionally, the suggested design achieves an exceptional Quality factor ($\text{Q}-\text{factor}$) of 1537.96 and a Figure of merit ($\text{FOM}$) of 1537.39 $RI{U}^{-1}$. A wide range of refractive index (RI) sensing applications could benefit from the sensor’s high performance and straightforward production procedure.

In this work, a versatile compound, 4-cyano-1,6-dimethyl-8-phenyl-7,8-dihydroisoquinoline-3(2H)-thione (3) was synthesized and utilized as a starting compound for the preparaton of the title compounds. Thus, reaction of 3 with iodomethane, 2-chloroacetamide, ethyl chloroacetate, chloroacetonitrile or N-(benzthiazol-2-yl)-2-chloroacetamide by heating in ethanol containing sodium acetate, gave 3-unsubstituted or 3-substituted methylsulfanyl-7,8-dihydroisoquinoline-4-carbonitriles 4 or 6, 8, 10 and 16 respectively. The latter compounds (6, 8, 10 and 16) contain an active methylene group that adds easily to the carbonitrile group to build a thiophene ring, fused to an isoquinoline moiety, upon heating with sodium ethoxide in ethanol thus affording the corresponding 6,7-dihydrothieno[2,3-c]isoquinolines 7, 9, 11 and 17, in nearly quantitative yields. Compounds 9, 11 and 17 underwent further reactions with some reagents to give other 6,7-dihydrothieno[2,3-c]isoquinolines 12-15 and 3,4-dihydropyrimidothienoisoquinoline 18. All synthesized compounds were screened for their biological activity as bactericidal and fungicidal agents. Some of them showed promising antifungal activity.