Although different metal–organic framework (MOF) membranes have been widely studied for gas separation, their application for water treatment is still in its infancy. MOF membranes with improved hydrophilicity and stability are particularly essential for water/wastewater treatment. Herein, we have successfully developed heterogeneous membranes (Zn/Co-ZIF-L) composed of vertically standing leaf-like crystals of Zn-ZIF-L grown in situ onto porous ceramic supports, followed by the subsequent heterogeneous growth of Co-ZIF-L. The heterogeneous membranes show improved hydrophilicity (WCA = 13.6 ± 1.6°) and enhanced anti-bacterial adhesion. Significantly, they simultaneously deliver a relative high water flux and much improved anti-bacterial adhesion when compared with the homogeneous membranes (Co-ZIF-L and Zn-ZIF-L). The improvements are attributed to the intrinsic hydrophilic nature of Co-ZIF-L, their epitaxial growth onto Zn-ZIF-L as well as the increased surface roughness. The success of constructing a heterogeneous MOF structure shows an effective strategy to achieve the hydrophilic MOF membranes with considerably enhanced stability for water treatment.

Supercapacitors (SCs) have been widely studied as a class of promising energy-storage systems for powering next-generation E-vehicles and wearable electronics. Fabricating hybrid-types of electrode materials and designing smart nanoarchitectures are effective approaches to developing high-performance SCs. Herein, first, a Ni-Co selenide material (Ni,Co)Se₂ with special cactus-like structure as the core, to scaffold the NiCo-layered double hydroxides (LDHs) shell, is designed and fabricated. The cactus-like structural (Ni,Co)Se₂ core, as a highly conductive and robust support, promotes the electron transport as well as hinders the agglomeration of LDHs. The synergistic contributions from the two types of active materials together with the superior properties of the cactus-like nanostructure enable the (Ni,Co)Se₂/NiCo-LDH hybrid electrode to exhibit a high capacity of ≈170 mA h g⁻¹ (≈1224 F g⁻¹), good rate performance, and long durability. The as-assembled (Ni,Co)Se₂/NiCo-LDH//PC (porous carbon) asymmetric supercapacitor (ASC) with an operating voltage of 1.65 V delivers a high energy density of 39 W h kg⁻¹ at a power density of 1650 W kg⁻¹. Therefore, the cactus-like core/shell structure offers an effective pathway to engineer advanced electrodes. The assembled flexible ASC is demonstrated to effectively power electronic devices.

Thin films of As₄₀S_60-xSe_x ((0 ≤ x ≥ 60) at. %) have been efficiently synthesized through the process of vacuum thermal evaporation. The present framework analyzes the thin films to determine both optical and electronic parameters as a function of change of Se concentrations. The thickness of the obtained films, d have been mathematically determined utilizing Swanepoel's computations and experimentally via an MII-4 interference microscope with an accuracy of 1%. The thickness of the studied films has been closed to 500 ± 15 nm. Additionally, the optical properties of these films have been scrutinized from the transmittance and reflectance spectra measured by a UV–Vis–NIR spectrophotometer. The transmission spectra, T (λ) of such films have been documented in the spectral region 400–2500 nm. Based on the optical measurements, all of the linear optical constants, the linear optical and dielectric parameters, the linear and non-linear optical susceptibility criteria, and the material dispersion coefficient M(λ) have been computed. Besides, the nonlinear refractive index, energies of the electronic polarization have been determined.

Different compositions of as-obtained As₄₀S_60-xSe_x thin films (x = 0 at.%, 20 at.%, 40 at.%, and 60 at.%) with fixed thicknesses were deposited by a thermal evaporation technique. Inheterogeneities of thin-film thickness is a problem that includes significant errors of optical calculations unless there is an optical model that prevents these errors, and the consequent gross errors, in the measurement of optical constants. If not taken into account, this may lead to rather large calculated values for the absorption coefficient or the incorrect presence of the absorption-band tail, as well as to significant errors in the calculated values of the refractive index and film thickness. The optical properties of As₄₀S_60-xSe_x thin films have been determined utilizing measurements of the optical transmission spectra. Owing to the shrinking of the transmission spectra in both the medium and strong absorption regions, we have resorted to applying the optical wedge model for the determination of the film thickness with high precision that equals approximately 725 nm. This paper therefore presents formulae for the transmittance spectrum of a thin dielectric film of selected thickness covering a thick, non-absorbing substrate as well as its upper and lower envelopes. The effect of the content variation on the interference fringes of the transmittance spectrum is analyzed in detail. The electrical properties of the As₄₀S_60-xSe_x thin films have been studied in terms of measuring the temperature-dependent AC conductivity. Both the dielectric constants and dielectric modulus were investigated and are discussed for applications in optoelectronic devices. The change in electrical properties of As₄₀S_60-xSe_x thin films has been interpreted in terms of changed morphological and structural properties. The ratios of the elements were analyzed by comparing them with the actual weight ratios of the bulk material using EDX technology, in addition to the assessment of the Amorphic structure and composition characteristics of the films examined by the x-ray and scanning electron microscopy.

This study reports the linear and nonlinear optical and electronic properties of as-prepared and annealed ∼240 nm thick Ge₂₀Te₈₀ films. The optical properties were studied based on the transmittance and reflectance spectra measured by spectrophotometer within the range of 380–1090 nm. The optical absorption data were described by Tauc’s relationship. The refractive index and extinction coefficient were evaluated, and a correlation between the refractive index and the optical bandgap is discussed. The dispersion and oscillator energies were analyzed by the Wemple-DiDomenico concept of the single oscillator. The dielectric constants, the loss tangent, and volume/surface energy loss functions were deduced. The electronic polarizability was computed by three different methods. The optical bandgap of thermally evaporated Ge₂₀Te₈₀ film and films annealed at 373–473 K (amorphous films) exhibit allowed direct and indirect transitions while the films annealed at 523–573 K (crystalline films) exhibits only allowed direct transition. The developments of crystal structure, optical parameters, and the optical conductivity upon thermal annealing, make the Ge₂₀Te₈₀ chalcogenide film candidates for numerous photonic applications.

Thermal analysis of chalcogenide glass similar to other materials is of great importance in order to increase the knowledge about its phase transitions, thermal stability, etc. The current study reports on the thermal kinetics of melt-quenched Zn₅Se₉₅ chalcogenide glass using differential thermal analysis (DTA) techniques under non-isothermal conditions. The glass-forming ability (GFA) and the relation between the glass transition and onset crystallization temperatures are found to show a linear behavior. In addition, Moynihan et al. Kissinger’s, and other approaches of Johnson-Mehl-Avrami utilized to determine the activation energy of the amorphous-crystalline and glass transition. It is found that the glass transition process cannot be concluded in terms of single activation energy, and that variation with the extent of conversion was analyzed using various iso-conventional methods. Therefore, the observed change of the activation energy throughout the glass transition reveals that the transition from amorphous to the supercooled liquid phase of Zn₅Se₉₅ glass is a complex process. The crystallization process at different heating rates is simulated using the Málek method, and Šesták–Berggren SB(M,N) model, in which the SB model show fairly good matching with the experimental DTA data. Moreover; the fragility index is a measure of the GFA of Zn₅Se₉₅ chalcogenide glass, which has been estimated using the glass transitions and activation energy values. We have found that the fragility index of Zn₅Se₉₅ glass values in between ∼13 and 30, depending on the heating rate, revealing that the synthesized glass is a strong liquid with excellent GFA.

Ge-In-Se system, similar to many other chalcogenide glasses, has attracted much attention due to its interesting physical properties and applications. This article reports thermal analysis and estimation of activation energies of the glass transition and amorphous-crystallization transformation of Ge₁₃In₈Se₇₉ chalcogenide glass. The kinetic parameters were investigated under a non-isothermal condition at different heating rates (7–40 K/min) using differential scanning calorimetric (DSC) technique. The amorphous nature of the samples was confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The activation energy was calculated from DSC data using five isoconversional methods: Kissinger–Akahira–Sunose (KAS), Flynn–Wall–Ozawa (FWO), Tang, Starink, and Vyazovkin. The results confirm that the activation energy of crystallization varies and depends on the degree of crystallization as well as temperature. It was also observed that the transformation from amorphous to the crystalline structure is complex involving different mechanisms of nucleation, diffusion, and growth.

Porous anodic alumina (PAA) templates have been extensively studied due to their unique morphology and extensive applications. The fabrication of PAA can be modulated to achieve a self-ordered pore structure with desired pore size and interpore separation. PAA thin film templates were fabricated from silicon doped aluminum film, Al-1 wt% Si, based on one-step anodization method at 22 °C. Effects of anodizing potential (10–20 V) as well as sulfuric acid concentrations (0.6–1.8 M) on current density, interpore distance, anodization rate, and volume expansion were evaluated. The results indicated that current density increased largely exponentially with a concentration of the electrolyte at a given anodizing voltage. In addition, distinct and well-ordered pores were obtained for anodization conducted at 15 V and 20 V. The volume expansion factor is proportional to the applied voltage. At 1.8 M sulfuric acid, the expansion factor increases with pore regularity with 1.4 considered as the transition point. The minimum current density (2.1 ± 0.15 mA cm⁻²) was observed at the minimum anodizing condition (0.6 M, 10 V). Also, maximum anodizing condition (1.8 M, 20 V) resulted in the highest current density of 34 ± 4 mA cm⁻². As expected, anodization time decreases with an increase in both anodization voltage and electrolyte concentration.

Different compositions of the bulk sample of Zn1-xGdxO (x = 0, 0.02, 0.04, 0.06, 0.08 and 0.1) are fabricated using co-precipitation technique. The current study investigates the structural, optical and magnetic properties of ZnO thin films doped by Gd. The desired films were deposited onto highly-clean glass substrates by electron beam technique. X-ray diffraction revealed the formation of hexagonal wurtzite single phase of ZnO and having intense (002) peak with a peak shift towards lower angle. The crystallite size of the films was found to be decreased with increasing Gd content. The effect of Gd dopant on the optical and magnetic properties of the prepared thin films was investigated. The optical energy gap decreases from 3.27 to 3.11 eV with increasing Gd content. In addition, ferromagnetism initially increases up to optimal Gd concentration at 0.06 after that the ferromagnetism decreases with increasing Gd concentration (at 0.08 and 0.1). The changes in the optical and magnetic properties of the prepared films were discussed based on the structural modification, which, further, enhances upon Gd-doping..

Two nanocomposite oxides, NiO/Co₃O₄ and CuO/Co₃O₄, have been considered. These nanocomposite oxides of (1-x)NiO/xCo₃O₄ and (1-x)CuO/xCo₃O₄ with different contents of (x = 30, 50 and 70 wt%) have produced successfully using microwave irradiation. The resulted powders of pure and mixed nanoparticles (NPs) have been characterized by thermogravimetry (TGA), differential thermal analysis (DTA) and x-ray diffraction (XRD). It can be observed in TGA that the mass loss end of Co₃O₄, NiO and CuO NPs is at three stages until reach to the decomposition of Co(OH)₂, Ni(OH)₂ and Cu(OH)₂, respectively. The process of mass loss is confirmed by endo- and exo- thermic peaks in DTA thermogram. The structural properties of these nanocomposites have been studied. The XRD result confirmed the formation of pure NPs as well as the nanocomposites of NiO/Co₃O₄ or CuO/Co₃O₄ NPs. Size of nanocomposites dependence on both type and concentrations of dopant have been studied. The formation of p-p type has been confirmed by structural investigations.