Highly sensitive and reliable gas sensors are needed for environmental monitoring of highly hazardous air pollutant nitrogen dioxide (NO₂). In this work, ZnO: CeO2 nanocomposite films prepared by hydrothermal method with different contents of CeO2 (5, 7 wt
Traditional polyimides (PI) have poor solubility in common organic solvents due to the high rigidity of the main chain and strong intermolecular forces. Consequently, the traditional negative photosensitive polyimides (PSPIs) processing needs to use a large amount of DMF, NMP and other toxic organic solvents to dissolve the poly(amic acid) (PAA), which causes the problems of volatile organic compounds emission, difficult recovery and high cost. With increasing environmental concerns, it is essential to fundamentally address the solubility limitations of PIs to reduce their dependence on hazardous solvents and improve environmental compatibility. 3,5-diaminobenzoic acid (DABA) was used to improve the solubility of PI. The carboxyl groups in DABA molecules were introduced as pendant groups along the PI main chains, which greatly increased the polarity of the polymer and provided more reactive sites for the photosensitive compound, thus significantly improving the solubility of PAA in a milder and more environmentally friendly solvent system. In this study, a series of photosensitive poly(amic acid) (PSPAA) samples with varying DABA contents were synthesized. The structure, mechanical properties, thermal properties, and morphology of PI were investigated by FTIR, DMA, TGA, and SEM, respectively, through which the optimal DABA ratio was obtained.
In contemporary technological contexts, binary Sb2S3 chalcogenide thin films assume a pivotal role. Sb2S3 nanocrystals were successfully synthesised from ethylene glycol as a solvent via a solution-based technique. The subsequent thin-film coating was achieved using the pure-phase material via thermal evaporation. A comprehensive analysis utilising XRD, FESEM, EDAX, Hall measurements, and UV–Vis spectroscopy provided insights into the characteristics of the prepared Sb2S3 thin films. After post-annealing at 250 °C, XRD data indicate the formation of polycrystalline Sb2S3 with an orthorhombic structure. UV–Visible spectroscopy investigations revealed a calculated direct band gap of approximately 1.7 eV, in close agreement with the ideal band gap for optimal solar cell efficiency in Sb2S3. Notably, the annealed thin films of Sb2S3 exhibit promise as a superior P-type absorber layer for low-price solar cells. This study elucidates the impact of annealing on phase transformations and underscores the efficacy of Sb2S3 solar cells for light capture.
The piezoelectric properties of Sm-doped 0.71PMN–0.29PT (Sm:PMN–PT) polycrystalline ceramics were systematically investigated under DC and AC poling conditions. For DC poling, the influences of poling time, applied electric field, and sample thickness were examined. In AC poling, additional parameters, including poling frequency, number of cycles, and waveform, were evaluated. Both poling methods were conducted within an electric-field range of 0.5 - 7 E_C ( E_C = 3 kV/cm). Under DC poling, optimal values of d_33 = 1100 ± 20 pC/N and k_eff = 55 ± 2% were achieved at a poling field of 4 E_C , for 5 min. In contrast, AC poling produced optimal values of d_33 = 1090 ± 20 pC/N and k_eff = 52 ± 2% at a lower field of 3 E _C , using a bipolar triangular waveform at 3 Hz for 15 cycles. Although both poling methods yielded comparable piezoelectric performance, AC poling achieved optimal properties more rapidly (shorter poling duration) and at a reduced electric field. Moreover, dielectric constant measurements at 10 kHz revealed an increase from ε ' = 27 947 (unpoled) to 32 602 (DC-poled) and 37 782 (AC-poled), with AC poling providing the highest enhancement. Compared to the DC-poled sample, AC-poled ceramics exhibited a 16
This study investigates the temperature-dependent dual gas sensing behavior of tin oxide (SnO2) films toward NO2 and H2S using the Substrate Rotation Chemical Bath Deposition (SRCBD) method. Vacuum annealing of as-deposited (60 °C) SnO2 films at 300°–500 °C for 1 h produced thicknesses from 156 –71 nm. XRD showed that the obtained films were of mixed-phase SnO2 and the preferred combination of tetragonal orthorhombic orientation changed with thickness. SEM revealed a transition from isolated grains to a granular network, while EDS and Raman confirmed a high surface oxygen content. The developed mixed-phase SnO2 film-based MOS sensor was tested for detecting low concentrations (0.5–5 ppm) of H2, CO2, NH3, NO2 and H2S test gases at operating temperatures of 50°–350 °C. The 156 nm thick SnO2 film sensor showed strong responses at 200° and 100 °C, with sensitivities of 6.68
The control of heat-affected modifications is a major challenge in ultrafast laser processing of polymers due to their low thermal diffusivity and phase transition temperatures. While these effects are typically localized in the vicinity of the ablation region, the interaction may evolve from positive heat-affected deformation to efficient material removal, depending on the irradiation conditions. In this work, we investigate how pulse duration (220 fs – 32 ps), beam radius (40 –118 μm), and repetition rate (100 Hz – 60 kHz) govern the laser-induced response of poly(vinyl chloride) (PVC) under 1030 nm ultrafast laser irradiation. These results reveal that heat accumulation strongly influences the interaction behavior even under fluence conditions above the single-pulse ablation threshold. Under heat accumulation conditions, heat-affected modifications decrease beyond a certain repetition rate, while ablation remains efficient. This behavior suggests that material removal may reduce the fraction of deposited energy contributing to heat diffusion into the surrounding region. These findings suggest that, in polymers with low thermal diffusivity, efficient material removal can contribute to reducing heat-affected modification at repetition rates well below the GHz regime typically discussed in the context of ablation cooling. This enables the investigation of this regime under conditions where the influence of additional effects, such as plasma or particle shielding is reduced. This work provides new insights into the interplay between heat accumulation and material removal in ultrafast laser processing, offering guidelines for the controlled fabrication of surface structures and the optimization of laser processing conditions.
A series of titanium borate strontium glasses doped with PbO of composition (67 − x)B₂O₃–18SrO–10TiO₂–4ZnO–1CeO₂–xPbO (x = 5, 9, 13, and 17 mol
Artificial two-dimensional lattices hosting flat bands, such as the Lieb lattice, provide versatile platforms for engineering materials with tailored longitudinal optical conductivity. Here, we present a comprehensive theoretical investigation of the longitudinal optical conductivity in a doped Lieb lattice under Holstein-type electron–phonon coupling and Zeeman splitting induced by a perpendicular magnetic field. Using the full-band one-loop Migdal approximation and the Kubo formula, we systematically examine how next-nearest-neighbour hopping ( t' ), staggered on-site potential ( ±Δ ), electron–phonon coupling strength, magnetic field, and doping level control the optical conductivity. Our results demonstrate that Holstein coupling suppresses the Drude weight through polaronic effects. Moreover, the magnetic field suppresses the low-frequency absorption and Drude weight. Importantly, both t' and the sublattice asymmetry induced by ±Δ serve as independent and powerful tuning parameters that significantly enhance optical absorption and introduce pronounced asymmetry in the spectra. These findings establish a robust multi-parameter framework for tailoring the longitudinal optical conductivity of flat-band two-dimensional systems. Given the experimental realization of Lieb lattices in photonic crystals and surface-engineered nanostructures, our predictions of tunable Drude weight and magnetic-field-controlled absorption offer directly testable signatures and practical design guidelines for developing novel materials with engineered optoelectronic functionalities in nanostructured and photonic platforms.
Localized surface plasmon resonance (LSPR) of gold nanoparticles (Au NPs) can modulate the undesirable brownish-yellow coloration of vanadium dioxide (VO2) films for smart windows. However, the phase transition of VO2 alters the local dielectric environment of Au NPs, thereby degrading the solar modulation ability (ΔTsol). Herein, HfO2 was as a buffer layer to stabilize the dielectric environment surrounding Au NPs. The effects of HfO2 thickness on the microstructures and thermochromic properties of Au/HfO2 and Au/HfO2/VO2 composite films were investigated. The results show that as the HfO2 thickness increasing from 0 to 300 nm, the LSPR peak of Au/HfO2 composite films redshifts from 529 nm to 597 nm, while that of Au/HfO2/VO2 composite films blueshifts from 665 nm to 616 nm, accompanied by a morphological transition of VO2 from discrete rectangular particles to compactly arranged flake like structures. Optical characterization demonstrates that HfO2 incorporation boost the ΔTₛₒₗ of Au/HfO2/VO2 films to 8.4
C/C-(Hf, Ta)C-SiC composites with different Hf/Ta ratios were fabricated using a combined process of precursor impregnation and pyrolysis as well as reactive melt infiltration. And an obvious Hf/Ta ratio deviation was caused by the high carbon content of HfC precursor, which brought significant influence to the density and phase composition of the composites at the same time. The composite with a Hf/Ta designed mole ratio of 1:1.5 exhibited the most excellent ablation resistance, with the mass and linear ablation rates of 0.085 mg/s and 0.092 μm/s respectively. During ablation, the (Hf, Ta, O) phases with different Hf/Ta ratios presented different ablation morphologies and the solid (Hf, Ta, O) pinning phases embedded in the molten SiO2, forming a dense and erosion-resistant oxide film that prevented further ablation of the internal material. Meanwhile, the reduced density and relatively lower (Hf, Ta)C content of the composites with high designed Hf/Ta ratio were the main cause for the inferior ablation resistance. And the development of ceramic precursor with high yield and stability is the research emphasis in the future fabrication of high temperature ceramic matrix C/C composites.
The present study reports the synthesis of the bimetallic nanocomposite MnS-Sb2S3 through a single source precursor method and evaluate its multifunctional performance for supercapacitor energy storage and electrochemical water splitting. Structural and optical analysis confirmed the coexistence of cubic MnS and orthorhombic Sb2S3 phases with an average crystallite size of 14.68 nm and a direct optical band gap of 3.4 eV. The finger print region for MnS-Sb2S3 nanocomposite in range between 400 and 850 cm− 1, whereas the binary nanocomplex displayed irregular, agglomerated and rough morphology. The electrochemical examination of MnS-Sb2S3 electrode exhibited a high specific capacitance of 1377.56 Fg− 1, together with a low series resistance Rs = 0.44Ω and a power density of Pg= 645.20 W Kg− 1. The prepared nanocomposite also demonstrated bifunctional electrocatalytic activity towards water splitting requiring over potentials of 360 mV for OER and 109 mV for HER, with corresponding Tafel slopes of 160 mV dec−1and 18 mV dec− 1. The improved electrochemical feedback can be attributed to the synergistic interaction between the MnS and Sb2S3 phases, which leads to improve the efficient charge transport kinetics and accessible electroactive sites. The acquired results highlight the potential of the synthesized material as cost effective electrode for high performance energy storage and water splitting applications.
Barium sodium borosilicate glass specimens doped with CeO2 having a chemical formula of (45-x) B2O3-15 SiO2-20BaF2- 20Na2O- x CeO2 with a value of x = 0.0:1.5 mol
Developing multifunctional electrode materials that integrate high energy storage capacity with catalytic activity is essential for next-generation energy systems. Herein, a hierarchically engineered NiSnSe₂@r-GO@Ni-MOF composite was synthesized by the use of a two-step hydrothermal process, combining the high conductivity of r-GO, the porous framework of Ni-MOF, and the redox activity of NiSnSe₂. Structural and morphological investigations (SEM, XRD, Raman, XPS, and BET–BJH) confirmed the formation of a well-integrated mesoporous architecture with a large available electroactive sites and effective electron–ion transport. Electrochemical evaluation exhibited a high specific capacity of 1297.8 C g⁻¹. The assembled asymmetric device (NiSnSe₂@r-GO@Ni-MOF//AC) achieved an energy density of 44.8 Wh kg⁻¹ and a power density of 1120 W kg⁻¹, with 90
This paper proposes a novel short circuit current limiter based on a double-sided high-temperature superconducting (HTS) thin film for hybrid AC/DC microgrid systems, with simultaneously limiting fault currents on both the AC and the DC sides firstly. In hybrid AC/DC microgrids, the increasing short circuit current may cause system islanding, disturb sensitive loads, damage critical equipment, and induce transient voltage fluctuations, etc. But, the existing current limiting (CL) device cannot simultaneously limit AC side and DC side fault currents, which will lead to the lower operating reliability, poor efficiency, and higher cost. Hence, based on the special structure of the double sided HTS thin film, a novel integrated device with AC and DC current-limiting functions is proposed in this paper. The current limiting calculation model of the HTS thin film is established, and the AC side and DC side current limiting performances are also analyzed under different structural parameters. It can be found from the analyzed results that, the proposed integrated device can effectively limit the short circuit currents on both AC side and DC side, and the thin film with different structural parameters has different current limiting protection characteristics. The significance of this work is that, it can offer a compact and lightweight current limiter design concept for limiting the AC side and DC side fault currents simultaneously in hybrid AC/DC microgrids system, with improving system stability and reliability.
NiO included ZnO nanocomposite gas sensors were studied in this work. The devices were characterized to detect hazardous gases like SO_2 and NH_3 at room temperature. Two devices were prepared using ZnO nanocomposites modified by 5 wt NiO ( Zn1 ) and 15wt NiO nano inclusions ( Zn2 ). Both devices show strong responses towards NH_3 and almost no response towards SO_2 gas. The sensitivity is found to be ∼55 % and ∼ 80 % for Zn1 and Zn2 device respectively for NH_3 . Materials are characterized and response curves were analyzed to identify the response parameters by fitting an appropriate mathematical function. The parameter τ indicate that Zn2 ( τ∼ 4 s ) responses faster than Zn2 ( τ∼ 9.5 s ) towards NH_3 gas.The cross-correlation factors between different responses of the devices toward target gases at different concentrations are calculated. These mathematical methods are used as calibrating tools for the devices to improve detection process for target gases with particular concentrations.
Nanocrystalline palladium oxide (PdO) nanoparticles were successfully synthesized using a simplified, scalable thermal treatment method that eliminates conventional drying (24–48 h) and grinding steps. The precursor solution was prepared by dissolving palladium (II) nitrate dehydrate (Pd (NO3)2 • 2H2O) and polyvinylpyrrolidone (PVP) as a capping agent in deionized water, followed by direct calcination at temperatures ranging from 500 ∘C to 800 ∘C for 4 h. Thermogravimetric analysis (TGA) confirmed the formation of single-phase, crystalline PdO nanoparticles with quasi-spherical morphology. Increasing the calcination temperature from 500 ∘C to 800 ∘C promoted crystalline growth, elevating average particle sizes from 22 nm to 46 nm (XRD) and 25 nm to 49 nm (TEM). Fourier-transform infrared (FTIR) spectroscopy verified the progressive elimination of organic functional groups and the establishment of Pd-O ionic bonds at elevated temperatures. UV-vis diffuse reflectance spectroscopy revealed a systematic reduction in the optical direct bandgap from 2.09 eV (500 ∘C) to 1.63 eV (800 ∘C), attributed to quantum confinement effects and particle growth. This modified synthesis route offers a low-cost, energy-efficient, and rapid approach for the mass production of size-controlled PdO nanostructures for catalytic and optoelectronic applications.
Indium tin oxide (ITO) films were deposited by RF magnetron sputtering with different H2 flow rates (0, 0.5, and 1 sccm) and subsequently annealed at 200 400 °C under Ar and air atmospheres. The results show that as-deposited ITO films exhibit significant compressive stress, along with a (211) preferred orientation. With increasing annealing temperature, the compressive stress in the films gradually releases, and the crystallite size initially decreases before increasing. Except for the emergence of a (400) preferred orientation in the films prepared with 0.5 sccm H2 after air annealing, the annealing generally results in the weakening or disappearance of the preferred orientation. For films deposited under Ar atmosphere (0 sccm H2), annealing in both Ar and air atmospheres significantly increases the carrier concentration. For films deposited under Ar + H2 atmosphere, the carrier concentration increases after Ar annealing but remains largely unchanged after air annealing. The chemical states of O, In, and Sn in the films were analyzed by XPS, and the changes in carrier concentration were discussed in relation to factors such as increased oxygen vacancy (VO) content, activation of Sn doping, and outdiffusion of hydrogen. The critical carrier concentration that determines crystallite boundary or ionized impurity scattering mechanism was identified through the relationship between mobility and carrier concentration. The optical transparency of the films first increases and then decreases with rising annealing temperature. With the change of annealing conditions, the trend of energy gap (Eg) and carrier concentration is consistent, confirming the Burstein-Moss (BM) effect.
Cancer and its effect on mankind can be treated by chemotherapy, the use of anticancer drugs in cancer cells. These drugs can impact both normal and cancerous cells. Nanocarrier-based drug delivery systems offer a promising strategy to improve targeted drug delivery and controlled drug release. The present study examines the efficiency of Mg-Al Layered Double Hydroxide (LDH) as a drug delivery carrier against HeLa cell. Mg-Al LDH was prepared by co-precipitation method and the anticancer drug 5-Fluorouracil (5-FU) was intercalated in the interlayers of LDH nanoparticles. Although Mg-Al LDH was previously investigated for 5-fluorouracil (5-FU) delivery, studies evaluating higher drug-feed ratios remain limited. In this work, Mg–Al LDH/5-FU with a 1:5 loading ratio was investigated to evaluate its effect on drug incorporation, encapsulation efficiency, in vitro drug release and cytotoxicity. The successful synthesis of Mg-Al LDH/5-U was studied using XRD, FT-IR, SEM and UV-Visible spectroscopy. From the powder XRD analysis, the crystallite size and the interlayer spacing were found to be 11.16 nm and 0.786 nm, respectively. FTIR analysis confirmed the presence of characteristic functional groups of 5-FU in the Mg–Al LDH/5-FU nanohybrid, indicating successful drug incorporation. The encapsulation efficiency and drug loading were found to be 18.79
In this paper, a Quasi-D-shaped photonic crystal fiber (PCF) sensor based on surface plasmon resonance (SPR) is proposed and numerically investigated using the finite element method (FEM). The fiber is fabricated from silica (SiO₂) and incorporates a central analyte-filled channel to enhance the interaction between the guided mode and the sensing medium. A thin gold (Au) layer is deposited on the polished quasi-D-shaped surface to excite surface plasmon waves. The proposed sensor operates over a refractive index (RI) sensing range from 1.42 to 1.45 with a step size of 0.005. Simulation results demonstrate an ultra-high maximum wavelength sensitivity (WS) of 35,200 nm/RIU. In addition, a maximum amplitude sensitivity (AS) of 653.61 RIU⁻¹ is obtained, along with a sensing resolution of 2.84 × 10⁻⁶ RIU and a maximum figure of merit (FOM) of 808.82 RIU⁻¹. Owing to its optimized structural design, simple configuration, high sensitivity, and excellent sensing performance, the proposed sensor provides an effective platform for high-precision refractive index (RI) measurements. Furthermore, the proposed design may be extended to biochemical and environmental sensing applications involving analytes with refractive indices within the investigated sensing range.
This study investigates the opto-mechanical properties and antimicrobial efficacy of PEEK fibers surface-modified with TiO₂ nanoparticles through cold-drawing processes. Michelson interferometry with Hilbert transform phase demodulation quantified spatially resolved refractive index distributions and birefringence evolution during mechanical deformation. TiO₂ grafting enhanced the extraordinary refractive index from 1.923 to 1.931 and increased birefringence from 0.31 to 0.312 in undrawn fibers, indicating nanoparticle-induced molecular alignment. TiO₂-grafted fibers demonstrated remarkable mechanical enhancement, achieving maximum draw ratios of 3.0 versus 2.0 for pristine PEEK. At maximum deformation, extraordinary refractive indices reached 1.992 with birefringence values of 0.458, representing 37
