Search Results (20,840)

Cancer remains one of the most pressing global health challenges, driving the need for innovative treatment strategies. Boron neutron capture therapy (BNCT) offers a highly selective approach to destroying cancer cells while sparing healthy tissues. To improve boron delivery, Fe₃O₄@Au nanoparticles were developed and functionalized with a boron-containing carborane compound. Fe₃O₄ nanoparticles were synthesized and covered by gold, followed by (3-Aminopropyl)triethoxysilane (APTES) modification to introduce amino groups for carborane immobilization. Comprehensive characterization using SEM, DLS, FTIR, EDX, Brunauer–Emmett–Teller (BET), and XRD confirmed successful functionalization at each stage. TEM confirmed the final structure and elemental composition of the nanoparticles. BET analysis revealed a surface area of 94.69 m²/g and a pore volume of 0.51 cm³/g after carborane loading. Initial release studies in PBS demonstrated the removal of only loosely bound carborane within 48 h, with FTIR confirming stable retention of the compound on the nanoparticle surface. The modified nanoparticles achieved a stable zeta potential of −20 mV. The particles showed low toxicity within a range of concentrations (0–300 μg Fe/mL) and were efficiently accumulated by U251MG cells. These results demonstrate the potential of the obtained nanoparticles to carry boron and gold for their possible application as a theranostic agent. Full article

Nanofluids (NFs), consisting of nanoparticles (NPs) suspended in base fluids, have attracted growing interest due to their superior physicochemical properties and multifunctional potential. In this review, conventional and green NF technology aspects, including synthesis routes, formulation, and applications, are discussed. Conventional NFs, involving NPs synthesized using physical and chemical approaches, have improved NP morphology control but are likely to cause environmental and safety concerns. In contrast, green NFs that are plant extract, microorganism, and biogenic waste-based represent a sustainable and biocompatible alternative. The effect of key parameters (e.g., NP size, shape, concentration, dispersion stability, and base fluid properties) on the performance of NFs is critically examined. The review also covers potential applications: in biomedical engineering (e.g., drug delivery, imaging, theranostics, and antimicrobial therapies), in heat transfer (e.g., solar collectors, cooling electronics, nuclear reactors), and precision machining (e.g., lubricants and coolants). Comparative insights regarding green versus conventionally prepared NFs are provided concerning their toxicity, environmental impact, scalability, and functional performance across various applications. Overall, this review highlights the new promise of both green and conventional NFs and provides key opportunities and challenges to guide future developments in this field. Full article

Carbon-based nanocomposites coated with iron oxides were synthesized using a wet impregnation method with thermally annealed coal and an iron nitrate precursor. The influence of the thermal treatment atmosphere (air, vacuum, or nitrogen) on the morphology, structure, and magnetic properties of the nanocomposites was examined by X-ray diffraction, Raman spectroscopy, and transmission electron microscopy. It was found that the vacuum thermal treatment produced carbon-based nanocomposite containing iron oxide with the highest crystallinity, according to XRD analysis, while also inducing the greatest degree of structural defects in the carbon matrix, as evidenced by Raman analysis. Mössbauer spectroscopy confirmed that all thermal treatment methods promote the formation of the hematite phase, which was found to be the only phase formed in the air-treated nanocomposites, whereas traces of magnetite and the formation of Fe(OH)₃ were detected in the vacuum- and nitrogen-treated nanocomposites, respectively. Magnetic characterization revealed that all nanocomposites exhibit ferromagnetic-like behavior, attributed to the weak ferromagnetic nature of hematite. The best magnetic response (highest saturation magnetization with the widest hysteresis loop) was observed in the vacuum-treated nanocomposites. These findings collectively demonstrate that the synthesis atmosphere plays a crucial role in tailoring the structural and magnetic characteristics of carbon-based iron oxide nanocomposites, offering pathways for their optimization in applications such as catalysis, environmental remediation, or sensing technologies. Full article

In this paper, a novel Tunneling-Drift-Diffusion Field-Effect Transistor (TDDFET) based on the combination of the quantum tunneling and conventional drift-diffusion mechanisms is proposed for the design of ternary logic circuits. The working principle of the TDDFET is analyzed in detail. Then, the device is packaged as a “black box” based on the table lookup method and further embedded into the HSPICE platform using the Verilog-A language. The basic unit circuits, such as the Standard Ternary Inverter (STI), Negative Ternary Inverter (NTI), Positive Ternary Inverter (PTI), Ternary NAND gate (T-NAND), and Ternary NOR gate (T-NOR), are designed. In addition, based on the designed unit circuits, the combinational logic circuits, such as the Ternary Encoder (T-Encoder), Ternary Decoder (T-Decoder), and Ternary Half Adder (T-HA), and the sequential logic circuits, such as the Ternary D-Latch and edge-triggered Ternary D Flip-Flop (T-DFF), are built, which has important significance for the subsequent investigation of ternary logic circuits. Full article

Integrating two-dimensional transition-metal dichalcogenides with graphene is attractive for low-power memory and neuromorphic hardware, yet sequential wet transfer leaves polymer residues and high contact resistance. We demonstrate a complementary metal–oxide–semiconductor (CMOS)-compatible, transfer-free route in which an atomically thin amorphous MoS₂ precursor is RF-sputtered directly onto chemical vapor-deposited few-layer graphene and crystallized by confined-space sulfurization at 800 °C. Grazing-incidence X-ray reflectivity, Raman spectroscopy, and X-ray photoelectron spectroscopy confirm the formation of residue-free, three-to-four-layer 2H-MoS₂ (roughness: 0.8–0.9 nm) over 1.5 cm × 2 cm coupons. Lateral MoS₂/graphene devices exhibit reproducible non-volatile resistive switching with a set transition (SET) near +6 V and an analogue ON/OFF ≈2.1, attributable to vacancy-induced Schottky-barrier modulation. The single-furnace magnetron sputtering + sulfurization sequence avoids toxic H₂S, polymer transfer steps, and high-resistance contacts, offering a cost-effective pathway toward wafer-scale 2D memristors compatible with back-end CMOS temperatures. Full article

Cd-based perovskite materials have the advantages of high emission efficiency and tunable emission, as well as broad application prospects in the field of optoelectronics. However, achieving multimode dynamic luminescence under UV light excitation in a single system is a great challenge. Here, we successfully prepared Sb³⁺/Pb²⁺ co-doped Cs₇Cd₃Br₁₃ crystals by a simple hydrothermal method. Tunable emission from orange to white and then to blue, covering the wavelength range between 370 and 800 nm, was achieved by varying the doping concentration of Pb²⁺ ions in Cs₇Cd₃Br₁₃:0.5%Sb³⁺. Temperature-dependent photoluminescence (PL) spectra and density functional theory (DFT) calculations confirm that the wide-band white-light emission of Cs₇Cd₃Br₁₃: Sb³⁺/Pb²⁺ crystal comes from the first self-trapped exciton (STE1) of undoped Cs₇Cd₃Br₁₃ intrinsic capture state and the emission of free excitons (FEs) and STE2 induced by the confining effect and the Jahn–Teller effect by Pb²⁺ incorporation, as well as the Sb triplet self-trapped exciton (STE3). More specifically, the samples with the best co-doped ratio exhibit significant excitation-wavelength-dependent luminescence characteristics and can realize the conversion of the emission color from white and blue to orange. Based on the tunable emission characteristics of three emission colors, the material has good prospects in encryption and anti-counterfeiting applications. This work provides a new strategy for the application of Cd-based halides in the field of anti-counterfeiting. Full article

Beyond the extensively studied two-dimensional transition metal dichalcogenides, a wide range of non-stoichiometric transition metal sulfides, such as molybdenum sulfides and tungsten sulfides (Mo₂S₃, W₂S₃, Mo₆S₈, Mo₆S₆, NiMo₃S₄), have attracted significant attention for their promising applications in sensing, catalysis, and energy storage. It is necessary to review the current advanced progress of non-stoichiometric transition metal sulfides for various applications. Here, we systematically summarize the synthesis strategies of the non-stoichiometric transition metal sulfides, encompassing methods such as the molten salt synthesis method, high-metal-content growth strategy, and others. Particular emphasis is placed on how variations in the metal-to-sulfur ratio give rise to distinct crystal structures and electronic properties, and how these features influence their conductivity, stability, and performance. This review will deepen the understanding of the state of the art of non-stoichiometric transition metal sulfides, including the synthesis, characterization, modification, and various applications. Full article

As micro–nano power devices have evolved towards high frequency, high voltage, and a high level of integration, the issue of thermal resistance at heterointerfaces has become increasingly prominent, posing a key bottleneck that limits device performance and reliability. This paper presents a systematic review of the current state of research and future challenges related to interface thermal resistance in heterostructures within micro and nano power devices. First, based on phonon transport theory, we conducted an in-depth analysis of the heat transfer mechanisms at typical heterointerfaces, such as metal–semiconductor and semiconductor–semiconductor, and novel low-dimensional materials. Secondly, a comprehensive review of current interface thermal resistance characterization techniques is provided, including the application and limitations of advanced methods such as time domain thermal reflection and Raman thermal measurement in micro- and nano-scale thermal characterization. Finally, in response to the application requirements of semiconductor power devices, future research directions such as atomic-level interface engineering, machine learning-assisted material design, and multi-physics field collaborative optimization are proposed to provide new insights for overcoming the thermal management bottlenecks of micro–nano power devices. Full article

Achieving simultaneous enhancement of Vickers hardness and fracture toughness remains a critical challenge in designing oxide ceramic materials due to their partially antagonistic nature. In this study, we address this trade-off by tailoring the microstructure of zirconia (ZrO₂) ceramics through Y₂O₃ doping and high-pressure high-temperature (HPHT) sintering. Nanostructured composites were synthesized using 50 nm monoclinic ZrO₂ and varying Y₂O₃ contents (3, 5, and 7 mol%) under 5 GPa at temperatures ranging from 400 to 2000 °C. Among them, 3 mol% Y₂O₃-doped zirconia (3Y-PSZ) sintered at 1200 °C achieved a well-balanced mechanical performance, with a Vickers hardness of 11.6 GPa and a fracture toughness of 9.26 MPa·m^1/2. These results demonstrate that it is feasible to retain a high hardness while significantly enhancing toughness by controlling phase composition and grain refinement under HPHT conditions. This work offers valuable insights into microstructural optimization strategies for zirconia-based ceramics aiming to overcome the conventional hardness–toughness trade-off. Full article

This study investigates the impact of oxygen-containing functional groups (COO-Li, CO-Li, and O-Li) on the electronic and optical properties of graphene, with a focus on hydrogen sensing applications. Using density functional theory (DFT) calculations, we evaluated the thermodynamic feasibility of the functionalization and hydrogen adsorption processes. The Gibbs free energy changes (ΔG) for the functionalization of pristine graphene were calculated as −1233, −1157, and −1119 atomic units (a.u.) for COO-Li, CO-Li, and O-Li, respectively. These negative values indicate that the functionalization processes are spontaneous (ΔG < 0), with COO-Li being the most thermodynamically favorable. Furthermore, hydrogen adsorption on the functionalized graphene surfaces also exhibited spontaneous behavior, with ΔG values of −1269, −1204, and −1175 a.u., respectively. These results confirm that both functionalization and subsequent hydrogen adsorption are energetically favorable, enhancing the potential of these materials for hydrogen sensing applications. Among the functional groups we simulated, COO-Li exhibited the largest surface area and volume, which were attributed to the high electronegativity and steric influence of the carboxylate moiety. Based on the previously described results, we analyzed the interaction of these functionalized graphene systems with molecular hydrogen. The adsorption of two H₂ molecules per system demonstrated favorable thermodynamics, with lithium atoms serving as active sites for external adsorption. The presence of lithium atoms significantly enhanced hydrogen affinity, suggesting strong potential for sensing applications. Further, electronic structure analysis revealed that all functionalized systems exhibit semiconducting behavior, with band gap values modulated by the nature of the functional group. FTIR (Fourier-Transform Infrared Spectroscopy) and Raman spectroscopy confirmed the presence of characteristic vibrational modes associated with Li-H interactions, particularly in the 659–500 cm⁻¹ range. These findings underscore the promise of lithium-functionalized graphene, especially with COO-Li, as a tunable platform for hydrogen detection, combining favorable thermodynamics, tailored electronic properties, and spectroscopic detectability. Full article

The burgeoning electromagnetic pollution from 5G/6G technologies demands lightweight, broadband, and mechanically robust electromagnetic microwave absorbers (EMWAs). Conventional carbon aerogels suffer from structural fragility and inadequate electromagnetic dissipation. Herein, we propose a defect-engineering strategy through precise optimization of the chitosan (CS)/cellulose nanocrystal (CNC) ratio to fabricate elastic boron nitride nanosheet (BNNS)-embedded carbon aerogels. By fixing BNNS content for optimal impedance matching and modulating the CS/CNC ratio of the aerogel, we achieve synergistic control over hierarchical microstructure, defect topology, and electromagnetic response. The aerogel exhibits a wide effective absorption bandwidth (EAB) of 8.3 GHz at a thickness of 3.6 mm and an excellent reflection loss of −52.79 dB (>99.999% attenuation), surpassing most biomass-derived EMWAs. The performance stems from CNC-derived topological defects enabling novel polarization pathways and BNNS-triggered interfacial polarization, while optimal graphitization (I_D/I_G = 1.08) balances conductive loss. Simultaneously, the optimal CS/CNC ratio facilitates the formation of a stable and flexible framework. The long-range ordered micro-arch lamellar structure endows the aerogel with promising elasticity, which retains 82% height after 1000 cyclic compression at 50% strain. This work paves the way for biomass-derived carbon aerogels as next-generation wearable and conformal EMWAs with broadband absorption. Full article

The poor selectivity of metal oxide semiconductor sensors is a major constraint to their application in the detection of chemical warfare agents. We prepared a (Pt+Pd+Rh)@Al₂O₃/(Pt+Rh)-WO₃ sensor by using (Pt+Pd+Rh)@Al₂O₃ as a catalytic film material and (Pt+Rh)-WO₃ as a gas-sensitive film material. Using temperature dynamic modulation, the (Pt+Pd+Rh)@Al₂O₃/(Pt+Rh)-WO₃ sensor was realised to improve the selectivity for mustard. Due to the catalytic effect of the (Pt+Pd+Rh)@Al₂O₃ catalytic film on mustard, mustard was able to be catalytically generated into mustard sulphoxide after passing through the (Pt+Pd+Rh)@Al₂O₃ catalytic film. Under a certain temperature dynamic modulation, the mustard concentration on the surface of the (Pt+Rh)-WO₃ gas-sensitive film showed an increase and then a decrease. Since the resistance response of the (Pt+Rh)-WO₃ gas-sensitive film to mustard was much higher than that of mustard sulphoxide, the change in the resistance of the (Pt+Rh)-WO₃ gas-sensitive film was mainly determined by the change in the concentration of mustard, which led to the peak signal in the curve of its resistance response to mustard. The experimental results showed that the (Pt+Pd+Rh)@Al₂O₃/(Pt+Rh)-WO₃ sensor had peak signals in the resistance response to mustard only, and not in the resistance response to 12 interfering gases, such as carbon monoxide. Full article

The long-term reliability of vacuum insulation panels (VIPs) is constrained by the barrier film degradation caused by micro-cracks during the flanging process. However, the correlation mechanism between process parameters and microleakage remains unclear. This study systematically investigates the impact of the number of flanging cycles on the barrier properties and insulation failure of aluminum foil composite film (AF) and metallized polyester film (MF). Accelerated aging tests revealed that the water vapor transmission rate (WVTR) of MF surged by 340% after five flanging cycles, while its oxygen transmission rate (OTR) increased by 22%. In contrast, AF exhibited significantly increased gas permeability due to brittle fracture of its aluminum layer. Thermal conductivity measurements demonstrated that VIPs subjected to ≥5 flanging cycles experienced a thermal conductivity increase of 5.22 mW/(m·K) after 30 days of aging, representing a 7.1-fold rise compared to unbent samples. MF primarily failed through interfacial delamination, whereas AF failed predominantly via aluminum layer fracture. This divergence stems from the substantial difference in mechanical properties between the metal and the polymer substrate. The study proposes optimizing the flanging process (≤3 bending cycles) and establishes a micro-crack propagation prediction model using X-ray computed tomography (CT). These findings provide crucial theoretical and technical foundations for enhancing VIP manufacturing precision and extending service life, holding significant practical value for energy-saving applications in construction and cryogenic fields. Full article

We present a dual biosensing strategy integrating Quartz Crystal Microbalance (QCM) and Surface-Enhanced Raman Spectroscopy (SERS) for the quantitative and molecular-specific detection of FKBP12. Silver nanodendritic arrays were electrodeposited onto QCM sensors, optimized for SERS enhancement using Rhodamine 6G, and functionalized with a custom-designed receptor to selectively capture FKBP12. QCM measurements revealed a two-step Langmuir adsorption behavior, enabling sensitive mass quantification with a low limit of detection. Concurrently, in situ SERS analysis on the same sensor provided vibrational fingerprints of FKBP12, resolved through comparative studies of the free protein, surface-bound receptor, and surface-bound receptor–protein complex. Ethanol-induced denaturation confirmed protein-specific peaks, while shifts in receptor vibrational modes—linked to FKBP12 binding—demonstrated dynamic molecular interactions. A ratiometric parameter, derived from key peak intensities, served as a robust, concentration-dependent signature of complex formation. This platform bridges quantitative (QCM) and structural (SERS) biosensing, offering real-time mass tracking and conformational insights. The nanodendritic substrate’s dual functionality, combined with the receptor’s selectivity, advances label-free protein detection for applications in drug diagnostics, with potential adaptability to other target analytes. Full article

Metal halide perovskites have appeared as a promising semiconductor for high-efficiency and low-cost photovoltaic technologies. However, their performance and long-term stability are dramatically constrained by defects at the surface and grain boundaries of polycrystalline perovskite films formed during the processing. Herein, we propose a defect-targeted passivation strategy using 2-chlorocinnamic acid (2-Cl) to simultaneously enhance the efficiency and stability of perovskite solar cells (PSCs). The crystallization kinetics, film morphology, and optical and electronic properties of the used formamidinium–cesium lead halide (FA_0.85Cs_0.15Pb(I_0.95Br_0.05)₃, FACs) absorber were modulated and systematically investigated by various characterizations. Mechanistically, the carbonyl group in 2-Cl coordinates with undercoordinated Pb²⁺ ions, while the chlorine atom forms Pb–Cl bonds, effectively passivating the surface and interfacial defects. The optimized FACs perovskite film was incorporated into inverted (p-i-n) PSCs with a typical architecture of ITO/NiO_x/PTAA/Al₂O₃/FACs/PEAI/PCBM/BCP/Ag. The optimal device delivers a champion power conversion efficiency (PCE) of 22.58% with an open-circuit voltage of 1.14 V and a fill factor of 82.8%. Furthermore, the unencapsulated devices retain 90% of their initial efficiency after storage in ambient air for 30 days and 83% of their original PCE after stress under 1 sun illumination with maximum power point tracking at 50 °C in a N₂ environment, demonstrating the practical potential of dual-site molecular passivation for durable perovskite photovoltaics. Full article