Materials Advances最新文献

This study focuses on developing room temperature (300 K) ammonia sensors utilizing carbon doped and co-doped (carbon and cobalt) zinc oxide (ZnO) thin films fabricated through the chemical spray pyrolysis technique. Spray pyrolysis is a cost-effective and scalable process for fabricating thin films for sensor applications. The structural analysis demonstrated that the deposited thin films have crystalline characteristics required for practical gas sensing applications. The gas sensing capabilities of both thin films were thoroughly investigated; notably, the carbon and cobalt co-doped ZnO sensors demonstrated good selectivity and sensitivity to ammonia gas at ambient temperature. The co-doped sensors were susceptible, detecting trace levels of ammonia even at ambient temperature. The response for 5 ppm of ammonia was 851 at 300 K, while for 50 ppm of ammonia, it was 2729. This significant attribute eliminates the need for elevated operating temperatures, reducing energy consumption and enhancing device longevity. The observed response to ammonia at 300 K underscores the potential of carbon and cobalt co-doped thin films as promising candidates for practical gas sensing applications.

This study focuses on the development of nickel-free stainless-steel nanocomposites with porosities tailored for surgical implants and biological applications. Alloy F2581 (Fe–17Cr–10Mn–3Mo–0.4Si–0.5N–0.2C wt%), modified by replacing Mo with metals such as Al, Cu, Ti, and W, was successfully fabricated via a solid-state reaction method. X-ray diffraction analysis revealed a significant alteration in the crystal phase, accompanied by the formation of nanostructures, including nanowires, square nanotubes, wave-like configurations reminiscent of a growing clover farm, and nanofibers. The particle sizes of these structures were determined to be 73, 27.2, 76 and 98.5 nm for Al, Cu, Ti, and W ions, respectively, indicating a distribution of nanopores. Biological evaluation of adult male Albino rats after exposure to single intraperitoneal doses of various concentrations (10, 20, and 50 mg kg⁻¹ wt%) were assessed with testing alloys (Cu, Al, W, and Ti, respectively). Over a subacute period lasting 60 days, a comprehensive evaluation of biological responses, including hepatic function, renal performance, oxidative and/or nitrosative stress parameters, and the levels of serum immune modulators was conducted. Notably, low doses elicited negligible immune responses, higher doses, barring copper, induced notable reactions. Interestingly, aluminum demonstrated optimization within biological settings, alongside titanium and tungsten. These findings highlight the applicability of copper and tungsten for medical implantation and biological applications under controlled circumstances, particularly at lower dosage levels.

Nerve agents are among the most hazardous chemical warfare agents, requiring easy detection and prompt remediation. To this end, we synthesized two fluorescent salen molecules, P-1 (dimeric) and P-2 (monomeric), for the detection of diethyl chlorophosphate (DClP), a mimic of sarin and soman, in an aqueous medium. P-1 exhibited a stronger fluorescence response (∼22.0-fold) towards DClP than P-2 (∼1.1-fold). This superior performance of P-1 could be attributed to its dimeric structure, difference in aggregation, and photophysical properties. The mechanistic studies revealed that DClP-mediated phosphorylation of the hydroxy groups led to changes in the keto–enol equilibrium and aggregation state of compound P-1. Unlike in an aqueous medium, P-1 in DMSO medium displayed a turn-on fluorescence response towards DClP. The minimum detectable limit for DClP resulted in ∼5.0 ppb in an aqueous medium. P-1 was also effective in detecting DClP in soil samples, with a detection limit of ∼15.0 ppb, a recovery of 95.4–97.8%, and a relative standard deviation (RSD) within 2–3%, demonstrating the reliability and robustness of the present method. Finally, chemically modified dye coated paper strips were developed for rapid and on site detection of release of nerve gas vapour beyond permissible limit.

This paper aims to synthesize tungsten-doped indium oxide thin film and to study its properties. Films with different tungsten dopant concentrations were deposited using the technique of spray pyrolysis. Raman spectroscopy and X-ray diffraction were used to investigate the structural features. It confirms the polycrystalline cubic structure of W-doped indium oxide. The morphological change observed with doping supports the preferred plane orientation change. Optical properties were studied using UV-visible spectroscopy. The photoluminescence spectra showed both near-band emission (NBE) and violet-blue emission. The suitability of the material for gamma sensing applications was confirmed by thermoluminescence (TL) spectroscopy. The binding energy obtained from the core XPS spectra of W corresponds to a 6+ oxidation state. The electrical resistivity decreased with tungsten doping and it is attributed to the increase in donor electrons. Indium oxide doped with 2 at% W has good structural, optical, and electrical characteristics that make it suitable for use in sensor applications.

Antibiotic resistance remains a global health challenge, necessitating the development of novel antimicrobial treatments. In this study, we report the microwave-assisted green synthesis of graphene quantum dots (GQDs) using Azadirachta indica (neem) leaf extract. Comprehensive characterization of GQDs via FT-IR, UV-vis, TEM, and EDX confirmed their formation and stability, revealing distinct functional groups and photoluminescent properties. The antioxidant and antibacterial activities of GQDs surpassed those of the neem extract, showing enhanced bioactivity. Furthermore, molecular docking and computational analysis provided insights into the binding interactions, energy profiles, and safety parameters of GQDs, supporting the experimental findings. This work demonstrates the potential of GQDs as multifunctional agents in biomedical applications, offering a sustainable approach to combating microbial resistance.

Advances in material science dictate the search for sustainable options that target diverse applications that impact climate change. In this context, we report the exfoliation and expansion of g-C₃N₄ using PEI polymer, followed by gelation as beads using calcium alginate for adsorptive desulfurization of thiophene compounds. Adsorbent characteristics were exemplified through FT-IR, FE-SEM-EDX, TGA, XRD, BET-N₂ isotherm, contact angle meter, XPS, HR-TEM, ZPC, and UTM. The PEI–g-C₃N₄ NSs@Ca-Alg bead composite with a mesoporous structure gave a specific surface area of 142.062 m² g⁻¹ yielding a high adsorption capacity of 183.03 mg S g⁻¹. The material exhibited an ultimate tensile strength of 3500 kPa and a compressive stress of 527 kPa, accompanied by a compressive strain of 79%. The isotherm, kinetics, and thermodynamic investigations confirmed that the system exhibits pseudo-first-order kinetics and exothermic characteristics with spontaneity. The composite material had good potential for re-use for up to 5 adsorptive–desorption cycles with the potential to decrease the sulfur content to 58% in commercial diesel fuel.

The growth of Gd₃Ga_2.7Al_2.3O₁₂:Ce and Gd₃Ga_2.7Al_2.3O₁₂:Ce,Mg crystals was accomplished by the laser-diode floating zone method (LDFZM) under a pressurized oxygen atmosphere. Optical, luminescence, and scintillation characterization were performed, which points to their comparable scintillation performance and lower charge trapping in the scintillation mechanism compared to commercial GAGG:Ce crystals grown by the Czochralski method. Theoretical electronic band structure calculations were performed for Gd₃Ga_2.7Al_2.3O₁₂, Gd₃Ga₅O₁₂ and Gd₃Al₅O₁₂ compositions and these are discussed in the light of the experimental results obtained.

This work presents a one-step electrochemical halogenation and exfoliation of copper phthalocyanine (CuPc), producing thin-layered halogenated CuPc with tunable physicochemical properties. By incorporating halogen into the CuPc structure, the copper centers acquire an enhanced positive charge, which significantly improves their affinity for water molecules. Coupled with the strong water-interactive properties of polyvinylpyrrolidone, this halogenation-driven modification creates a synergistic effect, resulting in markedly increased sensitivity and responsiveness for humidity sensing applications. As a proof of concept, chlorinated CuPc integrated with polyvinylpyrrolidone on flexible interdigitated electrodes achieves high sensitivity (1.2 × 10⁴%), excellent reproducibility (<5% RSD), and a broad dynamic range (11–94%RH), firmly establishing its potential as a high-performance humidity sensor.

Gold (Au) is extensively used in modern industry, which raises hard-to-ignore environmental problems due to its potential toxicity. Herein, highly luminescent carbon dots (CDs) are prepared from the carbon sources of o-phenylenediamine and hydroquinone, and applied for the selective quantification of Au³⁺. Significantly, fluorescence quenching is observed upon the addition of Au³⁺ in 2 min. The ions are reduced to gold shells which coat the surface of CDs, resulting in electron transfer and emission quenching. The degree of quenching varies linearly with an Au³⁺concentration from 0.1 to 7 μM. Biothiols are then introduced to interact with the gold shells. It is found that cysteine, glutathione, 3-mercaptopropionic acid and DL-dithiothreitol can be used to digest the shell, restoring the fluorescence emission. The “on–off–on” fluorescence biosensing strategy is challenged with environmental and biological samples with excellent results, demonstrating that this study provides a novel methodology to examine Au³⁺ and biothiol levels for potential practical applications.

This study introduces a novel approach for predicting solar cell efficiency and conducting sensitivity analysis of key parameters and their interactions, leveraging response surface modeling to optimize interacting solar cell structure parameters for the best performance. Integrating response surface modeling with solar cell simulation software enhances the efficiency prediction process that enables the solar cell capacitance simulator (SCAPS)-1D software to unlock the true potential of a material. Through the utilization of central composite design (CCD) and response surface modeling (RSM), this research minimizes material waste during synthesis, saves time, and conserves energy. The methodology involves selecting five input parameters within specific ranges, modeling them using the least square method to create a polynomial regression model, and validating the model through efficiency predictions compared to SCAPS-1D simulations. The parameter sensitivity analysis is validated using analysis of variance (ANOVA) test results, demonstrating the precision of the RSM in predicting solar cell efficiency with a maximum error of 1.93%.