Search Results (107)

Polylactic acid (PLA) fabrics exhibit significant sunlight reflectivity and high emissivity within the atmospheric window, making them suitable as the foundational material for this study. This research involves the modification of one side of the fabric with hydrophilic agents and titanium dioxide (TiO₂), while the opposite side is treated with MXene and subsequently coated with polydimethylsiloxane (PDMS) to inhibit oxidation of the MXene. Through these surface modifications, a thermal management fabric based on PLA was successfully developed, capable of passively regulating temperature in response to environmental conditions and user requirements. The study discusses the optimal concentrations of TiO₂ and MXene for the fabric, and characterizes and evaluates the functional surface of the PLA. Surface morphology analyses and tests indicate that the resulting functional PLA fabrics possess excellent ultraviolet (UV) resistance, favorable air permeability, high sunlight reflectivity on the TiO₂-treated side, and superior photothermal conversion capabilities on the MXene-treated side. Furthermore, photothermal effect tests conducted under a light intensity of 1000 W/m² reveal that the MXene-treated fabric exhibits a heating effect of approximately 25 °C, while the TiO₂-treated side demonstrates a cooling effect exceeding 5 °C. This study developed PLA functional fabrics with heating and cooling capabilities. Full article

Electromagnetic wave (EMW) absorption materials are crucial for a wide range of applications, yet most existing materials suffer from complex fabrication and narrow absorption bands, particularly under harsh environmental conditions. In this study, we introduce a broadband metamaterial absorber based on Ti₃C₂O₂ MXene, a novel two-dimensional material that uniquely combines high electrical and metallic conductivity with hydrophilicity, biocompatibility, and an extensive surface area. Through advanced finite-difference time-domain (FDTD) simulations, the proposed absorber achieves over 95% absorption from 0.3 µm to 18 µm. Additionally, other MXene variants, including Ti₃C₂F₂ and Ti₃C₂(OH)₂, demonstrate robust absorption above 85%. This absorber not only outperforms previously reported structures in terms of efficiency and spectral coverage but also opens avenues for integration into applications such as infrared sensing, energy harvesting, wearable electronics, and Internet of Things (IoT) systems. Full article

Owing to high electrical conductivity, layered structure, and abundant surface functional groups, transition metal carbides/nitrides (MXenes) have received enormous interest in the field of gas sensors at room temperature. In this work, we synthesize a heterostructured nanocomposite with indium oxide (In₂O₃) decorated on titanium carbide (Ti₃C₂T_x) nanosheets by electrostatic self-assembly and develop it for high-selectivity NO₂ gas sensing at room temperature. Self-assembly formation of multiple heterojunctions in the In₂O₃/Ti₃C₂T_x composite provide abundant NO₂ gas adsorption sites and high electron transfer activity, which is conducive to improving the gas-sensing response of the In₂O₃/Ti₃C₂T_x gas sensor. Assisted by rich adsorption sites and hetero interface, the as-fabricated In₂O₃/Ti₃C₂T_x gas sensor exhibits the highest response to NO₂ among various interference gases. Meanwhile, a detection limit of 0.3 ppm, and response/recovery time (197.62/93.84 s) is displayed at room temperature. Finally, a NO₂ sensing mechanism of In₂O₃/Ti₃C₂T_x gas sensor is constructed based on PN heterojunction enhancement and molecular adsorption. This work not only expands the gas-sensing application of MXenes, but also demonstrates an avenue for the rational design and construction of NO₂-sensing materials. Full article

Finding alternatives to platinum that exhibit high activity, stability, and abundant reserves as oxygen reduction electrocatalysts is crucial for the advancement of fuel cells. In this study, we first mixed FeCl₂·4H₂O, 1,10-phenanthroline, and Vulcan XC-72, followed by pyrolysis in a nitrogen atmosphere, to obtain FeNC. Subsequently, we combined FeNC with MXene produce FeNC/MXene composites. The FeNC/MXene catalyst achieved a half-wave potential of 0.857 V in an alkaline medium, exhibiting better oxygen reduction reaction (ORR) activity and durability than commercial Pt/C catalysts. The layered structure of MXene endows the material with a high specific surface area and facilitates efficient electron transfer pathways, thereby promoting rapid charge transfer and material diffusion. The cleavage of Ti-C bonds in Ti₃C₂ at elevated temperatures results in the transformation of MXene into TiO₂, where the coexistence of anatase and rutile phases generates a synergistic effect that enhances both the mass transfer rate and the electrical conductivity of the catalytic layer. Additionally, the unique electronic structure of the FeN_x sites simultaneously optimizes electrocatalytic activity and stability. Leveraging these structural advantages, the FeNC/MXene composite catalysts demonstrate exceptional catalytic activity and long-term stability in oxygen reduction reactions. Full article

An electrochemically active and promising binary composite that is made up of titanium-based MXene (Ti₃C₂T_x) and rGO is developed to simultaneously detect the Cd²⁺ and Cu²⁺, in water. XRD, FTIR, Raman, XPS, FESEM, elemental mapping, and EDX analysis affirmed the successful formation of the Ti₃C₂T_x-rGO composite. The produced Ti₃C₂T_x-rGO electrode exhibited a homogeneous rGO sheet covering the Ti₃C₂T_x MXene plates with all the detailed Ti2p, C1s, and O1s XPS peaks. The high-performance Ti₃C₂T_x-rGO composite was successfully tested for the Cd²⁺ and Cu²⁺ ions via differential pulse voltammetry (DPV), altering the pH, concentration, and the real water sample’s quality. The electrochemical performances revealed that the proposed Ti₃C₂T_x-rGO composite depicted excellent detection and quantification limits (LOD and LOQ) for both Cd²⁺ (LOD = 0.31 nM, LOQ = 1.02 nM) and Cu²⁺ (LOD = 0.18 nM, LOQ = 0.62 nM) ions, where the result is highly comparable with the reported literature. The Ti₃C₂T_x-rGO was proven highly sensitive towards Cd²⁺ (0.345 μMμA⁻¹) and Cu²⁺ (0.575 μMμA⁻¹) with great repeatability and reproducibility properties. The Ti₃C₂T_x-rGO electrode also exhibited excellent stability over four weeks with a retention of 97.86% and 98.01% for Cd²⁺ and Cu²⁺, respectively. This simple modification of Ti₃C₂T_x with rGO can potentially be advantageous in the development of highly sensitive electrochemical sensors for the simultaneous detection of heavy metal ions. Full article

Electrothermal superhydrophobic surfaces are regarded as possessing significant potential in anti-icing applications. However, their limited mechanical durability has constrained practical implementation. Herein, this work fabricated a robust electrothermal superhydrophobic surface by femtosecond laser texturing combined with the filling of functional coatings of Ti₃C₂ MXene and hydrophobic SiO₂ nanoparticles (modified with dimethyldichlorosilane), which shows great superhydrophobic anti-icing and electrothermal deicing properties, as well as outstanding mechanical durability. The as-prepared electrothermal superhydrophobic surface exhibited a water contact angle of 160.3° and achieved temperature elevation to 104.2 °C within 180 s under an applied voltage of 5 V. Furthermore, the as-prepared electrothermal superhydrophobic surface demonstrated exceptional anti-icing/deicing performance: ice formation time was prolonged to 75.2 s at −35 °C, ice adhesion strength was reduced to 14.65 kPa, and the frozen droplet on the surface melted rapidly within 10.12 s upon electrifying. Moreover, benefiting from the protection of the designed bionic armor structure (honeycomb-like structure), the as-prepared electrothermal superhydrophobic surface maintained outstanding electrothermal and anti-/deicing properties even after 200 times of blade abrasion. This work paves the way for designing robust electrothermal superhydrophobic surfaces in anti-/deicing applications. Full article

The growing global demand for sustainable energy solutions has led to increased interest in kinetic energy harvesting as a viable alternative to traditional power sources. High-foot-traffic environments, such as public spaces and religious sites, generate significant mechanical energy that often remains untapped. This study explores energy-harvesting technologies applicable to public areas with heavy foot traffic, focusing on Al-Haram Mosque in Saudi Arabia—one of the most densely populated religious sites in the world. The research investigates the potential of piezoelectric, triboelectric, and hybrid systems to convert pedestrian foot traffic into electrical energy, addressing challenges such as efficiency, durability, scalability, and integration with existing infrastructure. Piezoelectric materials, including PVDF and BaTiO₃, effectively convert mechanical stress from footsteps into electricity, while triboelectric nanogenerators (TENGs) utilize contact electrification for lightweight, flexible energy capture. In addition, this study examines material innovations such as 3D-printed biomimetic structures, MXene-based composites (MXene is a two-dimensional material made from transition metal carbides, nitrides, and carbonitrides), and hybrid nanogenerators to improve the longevity and scalability of energy-harvesting systems in high-density footfall environments. Proposed applications for Al-Haram Mosque include energy-harvesting mats embedded with piezoelectric and triboelectric elements to power IoT devices, LED lighting, and environmental sensors. While challenges remain in material degradation, scalability, and cost, emerging hybrid systems and advanced composites present a promising pathway toward sustainable, self-powered infrastructure in large-scale, high-foot-traffic settings. These findings offer a transformative approach to energy sustainability, reducing reliance on traditional energy sources and contributing to Saudi Arabia’s Vision 2030 for renewable energy adoption. Full article

Na−O₂ batteries are plagued by high cathodic oxygen reduction (ORR)/oxygen evolution (OER) overpotentials during discharging/charging. Herein, we constructed six carbide/nitride MXenes (M₂XO₂, M = Ti, Zr, and Hf, X = C, and N) and investigated their performance as cathodes for Na−O₂ batteries by first-principles calculations. M₂CO₂ MXenes have a pseudogap, showing semiconducting properties, while M₂NO₂ MXenes are conductive. The nucleophilic O on the M₂XO₂ surfaces prefers to bind with the Na atoms of Na_xO₂ intermediates to activate the Na−O bonds, improving the sodium deintercalation. For all M₂XO₂ MXenes, the OER overpotential is higher than the ORR overpotential, forming a performance bottleneck of Na−O₂ batteries. The overpotentials originate from the too-strong adsorption of Na_xO₂ on M₂XO₂ MXenes. Lowering the O p-band center of the M₂XO₂ MXenes can weaken the Na_xO₂ adsorption, thereby reducing the overpotential. Consequently, the overpotentials of the M₂CO₂ carbides are lower than those of the M₂NO₂ nitrides and further decrease with a decreasing M atomic number. The Ti₂CO₂ MXene shows extremely low ORR, OER, and total overpotentials (0.23, 0.32, and 0.55 V), suggesting a huge potential as cathodes in Na−O₂ batteries. Full article

This study presents an effective method to remove organic dyes from wastewater, using a composite of few-layered porous (FLP) Ti₃C₂T_x MXene and polythiophene (PTh) nanospheres. The FLP MXene, which was pre-synthesized by a series of intercalation, heat-induced TiO₂ formation, and its selective etching, was combined with PTh nanospheres via a simple solution method. The composite effectively removed various organic dyes, but its efficiency was altered depending on the type of dye. Particularly, the removal efficiency of methylene blue reached 91.3% and 97.8% after irradiation for 10 min and 1 h, respectively. The high dye removal efficiency was attributed to the large surface area (32.01 m²/g) of the composite, strong electrostatic interaction between the composite and dye molecules, and active photodegradation process. The strong electrostatic interaction and large surface area could facilitate the adsorption of dye molecules, while photocatalytic activity further enhance dye removal under light. These results are indicative that the PTh/FLP MXene composite may be a promising material for environmental remediation through synergistic processes of adsorption and photocatalysis. Full article

Heavy metal pollution has become an increasingly serious environmental issue, making the detection of heavy metals essential for safeguarding public health and the environment. This review aims to highlight the commonly used methods for detecting heavy metals (such as atomic absorption spectroscopy (AAS), atomic emission spectroscopy (AES), inductively coupled plasma–mass spectrometry (ICP-MS), square-wave anodic stripping voltammetry (SWASV), etc.), with a particular focus on electrochemical detection and electrode modification materials. Metal nanomaterials (such as titanium dioxide (TiO₂), copper oxide (CuO), ZIF-8, MXene, etc.) are emphasized as promising candidates for enhancing the performance of sensors due to their high surface area and excellent catalytic properties. However, challenges such as interference from non-target heavy metal ions and the formation of organometallic complexes with organic compounds can complicate the detection process. To address these issues, two potential solutions have been proposed: the development of advanced algorithms (such as machine learning (ML), back-propagation neural network (BPNN), support vector machines (SVM), random forests (RF), etc.) for signal processing and the use of pretreatment methods (such as Fenton oxidation (FO), ozone oxidation, and photochemical oxidation) to suppress such interferences. This paper aims to review commonly used methods for detecting heavy metals, with a particular emphasis on electrochemical techniques. It will also highlight the challenges faced in these methods, such as interference and sensitivity limitations, and propose innovative solutions, including the use of metal nanomaterials for improved sensor performance and the integration of advanced algorithms and pretreatment techniques to address interference and enhance detection accuracy. Full article

This study presents the production of FAMEs from non-edible Silybum marianum oil using a catalyst consisting of an MXene/SrTiO₃ composite. The primary aim of this study was to reduce our reliance on petroleum-based fuels by harnessing non-edible oil sources. The catalyst, once prepared, achieved an impressive conversion rate of 98.8%. The optimal parameters for this catalytic conversion included a 7 wt% catalyst concentration, a 1:12 molar ratio of oil to methanol, a 100 min reaction time, and a reaction temperature of 60 °C. These parameters ensured the successful completion of the FAME conversion process. The physicochemical properties of Silybum marianum oil confirmed its suitability as a biodiesel source on an industrial scale. The verification of the synthesized MXene/SrTiO₃ catalyst was conducted via XRD, SEM, EDX, and BET, and synthesized biodiesel was confirmed via ¹H and ¹³C-NMR, FTIR, and GC-MS. These results indicate that the catalyst described in this study exhibits significant potential for cost-effective biodiesel production under the appropriate reaction conditions. Full article

This study introduces the development of a W-M_1.0 electrochromic film, characterized by a “coral”-like TiO₂@WO₃ heterostructure, synthesized via a hydrothermal process leveraging the inherent instability of MXene. The film showcases exceptional electrochromic performance, with a coloring response time of 2.8 s, a bleaching response time of 4.6 s, and a high coloring efficiency of 137.02 cm²C⁻¹. It also demonstrates a superior light modulation ability of 73.83% at 1033 nm. Notably, the W-M_1.0 film exhibits remarkable cyclic stability, retaining over 90% of its initial light modulation capacity after 4000 cycles, outperforming many existing electrochromic materials. The film’s enhanced performance is credited to its coral-like structure, which boosts the specific surface area and promotes ion transport, and the TiO₂@WO₃ heterojunctions, which enhance charge transfer and stabilize the material. Devices fabricated with the W-M_1.0 film as the cathode and a PB film as the anode exhibit a seamless transition from dark blue to colorless, underscoring their potential for smart window and dynamic glass applications. Full article

Enhanced photo-induced electron utilization leads to efficient photocatalytic hydrogen production. The inefficient separation of photo-induced electron–hole pairs has hindered this process. This study introduces a synergistic approach using defect-rich SnS₂ and Ti₃C₂ MXene as cocatalysts in a two-step hydrothermal process to address this challenge. By integrating these materials with TiO₂ nanosheets, we create a novel composite, SnS₂/Ti₃C₂/TiO₂ (STT), that significantly boosts photocatalytic hydrogen evolution. The defect-rich SnS₂ provides abundant active sites for hydrogen generation, while Ti₃C₂ MXene facilitates photo-induced charge separation. The synergistic combination of charge carrier diffusion enhances chromophore absorption, thereby increasing the overall photocatalytic hydrogen-production rate, achieving several grams of hydrogen per hour per gram of double cocatalysts with molybdenum vacancies. Characterization techniques confirm the phase composition of the composite (STT). Compared to pristine TiO₂ and other composites, the STT composite, optimized with a 150 °C hydrothermal treatment, shows a photocatalytic H₂-production rate nearly 192 times higher than that of pure TiO₂ and 6 times higher than that of other composites. The presence of molybdenum vacancies in SnS₂ further enhances its specific activity for hydrogen evolution by suppressing carrier recombination and providing additional active sites. Moreover, Ti₃C₂ MXene and SnS₂ act as dual cocatalysts, improving electronic conductivity and electron-transfer efficiency. Our findings demonstrate the potential of combining defect-rich SnS₂ and Ti₃C₂ MXene to develop highly efficient and sustainable photocatalysts for hydrogen production. TiO₂ has been in situ grown on highly conductive Ti₃C₂ MXene, and SnS₂, rich in molybdenum vacancies, is uniformly distributed on the TiO₂/Ti₃C₂ composite through the two-step hydrothermal method. The presence of molybdenum vacancies in SnS₂ further enhances its specific activity for hydrogen evolution by suppressing carrier recombination and providing additional active sites. Moreover, Ti₃C₂ MXene and SnS₂ act as dual cocatalysts, improving electronic conductivity and electron-transfer efficiency. Our findings demonstrate the potential of combining defect-rich SnS₂ and Ti₃C₂ MXene to develop highly efficient and sustainable photocatalysts for hydrogen production. Full article

Supercapacitor/pseudocapacitor structures with electrodes and electrolytes based on conductive polymers, but not only, have been analyzed using advanced molecular dynamics simulation techniques. Results indicated in the literature were used to confirm the results obtained for the specific capacitance and energetic performances of the systems. New material classes like Polymer-MXene electrodes ((PANI)/Ti₃C₂, PFDs/Ti₃C₂T_x) present increased capacitance in comparison with simple polymeric composites (PETC or PTh). Combinations of polymers and metallic oxide, like PANI/V₂O₅, present high capacitance, but new variants can provide improved performance. Different techniques, like electrode doping, adding different salts in the electrolyte (gel electrolyte), and using porous electrodes, can also improve performance. Steps for the non-invasive simulation method with HFSS (Ansys) are defined, and the materials are described at the molecular level as well as the interactions between atomic groups. Macroscopic properties of the system are determined (conductivity, specific energy) and represented on parametric graphs. A complex set of parameters is varied in order to optimize the structures through parameter correlation. Different stages of correlation are considered in order to establish the final sample design and improve energetic performance. An increase of about 8–28% can be obtained concerning the specific energy of the supercapacitor. Prediction, design, atypical behavior, and resonance are addressed using this technique. Full article

Ammonia (NH₃) gas is prevalent in industrial production as a health hazardous gas. Consequently, it is essential to develop a straightforward, reliable, and stable NH₃ sensor capable of operating at room temperature. This paper presents an innovative approach to modifying SnO₂ colloidal quantum dots (CQDs) on the surface of Ti₃C₂T_x MXene to form a heterojunction, which introduces a significant number of adsorption sites and enhances the response of the sensor. Zero-dimensional (0D) SnO₂ quantum dots and two-dimensional (2D) Ti₃C₂T_x MXene were prepared by solvothermal and in situ etching methods, respectively. The impact of the mass ratio between two materials on the performance was assessed. The sensor based on 12 wt% Ti₃C₂T_x MXene/SnO₂ composites demonstrates excellent performance in terms of sensitivity and response/recovery speed. Upon exposure to 50 ppm NH₃, the frequency shift in the sensor is −1140 Hz, which is 5.6 times larger than that of pure Ti₃C₂T_x MXene and 2.8 times higher than that of SnO₂ CQDs. The response/recovery time of the sensor for 10 ppm NH₃ was 36/54 s, respectively. The sensor exhibited a theoretical detection limit of 73 ppb and good repeatability. Furthermore, a stable sensing performance can be maintained after 30 days. The enhanced sensor performance can be attributed to the abundant active sites provided by the accumulation/depletion layer in the Ti₃C₂T_x/SnO₂ heterojunction, which facilitates the adsorption of oxygen molecules. This work promotes the gas sensing application of MXenes and provides a way to improve gas sensing performance. Full article