Search Results (535)

Among the various available synthesis approaches, hydrolytic precipitation offers a simple, cost-effective, and scalable route for producing phase-pure NiO with a controlled morphology and crystallite size. However, the influence of calcination temperature on its crystalline phase, particle size, and antimicrobial activity remains an active field of research. This study aims to investigate the structural, morphological, and antibacterial properties of NiO nanoparticles synthesized via hydrolytic methods and thermally treated at different temperatures. XRD data indicate the presence of the hexagonal crystallographic phase of NiO (space group 166: R-3m), a structural variant less commonly reported in the literature, stabilized under mild hydrolytic synthesis conditions. The average crystallite size increases significantly from 4.97 nm at 300 °C to values of ~17.8 nm at 500–700 °C, confirming the development of the crystal lattice. The ATR-FTIR analysis confirms the presence of the characteristic Ni–O band for all samples, positioned between 367 and 383 cm⁻¹, with a reference value of 355 cm⁻¹ for commercial NiO. The displacements and variations in intensity reflect a thermal evolution of the crystalline structure, but also an important influence of the size of the crystallites and the agglomeration state. The results reveal a systematic evolution in particle morphology from porous, flake-like nanostructures at 300 °C to dense, well-faceted polyhedral crystals at 900 °C. With an increasing temperature, particle size increases. EDS spectra confirm the high purity of the NiO phase across all samples. Additionally, the NiO nanoparticles exhibit calcination-temperature-dependent antibacterial activity, with the complete inhibition of Escherichia coli and Enterococcus faecalis observed after 24 h for the sample calcined at 300 °C and over 90% CFU reduction within 4 h. A significant reduction in E. faecalis viability across all samples indicates time- and strain-specific bactericidal effects. Due to its remarkable multifunctionality, NiO has emerged as a strategic nanomaterial in fields ranging from energy storage and catalysis to antimicrobial technologies, where precise control over its structural phase and particle size is essential for optimizing performance. Full article

As lithium-ion batteries (LIBs) gain widespread use, detecting electrolyte–vapor emissions during early thermal runaway (TR) remains critical to ensuring battery safety; yet, it remains understudied. Gas sensors integrating oxide nanostructures offer a promising solution as they possess high sensitivity and fast response, enabling rapid detection of various gas-phase indicators of battery failure. Utilizing this approach, 3D ordered tin oxide (SnO₂) nanostructures were synthesized using polystyrene sphere (PS) templates of varied diameters (200–1500 nm) and precursor concentrations (0.2–0.6 mol/L) to detect key electrolyte–vapors, especially ethyl methyl carbonate (EMC), released in the early stages of TR. The 3D ordered SnO₂ nanostructures with ring- and nanonet-like morphologies, formed after PS template removal, were characterized, and the effects of template size and precursor concentration on their structure and sensing performance were investigated. Among various nanostructures of SnO₂, nanonets achieved by a 1000 nm PS template and 0.4 mol/L precursor showed higher mesoporosity (~28 nm) and optimal EMC detection. At 210 °C, it detected 10 ppm EMC with a response of ~7.95 and response/recovery times of 14/17 s, achieving a 500 ppb detection limit alongside excellent reproducibility/stability. This study demonstrates that precise structural control of SnO₂ nanostructures using templates enables sensitive EMC detection, providing an effective sensor-based strategy to enhance LIB safety. Full article

Glancing Angle Deposition (GLAD) has emerged as a versatile and powerful nanofabrication technique for developing next-generation gas sensors by enabling precise control over nanostructure geometry, porosity, and material composition. Through dynamic substrate tilting and rotation, GLAD facilitates the fabrication of highly porous, anisotropic nanostructures, such as aligned, tilted, zigzag, helical, and multilayered nanorods, with tunable surface area and diffusion pathways optimized for gas detection. This review provides a comprehensive synthesis of recent advances in GLAD-based gas sensor design, focusing on how structural engineering and material integration converge to enhance sensor performance. Key materials strategies include the construction of heterojunctions and core–shell architectures, controlled doping, and nanoparticle decoration using noble metals or metal oxides to amplify charge transfer, catalytic activity, and redox responsiveness. GLAD-fabricated nanostructures have been effectively deployed across multiple gas sensing modalities, including resistive, capacitive, piezoelectric, and optical platforms, where their high aspect ratios, tailored porosity, and defect-rich surfaces facilitate enhanced gas adsorption kinetics and efficient signal transduction. These devices exhibit high sensitivity and selectivity toward a range of analytes, including NO₂, CO, H₂S, and volatile organic compounds (VOCs), with detection limits often reaching the parts-per-billion level. Emerging innovations, such as photo-assisted sensing and integration with artificial intelligence for data analysis and pattern recognition, further extend the capabilities of GLAD-based systems for multifunctional, real-time, and adaptive sensing. Finally, current challenges and future research directions are discussed, emphasizing the promise of GLAD as a scalable platform for next-generation gas sensing technologies. Full article

Direct Air Capture (DAC) is emerging as a critical climate change mitigation strategy, offering a pathway to actively remove atmospheric CO₂. This comprehensive review synthesizes advancements in DAC technologies, with a particular emphasis on the pivotal role of nanostructured solid sorbent materials. The work critically evaluates the characteristics, performance, and limitations of key nanomaterial classes, including metal–organic frameworks (MOFs), covalent organic frameworks (COFs), zeolites, amine-functionalized polymers, porous carbons, and layered double hydroxides (LDHs), alongside solid-supported ionic liquids, highlighting their varied CO₂ uptake capacities, regeneration energy requirements, and crucial water sensitivities. Beyond traditional temperature/pressure swing adsorption, the review delves into innovative DAC methodologies such as Moisture Swing Adsorption (MSA), Electro Swing Adsorption (ESA), Passive DAC, and CO₂-Binding Organic Liquids (CO₂ BOLs), detailing their unique mechanisms and potential for reduced energy footprints. Despite significant progress, the widespread deployment of DAC faces formidable challenges, notably high capital and operational costs (currently USD 300–USD 1000/tCO₂), substantial energy demands (1500–2400 kWh/tCO₂), water interference, scalability hurdles, and sorbent degradation. Furthermore, this review comprehensively examines the burgeoning global DAC market, its diverse applications, and the critical socio-economic barriers to adoption, particularly in developing countries. A comparative analysis of DAC within the broader carbon removal landscape (e.g., CCS, BECCS, afforestation) is also provided, alongside an address to the essential, often overlooked, environmental considerations for the sustainable production, regeneration, and disposal of spent nanomaterials, including insights from Life Cycle Assessments. The nuanced techno-economic landscape has been thoroughly summarized, highlighting that commercial viability is a multi-faceted challenge involving material performance, synthesis cost, regeneration energy, scalability, and long-term stability. It has been reiterated that no single ‘best’ material exists, but rather a portfolio of technologies will be necessary, with the ultimate success dependent on system-level integration and the availability of low-carbon energy. The review paper contributes to a holistic understanding of cutting-edge DAC technologies, bridging material science innovations with real-world implementation challenges and opportunities, thereby identifying critical knowledge gaps and pathways toward a net-zero carbon future. Full article

Aminotris(methylene phosphonic acid) (ATMP) and poly(acrylic acid) sodium salt (PAA) have shown favorable results in the treatment of porous building materials against weathering damage, showing promising potential as mixed-in additives during the production of lime-based mortars. This study investigates the impact of these additives on microstructure and mechanical properties. Additives were introduced in various concentrations to assess their influence on CaCO₃ crystallization, porosity, strength, and carbonation behavior. Results revealed significant modifications in the morphology of CaCO₃ precipitates, showing evidence of nanostructured CaCO₃ aggregates and vaterite stabilization, thus indicating a non-classical crystallization pathway through the formation of amorphous CaCO₃ phase(s), facilitated by organic occlusions. These nanostructural changes, resembling biomimetic calcitic precipitates enhanced mechanical performance by enabling plastic deformation and intergranular bridging. Increased porosity and pore connectivity facilitated CO₂ diffusion towards the mortar matrix, contributing to strength development over time. However, high additive concentrations resulted in poor mechanical performance due to the excessive air entrainment capabilities of short-length polymers. Overall, this study demonstrates that the optimized dosages of ATMP and PAA can significantly enhance the durability and mechanical performance of lime-based mortars and suggests a promising alternative for the tailored manufacturing of highly compatible and durable materials for both the restoration of cultural heritage and modern sustainable construction. Full article

Developing high-performance photocatalysts for solar hydrogen production requires the synergistic modulation of chemical composition, nanostructure, and charge carrier transport pathways. Herein, we report a Cs and P co-doped tubular graphitic carbon nitride (Cs/PTCN-x) photocatalyst synthesized via a strategy that integrates elemental doping with morphological engineering. Structural characterizations reveal that phosphorus atoms substitute lattice carbon to form P-N bonds, while Cs⁺ ions intercalate between g-C₃N₄ layers, collectively modulating surface electronic states and enhancing charge transport. Under visible-light irradiation (λ ≥ 400 nm), the optimized Cs/PTCN-3 catalyst achieves an impressive hydrogen evolution rate of 8.085 mmol·g⁻¹·h⁻¹—over 33 times higher than that of pristine g-C₃N₄. This remarkable performance is attributed to the multidimensional synergy between band structure tailoring and hierarchical porous tubular architecture, which together enhance light absorption, charge separation, and surface reaction kinetics. This work offers a versatile approach for the rational design of g-C₃N₄-based photocatalysts toward efficient solar-to-hydrogen energy conversion. Full article

The study of the processes of low-temperature synthesis of one-dimensional particles, which are the basis for two- and three-dimensional structures, is relevant for materials science. The modified metal-stimulated electrochemical etching method made it possible to synthesize silicon nanowires with an average thickness of about 292.6 nm. Scanning electron microscopy has shown the formation of nanowires, flower-like structures, and clusters of matter after the deposition of zinc oxide on the porous surface. The hexagonal structure of ZnO crystallites was determined by X-ray diffraction spectroscopy. Studies of the initial sample by electron paramagnetic resonance (EPR) spectroscopy revealed a narrow signal in the center of the spectrum. The subtraction of the EPR spectra with a sequential increase in microwave power up to 8 mW shows the absence of saturation of the signal. This indicates an almost free flow of charges through the surface nanostructures under the influence of an external field. Heat treatment in an air atmosphere at 300 °C caused a significant increase in the intensity of the EPR spectrum. This led to an increase in the intensity of charge transfer through paramagnetic centers. Full article

Despite their outstanding thermal insulation and ultralight structure, silica aerogels suffer from inherent mechanical fragility, making the investigation of their mechanical behavior crucial for expanding their practical utility in advanced applications. To enhance their mechanical performance, this study introduces a dual-phase reinforcement strategy by anisotropically incorporating carbon nanotubes (CNTs) and graphene oxide (GO) sheets into the aerogel matrix. Using molecular dynamic simulations, we systematically investigate the tensile behavior and pore structure evolution of these hetero-structured composites. The results reveal a non-monotonic dependence of tensile strength on loading ratio, distinguishing three strain-dependent reinforcement regimes. High loading content (11.1%) significantly improves strength under low strain (0–26%), whereas low loading levels (1.8%) are more effective at preserving structural integrity under large strain (44–50%). Moderate loading (5.1%) yields balanced performance in intermediate regimes. While increasing carbon content reduces initial pore size by partially filling the framework, tensile deformation leads to interfacial debonding and the formation of larger pores due to CNT–GO hybrid structure interactions. This work elucidates a dual reinforcement mechanism—physical pore confinement and interfacial coupling—highlighting the critical role of nanostructure geometry in tuning strain-specific mechanical responses. The findings provide mechanistic insights into anisotropic nanocomposite behavior and offer guidance for designing robust porous materials for structural and functional applications. Full article

Co₃O₄ nanoparticles synthesized by solution combustion synthesis present a versatile platform for the development of porous nanostructures with tunable morphology and physicochemical properties. Synthesis conditions and parameters such as fuel type; fuel-to-oxidizer ratio and temperature control lead yielding; and Co₃O₄ NPs with fine particle size, surface area, and porosity result in enhancing their electrochemical and catalytic capabilities. This review evaluates present studies about SCS Co₃O₄ NPs to study how synthesis parameter modifications affect both surface morphology and material structure characteristics including porosity features, which make their improved performance ideal for lithium-ion batteries and supercapacitors. Moreover, the integration of dopants with carbon-based hybrid composites enhances material conductivity and stability by addressing both capacity fading and low electronic conductivity concerns. This review mainly aims to explore the significant relation between fundamental material design principles together with practical uses and provides predictions about future research advancements that aim to enhance the performance of Co₃O₄ NPs in next-generation energy and environmental technology applications. Full article

Metal–organic frameworks (MOFs), formed by the self-assembly of metal ions/clusters and organic linkers, have attracted considerable attention due to their well-exposed active sites, exceptionally high porosity, and diversified pore architectures. MOF-derived materials obtained through high-temperature pyrolysis or composite structural design not only inherit the porous framework advantages of their precursors but also demonstrate significantly enhanced electrical conductivity and structural stability via the formation of carbon-based frameworks and in situ transformation of metallic species. However, conventional MOF-derived materials struggle to address persistent technical challenges in contemporary energy storage systems, particularly those requiring ultralong cycling stability and ultrahigh-rate capability under practical operating conditions. The integration of MXene, characterized by its abundant surface functional groups (-O, -OH, -F) and exceptional electrical conductivity, with MOF-derived materials presents a viable strategy to address these challenges. Multidimensional nanocomposites constructed through in situ growth and self-assembly techniques synergistically integrate MXene’s conductive network scaffolding effect with the structural tunability of MOF-derived frameworks. This unique architecture enables the following: (i) enhanced exposure of electroactive sites, (ii) optimized ion diffusion kinetics, (iii) mechanical integrity maintenance, collectively boosting the applicability of MXene/MOF hybrids in advanced energy storage systems. This review summarizes the synthesis methods, energy storage performance, and applications of multidimensional nanostructured MXene/MOF-derived composites. Finally, it discusses the opportunities and challenges for MXene/MOF-derived composites in future energy storage applications. Full article

This study evaluated the relationship between the microstructure, photoluminescence, and photocatalytic properties of newly synthesized nanostructured phosphor materials. The combustion method was used to create samples of down-converting SrGd₂O₄ doped with Dy³⁺ ions (1, and 7 at%) and up-converting SrGd₂O₄ co-doped with varying quantities of Yb³⁺ ions (2, and 6 at%) and a constant quantity of Ho³⁺ ions (1 at%). Transmission electron microscopy (TEM) revealed the existence of porous agglomerated round-shaped particles, with the size around 150 nm, arranged in network-like structures. Energy dispersive X-ray spectroscopy (EDS) confirmed the presence of all structural elements and their homogeneous distribution throughout the particles. The presence of specific emission peaks associated with Dy³⁺ or Ho³⁺ dopant ions was demonstrated by luminescent measurement. The degradation processes of specific organic dyes (methylene blue for up-converters and rhodamine B for down-converters) under simulated sun irradiation were used to investigate photocatalytic activity. A reduction in dye concentration in aqueous solutions was measured using UV/Vis absorption spectroscopy. The results showed a successful dye breakdown rate after 4 h, and aliquots of the working solutions were obtained at precise intervals. Additionally, the results indicated that samples with the highest luminescence intensity exhibited superior photocatalytic activity, suggesting a significant promise for usage as multifunctional materials. Full article

Porphyrins and their derivatives are excellent materials with specific physical and photochemical properties in medical, chemical, and technological applications. In chemistry, their properties are applied to create new functional materials with specific characteristics, such as porphyrin-based sorbents combined with porous organic polymers, silica, carbon nanostructures, or metal–organic frameworks. This review covers the applications of porphyrins and metalloporphyrins in preparing and using sorbents for metal ion enrichment and their separation. Uncommon applications that utilize specific properties of porphyrins, such as light-enhanced processes and redox properties for selective sorption and photocatalytic conversion of metal ions, are also discussed. These applications suggest new fields of use, such as the removal or recycling of metals from electronic waste or the selective elimination of heavy metals from the environment. Full article

Carbon nanomaterials that include different forms such as graphene, carbon nanotubes, fullerenes, graphite, nanodiamonds, carbon nanocones, amorphous carbon, as well as porous carbon, are quite distinguished by their unique structural, electrical, and mechanical properties. This plays a major role in making them pivotal in various medical applications. The synthesis methods used for such nanomaterials, including techniques such as chemical vapor deposition (CVD), arc discharge, laser ablation, and plasma-enhanced chemical vapor deposition (PECVD), are able to offer very precise control over material purity, particle size, and scalability, enabling for nanomaterials catered for different specific applications. These materials have been explored in a range of different systems, which include drug-delivery systems, biosensors, tissue engineering, as well as advanced imaging techniques such as MRI and fluorescence imaging. Recent advancements, including green synthesis strategies and novel innovative approaches like ultrasonic cavitation, have improved both the precision as well as the scalability of carbon nanomaterial production. Despite challenges like biocompatibility and environmental concerns, these nanomaterials hold immense promise in revolutionizing personalized medicine, diagnostics, and regenerative therapies. Many of these applications are currently positioned at Technology Readiness Levels (TRLs) 3–4, with some systems advancing toward preclinical validation, highlighting their emerging translational potential in clinical settings. This review is specific in evaluating synthesis techniques of different carbon nanomaterials and establishing their modified properties for use in biomedicine. It focuses on how these techniques establish biocompatibility, scalability, and performance for use in medicines such as drug delivery, imaging, and tissue engineering. The implications of nanostructure behavior in biological environments are further discussed, with emphasis on applications in imaging, drug delivery, and biosensing. Full article

In this study, we present an innovative optical biosensor designed to detect Interleukin-6 (IL-6), a pivotal cytokine implicated in many pathological conditions. Our sensing platform is made of a porous silicon (PSi) nanostructured substrate modified with a thin (~5 nm) molecularly imprinted polymer (MIP), ensuring both high specificity and sensitivity toward IL-6 molecules. The fabrication process involves electrochemical etching of silicon chips to create the porous structure, followed by the electrodeposition of the MIP, which is tailored to selectively bind the IL-6 target. Extensive testing over a broad IL-6 concentration range demonstrates a clear, proportional optical response, yielding a limit of detection (LOD) of 13 nM. Moreover, the biosensor robustness was verified by evaluating its performance in bovine serum, a complex biological matrix. Despite the presence of various interfering components, the sensor maintained its selectivity and displayed minimal matrix effects, underlining its practical applicability in real-world diagnostic scenarios. Full article

Solar desalination is widely regarded as an effective way to solve freshwater scarcity. However, the balance between the costs of micro-nanostructures, thermal regulation, and the durability of interface evaporators must all be considered. In this study, a super-hydrophobic copper foam with hierarchical micro-nanostructures exhibited temperatures greater than 66 °C under solar illumination of 1 kW·m⁻². Significantly, the modified copper foam acting as a solar interface evaporator had a water harvesting efficiency of 1.76 kg·m⁻²·h⁻¹, resulting from its good photothermal conversion and porous skeleton. Further, the anti-deicing, self-cleaning, and anti-abrasion tests were carried out to demonstrate its durability. The whole fabrication of the as-prepared CF was only involved in mechanical extrusion and spray-coating, which is suitable for large-scale production. This work endows the interface evaporator with super-hydrophobicity, photo-thermal conversion, anti-icing, and mechanical stability, all of which are highly demanded in multi-scenario solar desalination. Full article