Search Results (221)

Aflatoxin B1 (AFB1), a highly carcinogenic mycotoxin, has been the focus of research for the development of efficient detection methods. In this study, a novel magnetic immuno-ratiometric fluorescent sensing system was constructed for the quantitative detection of AFB1. Green-emitting carbon quantum dots were conjugated with AFB1 monoclonal antibody to obtain GCDs@AFB1 mAb, and AFB1 oxime was immobilized on Fe₃O₄ magnetic microspheres to prepare AFB1-Ox@Fe₃O₄ NPs. After the immune-competitive adsorption of GCDs@AFB1 mAb by AFB1-Ox@Fe₃O₄ NPs and free AFB1, magnetic separation was performed. Red fluorescent silver nanoclusters were introduced as an internal reference to construct a GCDs-AgNCs ratiometric fluorescent system. The sensor exhibited a good linear response in the range of 0~240 pg/mL with a low limit of detection of 18 pg/mL and excellent selectivity. The spiked recoveries in real samples ranged from 92.14% to 110.02%, with a relative standard deviation of 0.57% to 4.58%. Combining the specific antigen–antibody recognition with magnetic separation technology, this method addresses the issues of poor stability and high environmental interference of traditional fluorescent sensors, and provides a new strategy for the sensitive and stable detection of AFB1. Full article

Transition-metal sulfides are promising electrode materials for high-performance supercapacitors but are often limited by poor conductivity, particle agglomeration, and insufficient active sites. Herein, Co-doped NiS₂ with tunable sulfur vacancies was directly grown on flexible carbon cloth via a facile one-step solvothermal method by systematically controlling sulfur source ratio, Ni:Co ratio, temperature, and reaction time. Structural analyses reveal that the optimized conditions of S:(Ni + Co) = 3:1, Ni:Co = 2:1, 160 °C, and 15 h promote the formation of phase-pure Co-doped NiS₂ hierarchical microspheres with enhanced crystallinity and abundant active sites from the synergistic interaction between Ni and Co. Consequently, the optimized electrode delivers an impressive capacitance of 1296 F g⁻¹ at a current density of 1 A g⁻¹, along with excellent rate performance, retaining more than 88% of its capacitance after 1500 charge/discharge cycles at current densities ranging from 2 to 20 A g⁻¹. This work highlights the critical role of synthesis parameter engineering in regulating defect chemistry, structure, and electrochemical performance in advanced energy storage applications. Full article

This study presents a sodium alginate/chitosan/activated carbon (SA/CS/AC) gel microspheres loaded with Citrus reticulata peel allelochemicals for continuous inhibition of Microcystis aeruginosa by controlled release. Preparation parameters were optimized via response surface methodology (RSM) for improved algal inhibition, yielding an optimal formulation: 1.97% SA, 0.76% CS, 0.31% AC. The optimized gel microspheres showed a 7-day inhibition rate of 85.17 ± 2.49%, consistent with the predicted 85.29%. Characterization revealed that AC optimized the gel’s porous structure and surface functionality, providing more adsorption sites for allelochemicals. This helps improve the loading capacity of the gel microspheres and enables stable sustained release, with a cumulative release of 70% over 25 days. Algal inhibition declined slightly from day 7 to 30 due to allelochemical depletion but remained 76.27%, versus 30.58% for the blank SA/CS/AC carrier and 52.81% for the allelochemical-loaded SA/CS gel microspheres. AC thus synergistically strengthens algal inhibition by elevating allelochemical loading and prolonging activity, providing a feasible strategy for sustainable cyanobacterial bloom control. Full article

In this work, monodisperse carbon microspheres with an average diameter of approximately 900 nm were successfully synthesized via a hydrothermal method. To further tailor their surface properties, the layer-by-layer (LbL) self-assembly technique was employed, where the cationic polyelectrolyte poly(diallyldimethylammonium chloride) (PDDA) and the anionic polyelectrolyte poly(styrene sulfonate) (PSS) were alternately deposited on the microsphere surface, forming two and four bilayer assemblies, respectively. The resulting composite microspheres exhibited remarkable adsorption performance toward representative dyes in water solution, such as rhodamine B (RhB) and methylene blue (MB). Experimental results demonstrated that the incorporation of a single bilayer significantly reduced the specific surface area but introduced additional active adsorption sites, thereby enhancing dye removal efficiency. However, when the number of bilayers was further increased to two, partial pore coverage and blockage occurred, leading to a reduced surface area and consequently diminished adsorption capacity. These findings highlight that in LbL surface modification, more layers do not necessarily yield better performance, but rather an optimal assembly thickness exists. This insight provides valuable guidance for the rational design of advanced adsorbent materials for wastewater treatment. Full article

Biomass valorization into carbon-rich materials has attracted increasing attention as a sustainable alternative to fossil-based resources. This work is devoted to the study of hydrothermal carbonization (HTC) of spruce lignocellulose liquid pyrolysis products (the target product of the pyrolysis is levoglucosan)—bio-oil (B). In addition, the fractionated B compounds, including the phenol-enriched fraction remaining after anhydrosugar removal, were evaluated as potential precursors for hydrochar production. Hydrochars were produced at 200, 250, and 300 °C and characterized using SEM, revealing that spherical morphology agglomerates can also be obtained from the phenol-enriched fraction. The chemical composition and structural evolution of the hydrochars were investigated by Py-GC/MS, elemental analysis, and FTIR, demonstrating the significant influence of both precursor composition and carbonization temperature on hydrochar chemistry. In addition, the organic compounds in the process water were analyzed using UHPLC and complementary chemical analysis. The results show that the chemical composition of the precursor strongly influences the yield, morphology, and chemical composition of the obtained hydrochar. Full article

Carbon materials are regarded as cost-effective adsorbents due to their ability to remove heavy metals and organic pollutants from contaminated water. In this study, a novel phenol–formaldehyde resin-derived carbon microsphere (HCM_2.5) was designed and synthesized via a hard-template method combined with KOH activation. The prepared HCM_2.5 exhibits high selectivity and removal efficiency toward heavy metal ions and delivers an ultrahigh specific surface area of 2165 m²/g. A Cr(VI) removal efficiency exceeding 99.6% could be achieved in 50 ppm acidic solution, with excellent performance at pH 2–5. X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) nitrogen adsorption–desorption analysis, and scanning electron microscopy (SEM) were used to confirm its porous structure with a high specific surface area. The results of X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) reveal that the efficient heavy metal removal performance of HCM_2.5 is mainly attributed to its high specific surface area, as well as coordination and redox reactions between oxygen-containing functional groups and heavy metal ions. Furthermore, benefiting from its outstanding specific surface area and well-developed pore structure, a physical–chemical synergistic adsorption mechanism was proposed and systematically elucidated. Full article

Facing the increasingly severe energy challenges and environmental problems, the development of thermally stable, lightweight, and thermal insulating materials is critical. Herein, we report an organic-inorganic composite strategy combined with a high-temperature carbonization step to fabricate aerogel-containing composites synergistically reinforced with chopped glass fibers and hollow glass microspheres. By systematically varying the ratio of acrylic emulsion to potassium silicate solution, we investigated the effects on the forming behavior, microstructure, hydrophobicity, thermal stability, and thermal insulation performance. Increasing the acrylic emulsion fraction substantially enhanced hydrophobicity, yielding a maximum water contact angle of 129.3°. Concurrently, the apparent density decreased from 0.18 g/cm³ to 0.09 g/cm³ and the thermal conductivity dropped from 57.9 mW/(m·K) to 29.0 mW/(m·K). Mechanical testing revealed that the compressive Young’s modulus decreased with increasing acrylic content, from 3.6 MPa for the purely inorganic sample to 0.55 MPa at 70% acrylic content, reflecting a trade-off between stiffness and organic-derived porosity. Microstructural characterization revealed a hierarchical porous network in which uniformly dispersed hollow glass microspheres and the aerogel-derived silica network form an efficient thermal barrier system. Thermogravimetric analysis demonstrated excellent thermal stability, with total weight loss below 5% up to 800 °C. Infrared thermography analysis showed that, after unilateral heating at 300 °C and 400 °C for 10 min, the backside surface temperature of the composites decreased as the acrylic emulsion content increased. At 300 °C, the temperature decreased from 176.1 °C for AP-1 to 151.0 °C for AP-4, while at 400 °C, it decreased from 228.5 °C to 199.3 °C. These results indicate that the composites exhibit effective thermal insulation and maintain structural stability under high-temperature exposure. Taken together, this facile and scalable approach yields these aerogel-containing composites that combine low density, low thermal conductivity, robust structural integrity, and good environmental resistance, as evidenced by a water contact angle of 129.3°, making them promising candidates for aerospace, building, and industrial high-temperature insulation applications. Full article

Mesophase pitch (MP) is a high-performance precursor for carbon materials. However, its conventional preparation process is limited by stringent conditions and high costs. In this study, heavy coal tar (HCT) was used as a low-cost carbon source, and polyethylene (PE) was introduced as a modifier to induce MP formation under relatively mild conditions, thereby promoting the thermal polycondensation of HCT. Characterization results show that the addition of different types of PE facilitates the condensation of aromatic molecules and significantly enhances the conversion efficiency of HCT to MP. Among the tested PE types, HDPE exhibits the best performance, with an optimal addition of 6 wt.% at 400 °C, yielding the highest number of uniform mesophase carbon microspheres and the most ordered structure. Based on comprehensive characterization data, an average molecular structure model of the product was constructed, addressing a research gap regarding the role of PE in the thermal polycondensation of HCT. This work provides a new pathway for the energy-efficient preparation and property regulation of MP. Full article

The decline of fossil fuel resources and the negative impact of fuel combustion on the environment are forcing scientists to develop new technologies for producing functional carbon materials with various useful properties. This work is devoted to a detailed study of the transformations of monosaccharides, glucose and levoglucosan, during hydrothermal carbonization, aimed at the formation of carbon microspheres. Hydrochars were obtained at temperatures of 200, 250, and 300 °C and characterized using SEM, Py-GC/MS, and elemental analysis. Changes in the chemical composition of the liquid phase were studied, depending on the HTC temperature and precursor concentration. Expanded knowledge of microsphere formation enriches information on the mechanism of monosaccharide transformation for the production of new carbon materials through synthesis from inexpensive precursors. Full article

Nuclear energy has emerged as a crucial technological solution for ensuring energy security and achieving carbon neutrality goals, given its ultra-high energy density and near-zero carbon emissions against the backdrop of rapid socioeconomic development, increasing energy demands, and accelerated global transition toward low-carbon energy structures. As the core component for energy conversion in nuclear reactors, fuel elements critically determine reactor efficiency and safety performance, with the fission product retention capability of silicon carbide layers in multilayer-coated fuel particles having been thoroughly validated through high-temperature gas-cooled reactor irradiation tests. The precise sphericity control of large-sized UO₂ fuel kernels represents a fundamental requirement for enhancing tristructural isotropic (TRISO) fuel particle performance and advancing Generation IV nuclear power plant development. This study presents a sphericity control strategy based on sol–gel processing that synergistically integrates physicochemical regulation of gelling media with multi-field washing flow field optimization. By implementing silicone oil-mediated interfacial tension gradient control, we effectively suppressed gel sphere destabilization while developing an innovative three-phase sequential washing technique involving kerosene washing, anhydrous ethanol interfacial transition, and ammonia solution replacement, which significantly enhanced mass transfer diffusion in stagnant liquid films and revolutionized fuel microsphere washing technology with improved efficiency and quality. Experimental results demonstrate that this integrated approach increases kernel sphericity qualification to 99.8%, reduces washing solution consumption by 79%, and achieves an average sphericity of 1.03. The research establishes a coupling mechanism between gelling media and multi-field washing processes, elucidating the synergistic effect between interfacial tension regulation and washing optimization, thereby providing both theoretical foundations and engineering application basis for the precision manufacturing of high-performance nuclear fuels. Full article

In this work, a flexible and sustainable radar-absorbing material (RAM) based on porous carbon derived from raw Kraft black liquor was developed. The porous carbon filler was synthesized through a simple, eco-friendly one-pot polymerization route, thereby avoiding lignin extraction, purification, and chemical activation steps. Macroporosity was introduced by using poly(methyl methacrylate) microspheres as a hard template, yielding a lightweight carbon material with a foam-like morphology, low density, and high porosity. The carbon filler was incorporated into a silicone rubber matrix at different loadings (5–25 wt.%) to produce flexible composites. The structural, morphological, and textural properties of porous carbon were investigated by SEM, EDX, Raman spectroscopy, nitrogen adsorption, and mercury porosimetry. The electromagnetic properties of composites were measured in the X-band (8.2–12.4 GHz) using a vector network analyzer. The mechanical behavior was evaluated through Young’s modulus. The results show that increasing filler content enhances dielectric losses and attenuation capability. Among all composites, the sample containing 20 wt.% of porous carbon exhibited the best electromagnetic performance, achieving a reflection loss of −42.3 dB at 10.97 GHz with a thickness of 2.43 mm, corresponding to an absorption efficiency of 99.99%. This performance is attributed to a favorable combination of impedance matching and quarter-wavelength cancellation effects. The developed sustainable, lightweight, and flexible composites demonstrate potential as low-cost RAM for aerospace and electromagnetic interference mitigation applications. Full article

The sustainable management of olive wastes represents an important environmental challenge. Biochars and hydrochars derived from biomass are promising adsorbents for removing emerging pollutants from water. In the present work, olive stone wastes were converted into biochar and hydrochar by using pyrolysis (500 °C for 30 min) and hydrothermal carbonization (HTC) processes (220 °C for 10 h). Then, the obtained materials were physically activated by using CO₂ gas (750 °C for 30, 60 and 180 min). Various analytical techniques were applied for the chemical, textural and structural characterization of these carbonaceous materials (i.e., ultimate and proximate analysis, scanning electron microscopy (SEM), BET surface area, Raman spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy). Afterwards, the selected activated biochar and hydrochar were applied for the removal of amoxicillin from aqueous solutions. The experimental results show that the generated hydrochar has many microspheres on its surface and inside, while the produced biochar exhibits a porous structure with irregular forms. CO₂ physical activation has induced an important improvement of the biochar and hydrochar’s structural, textural, and surface chemistry properties. For instance, the activated biochar samples show a highly porous structure, with large specific surface areas that increase with the burn-off, reaching 1349.3 m² g⁻¹ following 3 h of activation. Regarding the activated hydrochar samples, they exhibit a spherical morphological structure with an important specific surface area, which increased to 846.7 m² g⁻¹ after 3 h of activation. Moreover, both activated materials have an amorphous structure with low oxygen surface groups. The selected novel CO₂-activated biochar and hydrochar efficiently remove amoxicillin from aqueous solutions under wide experimental conditions, with adsorption capacities of 386.4 and 215.9 mg g⁻¹, respectively. These efficiencies are higher than those reported for various activated biochars derived from lignocellulosic biomass, from sewage sludge, and from animal manure. Future research works are required to assess these materials’ effectiveness in treating real pharmaceutical effluents, to optimize the regeneration of the amoxicillin-loaded materials, and to design full-scale devices for a real application. Full article

In the context of the “dual-carbon” targets and the development of green building materials, lightweight mortar has attracted considerable attention, owing to its low density and excellent thermal insulation properties. However, lightweight aggregates, such as vitrified microspheres, while effectively reducing mortar density, exhibit high porosity and weak interfacial bonding, which compromise mechanical performance. To address this issue, this study introduces sugarcane bagasse fiber (SBF) as a reinforcing material, with contents of 0%, 0.4%, 0.8%, 1.2%, and 1.6%. The effects of SBF on physical properties (consistency, density, water absorption) and mechanical properties (compressive strength, flexural strength, and tensile bond strength) were systematically evaluated. Furthermore, low-field nuclear magnetic resonance (LF-NMR) and scanning electron microscopy (SEM) were employed to analyze pore structure and interfacial transition zone (ITZ) characteristics at multiple scales. The results indicate that: (1) at low contents (0.4–0.8%), SBF was uniformly dispersed, improving matrix compactness; (2) compared with the control group, the 28-day compressive, flexural, and tensile bond strengths increased by 7.1%, 13.1%, and 25%, respectively; (3) NMR analysis revealed that the incorporation of SBF significantly increased the proportion of capillary pores, reduced total porosity, and enhanced mortar compactness, thereby improving mechanical strength; (4) fractal dimension analysis showed that contents of 0.4% and 0.8% increased structural complexity while reducing pore connectivity, leading to higher compressive strength; (5) SEM observations further demonstrated that the fibers provided bridging and anchoring effects within the ITZ, promoted the deposition of hydration products, and enhanced interfacial compactness. Full article

Potassium-ion batteries hold great promise for large-scale energy storage, but their commercialization is hindered by the large ionic radius of potassium, which causes sluggish kinetics and severe volume expansion in anode materials. To address this, we present a scalable spray-drying strategy coupled with NaCl salt-templating to synthesize hierarchical porous carbon/vanadium sulfide microspheres (p-V₃S₄/C MS). In this structure, V₃S₄ nanoparticles are uniformly encapsulated within a dextrin-derived amorphous carbon matrix, and pores are formed via selective NaCl etching. This unique architecture accommodates volume fluctuations while providing rapid ion diffusion pathways. As a result, the p-V₃S₄/C MS anode exhibits outstanding electrochemical performance, maintaining a reversible capacity of 107 mA h g⁻¹ after 2000 cycles at 2.0 A g⁻¹, and achieves a high pseudocapacitive contribution of 93% at 2.0 mV s⁻¹. Furthermore, a full cell paired with a Prussian blue (PB) cathode demonstrates practical viability and robust reversibility. Our findings demonstrate that this structural engineering effectively mitigates internal resistance and structural degradation, offering a cost-effective route for mass-producing high-performance anodes for next-generation energy storage. Full article

The intermittency of renewable-based power is a major barrier for long-term supply of clean energy, which necessitates the development of reliable solutions for clean energy storage and transition towards a carbon-neutral economy. Although hydrogen has emerged as a promising clean energy carrier to address this, its high compressibility requires safe, efficient and practical storage technologies for widespread deployment. Surface storage technologies for hydrogen have garnered attention due to their mobile and stationary applications, paving the way for a future hydrogen-based economy. This review provides a comprehensive review of surface hydrogen storage technologies, covering metal hydrides, metal-organic frameworks (MOFs), liquid organic hydrogen carriers (LOHCs), glass microspheres, capillary arrays, etc. Where previous reviews mostly address the chemistry behind these storage technologies, this study highlights practical integration and techno-economic assessment. Comparative analysis reveals that while LOHC and hydrides dominate in Technology Readiness Level, MOFs and carbohydrate-based systems offer high gravimetric potential, though they are currently quite costly. Other challenges like thermal management and large-scale regeneration remain critical for practical deployment. Moreover, recent advancements in Artificial Intelligence and Machine Learning offer unique insights, demonstrating their growing role in material screening, performance prediction, and the optimization of storage system designs. This review outlines the key challenges and research pathways required to support future deployment. Full article