Search Results (771)

Constructing Schottky heterojunctions with plasmonic components offers a promising route to enhance photocatalytic performance, yet the synergistic roles of the Schottky barrier and localized surface plasmon resonance (LSPR) in pollutant degradation remain insufficiently elucidated. Herein, a series of Ti₃C₂/Ag-Ag₂NCN (TAN) composites with varied Ag loadings was prepared via an in situ precipitation–chemical reduction method. The pseudo-first-order rate constant of the TAN-30 heterojunction reached roughly 7.0 times the value of bare Ag₂NCN, while its tetracycline degradation efficiency under visible light reached 87.0% at 240 min. Moreover, the heterojunction exhibited outstanding reusability over five successive runs. Comprehensive characterizations reveal that the Schottky barrier at the Ti₃C₂/Ag₂NCN interface effectively suppresses photogenerated carrier recombination, while the LSPR effect of metallic Ag⁰ broadens the light absorption range and elevates the local surface temperature, synergistically accelerating charge migration. The dominance of h⁺ and •O₂⁻ among the reactive species was established by both radical trapping assays and ESR spectroscopic analysis. This work provides mechanistic insights into LSPR-enhanced Schottky heterojunctions and offers a rational design strategy for MXene-based photocatalysts toward efficient antibiotic wastewater treatment. Full article

The selective removal of electron-rich emerging organic contaminants (EOCs) from aquatic environments remains a critical challenge, as conventional radical-based oxidation processes suffer from poor selectivity and interference from background constituents. To address this issue, we report an electron-transfer-mediated catalytic oxidation system using peroxydisulfate (PDS) activated by hollow multi-shelled Co₃O₄ (HoMS Co₃O₄) nanoreactors derived from plant-based tannic acid. The triple-shelled hollow architecture affords a high specific surface area with abundant accessible active sites, enabling the HoMS Co₃O₄/PDS system to achieve complete bisphenol A (BPA, 0.04 mM) removal within 90 min (k = 0.045 min⁻¹). Mechanistic investigations, integrating electron paramagnetic resonance spectroscopy, radical quenching, electrochemical analyses and in situ Raman/FTIR spectroscopy, reveal that the degradation proceeds via an electron-transfer-mediated non-radical pathway, in which surface-complexed PDS serves as the primary reactive species. This pathway enables selective oxidation of electron-rich pollutants and endows the system with broad pH adaptability, strong resistance to coexisting water constituents, and robust performance in real water matrices (>93% BPA removal). Moreover, the system maintains stable operation in a continuous flow-through reactor over 72 h with negligible Co²⁺ leaching, offering a sustainable strategy for the selective remediation of EOC-contaminated waters. Full article

Raw Chinese lacquer, tapped from the sap of Toxicodendron vernicifluum, is a natural water-in-oil microemulsion containing urushiol, polysaccharides, proteins, and laccase. Because this reactive system continues to oxidize and polymerize after harvesting, handling conditions directly determine water content, viscosity, and later film-forming performance. This review analyzes potential in situ stabilization routes that couple purification, low-temperature vacuum dehydration, and quality conditioning at, or near, the collection site. Emphasis is placed on how laccase retention, oxygen exposure, and urushiol polymerization are controlled together to limit transport losses and premature crusting. Portable filtration devices, reported centrifugal filtration systems, and proposed vacuum dehydration strategies are compared in terms of throughput, field compatibility, and process control. Physical and bio-based conditioning strategies, including shear adjustment, oxygen management, and natural film-forming aids, are further considered for on-site regulation. Surface-enhanced Raman spectroscopy (SERS) and portable spectroscopic devices are examined as feedback tools for parameter adjustment under field temperatures, humidity, and storage variation; however, these signals are treated as decision-support indicators that still require lacquer-specific calibration after tapping. The central task is to define a field-compatible process window for water removal, laccase retention, viscosity control, drying behavior, and storage stability before downstream coating preparation. The remaining challenges involve miniaturized equipment, standardized evaluation, evidence-level classification, and dynamic control of coupled variables. Full article

The global energy transition and rapid electrification are driving increased demand for copper. However, conventional pyrometallurgical and hydrometallurgical extraction routes are increasingly challenged by declining ore grades and stricter environmental regulations. Bioleaching involves the microbial catalysis of sulfide mineral dissolution and provides a sustainable method for copper recovery from low-grade ores, tailings and secondary resources. This review provides a critical and integrated analysis of copper sulfide bioleaching, covering microbial diversity, molecular mechanisms, mineralogical controls, operational parameters, and industrial applications. This review also examines the functional roles of prominent acidophiles, including the functional roles of prominent acidophiles, including Acidithiobacillus spp., Leptospirillum spp. and thermophilic archaea, in the oxidation of iron and sulfur, mitigation of passivation, and metal solubilization. The molecular underpinnings of these processes are explored by investigating iron and sulfur oxidation gene networks (the rus operon and sox cluster), copper resistance systems (CopA, CusCBA) and biofilm formation pathways. The mineralogical controls on the behavior of chalcopyrite (refractory/passivating), chalcocite (highly reactive) and bornite (intermediate) are critically assessed. The synergistic effects of key operational parameters (temperature, pH, redox potential, aeration and particle size) on leaching kinetics and microbial community dynamics are investigated. The scalability, efficiency and environmental footprint of industrial applications such as heap, dump, stirred-tank and in situ bioleaching are discussed. Despite more than four decades of commercial development, several challenges remain, such as slow chalcopyrite dissolution, passivation, metal toxicity, and scale-up limitations. Emerging solutions such as synthetic microbial consortia, multi-omics technologies, artificial intelligence-assisted optimization, and digital twins are identified as transformative approaches for next-generation biomining. In this review, microbiology, mineralogy, electrochemistry, and process engineering are integrated to demonstrate that biotechnological leaching is among the most promising technologies for the sustainable production of copper and to identify future directions for its industrial application. Full article

Thin spray-on liner (TSL) technology provides rapid and highly automated surface support for underground coal mine roadways. However, in deep roadways affected by high in situ stress, mining-induced disturbances, and fractured surrounding rock, conventional TSL materials require improved tensile–shear resistance, deformation compatibility, and support adaptability. Although fiber reinforcement is an effective method for enhancing polymer composites, systematic studies on the effects of fiber type and dosage in reactive polymer-based TSL materials remain limited. In this study, a commercially available two-component polyurea-silicate-based TSL matrix was reinforced with polyvinyl alcohol (PVA) fibers, polypropylene mesh fibers, and toughened polypropylene fibers at volume fractions of 0.25–1.50%. A stepwise experimental program, including uniaxial compression, variable-angle shear, tensile, circular-indenter buffered shear, and true triaxial tests, was conducted to evaluate the mechanical behavior and support-related performance of the fiber-reinforced TSL materials. The basic mechanical tests showed that the 0.75% toughened polypropylene fiber group maintained favorable compressive and shear resistance, achieving a cohesion of 8.65 MPa and an internal friction angle of 24.12°. PVA fibers exhibited higher tensile reinforcement efficiency at relatively low contents, with the 0.25% PVA fiber group reaching a peak tensile stress of 13.61 ± 1.00 MPa. The 1.0% PVA fiber group showed good deformation coordination, with a compressive strength of approximately 49.87 MPa. In the circular-indenter buffered shear test, the 1.0% PVA fiber group reached a peak load of 0.636 ± 0.055 kN and an absorbed energy of 3.118 ± 0.832 J at 10 mm displacement. Under true triaxial loading, the 1.0% PVA fiber group absorbed 311.4 J of energy at a displacement of 10 mm, approximately 5.5% higher than that of the 0.75% toughened polypropylene fiber group. Therefore, 1.0% PVA fiber reinforcement is recommended as the optimal reinforcement scheme for polymer-based TSL materials used in deep, fractured, and large-deformation coal mine roadways. Full article

The rapid growth of tennis participation and the widespread use of lithium-ion batteries have led to increasing volumes of rubber waste and spent battery materials, underscoring the need for integrated recycling strategies. In this work, a thermochemical co-pyrolysis process is developed to convert waste tennis ball rubber particles (TBRPs) and spent lithium-ion battery (LIB) cathodes into valuable products. The decomposition of TBRPs generates reactive gaseous and liquid hydrocarbons that function as in situ reductants, enabling the breakdown of high-valence transition metal oxides in the cathode material. Subsequent magnetic separation and mild acid-washing yield nonmagnetic solids enriched in lithium compounds and carbonaceous residues. Structural and chemical analyses (SEM, XRD, TEM, EDS, and XPS) confirm extensive cathode reduction and the formation of Li₂CO₃ at optimized conditions (650 °C, 1 h, cathode-to-TBRPs mass ratio 1:0.65). The carbonized rubber evolves into a highly porous carbon material with a carbon purity of approximately 95.37 At%. This study demonstrates a low-energy, environmentally friendly pathway for the co-valorization of two challenging waste streams while simultaneously recovering lithium salts, reduced metal oxides, and functional porous carbon. Full article

To demonstrate the applicability of the “dynamic self-vulcanization of bifunctional monomers” strategy for toughening polylactic acid (PLA), hydroxylated oleic acid (HOA) was synthesized via UV-initiated thiol–ene click chemistry, using oleic acid as the starting material. In the presence of an excess molar quantity of hexamethylene diisocyanate (HDI), the dynamic self-vulcanization of bifunctional monomers was employed to design PLA blends featuring extraordinary impact toughness. During the one-pot melt compounding, in situ formation and self-crosslinking of flexible poly(urethane-co-amide) (HPUA) toughening phase, together with its reactive compatibilization with the PLA matrix, were simultaneously accomplished. The aggregation of the HPUA domains enabled the morphological transformation of the PLA blend from a sea-island structure to a partially or fully bi-continuous one. At HPUA contents of 20 wt% or higher, the blend exhibited a bi-continuous morphology with a crosslinked HPUA network, attaining a notched impact strength exceeding 110 kJ/m² and an elongation at break above 200%. In particular, when the HPUA content reached 20 wt%, the resulting PLA blend exhibited optimal impact toughness, with a notched IS of 132.1 kJ/m² (30.7 times that of neat PLA). The primary toughening mechanism was determined to be the internal cavitation of the HPUA domains, which subsequently initiates the yielding of the surrounding PLA matrix. This study proposes an applicable and facile method for fabricating polymer materials that possess excellent impact toughness. Full article

Aiming at the rapid corrosion of degradable magnesium alloys in physiological environments and the insufficient long-term protection of single plasma electrolytic oxidation (PEO) coatings, Mg-Mn-Fe layered double hydroxide (LDH) and baicalin (BA)-loaded LDH/BA composite coatings were prepared in situ on PEO-pretreated ZE21C magnesium alloy substrates. BA was stably anchored on the LDH surface via coordination bonds between its oxygen-containing functional groups and laminate metal sites. Benefiting from the physical barrier of the LDH lamellar structure and the corrosion inhibition effect of baicalin, the LDH/BA coating significantly improved the corrosion resistance of the magnesium alloy matrix. The composite coating exhibited peroxidase-like catalytic activity for reactive oxygen species generation, which could be enhanced by near-infrared irradiation. It also possessed stable photothermal conversion performance and pH-responsive drug release behavior under acidic conditions. Biological characterization demonstrated that BA-loaded LDH composite coatings exert potent inhibitory effects on 143B cell proliferation. This work integrates long-term corrosion resistance, controlled drug release, and photoresponsive catalytic functions onto magnesium alloy surfaces, providing an effective strategy for developing high-performance biodegradable magnesium alloys. Full article

Improving the separation efficiency between methyldichlorosilane (CH₃SiHCl₂) and trichlorosilane (SiHCl₃) is one of the key urgent problems to be solved for the quality improvement and consumption reduction in high-purity polysilicon. In this work, three types of porous supported catalysts were prepared via an in situ reaction method, taking aluminum chloride (AlCl₃) as the active component and activated carbon, silica gel and activated alumina as support; the catalytic reaction mechanisms of CH₃SiHCl₂ and silicon tetrachloride (SiCl₄) over the as-prepared porous supported catalysts were investigated, based on density functional theory (DFT). The results reveal that among the three supported catalysts, the activated carbon-supported aluminum chloride catalyst (C@AlCl₃) possesses the maximum binding energy (−3.20 eV) between the active component and support. CH₃SiHCl₂ and SiCl₄ possess the lowest co-adsorption energy (−1.8 eV) and the minimum reaction energy barrier (0.8 eV) on C@AlCl₃, accompanied by the maximum charge transfer to the catalyst surface (−2.65 e and −2.80 e), thus exhibiting the highest catalytic activity, with the maximum single-pass conversion of CH₃SiHCl₂ exceeding 90%. This work provides material basis and theoretical guidance for constructing a reactive distillation strategy for high-efficiency and low-energy separation of CH₃SiHCl₂ from SiHCl₃. Full article

The study presents a sustainable, metal-free tanning system based on 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) and N-methylmorpholine (NMM), which stabilizes collagen through a zero-length crosslinking mechanism. Reactive triazine intermediates, generated in situ, selectively activate collagen carboxyl groups, forming active esters that subsequently react with amine functionalities to form amide bonds. Unlike conventional tanning systems, no metals or toxic chemicals are incorporated into the tanned leather. Optimization of reagent concentration, temperature, and dosing strategy revealed that the gradual formation of reactive intermediates is essential to balance reaction kinetics and diffusion throughout collagen. Under pickle-free conditions, hydrothermal stability was achieved with only 2.5–3.4 wt% CDMT/NMM, yielding shrinkage temperatures of 81–85 °C that surpass most reported chrome-free tanning systems. The resulting leather displayed a bright white appearance, excellent dyeability, and outstanding physical-mechanical performance, including superior tear resistance and competitive tensile strength. These properties are consistent with the formation of a homogeneous collagen network reinforced by direct covalent amide crosslinks while maintaining fiber flexibility. Furthermore, avoiding pickling significantly reduces chemical consumption and improves wastewater biodegradability, enhancing the environmental sustainability of the process. Overall, CDMT/NMM emerges as a scalable, environmentally friendly tanning technology that combines mechanistically controlled collagen crosslinking with excellent leather performance. Full article

The traditional geological view holds that overpressure resists mechanical compaction during sedimentary burial, keeping effective stress approximately constant and thereby passively preserving porosity and permeability in deep reservoirs. However, this assumption has relied predominantly on theoretical inference and struggles to explain a widespread geomechanical paradox: in many overpressured formations, the magnitude of permeability enhancement significantly outpaces the degree of porosity preservation. To decode this paradox, we conducted a fundamental proof-of-concept study utilizing high-pressure percolation coupled with in situ micro-CT and fractal analysis to dynamically simulate the effects of overpressure on porous sandstone under constant mean effective stress. The results reveal a counterintuitive phenomenon: while the global porosity remained fundamentally stable, the absolute permeability demonstrated a significant ~8% enhancement. Microstructural analysis indicates that this enhancement is driven by localized hydraulic wedging and the reactivation of sub-resolution throats acting as topological bridges. This active topological optimization physically and mathematically manifests as: (1) the massive reconnection of macroscopic isolated pores; (2) an enhanced space-filling capacity of the flow network, evidenced by an increased coordination number and 3D pore space fractal dimension (D_f); and (3) the structural straightening of fluid pathways, rigorously quantified by a reduction in flow tortuosity and tortuosity fractal dimension (D_T). These findings, derived from a single well-characterized sandstone sample, demonstrate that overpressure-driven permeability enhancement is a physically plausible mechanism in tight sandstones. This discovery offers a candidate physical explanation for the anomalously high permeability observed in certain deep overpressured reservoirs. However, the generalizability of these results to reservoirs with differing porosities, mineralogies, and diagenetic histories remains to be evaluated through multi-sample studies. Full article

Sandstone-hosted uranium deposits represent one of the world’s most important uranium resources and are strategically significant for nuclear energy development, energy transition, and carbon emission reduction. Compared with conventional open-pit or underground mining, in situ leaching has become the dominant approach for sandstone-hosted uranium deposits due to its minimal surface disturbance, higher resource utilization efficiency, and reduced environmental footprint. However, most sandstone-hosted uranium deposits exhibit pronounced reservoir heterogeneity, including permeability contrasts, uneven flow pathways, complex uranium occurrence, and non-uniform advancement of reaction fronts. These factors collectively restrict leaching solution transport, limit uranium mobilization, and reduce recovery efficiency and sustainability of in situ leaching operations. Therefore, achieving efficient, environmentally friendly, and sustainable development of complex heterogeneous sandstone uranium deposits has become a key challenge in in situ leaching research and engineering practice. This review summarizes recent advances in recovery enhancement technologies for in situ leaching of sandstone-hosted uranium deposits over the past decade. Based on the geological and hydrogeochemical characteristics of these deposits, the mechanisms of in situ leaching are first outlined, followed by technological developments in four areas: flow field regulation, reservoir permeability enhancement, geochemical regulation, and reactive-transport coupling enhancement. Current challenges and future research directions are also discussed. This review provides a systematic framework for improving uranium recovery while advancing efficient, environmentally responsible, and sustainable in situ leaching development. Full article

Be–Al alloys are attractive for aerospace and precision-engineering applications because of their low density, high specific stiffness, and excellent dimensional stability. However, their broader application is constrained by multiscale defects arising from the low mutual solubility of Be and Al, their large melting-point difference, and the high reactivity of the Be/Al interface. This review critically examines defect formation and microstructural evolution in Be–Al alloys produced by casting, powder metallurgy, pressure infiltration, thermomechanical processing, and additive manufacturing, with particular emphasis on additive manufacturing. Rapid solidification can refine the Be-rich phase and suppress coarse segregation, but unstable melt-pool behavior, restricted gas escape, cyclic thermal loading, and insufficient interfacial diffusion may also promote porosity, compositional heterogeneity, residual stress, and interfacial degradation. The mechanical properties of Be–Al alloys depend strongly on Be-phase morphology, continuity of the Al matrix, interfacial integrity, and the spatial distribution of processing-induced defects. Recent progress in alloy design, process optimization, interfacial engineering, and post-processing is evaluated, together with the limitations of the available evidence. Future research should establish quantitative processing–defect–microstructure–property relationships through in situ monitoring, multiscale characterization, predictive modeling, and standardized mechanical validation. These advances are essential for the reliable manufacture of complex, high-performance Be–Al components. Full article

Precise quantitative monitoring of 17β-estradiol (E2) is important for reproductive management in precision livestock farming. However, E2 determination in complex biological matrices remains challenging because of matrix-derived background and signal variability. Here, we developed a nanoconfinement-assisted solid-state ratiometric fluorescent aptasensor integrating target-induced strand displacement (TISD), magnetic separation, and anodic aluminum oxide (AAO) nanochannel confinement. The sensing probe consisted of streptavidin-coated magnetic nanoparticles (MNPs) carrying a FAM-labeled cDNA internal reference and a Texas Red-labeled E2 aptamer reporter. E2 binding promoted dissociation of the Texas Red-labeled aptamer from the magnetic probe. Magnetic separation and washing reduced soluble matrix-derived interference, while subsequent deposition of the sensing complexes onto an AAO membrane mitigated coffee-ring-associated nonuniformity and produced a more spatially uniform dual-color fluorescence distribution for ratiometric analysis. Under matrix-matched calibration conditions, linear ranges of 5.0–50.0 pM were obtained in tap water and sow saliva, 5.0–40.0 pM in whole milk, and 5.0–15.0 pM in post-estrus sow urine. The LOD determined in tap water was 3.62 pM. The different calibration slopes obtained among the four matrices indicated that residual matrix-dependent effects remained and that matrix-specific calibration was required for quantitative analysis. Matrix-matched spike recoveries ranged from 86.92% to 119.54% across the investigated matrices. The aptasensor exhibited the strongest response toward 17β-E2 among the tested compounds; however, cross-reactivities of 77.3% for E3 and 47.3% for 17α-E2 indicated preferential rather than exclusive recognition. Molecular docking suggested a putative binding pose but did not experimentally establish the molecular recognition mechanism. Overall, the platform demonstrated laboratory-scale analytical feasibility in pretreated tap water, sow saliva, whole milk, and post-estrus sow urine. Further development of sample preparation, magnetic handling, membrane loading, probe selectivity, and portable fluorescence readout will be required before in situ or on-site application. Full article

The escalating frequency of extreme hydrological events under environmental uncertainty poses a severe socio-economic threat to floodplains such as the Brazilian Pantanal, the world’s largest tropical wetland. Mitigating dynamic flooding and drying cycles is highly challenging due to a critical scarcity of in situ monitoring, leaving flood risks poorly understood. To address these data gaps, this study presents an advanced deep learning forecasting framework that integrates multisource environmental data, fusing satellite-derived precipitation (CHIRPS) and global land data assimilation evapotranspiration (GLDAS) data with historical river gauge telemetry. Multi-layered neural network architectures were optimized and combined with progressive moving average filters (10− and 15−day windows) to capture the complex hydrometeorological patterns of the data-scarce Miranda River Watershed. The optimal deep learning configuration, utilizing a robust two-hidden-layer topology (15 and 60 neurons), consistently outperformed standard baselines. Although purely exogenous data blocks successfully minimized satellite noise and captured seasonal trends (NSE ≥ 0.92), structural underestimation of peak flows was observed. When incorporating the previous day’s streamflow (lag t−1) as a physical anchor, this limitation was noticeably alleviated, increasing both the Nash–Sutcliffe Efficiency (NSE) and Coefficient of Determination (R²) values above 0.99. While this performance surge is driven by the strong temporal persistence inherent to the autoregressive lag, it introduces an operational trade-off by restricting the forecast to a reactive 24 h window. In this regard, an evaluation of the operational forecast horizons revealed that the exogenous deep learning blocks maximize warning lead times, providing a vital tool for proactive civil defense and disaster risk reduction. Ultimately, this multisource framework establishes a methodological foundation for automated decision support systems, providing the high-accuracy streamflow forecasting capability required to support future flood mitigation frameworks. Full article