Search Results (671)

To achieve efficient development of medium-depth and shallow high-rank coalbed methane in the Qinshui Basin of Shanxi Province, the authors focused on the microscopic methane release mechanism. Through scanning electron microscopy, nuclear magnetic resonance, and isothermal adsorption experiments, the pore structure, distribution patterns, and influence of hydration effects in this type of coal were revealed. It was clarified that the ineffective utilization of “bound-state” methane within nanopores is the key factor leading to low productivity and efficiency in coalbed methane development. Further, based on molecular simulations, the competitive adsorption characteristics between water and methane molecules were quantified, indicating that about 78% of the methane in the internal pores of 4 nm coal molecular clusters cannot be desorbed through pressure reduction. Meanwhile, the production enhancement mechanism of hydraulic fracturing on coal seam depressurization, permeability enhancement, reduction in low-speed diffusion distance, and enhancement of high-speed linear flow was clarified. Through large-scale pad water injection and stepwise slow production increase, the coal seam can be fully communicated, the reservoir effectively stimulated, and the adsorbed methane sufficiently released. This paper establishes a “channeled” fracturing concept and its supporting technological system for medium-depth and shallow high-rank coal, which has been successfully applied in field operations. The pilot well group achieved stable daily production exceeding 50,000 cubic meters per day, laying a solid foundation for the continuous and stable production increase in medium-depth and shallow high-rank coalbed methane in the Qinshui Basin. Full article

The widespread use of plastics has inevitably led to the accumulation of persistent plastic debris in aquatic systems, where gradual fragmentation generates microplastics (MPs) that threaten ecological and biological health. Their small size, chemical stability, and resistance to degradation make effective removal particularly challenging. In this work, a composite adsorbent was fabricated through the in situ solvothermal growth of Materials of Institute Lavoisier 100 (Iron) (MIL-100(Fe)) onto coconut shell-derived activated carbon (CSAC), yielding a monolithic material denoted as CSAC@MIL-100(Fe). The integration of porous C with a metal–organic framework created a hierarchically structured adsorbent rich in accessible binding sites. The composite achieved a maximum polystyrene (PS) removal efficiency of 97.4% and maintained 91.44% efficiency after seven regeneration cycles. Stable adsorption performance was observed across a broad pH range. Structural and chemical analyses (scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS)) combined with adsorption modeling revealed heterogeneous multilayer adsorption behavior consistent with the Freundlich isotherm and pseudo-second-order kinetics. π–π interactions, electrostatic attraction, and coordination effects jointly governed PS capture. The Langmuir maximum adsorption capacity reached 746.27 mg/g. These findings demonstrate a practical and recyclable strategy for efficient MP remediation in aquatic environments. Full article

The Cinnamomum camphora seed kernel (CCSK) shows great promise as a natural source of bioactive alkaloids. However, there is little data about recovering alkaloids from CCSK by-products after oil extraction using an aqueous method. This study aimed to establish an efficient technology for enriching CCSK alkaloids (including magnoflorine, lindoldhamine and N,N-methyldomesticinium) using macroporous resin technology. The results showed that XR918C resin was the most suitable adsorbent due to its high adsorption/desorption capacity for CCSK alkaloids. The adsorption process was best described by Langmuir isotherm models and pseudo-second-order kinetics; it was spontaneous and physical in nature. The optimum procedure for CCSK alkaloids enrichment using XR918C resin was as follows: for adsorption, the injection flow rate and sample volume were 2.0 BV/h and 7.0 BV, respectively; for desorption, the eluent type, elution flow rate and volume were 80% ethanol, 2.0 BV/h and 6.0 BV, respectively. Furthermore, the scale-up of the CCSK alkaloid enrichment process was performed under optimal conditions. Following the 10-fold scale-up enrichment, the content of CCSK alkaloids was raised 4.41-fold, with a recovery rate of 89.19 ± 0.01%. After nine regeneration cycles, the efficiency of the XR918C resin remained stable, indicating its good reusability. In addition, CCSK alkaloids exhibited strong in vitro antioxidant activity. This study provides a useful reference for the industrial-scale enrichment of CCSK alkaloids. Full article

Sulfonamide antibiotics (SAs) are ubiquitous and persistent organic contaminants in aquatic and soil ecosystems due to their extensive application and high structural stability, causing rising environmental hazards. Conventional treatment approaches, generally based on physical adsorption or biological processes, remain limited in achieving efficient and stable removal as well as deep molecular modification of SAs. In recent years, modified biochar has developed as a flexible environmental functional material incorporating adsorption and reaction regulation capabilities, owing to its customizable pore structure, surface chemistry, and electronic characteristics. This study comprehensively highlights current achievements in the adsorption and degradation of sulfonamide antibiotics by modified biochar, with specific emphasis on modification techniques, structural modulation, structure–performance connections, and interfacial reaction processes. Through physical activation, heteroatom doping, defect engineering, and metal integration, biochar has developed from a traditional adsorbent into a carbon-based interfacial reactor capable of pollutant adsorption, molecular activation, and directed transformation. Surface-confined reaction interfaces, where π–π interactions, hydrogen bonding, electrostatic interactions, and metal coordination cooperatively control adsorption and transformation processes, are primarily responsible for the elimination of SAs. Moreover, the dual functions of modified biochar in driving both radical and non-radical pathways are explored, showing the vital importance of interfacial electronic structure modulation and electron-transfer mechanisms in influencing reaction efficiency and selectivity. The impact of sulfonamide molecular configurations, ambient circumstances, and concomitant chemicals on removal performance are also explored. Unlike previous reviews that mainly summarize adsorption efficiency or oxidant activation systems separately, this work integrates structural modulation, interfacial electronic regulation, and bond-selective transformation mechanisms into a unified structure–chemistry–reactivity framework. By correlating sulfonamide molecular configuration with biochar electronic structure, this review provides a mechanistic roadmap for the rational design of next-generation catalytic biochar systems. Finally, key challenges related to structural controllability, long-term stability, and engineering scalability are identified, and future research directions are proposed to support the rational design of high-performance biochar materials and the practical control of sulfonamide antibiotic pollution. Full article

Bacillus cereus is a major foodborne pathogen responsible for food spoilage and foodborne illness, including strains producing emetic toxins. In this study, two bacteriophages, PBC_MG88 and PBC_MG99, were isolated from wastewater using emetic B. cereus strains as hosts and were comprehensively characterized. Both phages formed clear plaques with halos and exhibited siphovirus morphology. Host range analysis against 172 B. cereus strains showed that PBC_MG88 and PBC_MG99 infected 50 and 60 strains, respectively. One-step growth experiments revealed efficient lytic activity, with latent periods of 20–25 min and burst sizes of 59–63 PFU per infected cell. More than 90% of phage particles adsorbed to host cells within 15 min. Both phages were stable across a wide temperature range (4–55 °C) and pH values (4–11). Genome sequencing revealed ~37 kb double-stranded DNA genomes lacking antibiotic resistance or virulence genes; however, the presence of lysogeny-related genes suggests a temperate lifestyle. Comparative genomic analyses indicated that both phages represent novel species within the genus Lwoffvirus. Biofilm assays demonstrated significant inhibition of B. cereus biofilm formation and reduction of pre-established biofilms. Overall, this study expands knowledge of B. cereus phage diversity and highlights the importance of genomic characterization in phage-based biocontrol research. Full article

The sluggish reduction kinetics of thionyl chloride and the cathode passivation induced by the densification deposition of discharge product LiCl are critical challenges that severely hinder the commercialization of lithium/thionyl chloride (Li/SOCl₂) batteries. In this work, a dual-catalyst cobalt tetrapyridine porphyrin (CoTAP) and copper phthalocyanine (CuPc) supported on activated carbon (AC) were proposed to synergically regulate SOCl₂ reduction and product deposition. When the CoTAP/CuPc/AC catalyst was synthesized and applied as the cathode of Li/SOCl₂ batteries, UV-Vis spectroscopy, crystal field coordination structure analysis, DFT calculations and XPS measurements collectively demonstrated that CoTAP catalyzes SOCl₂ reduction through coordination at Co sites and strongly adsorbs Cl⁻, while CuPc features a weakly coordinated Cu center that facilitates the migration of LiCl products from the cathode surface. This collaborative effect in CoTAP/CuPc/AC cathodes effectively accelerates the reduction kinetics of SOCl₂ and promotes the ordered deposition of product LiCl, thereby guaranteeing the continuous and progressive discharge process in Li/SOCl₂ batteries. As a result, the CoTAP/CuPc/AC-catalyzed batteries exhibited excellent electrochemical performance with a stable discharge voltage of 3.16 V and high discharge capacity of 15.08 mAh, superior to the counterpart batteries without catalysts. This work provides a design idea for the development of advanced Li/SOCl₂ batteries. Full article

This paper presents paper-based dye-sensitized solar cells (paper DSSCs) fabricated using carbon nanotube (CNT) composite paper produced from mixtures of CNT and pulp dispersions. DSSC is composed of a dye-adsorbed semiconducting electrode, a counter electrode, and an electrolyte. In this study, our DSSC is constructed using n-type semiconducting CNT composite paper as the semiconducting electrode, metallic CNT composite paper as the counter electrode, and ordinary paper for keeping the electrolyte. In our previous study, potassium hydroxide was used to convert semiconducting CNT composite paper to n-type, but the performance was limited. Therefore, we aim to achieve a more stable and higher-performing paper DSSC by annealing the semiconducting CNT composite paper in a hydrogen–argon atmosphere to induce n-type properties. For this, CNT composite paper was prepared using the cationic surfactants DODMAC( dimethyl octadecyl ammonium=chloride, cationic surfactant) and DDAC as dispersing agents. The fabricated DSSCs were evaluated in terms of photoelectric conversion efficiency and fill factor (FF). As a result, DSSCs using DODMAC increased the efficiency from 5.04 × 10⁻³% to 13.37 × 10⁻³% and the FF from 0.13 to 0.21. When DDAC was used, the efficiency increased to 17.11 × 10⁻³% and the FF improved to 0.27. Full article

Two-dimensional magnetic materials with weak spin-orbit coupling would endow them with great potential for applications in low-power spintronic logic devices. In this work, the stability and magnetism of nonmetal (N, O, F, P) doped 1T-ZrS₂ monolayers is systematically studied by using first principles calculations based on density functional theory. Pristine ZrS₂ monolayer is a nonmagnetic semiconductor with an indirect band gap of 1.15 eV. Among the configurations of nonmetal-atom adsorption, substitutional doping, and vacancy defects, fluorine adsorption on the ZrS₂ monolayer is regarded as an optimal doping strategy. At the concentration of 11.11% in F-adsorbed ZrS₂, the spontaneous magnetization of F-adsorbed ZrS₂ monolayer occurs at the ground state with the stable magnetic states; the magnetic moments are about 0.674 μ_B, which mainly originates from the hybridization between the p-orbitals of S atoms and F atoms (0.315 μ_B) and d-orbitals of Zr atoms (0.323 μ_B). Moreover, the F-adsorbed ZrS₂ monolayer under 0–4% strain delivers consistently low spin polarization energy with stable p-d hybridization, offering their promising potential for their practical applications in low-power spintronic devices. Full article

Colistin sulfate (COL), a critical last-line antibiotic, poses a severe environmental threat due to its persistence and role in spreading mobile resistance genes. This study introduces a novel quaternary Ni-Co-Zn-Al layered double-hydroxide/activated carbon composite (Q-LDH/AC) for highly efficient COL remediation. The composite’s unique architecture, revealed through comprehensive characterization, enables an exceptional adsorption capacity of 952.52 mg·g⁻¹ under optimal conditions (pH 7, 55 °C), a value that significantly surpasses those reported for most previous adsorbents. The process was spontaneous and endothermic, with kinetics and isotherms best described by the pseudo-second-order and Langmuir–Freundlich models, respectively, indicating a complex mechanism dominated by chemisorption on both homogeneous and heterogeneous sites. A key innovative feature is the successful regeneration and reusability of the composite, which retained over 70% efficiency after five cycles, enhancing its potential for practical, cost-effective water treatment applications. The thermodynamic parameters (ΔG° = −8140.68 kJ/mol, ΔH° = +61.22 kJ/mol) indicate that the reaction is spontaneous and endothermic. The interaction mechanism of COL on Q-LDH/AC can be deduced by FT-IR including hydrogen bonding, π-π bonding, electrostatic interactions, and surface complexation. Beyond mere regeneration, this work demonstrates a pioneering circular economy strategy by repurposing the spent COL-laden adsorbent not as waste, but as a high-performance electrocatalyst. In direct urea fuel cell tests, this electrode achieved a superior and stable current density of 45.63 mA/cm² for Q-LDL/AC, substantially outperforming the pristine Q-LDH/AC/COL (206.63 mA/cm²) and highlighting how the captured pollutant enhances functionality. This dual-purpose approach successfully closes the loop, transforming the environmental liability of antibiotic-laden waste into a valuable resource for energy applications. With a production cost of 2.755 USD/g, this work presents not only a highly effective adsorbent but also a transformative, circular strategy that simultaneously addresses water pollution and energy recovery. These findings offer a promising dual-purpose solution for mitigating the environmental spread of antibiotic resistance through a sustainable cycle that enables efficient antibiotic removal from wastewater while simultaneously converting the captured pollutant into a useful energy resource. Full article

In this paper, we show that the sphere-in-contact model can predict long-range surface adsorption phenomena based on adsorbate-adsorbate repulsions and their geometric distance, assuming that their negative surface-induced charge is smeared on the surface of the adsorbate atoms. Additionally, it can be used to model collective surface diffusion mechanisms such as the domino-type surface diffusion of adsorbate rows on close-packed metal HCP and FCC surfaces. We have recently shown that the sphere-in-contact model can be used as an educational and research tool in various contexts, such as the visualization of carbon structures (e.g., graphene, carbon nanotubes, carbon nanocones, and graphite), heterogeneous catalysts, metal nanoparticles, and organic molecules. Here we present how it can be used to model the adsorbate structure of monoatomic elements on the hexagonal close-packed surface of HCP and FCC metals to study long-range ordering phenomena of monoatomic adsorbates on metals. We have used atoms of varying radius and color to represent the metal surface atoms and the adsorbate atoms. The study reveals that many surface configurations are possible for a fixed adsorbate coverage (θ) by the movement of the adsorbate atoms in response to surface adsorbate-adsorbate repulsions. The movement of the particles (e.g., particle diffusion) can be seen directly in the model, and this is caused by the user intervention. This has great educational and research value, as one can directly see how the adsorbate atoms reorder on the surface of a metal and therefore study diffusion mechanisms. We calculate the repulsive interaction energy of adsorbates using the sphere-in-contact model and can identify which surface-adsorbed configuration is the lowest energy. We find that at a surface coverage of 1/3 (0.333 ML), the most stable adsorbate configuration places adsorbates at the third nearest neighbor 3-fold hollow sites, forming a hexagonal pattern. We find that this model will be useful in the rational design of catalytic materials and material coatings with new technological applications where long-range ordering of surface adsorbates is essential and adsorbate interactions are mainly repulsive interatomic interactions. Full article

The development of sustainable pigments from natural sources is gaining interest due to environmental concerns and the need for bio-based alternatives to synthetic dyes. This study investigates the synthesis of hybrid pigments by adsorbing anthocyanins—extracted from pomegranate agro-waste—onto halloysite (HA) nanotubes. A full factorial design was applied to evaluate the influence of pH and surfactant type (cetylpyridinium bromide and sodium dodecyl sulfate) on pigment colour and the thermal and structural stability of the hybrids. Adsorption was carried out in 400 mL dispersion baths containing 10 g of HA and 5% w/w anthocyanins. Surfactants (2% w/w) were added before the pigment, followed by 200 µL of silane. Dispersions were stirred at high speed for 1 h and then at 500 rpm for 23 h to ensure adsorption without premature desorption. Characterisation (TGA, XRD, FTIR, UV-Vis/NIR, SEM, EDX, BET) confirmed the preservation of HA structure and minimal changes in thermal behaviour. Pigment colour varied with synthesis conditions, especially pH: a higher pH increased brightness and yielded yellowish tones, while a lower pH resulted in reddish-blue hues with greater variability. The results confirm halloysite’s potential as a stable carrier for natural dyes and demonstrate that pH effectively tunes hybrid pigment colour. Full article

Soil mineral nitrogen (N) supply and the ammonium-to-nitrate ratio (NH₄⁺-N:NO₃⁻-N) are critical for vegetable yield and quality. Under current urea N-reduction practices, inadequate soil N often limits continuous vegetable growth. This study evaluated novel N fertilizer prepared by adsorbing different ratios of ammonium nitrogen and nitrate nitrogen onto rice straw extract (AX1–AX5), different N gradient conventional urea (U1, U2) and a control without N fertilizer (CK) in an incubation experiment. Results showed that ammonium-loaded novel N fertilizers (AX1, AX2) maintained a stable soil NH₄⁺-N:NO₃⁻-N (~1:1), while nitrate-loaded ones (AX4, AX5) exhibited slow-release effects, increasing cumulative mineral N by ~70% over U1. Novel N fertilizers also raised cumulative CO₂ (3451–4513 μg kg⁻¹) and N₂O (9.6–12.0 μg kg⁻¹) emissions versus U1, reflecting stimulated microbial activity supported by higher sucrase and nitrate reductase activities. The treatment (AX2) showed “fast-early, stable-late” N release, with mineral N consistently exceeding U1 and a maintained NH₄⁺-N:NO₃⁻-N near 1:1. Field validation is needed to assess agronomic and environmental performance under real farming conditions. Full article

Effective treatment of coal slime water is essential for sustainable coal preparation plant operation but hindered by the stable suspension of fine, negatively charged particles. To address this, a novel star-shaped inorganic–organic hybrid polymer (aluminum hydroxide-polyacrylamide, Al-PAM) was synthesized via in situ polymerization. Its performance was systematically compared with well-established coagulants/flocculants—polyaluminum chloride (PAC), non-ionic polyacrylamide (NPAM), and their binary combination through settling tests and quartz crystal microbalance with dissipation monitoring (QCM-D). The results showed a positive correlation between the molecular weight of Al-PAM and its flocculation efficiency. The optimal variant, Al-PAM-442, achieved an exceptionally high initial settling rate (50.4 m/h) and low supernatant turbidity (45.77 NTU) at an ultralow dosage of 6 mg/L. QCM-D analysis elucidated the mechanism: Al-PAM forms a thick, soft, and irreversibly adsorbed hydrated layer on silica, enabling strong electrostatic anchoring and effective polymer bridging. In contrast, PAC adsorption was reversible, while NPAM formed a thin, compact film with poor bridging capacity. Although the combined PAC/NPAM system showed synergistic performance, it required a significantly higher dosage (70 mg/L). This study demonstrates that the star-shaped Al-PAM architecture successfully integrates charge neutralization and bridging into a single molecule, offering a highly efficient and practical solution for industrial coal slurry dewatering. Full article

The development of oxidation-resistant and regenerable materials remains a major challenge for mercury removal from contaminated waters and industrial effluents. In this study, a zwitterionic mesoporous silica gel functionalized with L-cysteine (SG-3PS-Cys) was synthesized, where the thiol group is covalently anchored to the silica framework, preventing oxidative degradation while preserving –NH₃⁺ and –COO⁻ groups for Hg(II) coordination. Spectroscopic analyses (FTIR, XPS, and ¹³C NMR) confirmed the formation of a stable, thiol-free binding environment in which mercury interacts through carboxylate oxygen atoms, electrostatically stabilized by neighboring ammonium groups. The material exhibited a high surface area (134 m² g⁻¹) and uniform mesoporosity (9.8 nm), achieving a maximum Hg(II) uptake of 82.7 mg g⁻¹ at pH 3 with rapid kinetics and cooperative S-type isotherms. The adsorbent retained 72% of its capacity after five regeneration cycles and maintained 38.7% selectivity toward Hg(II) in multicomponent solutions. DFT-based surface energy distribution analysis supported the zwitterionic coordination mechanism, revealing energetically homogeneous and high-affinity binding domains. Beyond its chemical stability, the material introduces a sustainable route for mercury remediation, linking surface energy, electrostatic effects, and porosity to achieve durable performance under acidic and complex aqueous conditions. These findings provide a mechanistic and design framework for the next generation of non-thiol adsorbents capable of selective and reusable Hg(II) removal in environmentally relevant scenarios. Full article

Amine-functionalized solid adsorbents are widely recognized as promising candidates for direct air capture of CO₂; however, their practical deployment remains constrained by humidity-dependent adsorption behavior and poor packed-bed operability arising from irregular particle morphology and fines generation. Rather than focusing solely on maximizing intrinsic adsorption capacity, this study addresses these process-level limitations through an integrated design strategy combining particle morphology control with surface chemistry optimization. Uniform spherical magnesium silicate particles with a mean diameter of approximately 15 μm were synthesized via a water-in-oil emulsion route to suppress fines formation and reduce hydrodynamic resistance. Controlled acid pretreatment was subsequently applied to adjust surface hydroxyl accessibility and enable efficient amine grafting without altering bulk composition. The optimized spherical magnesium silicate amine adsorbents exhibited pronounced humidity-enhanced carbon dioxide capture, achieving capacities of 1.7 to 1.8 millimoles/g at 50% relative humidity, representing an approximately fourfold increase compared with dry conditions. This enhancement is attributed to a humidity-induced mechanistic transition from carbamate formation under dry conditions to water-assisted bicarbonate formation under humid conditions. Complete regeneration was achieved at 100 °C, with stable adsorption desorption behavior maintained over ten consecutive cycles, demonstrating short-term reversibility. These findings highlight morphology controlled scalability. Future work should prioritize durability beyond 100 cycles, mechanical robustness, and techno-economic viability at scale. Full article