Force For Adsorption Research Articles

In-situ doping of nitrogen and aluminum on microporous carbon for efficient dichloromethane adsorption

Chlorinated volatile organic compounds (Cl-VOCs) pollute the ecological environment and damage the human health due to their extraordinary stability. To circumvent these risks, a concise integration strategy was proposed to synthesize porous carbon (PC) by N/Al co-doping with decent surface area and concentrated micropore distribution for effective Cl-VOCs adsorption. N/Al co-doped microporous carbon (NAlPC) presented superior dichloromethane (DCM) adsorption capacity (182.50 mg/g at 0.02 kPa and 611.29 mg/g at 39.73 kPa) and outstanding recycling performance (maintaining 87 % of DCM adsorption capacity after five adsorption/desorption regeneration cycles). DCM adsorption experiments showed that pore structure and surface chemistry of NAlPC have a distinct impact on DCM adsorption behavior under different pressure. Desorption tests and theory simulations jointly proved that the introduction of N could develop the micropores of NAlPC, which is beneficial to DCM adsorption. And the doping of Al could counteract the prevention of N in the interaction between NAlPC and DCM, maintaining the powerful binding of NAlPC with DCM. This work provides a facile and economic method to prepare microporous carbon by changing its pore structure and regulating its surface chemistry to enhance the DCM adsorption force and capacity, offering a great insight to the fabrication of microporous carbon adsorbents with hierarchical pore structure and doped heterogeneous element for VOCs abatement.

Design the bionic sucker with high adsorption performance based on Sinogastromyzon szechuanensis

Based on the observed micromorphology of the Sinogastromyzon szechuanensis, a groove morphology was designed on the sucker working surface. The length, width, and number of the grooved morphology were selected as the design factors for the bionic morphology. The bionic and standard sucker was fabricated using the mold method, and the sucker adsorption performance was tested. Compared to the standard sucker adsorption force on the substrate (33.20 N), the bio-inspired sucker adsorption force could increase by a maximum of 71.22 %. The change law of the adsorption force was the same as the change law of negative pressure holding time. The bionic sucker could form multiple micro-sealing cavities from the groove morphology while forming a normal sealing cavity with the substrate. The bionic sucker adsorption force was greater than that of the standard sucker. As the length and width of the groove increased, the micro-sealing cavity formed by the groove shape made it difficult to form micro-suckers during the adsorption process, and the adsorption force was affected. With the increase in the number of grooves, the number of micro-suckers formed between the morphology and the substrate during the adsorption process could increase, and the adsorption force was increased.

Research on passive adaptive wall-climbing cleaning and inspection robot of marine cylindrical steel structure based on conical magnetic adsorption wheel

The marine growth cleaning and structural defect detection of steel structures of offshore underwater facilities are essential parts of the inspection and maintenance of offshore platforms. However, a majority part of underwater structures of offshore facilities, such as offshore wind turbines, Jacket platforms, Jack-up platforms, etc., are cylindrical structures. Compared with the planar structures, cylindrical structures have large curvature, and less supporting area, and therefore put forward higher requirements for the performance of the attached surface working robot. This paper proposes a wall-climbing cleaning robot that can move freely on the wall of cylindrical steel structures and passively adapt to cylindrical structures with various curvatures and diameters. According to the structural characteristics of the robot, a static failure model is established to analyze the different instability forms of the robot and the minimum critical magnetic adsorption force is determined. To ensure the minimum mass and the maximum magnetic adsorption force of the conical magnetic adsorption wheelsets, the effects of air gap and cone angle on the performance of the conical magnetic adsorption wheelsets were analyzed parametrically, and the optimal structural size was obtained. Finally, the mobility and capability of the robot on the surface of the different diameter cylindrical structures has been validated through prototype experiments.

Corrosion inhibition performance of protein derived carbon quantum dots as corrosion inhibitors on low carbon steel in sulfuric acid solution

Protein derived carbon quantum dots (PCQDs) were successfully fabricated via a hydrothermal method with shrimp meat as the precursor. Subsequently, their corrosion-inhibiting performance on mild steel (L-steel) in a 0.5 mol/L H2SO4 solution was evaluated. Electrochemical impedance spectroscopy (EIS) tests demonstrated that at a concentration of 250 mg/L, the corrosion inhibition efficiency of PCQDs exceeded 90 %. Potentiodynamic polarization (PDP) tests indicated that when the concentration of PCQDs reached 500 mg/L, the corrosion inhibition efficiency was as high as 97.45 %. Comprehensive characterizations of the PCQDs, including X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and ultraviolet–visible spectroscopy (UV–Vis), verified the existence of functional groups such as carboxyl, hydroxyl, and aromatic rings within the PCQDs. These groups are conducive to forming a strong adsorption force on the surface of L-steel and creating a protective layer. Surface morphology analyses carried out by scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed that the surface of L-steel treated with PCQDs was significantly smoother in comparison to untreated samples exposed to acidic conditions. Adsorption studies disclosed a mixed physical and chemical adsorption behavior, and theoretical calculations showed that the N and S atoms in PCQDs preferentially adsorb in a parallel direction. The addition of PCQDs led to a reduction in the diffusion coefficient, indicating that the diffusion of corrosive ions was effectively hindered. The distribution function of PCQDs was 3.48 Å, which suggested that the chemisorption mechanism played a dominant role in the inhibition process.

Methane Desorption-Diffusion Behaviors in Micropores of Coal under Different Water Displacement Pressures.

Hydraulic fracturing not only enhances the flow conductivity of coal seams but also transforms the CH4 adsorbed in coal seams into free CH4 and then outputs it via the desorption-diffusion process, thus improving the output quantity and efficiency of CH4. In this paper, taking the coal from Changping mine in Shanxi as the research object, the 3D macromolecule model of coal was established by using analytical test experiments, and the molecular dynamics simulation method of desorption and diffusion was applied to study the characteristics of methane desorption rate and diffusion behaviors under different driving water pressures through the parameters of gas-water concentration distribution, desorption and diffusion rates, and the interaction energies between the coal and the gas-liquid. The results show that the water drive can increase the desorption rate of methane. With the increase of methane adsorption pressure, the desorption effect of water drive becomes stronger and then weaker. The desorption effect of water drive was best when the methane adsorption pressure was 5 MPa and the pressure difference was 2 MPa. Generally, the water drive promoted the methane diffusion, but if the water drive time was too long, it formed a water plug, and the water drive methane inhibited the diffusion. In shallow reservoirs, water drive can obviously promote the desorption-diffusion of methane. The binding energy between CH4 molecules is mainly composed of the repulsive force, while that between water molecules is mainly the adsorption force. In the binding energy between CH4 molecules and coal structures, the van der Waals (VDW) force accounts for 99% of the effect; in the binding energy between water molecules and coal structures, the electrostatic force contributes 84% to ∼88% thereto. The VDW force is significantly influenced by the pressure, while the electrostatic force is slightly affected. As the water displacement differential pressure is increased, the binding energy between CH4 molecules and coal structures decreases.

Interactions of the Biphenylene Network with α-Helical and β-Sheet Proteins: Molecular Dynamics Simulations.

In recent years, nanomaterials have been widely used in the biomedical field. The biphenylene network is a highly promising planar carbon nanomaterial. To better explore its biomedical applications, we need to understand the biological effects of the biphenylene network. To investigate the biological effects of the novel nanomaterial biphenylene network, we used molecular dynamics simulations to study the interactions of the novel planar carbon nanomaterial biphenylene network with α-helical and β-sheet proteins. We found that both types of proteins adsorb flatly on the surface of the biphenylene network; the strong van der Waals interaction is the main adsorption force, while π-π stacking also provides an auxiliary force for the adsorption. When the HP35 protein whose secondary structure is an α-helix was adsorbed on biphenylene network, the entire structure of α-helix 2 was disrupted and α-helix 3 partly recovered its helical structure after being disrupted. In contrast to the β-sheet YAP65 protein, only part of the structure of β-sheet 1 was disrupted. Therefore, the biocompatibility of the biphenylene network with the β-sheet YAP65 protein is better than that of the α-helical HP35 protein, which may be due to the different surface curvature of the protein's secondary structure. Our research promotes the application of the biphenylene network in biomedicine and provides a theoretical basis and experimental direction for practical experiments.

Performance of orange peels crosslinked β-cyclodextrin (OP-β-CD) to uptake lanthanum from water: Conventional adsorption studies and ultrasound-assisted desorption

Even though adsorption has been widely employed to recover rare earth elements such as lanthanum, desorption remains challenging since selectivity is often linked to strong adsorption forces. Herein we propose the grafting between orange peel (OP) wastes with beta-cyclodextrins (β-CD) for producing a highly reusable and stable adsorbent that allows the easy recovery of lanthanum in repeated cyclic runs. The morphological analysis confirmed that the OP-β-CD adsorbent was successfully functionalized with –OH groups, with β-CD grafting via citric acid expanding and stabilizing its structure. The pseudo-first-order model better represented the kinetics of lanthanum adsorption, while the isothermal behavior was better represented by the Langmuir model (qmax=95.79mgg−1), as shown by the thermodynamic analysis, which confirmed that the process was endothermic and spontaneous. The mechanism behind the efficiency of adsorption-desorption of lanthanum by OP-β-CD adsorbent was concluded to rely on: i) electrostatic and reversible interactions and ii) a driving force that increased as the amount of lanthanum increased in solution, leading to the formation of a monolayer. Around 95 % of lanthanum was desorbed using an ultrasound-assisted technique with citric acid, maintaining stable adsorption capacity for 5 cycles. In real matrices containing other rare earth elements and high calcium concentrations the removal exceeded 80 %. Thus, OP-β-CD's remarkable stability during desorption underscores its potential as a highly effective and sustainable solution for rare earth element recovery and removal.

Bionic Design and Adsorption Performance Analysis of Vacuum Suckers.

This study addresses the problem that the traditional method is not effective in improving the adsorption performance of vacuum suckers. From the perspective of bionics, the adsorption performance of bionic suckers based on the excellent adsorption of the abalone abdominal foot was studied. A bionic sucker was designed by extracting the sealing ring structure of the abdominal foot tentacle. The bionic sucker was subjected to tensile experiments using an orthogonal experimental design, and the adsorption of the bionic sucker was simulated and analyzed to explore its adsorption mechanism. The results show that the primary and secondary factors affecting the adsorption of the sucker are the number of sealing rings, the width of sealing rings and the spacing of sealing rings. At 60% vacuum, the bionic sucker with two sealing rings, a 1.5 mm sealing ring width and 3 mm sealing ring spacing has the largest adsorption force, and its maximum adsorption force is 15.8% higher than that of the standard sucker. This study shows that the bionic sucker design can effectively improve the adsorption performance of the sucker. The bionic sucker had a different stress distribution on the sucker bottom, which resulted in greater Mises stress in the sealing ring and the surrounding area, while the Mises stress in the central area of the sucker was smaller.

Adsorption performance and mechanism of single-component and multi-component VOCs by Beta zeolites with different Si/Al ratios

The physical and chemical properties of VOCs and zeolite materials generally affect adsorption efficacy for VOCs removal. Here, toluene and methanol were chosen as typical VOCs with different polarities and molecular diameters to investigate the performance and mechanism of their adsorption on Beta zeolites with various Si/Al ratios. It was found that high-silica Beta exhibited superior toluene adsorption capacity, while low-silica Beta showed higher methanol adsorption capacity. Compared with single-component adsorption, in the case of co-adsorption of toluene and methanol, the saturation adsorption capacities for toluene and methanol only changed slightly even with the existence of competitive adsorption and weakened adsorption strength. Importantly, there was almost no decrease in absorption capacity after 10 repeated adsorption-regeneration cycles, showing the excellent reusability of Beta zeolites for toluene and methanol removal. Whether on low-silica or high-silica Beta, physical adsorption of toluene and methanol was dominant, along with a small proportion of chemical adsorption on low-silica Beta based on acid sites. Similar size between the diameters of toluene and the pore channels of Beta zeolites was responsible for strong adsorption force, increase of adsorption capacity, and minor effect on absorption performance in the process of competitive adsorption. Strong interaction between acid sites and polar methanol through H-bond or non-polar toluene by electrostatic attraction promoted chemical adsorption. Furthermore, toluene and methanol both tended to absorb in the twelve-membered-ring of Beta zeolites on Si-OH-Al, Al-OH, and Si-OH sites. This study provides insight into the factors influencing the adsorption performance and mechanism of toluene and methanol on zeolites, which gives potential guidance for the selection of adsorbents for high-efficiency VOCs removal.

Применение моделей адсорбции при исследовании поглощения ионов никеля почвой

The aim of the presented work is to study the absorption of nickel ions by soils of the Udmurt Republic using four sorption models. Humus horizons (0–20 cm) of Albeluvisols Umbric, Leptosols Rendzinic and Phaeozems Albic soils widely distributed in Udmurtia were selected as objects of nickel adsorption research. According to the Langmuir model, good sorbents are characterized by high Amax values and low – KL, therefore, the best sorbent of nickel ions is Albeluvisols Umbric (Amax=0.0562 mol/kg, KL=2075.19 dm3/mol), and a weaker absorber is Phaeozems Albic (Amax=0.0192 mol/kg, KL=19474.48 dm3/mol), Leptosols Rendzinic occupies an intermediate position (Amax=0.0289 mol/kg, KL=14766.47 dm3/mol). The negative value of the Gibbs energy (∆G=–17.97 kJ/mol for Albeluvisols Umbric, –22.59 kJ/mol for Leptosols Rendzinic and –23.24 kJ/mol for Phaeozems Albic) indicates the spontaneous nickel adsorption by soil absorbing complex (SAC). In accordance with the Freundlich model, in all types of studied soils, the nickel ion – SAC binding energy decreases as the surface is filled, herewith the studied soils are characterized by heterogeneity of sorption centers. The approximation coefficient of the Temkin model is in the range of 0.80–0.85, therefore, the discrepancy between the experimental data of the theoretical model indicates the absence of interaction between the adsorbed particles. The Dubinin – Radushkevich model allows us to determine the nature of adsorption forces, as well as the value of the average free energy of adsorption: E=8,325 kJ/mol in Albeluvisols Umbric, 9.5477 kJ/mol in Leptosols Rendzinic and 9.6296 kJ/mol in Phaeozems Albic. Consequently, chemisorption is characteristic of all soils, and proceeds by an ion-exchange mechanism.

Investigation of interaction mechanism between polyvinyl chloride microplastics and phthalate acid esters using APGC-MS/MS

Phthalate acid esters (PAEs) are a kind of typical endocrine disruptors chemicals (EDCs). PAEs can be enriched, migrated and released into organisms through microplastics (MPs), causing high toxicological risks. This study presented an atmospheric pressure gas chromatography-tandem mass spectrometry (APGC-MS/MS) method for 10 PAEs trace analysis. Based on this method, the interaction mechanism between polyvinyl chloride microplastics (PVC MPs) and PAEs was explored. The established APGC-MS/MS method achieved 10 PAEs analysis in 14 min with the satisfied detection limit as low as 0.0025 μg/L and excellent linearity (R2 = 0.99868–0.99996). The interaction mechanism investigation showed that PVC MPs had high adsorption and desorption capacities for PAEs. The adsorption mechanism involves adsorption distribution, surface adsorption, hydrophobic interaction and intermolecular van der Waals force. Temperature, diffusion channels, pore filling, hydrophobicity and solubilization may be potential desorption mechanisms. Moreover, the intestinal environment of warm-blood organisms has the highest bioavailability of PAEs. Overall, this APGC-MS/MS method of PAEs had the virtue of simplicity, efficiency, reliability and sensitivity, and could serve as a potential tool for risk analysis of MPs and PAEs exposure.

Built-in Electric Field Within CoSe2-FeSe2 Heterostructure for Enhanced Sulfur Reduction Reaction in Li-S Batteries.

The conversion of Li2S4 to Li2S is the most important and slowest rate-limiting step in the complex sulfur reduction reaction (SRR) for Li-S batteries, the adjustment of which can effectively inhibit the notorious "shuttle effect". Herein, a CoSe2-FeSe2 heterostructure embedded in 3D N-doped nanocage as a modified layer on commercial separator is designed (CoSe2-FeSe2@NC//PP). The CoSe2-FeSe2 heterostructure forms a built-in electric field at the two-phase interface, which leads to the optimized adsorption force on polysulfides and the accelerated reaction kinetics for Li2S4-Li2S evolution. Density functional theory (DFT) calculations and experimental results combine to show that the liquid-solid reaction (Li2S4-Li2S2/Li2S) is significantly enhanced in terms of thermodynamics and electrodynamics. Consequently, the batteries assembled with CoSe2-FeSe2@NC//PP delivered an excellent rate capability (606 mAh g-1 under 8.0 C) and a long cycling lifespan (only 0.056% at 1.0 C after 1000 cycles). In addition, the cells can provide high initial capacity of 887 mAh g-1 at sulfur loading of 5.8mg cm-2 and 0.1 C. This work would provide valuable insights into binary metal selenide heterostructures for liquid-solid conversion in Li-S batteries.

Alginate-derived biomass carbon‑molybdenum disulfide heterogeneous materials: Vertically grown/uniformly dispersed molybdenum disulfide nanosheets/nanoflowers for wastewater treatment

In order to improve the dispersion of molybdenum disulfide (MoS2) and enhance the performance of MoS2, two alginate-derived biomass carbon-MoS2 (BC-MoS2) composites: CMB/CMS, were prepared by introducing BC during the synthesis of MoS2 by hydrothermal. The effects of different gels, times and temperatures of the synthesized BC-MoS2 were investigated, and the adsorption capacity for methylene blue (MB), basic fuchsin (BF) and copper ions (Cu2+) was tested. The results indicated that the vertical growth of MoS2 on the BC surface could be realized when using xero-gel, while the BC and MoS2 were mixed uniformly when using wet-gel. Compared with MoS2, the hydrophilicity and water dispersibility of BC-MoS2 were greatly improved, and BC-MoS2 had better adsorption capacity for MB/BF/Cu2+ (99.61/86.83/60 mg/g). The adsorption mechanism exhibits that the adsorption force of BC-MoS2 on MB/BF is mainly based on the electrostatic force, and the adsorption on Cu2+ comes from the electrostatic force and the Lewis soft-soft interaction. This study dramatically enriches the application of transition metal chalcogenides and provides a meaningful reference for wastewater treatment.

Hypostomus plecostomus-inspired soft sucker to adsorb slippery tissues: a stabilizing post-valvular cavity and stiffness gradient materials provide excellent adsorption performance

The hard suckers commonly used in surgical operations often cause adsorption extrusion damage to the biological tissue. To tackle this problem, from the perspective of bionics, through in-depth observation and research on the special sucker adsorption process and adsorption mechanism of hypostomus plecostomus (HP), this paper proposes a bionic soft hypostomus plecostomus sucker (BSHPS) with a variable stiffness gradient structure with a good adsorption performance on soft moist irregular biological tissues. The BSHPS comprises a lip disc, a pre-valvular cavity, and a post-valvular cavity. Through the volume changes of the pre- and post-valvular cavities, a pressure difference is generated between the inside and outside of the sucker, enabling the lip disc to remain sealed. The experiments were carried out by an automatic tensile force measurement system equipped with a vacuum pump, and the results showed that in slippery environment, the adsorption performance of the BSHPS is improved by a maximum of 61.9% compared to that in dry environment. On a biological tissue surface, the adsorption force is as high as 13.7765 N. The most important advantage of the proposed BSHPS is that it can be firmly adsorbed the surface of soft moist irregular biological tissues, effectively slowing down or avoiding adsorption extrusion damage to the biological tissue. Therefore, the BSHPS is expected to have good application prospects in modern surgical medicine.

Adsorption of ionic contaminants from complex water matrices by versatile chitosan-based beads

Most adsorbents are currently restricted by their single function in pollutant removal from complex wastewater. Herein, we constructed a versatile chitosan-based adsorbent (MC-DA) by grafting amphoteric copolymers with high pH-responsiveness property, aiming at the removal of multiple ionic contaminants. Specifically, the surface charge and hydrophobicity/hydrophilicity of MC-DA can be finely tuned under different pH conditions. As a result, the effective adsorption of cationic methylene blue (MB) and anionic Acid Orange 7 (AO7) with capacities of 627.4 mg/g and 1146.8 mg/g were achieved respectively, superior to most reported materials. Regarding the characterization results, the adsorption mechanisms for MB adsorption were electrostatic and hydrophobic interactions, while the electrostatic attraction was the main driving force for AO7 adsorption. Apart from the versatile adsorption performance, high acid resistance (pH ≥ 2.0), good reusability and rapid separation property under an external magnetic field suggested MC-DA’s promising environmental benefits and practical application potential in water remediation.

Adsorption and desorption of parachlormetaxylenol by aged microplastics and molecular mechanism

The addition of active ingredients such as antibacterial agent and non-active ingredients such as plastic microspheres (MPs) in personal care products (PCPs) are the common pollutants in the aquatic environment, and their coexistence poses potential threat to the aquatic ecosystem. As a substitute for the traditional antibacterial ingredients triclosan and triclocarban, the usage of parachlormetaxylenol (PCMX) is on the rise and is widely used in PCPs. In this study, the adsorption and desorption behaviors of PCMX were investigated with two typical MPs, polyvinyl chloride (PVC) and polyethylene (PE), and the effects of different aging modes and molecular mechanisms were explored through batch experiments and density functional theory calculation. Both laboratory aging and field aging resulted in surface wrinkles of MPs, along with an increased proportion of oxygen-containing functional groups (CO, -OH). At the same aging time, the degree of laboratory aging was stronger than that of field aging, and the aging degree of PVC was greater that of PE. The aging process enhanced the adsorption capacity of MPs for PCMX. The equilibrium adsorption capacity of PVC increased from 3.713 mg/g (virgin) to 3.823 mg/g (field aging) and 3.969 mg/g (laboratory aging), while that of PE increased from 3.509 mg/g to 3.879 mg/g and 4.109 mg/g, respectively. Meanwhile, aging also resulted in an increase in the desorption capacity of PCMX from PVC and PE. Oxygen-containing functional groups in aged MPs could serve as adsorption sites for PCMX and improved the electrostatic adsorption capacity. Oxygen-containing groups generated on the surface of aged MPs formed hydrogen bonding with the phenolic hydroxyl groups of PCMX, which became the main driving force for adsorption. Our results reveal the potential impact and mechanism of aging on the adsorption of PCMX by MPs, which provides new insights for the interaction mechanism between environmental MPs and associated contaminants.

SO3 removal by submicron absorbents synthesized via inhibition method: The product layer grows like parallel peaks

Injecting calcium hydroxide powder into the flue gas is an effective strategy for SO3 removal. However, commercial calcium hydroxide has several disadvantages, including large particle size, low efficiency, and unsuitability for excessive grinding. In this work, sub-micron calcium hydroxide was synthesized by an inhibition method and its performance for SO3 removal from flue gas was investigated on a pilot-scale platform (120 Nm3/h). When the concentration of sodium alginate solution was 100 mg/L, the average particle size of calcium hydroxide decreased from 13.66 µm to 0.84 µm, which improved the SO3 removal (92.1 %) and conversion of the absorbent. The results of the fixed-bed experiments indicate that the absorption kinetics of the reaction is consistent with the Bangham model. In addition, density functional theory verifies that calcium hydroxide captures SO3 by chemisorption. The AFM image shows that the calcium sulfate whiskers produced during the reaction grow like parallel peaks on the adsorbent surface. The calculations suggest that the driving force for SO3 adsorption originates from Ca-p orbital (Ca(OH)2) and O-s orbital (SO3) hybridization. This study complements the island growth mechanism for gas-solid two-phase reactions and provides an effective method for removing SO3 from flue gas in coal-fired power plants. In addition, it will provide an important reference for the development of submicron adsorbents.

Elucidating the selective adsorption of heavy rare earth by phosphate modified silica: The cooperation of pore confinement and surface structure regulating

Rare earths are considered strategic metals, with heavy rare earth elements of greater importance due to their supply and utilization field. However, efficient separation of heavy rare earth elements is a great challenge as the similar physicochemical properties between light and heavy rare earths. In this study, the highly efficient adsorbents with confinement effect are synthesized by the modification of MCM-41 materials with dimethyl clodronate (NP2) and methylene dichlorophosphate (NDP2). The adsorbents were characterized by XRD, TEM, SEM-EDS, N2 adsorption–desorption, FTIR, TG, 13C NMR, and XPS. It was discovered that the pore size of MCM-41 affected markedly the adsorption selectivity, and the cooperation of the organic adsorption center and pore confinement of MCM-41 support enabled the selective adsorption of heavy rare earth ion. The adsorbent modified by NP2 exhibited high adsorption selectivity toward heavy rare earth ions (Lu3+) with the increase in pore size of MCM-41. In contrast, the expanded pore of MCM-41 enhanced the selectivity of light rare earth ions for the NDP2 modified adsorbents. The distribution coefficient of Lu3+ adsorption over NP2-MCM-41(III) adsorbent reached 20,132 mL g−1 and the separation factor of Lu to La reached 82.17. DFT calculations revealed that a vital driving force for the selective adsorption of Lu was the gap of binding energy between Lu and La complexes with the surface NP2/NDP2 groups. The synergy of pore confinement and organic functional groups in adsorbents in this paper offers a valuable strategy for designing efficient materials in the separation of rare earth elements.

Facilitating sulfur species capture and bi-directional redox in Li-S batteries with single-atomic Co-O2N2 coordination structure

Lithium-sulfur (Li-S) batteries suffer from the shuttle effect of soluble lithium polysulfides (LiPSs) and slow redox kinetics, significantly limiting their practical application. Although single-atom catalysts (SACs) offer a promising strategy to address these challenges, designing materials with optimal adsorption force and high catalytic activity remains a grand challenge. Here, we present a cobalt (Co)-based SAC with unique Co-O2N2 coordination structures for Li-S batteries. Both experimental and theoretical studies demonstrate that O, N-coordinated Co single atoms anchored on a porous carbon framework (Co/NOC) effectively capture LiPSs and dramatically catalyze bidirectional polysulfide conversion. The expanded carbon layer spacing facilitates lithium ions diffusion and maximizes the exposure of active sites. As a result, Li-S batteries incorporating Co/NOC as separators exhibit outstanding rate performance (906.6 mAh g−1 at 3 C) and exceptional cycling stability, even at −10 °C. Furthermore, with a high sulfur loading of 12.0 mg cm−2, the areal specific capacity reaches up to 12.36 mAh cm−2. This work provides some useful insights for the design of high-performance SACs for Li-S batteries.

Quantitative evaluation of particle–binder interactions in ceramic slurries via differential centrifugal sedimentation

In diverse materials science spanning from fine ceramics to lithium-ion batteries and fuel cells, the particle–binder interactions in slurries play a crucial role in governing the ultimate performance. Despite numerous efforts to date, quantitatively elucidating these hidden interactions has remained a longstanding challenge. Here, we demonstrate a dynamic approach to evaluate adsorptive interactions between ceramic particles and polymeric binders entangled in a slurry utilizing differential centrifugal sedimentation (DCS). Particles settling under a centrifugal force field impart significant viscous resistance on the adsorbed binder, leading to its detachment, influenced by particle size and density. This behaviour directly reflects the particle–binder interactions, and detailed DCS spectrum analysis enables the quantitative assessment of nano-Newton-order adsorption forces. An important finding is the strong correlation of these forces with the mechanical properties of the moulded products. Our results provide insight that forming a flexible network structure with appropriate interactions is essential for desirable formability.