Activating lattice oxygen oxidation mechanism (LOM) boosts oxygen evolution reaction (OER) performance beyond the adsorbate evolution mechanism (AEM), yet LOM catalysts suffer a critical activity-stability trade-off limiting durability. In this work, we fabricate pompon-like F-modified spinel NiCo2O4 (R-NiCo2O4-2xFx-2) via anion engineering to resolve this conflict. F- partially replaces lattice O2-, tuning coordination and electronic states, stabilizing high-valence metal sites, generating moderate oxygen vacancies and weakening metal–oxygen bonds for reversible lattice oxygen redox without structural collapse. Its pompon architecture delivers superhydrophilic/superaerophobic surfaces and fast mass transfer. The catalyst delivers a 213 mV overpotential at 10 mA cm-2 and 100 h robust alkaline stability, exceeding most NiCo2O4-based counterparts. In situ spectra and DFT verify F drives LOM-dominated OER and reduces O–O coupling barriers. This universal anion modulation balances LOM activity and stability for practical alkaline water electrolysis.

This study employed molecular dynamics simulations to systematically investigate the separation performance and mechanism of ionic liquid (IL)-functionalized MXene nanopore composite membranes for CO2/CH4 mixtures. Three imidazolium-based ILs ([EMIM][Tf2N], [EMIM][PF6], and [EMIM][BF4]) and three surface-functionalized MXene nanosheets (with-F, -O, and-OH groups) were selected to construct nine composite membrane models. Based on the analysis of gas permeance and selectivity, the [EMIM][PF6]/MXene-F composite system was identified as the optimal configuration. Further investigations by regulating the IL layer thickness (2-6 & Aring;) and nanopore diameter (16-22 & Aring;) revealed the influence of structural parameters on separation performance. The separation mechanism was elucidated from the perspectives of microscopic structural characteristics, intermolecular interactions, and gas dynamic behavior: the spatial confinement effect of MXene promotes partial penetration of the IL into the nanopores, reducing the effective free volume and thereby significantly suppressing CH4 diffusion. In contrast, CO2 preferentially permeates following an adsorption-diffusion mechanism, owing to its high solubility in the IL and stronger interactions with the composite membrane. The synergistic effect between the IL and MXene plays a key role in achieving efficient separation, with diffusion behavior dominating the overall selectivity. This study provides a theoretical foundation and structural optimization strategy for designing high-performance IL-supported functionalized MXene nanoporous gas separation membranes.

Organic solvent nanofiltration (OSN) is a key technology for solvent recovery and energy reutilization, offering notable advantages in separation efficiency and energy reduction, and has thus gained significant attention in membrane research. Developing OSN membranes that combine high flux with high selectivity remains a central challenge. Molybdenum disulfide (MoS2) and transition metal carbides/nitrides (MXene), as chemically stable two-dimensional materials, show considerable potential for building high-performance separation membranes. In this study, MoS2/Ti3C2O2 hybrid membranes with varied interlayer spacings were modeled, and their nanofiltration performance toward five organic solvents (n-hexane, methanol, ethanol, acetonitrile, acetone) and the model solute paracetamol (PRM) was systematically studied using molecular dynamics simulations. Results show that solvent flux is governed collectively by molecular size, viscosity, solvent-membrane interactions, and interlayer spacing. As spacing increases, flux correlates inversely with viscosity. Solute rejection is largely controlled by solvent-solute interactions and differs markedly across solvents. Compared to pure MoS2 and pure Ti3C2O2 membranes, the hybrid membrane shows superior flux in most solvents (except n-hexane), while its rejection lies between those of the two pure membranes, except in n-hexane and ethanol systems. This study clarifies the molecular-level transport and rejection mechanisms in MoS2/Ti3C2O2 hybrid membranes, offering theoretical guidance for the rational design of high-performance OSN membranes.

In recent years, supported ionic liquid membranes (SILMs) have attracted widespread attention due to their remarkable performance in gas separation. Two-dimensional (2D) nanomaterials, characterized by atomic-scale thickness, high specific surface...

Biphasic solvent pretreatment selectively partitions lignocellulosic compositions between immiscible phases, facilitating fractionation and valorization. However, the molecular determinants of lignin partitioning remain unclear. Herein, lignin partitioning in n-pentanol/H2O and methyl isobutyl ketone (MIBK)/H2O biphasic systems was investigated across pH 1-13 using combined experiments and molecular dynamics (MD) simulations. Higher proton activity (lower pH) promoted lignin transfer into the organic phase, whereas alkaline conditions deprotonated lignin and drove its accumulation in the aqueous phase. In the n-pentanol/H2O system, lignin fragments enriched in syringyl (S) units preferentially partitioned into the n-pentanol phase, followed by guaiacyl (G) and p-hydroxyphenyl (H) units. MD simulations showed that the total interaction energies between lignin units and the n-pentanol/H2O system were stronger than those in the MIBK/H2O system, especially for S and G units, while the difference for H units was marginal. van der Waals forces dominated the lignin-n-pentanol interactions, with strengths in the order S > G > H. n-Pentanol also exhibited stronger affinity for ferulate (FA) than for p-coumarate (PCA). This study elucidated lignin partitioning mechanisms in biphasic solvents, providing a theoretical basis for optimizing biphasic pretreatment and tuning lignin structure.

In recent years, supported ionic liquid membranes (SILMs) have attracted widespread attention due to their remarkable performance in gas separation. Two-dimensional (2D) nanomaterials, characterized by atomic-scale thickness, high specific surface area, and tunable mass transport pathways, are ideally suited for enhancing the separation efficiency of composite membranes through precise regulation of ionic liquids (ILs) and support architecture. In this study, a composite membrane system was constructed via molecular dynamics (MD) simulations, in which [BMIM][BF4] was confined within molybdenum diselenide (MoSe2) interlayers, and its performance in separating CO2/N2 mixtures was systematically evaluated. The separation efficiency was optimized by tuning key structural and operational parameters, including interlayer spacing, IL loading, and temperature. The results demonstrate that the optimal separation is achieved at 300 K with an IL loading ratio of 65% and an interlayer spacing of 4 nm. Furthermore, analysis of density distributions and cation orientation elucidated the microstructural characteristics and separation mechanisms of the membrane channels. The confined ILs within the MoSe2 nanochannels exhibits a structure distinct from its bulk-phase counterpart, showing a stronger tendency to interact with gas molecules. The difference in gas solubility within the IL phase is identified as a key factor driving efficient separation. This study offers theoretical insights and design guidance for the development of 2D nanomaterial-based supported ionic liquid membranes (2D-SILMs) for CO2/N2 separation.

This study employed molecular dynamics simulations to systematically evaluate the CO2/N2 separation performance of composite membranes composed of a porous organic cage (CC3) surface coated with four distinct imidazolium-based ionic liquids (ILs): [BMIM][BF4], [BMIM][PF6], [BMIM][Tf2N], and [BMIM][SCN]. The results indicate that the CC3/[BMIM][BF4] composite membrane, with a thickness of 8 Å, demonstrates the optimal CO2/N2 selectivity (20.6) coupled with a significant CO2 permeance (1.59 × 104 GPU). Mechanistic analysis reveals that the strength of CO2-anion interactions follows the order [Tf2N]- > [PF6]- > [BF4]- > [SCN]-, consistent with the order of CO2 permeance in the composite membranes. Additionally, the interaction between CO2 and the composite membrane is markedly stronger than that observed for N2. Further examination of gas transport behavior suggests that different solubility of CO2 and N2 within the IL phase, together with their distinct diffusion behavior at the IL-CC3 interface, synergistically facilitate effective gas separation. Comparative assessments involving related POC materials, including CC1 and CC2, demonstrate that the CC3-based composite membrane achieves superior separation performance. This investigation elucidates the molecular-level mechanisms underlying gas separation in CC3/IL composite membranes, offering theoretical insights to inform the design and optimization of advanced gas separation membranes.

Conventional formaldehyde-based adhesives pose serious risks to the environment and human health. Lignin and hydroxymethylfurfural (HMF) show great potential in the production of green, recyclable bio-based waterborne polyurethane adhesives, reducing reliance on fossil resources and minimizing environmental impact. However, lignin-furan resins typically exhibit low reactivity, brittleness, poor durability, and limited reprocessing ability, which constrain their practical application. In this work, low-molecular-weight alkali lignin obtained by ethanol extraction was demethylated to increase the phenolic-OH content, reduce steric hindrance, and enhance reactivity toward HMF. The modified lignin and HMF fully replaced phenol and formaldehyde to construct a bio-based resin, and a flexible isocyanate-terminated carbon dioxide copolyester oligomer was introduced as a toughening agent. During curing, HMF preferentially condenses at the ortho/para positions of lignin phenolic hydroxyl groups, while -NCO/-OH reactions form urethane and phenolic carbamate linkages. These synergistic pathways increase the cross-linking density and network stability, affording high lap-shear strength (> 16 MPa), weathering durability, reusability and ethanol-assisted recyclability while avoiding high-boiling organic solvents. This strategy achieves, for the first time, the synergistic integration of high-phenolic lignin with HMF, providing a general route to high-performance, recyclable, bio-based waterborne polyurethane adhesives.

The reverse osmosis (RO) desalination technology is regarded as one of the most effective methods to alleviate freshwater scarcity. However, the development of novel and efficient RO membranes is essential. In this study, we utilize in silico simulations to demonstrate the excellent desalination performance of three different pore sizes of carbon nitride membranes (P1-, P2-, and P3-C3N3). The size of the C3N3 nanopores significantly influence water permeance. Notably, the water permeance through the nanoporous P3-C3N3 membrane can reach 17.01 L/ cm2/day/MPa, with a high salt rejection rate of 88.7 % under an external pressure of 50 MPa. Increasing both the pore size and the driving pressure can substantially enhance water permeance. The water permeance of all three studied nanopores is much higher than that of conventional commercial membranes, indicating that nanoporous C3N3 membranes are superior for seawater desalination. In-depth analyses reveal that larger pores facilitate the rapid permeation of water molecules. Additionally, potential of mean force calculations further confirm that the significant water permeation is due to the low energy barrier for water molecules traversing the nanopores. These findings demonstrate that nanoporous C3N3 membranes can be effectively utilized as desired RO membranes for efficient seawater desalination, which holds great significance for the design of future filtration membranes.

Manganese dioxide nanosheets (MnO2 NSs) have garnered significant attention in analytical sensing, while the majority of the previous reports suffer from a complex preparation process involving reducing agents, template or high-temperature. In this work, a novel MnO2 NSs decorated Ti3C2Tx MXene nanoribbons (Ti3C2TxNR@MnO2) composite was firstly assemblied via a facile one-step strategy and applied as a bi-signal generator to enable colorimetric and fluorescence (FL) dual-response sensing. During the assembly process, Ti3C2TxNR innovatively acted as both reductant and carrier to prevent the aggregation of MnO2 NSs. Benefiting from the strong metal oxide-support interaction (SMOSI) between Ti3C2TxNR and MnO2, the as-obtained multifunctional probe displayed enhanced oxidase-like activity and oxidation property. The oxidase-like activity and oxidation property of Ti3C2TxNR@MnO2 were evaluated using 3,3,5,5-tetramethylbenzidine (TMB) and thiamine (TH) as substrates, respectively. In the absence of trichlorfon (TCF), the MnO2 coating on Ti3C2TxNR surface exhibited specific recognition towards thiocholine (TCh), which originated from the hydrolysis of acetylthiocholine catalyzed by acetylcholinesterase (AChE). Consequently, TCh caused decomposition of MnO2 into Mn2+, resulting in diminished colorimetric and FL signals. However, in the presence of TCF, its inhibitory effect on AChE activity prevented the resolution of MnO2 into Mn2+ by TCh, thereby restoring both colorimetric and FL signals. More importantly, the strong SMOSI effect and TCh-specific recognition unit of Ti3C2TxNR@MnO2 led to an enhanced detection sensitivity of the dual-mode sensor, which presented a low detection limit of 0.0856 and 0.798 ng mL-1 using colorimetric and FL measurements, respectively. In summary, this approach presents a new inspiration to construct multifunctional probe for convenient and accurate detection in biosensing.

Two-dimensional (2D) covalent organic frameworks (COFs) are a promising class of materials exhibiting significant potential for diverse applications owing to their unique structural characteristics. In particular, some applications crucially rely on mechanoresponsive behaviors of 2D COFs, which thus require a comprehensive understanding. Herein, a machine-learning potential is developed for two representative monolayer 2D COFs (COF-1 and COF-5), which demonstrates both high computational efficiency and accuracy in molecular dynamics (MD) simulations of their mechanical behaviors. Our machine-learning MD simulations reveal distinct planar-to-nonplanar conformation transitions occurring in COF-1 and COF-5 at large tensile strain in the armchair direction. According to density functional theory calculations, the tension-induced conformation transitions in 2D COFs are driven by strong H-H steric repulsions between aryl rings within their deformed linker or knot components. The observed conformation transition is anticipated to provide a new strategy for modulating electronic properties, fracture behaviors, and gas adsorption characteristics of 2D COFs.

The improper application of pesticides has resulted in significant environmental contamination. Therefore, determining the level of residual contamination in environmental samples is crucial. Herein, a novel molecularly imprinted polymer-based electrochemical (MIP-EC) sensor based on polyethyleneimine-modified carbon nanotubes/tin sulfide (MWCNTs-PEI/SnS (2) ) was developed for the sensitive and selective assay of diuron (DU) in soil samples. The MWCNTs-PEI/SnS (2) was prepared by simply mixing MWCNTs-PEI and SnS (2) nanoflower via ultrasonic dispersion. The as-prepared MWCNTs-PEI/SnS (2) exhibited a large effective surface area, low electron transfer resistance, and superior electrocatalytic activity. Subsequently, a film of MIP was then fabricated in situ on the MWCNTs-PEI/SnS (2) modified glassy carbon electrode surface (MWCNTs-PEI/SnS (2) /GCE) by electropolymerization, using DU as template molecule and o-phenylenediamine (o-PD) as functional monomer. Under the optimal conditions, the developed MIP-EC sensor exhibited two segments of linear relationships in the DU concentrations range of 0.1-2.0 mu M (R (2) =0.997), and 2.0-60 mu M (R (2) =0.996) with a detection limit of 0.02 mu M. Besides, the proposed sensor possessed outstanding analytical performance such as superior selectivity, excellent reproducibility, and great stability. Moreover, the MIP-EC sensor has been successfully applied for DU determination in farm soil and achieved satisfactory recoveries.

Quantitative understanding of ion transport mechanism is crucial for numerous applications of two-dimensional (2D) nanochannels, but is far from being resolved. Here, we formulated a theoretical framework for both self-diffusion and electromigration of hydrated monatomic ions in various 2D nanochannels (e.g. graphene, h-BN, g-C3N4, MoS2), by molecular dynamics simulations. The self-diffusivity and mobility of ions in 2D nanochannels both increases linearly with ion-wall distance for small hydrated ions, yet keeps constant for large ones. The underlying mechanism reveals that when ions approach water-layers in nanochannels or possess large hydration shell, their hydration shells become severely distorted. This increases the free energy difference between hydration shell and the surrounding water-layers, water residence time in hydration shell and ion-water friction. Several involving quantitative relations were revealed, with Nernst-Einstein relation validated with both simulations and theoretical derivation. This work shows profound implications for various applications, including ion-sieving, nanodevices and nano-power generators, etc.

The rapid development of two-dimensional (2D) hybrid membranes has provided new research avenues for membrane-based seawater desalination technologies. In this study, four types of three-layer stacked hybrid membrane structures were constructed by combining hydrophilic graphene oxide (GO) membranes with hydrophobic tungsten disulfide (WS2) membranes, and the desalination mechanisms of these hybrid membranes were thoroughly investigated using molecular dynamics (MD) simulations. The results demonstrate that the configuration of edge atoms in the WS2 membrane significantly influences its desalination performance: The W-S membrane exhibits the highest water permeance, while the S-S membrane shows the highest ion rejection rate. Based on these findings, four distinct hybrid membrane stacking configurations were designed. The simulation results reveal that the GO-S-GO configuration with an interlayer spacing of 9 & Aring; demonstrates optimal overall performance, achieving a water permeance of 21.57 x 102 L/m2/h/bar with ion rejection rates of 100 % for Na+ and 98.1 % for Cl-. Furthermore, by reducing the oxidation degree of GO and optimizing the interlayer spacing, the water permeance can be enhanced without compromising the 100 % ion rejection rate. This study elucidates the influence of surface characteristics of WS2/GO hybrid membranes on water permeation and ion trans-membrane transport, providing critical theoretical guidance for the development of high-efficiency, energy-saving novel desalination membrane materials.

Hemicellulose depolymerization plays a pivotal role in industries such as papermaking, bioethanol production, and sugar refining. However, the microscopic mechanism of its acid-catalyzed hydrolysis remains poorly understood, even though a wide variety of species are generated in acidic environments. This study thus focuses on investigating the depolymerization propensity of xylan (a representative hemicellulose) and its underlying mechanisms across different structural configurations and reaction parameters by combining molecular dynamics simulations with density functional theory calculations. Our results indicate that the glycosidic bonds at the reducing terminal of xylan chains with a low degree of polymerization (e.g., DP3-15) are more susceptible to cleavage, followed by those at the non-reducing terminal and mid-chain units. While the DP increases from 30, 50 to 100, enhancing the cleavage probability of glycosidic bonds at mid-chain units. Mechanistic analysis revealed that external hydroxyl groups first attracted the H3O+ to the xylan molecular surface. Subsequently, proton transfer from H3O+ to the glycosidic oxygen induces an asymmetric electron flow towards the neighboring C1 and C4 atoms. The stronger electron-withdrawing ability of C1 relative to C4 thus facilitates cleavage of the C1-O1 bond. This study deepens our understanding of xylan hydrolysis and offers valuable theoretical guidance for optimizing pretreatment conditions in hemicellulose-based biorefinery processes.

The utilization of biomass derived platform molecules for the production of gamma-valerolactone (GVL) offers a highly promising approach for sustainable biomass upgrading, yet remaining a significant challenge in achieving efficient GVL production and in the lack of an in-depth studies on the effect of reactive sites. Herein, a series of heterogeneous Hf-based phosphonates catalysts, decorated with five different ligands, acid-base pair species (Hf4+-O2-) and Br & oslash;nsted acidic species (-PO3H2 or -COOH), have been reported to demonstrate exceptional catalytic performance in the GVL production from ethyl levulinate (EL) via transfer hydrogenation. Specifically, Hf-HEDP (etidronic acid) exhibited remarkable reactivity within 2 h at 180 degrees C, realizing a nearly quantitative yield (90.02 % GVL and 5.79 % isopropyl levulinate). The delightful performance is then primarily attributed to the optimal Br & oslash;nsted/Lewis acid ratio (similar to 0.2) and high base content (0.43 mmol/g) within the catalyst. These properties facilitate the transfer hydrogenation and lactonization of EL, as well as the dissociation of the hydroxyl group in isopropanol. Density functional theory (DFT) calculation was conducted to gain a deeper understanding of the reaction mechanism, clearly illustrating that the activation of the carbonyl group in EL and hydroxyl group in isopropanol is mainly achieved through the synergistic reaction of two Hf-HEDP modules. More importantly, Hf-HEDP revealed good recyclability, retaining its catalytic performance for at least five runs, thereby showing promising potential for application in practical situations.

Highly efficient production of fructose via glucose isomerization is posited as the paramount step determining the cellulosic biomass valorizing efficiency. To advance this goal, herein, a catalyst was designed from tea residue to incorporate coupled acid-base sites. The catalyst, featuring a stem-like channel structure and uniformly distributed active sites, achieved 43.98 % glucose conversion, 40.73 % fructose yield, and 92.60 % selectivity at 90 degrees C for 1 h. The activity was related to its abundant ordered-channel pores and balanced weak acidic (0.32 mmol/g, Al-O species) and basic sites (0.57 mmol/g, MgO, K2CO3, and MgCO3). Isotope labeling and density functional theory (DFT) calculations elucidated a dual-path reaction mechanism, in which the basic sites predominantly drive the isomerization process by facilitating glucose ring-opening with higher catalytic activity (Delta G =- 48.23 kcal/mol), while the acidic sites enhance fructose selectivity through C2-H bond activation. This work provided a method for preparing a bifunctional acid-base catalyst from tea residue that not only achieves the efficient isomerization of glucose but also lays the foundation for broad applications in sustainable biorefining.

Separating He from CH4 or N2 is crucial for natural gas He extraction, a prevailing industrial approach. Herein, molecular simulation and machine learning (ML) were combined to screen 801 experimentally synthesized COFs for He/CH4 and He/N2 separation, either by means of adsorption or membrane separation. Top 10 COFs for 4 different gas separation purposes (CH4/He or N2/He separation with either adsorption or membrane) were identified respectively. The highest adsorption performance score (APSmix, defined as the product of working capacity and adsorption selectivity for mixture gas) reached 447.88 mol/kg and 49.45 mol/kg for CH4/He and N2/He, with corresponding adsorption selectivity of 115.56 and 30.33. He permeabilities of 1.5 × 106 or 1.2 × 106 Barrer were achieved for equimolar He/CH4 or He/N2 mixture gas separations, accompanied by permselectivity of 5.47 and 11.80 well surpassing 2008 Robeson's upper bound. Best performing COFs for adsorption separation are 3D COFs with pore diameter below 0.8 nm while those for membrane separation are 2D COFs with large pores. Additionally, ML models were developed to predict separation performance, with key descriptors identified. The mechanism for how COFs' structure affects their separation performance was also revealed.

Colorimetric analysis methods based on nanozymes have been widely applied in Hg2+ sensing. Despite exhibiting excellent performance and preferable stability as nanozymes, Fe-MOFs have been largely confined to sensing applications due to the singularity of their active sites and the absence of specific recognition sites. According to reports, the cycle of valence states of Fenton-type metal sites is considered to be a key factor affecting the catalytic performance of Fe-MOFs. Therefore, gold nanoparticles (AuNPs) were incorporated as co-catalysts to accelerate the rate-limiting step in the conversion of Fe3+/Fe2+ in Fe-MOFs, thereby facilitating the decomposition of H2O2 to produce reactive oxygen species (ROS) and ultimately enhancing the enzyme mimic activity of the composite material. Furthermore, the specific interaction between AuNPs and Hg2+ was utilized to achieve highly selective detection of Hg2+ through the enhancement of enzyme-like activity triggered by Hg2+. Using 3,3,5,5-tetramethylbenzidine (TMB) as a substrate, the synthesized AuNPs@Fe-MOFs composite exhibited peroxidase-like (POD-like) activity approximately 3.1 times higher than that of the original Fe-MOFs, thus achieving rapid and sensitive colorimetric detection of Hg2+. In conclusion, a simple and rapid one-step strategy for constructing MOFs-based nanozymes with high activity and selectivity was proposed in this work, which will greatly promote its application in pollutant monitoring.