Search Results (142)

Nano–bio hybrid catalysts have emerged as a promising platform for sustainable energy conversion by integrating the high selectivity of enzymes with the structural robustness and conductivity of nanomaterials. In recent years, the growing demand for clean energy technologies has driven the development of biohybrid systems capable of efficient electron transfer, enhanced catalytic activity, and improved operational stability. This review comprehensively discusses the design principles, mechanistic foundations, and performance metrics of enzyme–nanomaterial interfaces for energy-related applications. We first outline the fundamentals of enzymatic redox catalysis and the limitations of free enzymes in practical systems. Subsequently, we examine the functional roles of nanomaterials including carbon-based materials, metal and metal oxide nanoparticles, and two-dimensional platforms such as MXenes in facilitating enzyme immobilization and promoting direct or mediated electron transfer. Special emphasis is placed on engineering strategies at the bio–nano interface, including immobilization techniques, surface functionalization, and structural tuning to optimize catalytic efficiency. The review further highlights representative hybrid systems based on laccase, glucose oxidase, peroxidase, and hydrogenase enzymes, and evaluates their applications in biofuel cells, solar–bio hybrid systems, green oxidation reactions, and self-powered biosystems. Stability challenges, deactivation mechanisms, and enhancement strategies such as polymer coatings, cross-linking, and nanoconfinement are critically analyzed. Finally, emerging directions including artificial enzymes, AI-guided catalyst design, and self-healing bioelectrodes are discussed to provide a forward-looking perspective on next-generation sustainable bioelectrocatalytic systems. Full article

Controlling radical selectivity within nanoreactors remains a formidable challenge due to the inherent high reactivity and short half-lives of reactive species. Herein, we report a novel size-matched nanoconfinement strategy using a cobalt-nickel-layered double hydroxide (CoNi-LDH) nanoreactor for the highly selective generation and stabilization of sulfate radicals (SO₄^∙−) via piezoelectric activation of peroxymonosulfate (PMS). By precisely tailoring the LDH interlayer spacing to 5.27 Å to match the kinetic diameter of SO₄^∙−, the nanoreactor effectively suppresses non-selective side reactions and radical quenching. Consequently, the CoNi-LDH achieves an unprecedented reaction rate (k_obs = 0.40 min⁻¹) and superior defluorination efficiency (78.9%) for fluoroquinolone antibiotics, significantly outperforming non-size-confined counterparts. Mechanistic insights reveal a synergistic pathway where piezo-generated hot electrons, mediated by Ni sites, accelerate the Co²⁺/Co³⁺ redox cycle to ensure long-term catalytic stability. The robustness of this nanoconfined system is further demonstrated by its exceptional tolerance to complex water matrices and its practical operability in a continuous-flow reactor. This study provides a pioneering approach for spatial radical control at the nanoscale to achieve efficient and targeted environmental remediation. Full article

The effect of the confinement of fluorophores (rhodamine 6G) in nano-cavities of porous 3D sculptured coatings made by glancing-angle deposition (GLAD) was investigated by fluorescence-lifetime imaging microscopy (FLIM). Shortening of fluorescence/ photoluminescence lifetime by ∼10% was observed from the dye-permeated (in liquid) structure; however, there was no rotational hindrance of dye molecules. When dried, a strong rotational hindrance $89\%$ was observed for the orientation along the ordinary optical axis (slow-axis), and the hindrance was smaller than $57\%$ for the extraordinary direction (fast axis). Light-intensity distribution inside the nano-structure with a form birefringence was numerically modeled using plane-wave illumination and a dipole source. Nanoscale localization of light intensity due to dipole nature $I\sim 1/radiu{s}^6$ and boundary conditions for E-field allows efficient energy deposition inside the region of lower refractive index (nanogaps). Full article

Since the first synthetic macrocyclic receptors were shown to bind ions selectively, supramolecular host–guest chemistry has enabled the translation of molecular recognition events into physical signals. Early coupling of such receptors to ion-sensitive field-effect transistors established a bridge between supramolecular chemistry and solid-state electronics. Today, this bridge is rebuilt in iontronics, where ions carry information through nanoconfined media and ionic transport becomes highly sensitive to electrostatic gradients, surface charge, and surface molecular interactions. As a result, ionic flux can serve as an efficient transduction mechanism that responds precisely, reversibly, and rapidly to changes in the chemical environment. Within this regime, host–guest chemistry offers a powerful means to exert direct control over ionic behavior, allowing molecular recognition to modulate conductance, rectification, and ion selectivity, thereby conferring practical function to nanofluidic systems. This review highlights systems in which host molecules act as chemical actuators that modulate nanochannel surface chemistry, thereby regulating ionic flux and enabling reversible, tunable, and stimulus-responsive behaviors. We survey architectures in which crown ethers, calixcrowns, pillararenes, and related hosts are integrated into solid-state nanochannels, emphasizing representative achievements such as biological-level Na⁺/K⁺ selectivity in crown ether-based systems and nanomolar-level detection of ions using calixcrowns- and pillararene-functionalized nanochannels. Finally, we discuss how temperature, pH, light, and redox state act as external stimuli that reversibly switch between conductive states, yielding ion-selective platforms for sensing and ion sieving. Full article

Songliao Basin hosts abundant shale oil and gas resources, yet the phase behavior of the fluids is still unclear since the confinement effect of the shale reservoir alters the adsorption effect on the pore walls. In this study, molecular dynamics (MD) simulations were employed to clarify this issue. A binary mixture was built to represent Gulong shale oil and the phase state properties under the confinement effect were evaluated. In addition, a series of pure alkane models were constructed to analyze the influence of hydrocarbon type, temperature, and mineral composition on phase behavior. The simulation results showed that the typical Gulong shale fluid remains liquid state in the nanopores. Owing to the confinement effect, both viscosity and density under nano space decrease sharply compared to those at bulk space. Therefore, field development should somewhat rely on high-pressure stimulation to create flow paths, followed by CO₂ huff-and-puff technology to maintain production pressure. In addition, fluid composition, temperature, and mineral type are the primary factors governing the magnitude of the confinement effect. Full article

Aiming at the unclear mechanisms of fluid migration in nanopore-throat systems within tight oil reservoirs, this study focuses on the microscopic interactions at the oil–water interface in nanoconfined spaces. Based on molecular dynamics simulation, water-flooding models within nanopores of tight oil reservoirs under varying salinity conditions were constructed. The microscopic flow behaviors of oil and water in the pores were investigated, and the mechanism by which interfacial hydrogen bonding influences displacement efficiency under nanoconfinement was elucidated. The results demonstrate that due to the strong hydrogen bonding interactions between acetic acid and water, it is impossible to establish an effective displacement process or form stable displacement pathways within the pores. The extensive hydrogen-bonding network formed by acetic acid molecules at the oil–water interface severely restricts the transport capacity of water. Salinity exerts a nonlinear regulatory effect on hydrogen bonding. High-salinity (246.5 g/L) waterflooding shortens hydrogen bond lengths, enhances local bonding strength, and restricts the expansion of water channels; low-salinity (21.9 g/L) waterflooding mitigates ionic interference, resulting in the highest diffusion capacity of alkanes. The diffusion coefficient increases by 1.4 times compared to that under high-salinity conditions, leading to the highest degree of crude oil mobility. The research findings provide important guidance for enhanced oil recovery in tight oil reservoirs. Full article

Shale oil is primarily hosted within nanopores, where its flow behavior exhibits significant deviations from classical Darcy flow. The combined influences of nanoscale confinement and interfacial interactions represent key scientific challenges that hinder efficient shale oil recovery. The results show that under 25 °C and 1 MPa, the displacement distances of shale oil within 12 s in 100, 200, and 300 nm channels were 2.88, 5.67, and 11.01 mm, respectively. As pore size decreases, flow capacity drops sharply, and the displacement–time relationship evolves from quasi-linear to strongly nonlinear, indicating pronounced nanoscale non-Darcy behavior. By incorporating an equivalent resistance coefficient into the plate-channel flow model, the experimental data were accurately fitted, enabling quantitative evaluation of the additional flow resistance induced by nanoconfinement and interfacial adsorption. The equivalent resistance coefficient increases markedly with decreasing pore size but decreases progressively with increasing temperature and driving pressure. Increasing temperature and pressure partially mitigates nanoconfinement effects. In 200 nm channels, the equivalent resistance coefficient decreases from 1.87 to 1.20 as temperature rises from 25 to 80 °C, while in 100 nm channels it decreases from 2.43 to 1.65 as driving pressure increases from 1 to 6 MPa. Nevertheless, even under high-temperature and high-pressure conditions, shale-oil flow does not fully recover to ideal Darcy behavior. This work establishes a nanofluidic-based prediction and evaluation framework for shale oil flow, offering theoretical guidance and experimental reference for unconventional reservoir development and the optimization of enhanced oil recovery strategies. Full article

Recently, the kinetic improvement of the nitrogenation reaction of lithium hydride (LiH) to form lithium imide (Li₂NH) by adding a scaffold was reported. The scaffold prevents agglomeration of Li₂NH and maintains the activity of LiH, achieving a reduction in reaction temperature and an increase in reaction rate. In this work, a Li–Si alloy, Li₂₂Si₅, was used as a starting material to form nano-sized LiH dispersed in a Li alloy matrix. Lithium nitride (Li₃N) is generated by the reaction between Li₂₂Si₅ and N₂ to form Li₇Si₃, and then Li₃N is converted to LiH with ammonia (NH₃) generation during heat treatment under H₂ flow conditions. Since Li₃N is formed at the nano-scale on the surface of alloy particles, LiH generated from the above nano-Li₃N is also nano-scale. The differential scanning calorimetry results indicate that direct nitrogenation of LiH in the alloy matrix occurred from around 280 °C, which is much lower than that of the LiH powder itself. Such a highly active state might be achieved due to the nano-crystalline LiH confined by the Li alloy as a self-transformed scaffold. From the above experimental results, the nano-confined LiH in the alloy matrix was recognized as a potential NH₃ synthesis technique based on the LiH-Li₂NH type chemical looping process. Full article

In deep coal seams, where nanopores (~2 nm) dominate, wettability effects, which govern molecule–wall interaction strength, critically control the methane storage, yet remain poorly understood. This work establishes, for the first time, a theoretical framework coupling the Simplified Local Density (SLD) model with wettability effects to systematically describe nanoconfined methane behavior. Key innovations include modifying the equation of state (EoS) by incorporating a molecule–wall interaction term, correlating the nanopore wall energy parameter and adsorption layer thickness with the interaction strength, and deriving wettability-dependent shifted critical properties. This approach successfully relates the local methane density distribution to the surface contact angle, bridging the knowledge gap between nanoconfined behavior and both pore size and wettability. The results show that (a) the bulk-like gas proportion in deep seams exceeds 35%, far higher than in shallow seams, indicating superior development potential; (b) the bulk-like gas increases faster with pressure than adsorbed gas, while the adsorption amount decreases by up to 46%, as the contact angle rises from 0° to 80°; (c) the modified EoS significantly impacts the bulk-like gas, reducing its amount by about 8% in 3 nm pores due to weakened intermolecular interactions. This study underscores the necessity of integrating wettability to accurately predict the nanoconfined fluid behavior, especially for deep coal seam gas. Full article

China possesses abundant tight conglomerate oil resources. However, these reservoirs are typically characterized by low porosity and permeability, high clay mineral content, and complex pore structures, resulting in poor performance of conventional waterflooding development. Challenges including insufficient energy replenishment and high flow resistance ultimately lead to low oil recovery factors. This study systematically investigates surfactant-assisted CO₂ huff-n-puff (SA-CO₂-HnP) for enhanced oil recovery in tight conglomerate reservoirs. For a tight conglomerate reservoir in a Xinjiang block, a fully implicit, multiphase, multicomponent dual-porosity numerical model was established. By integrating pore–throat distributions acquired through high-pressure mercury intrusion with a self-developed MATLAB PVT package, nanoconfinement-induced shifts in the phase envelope were rigorously embedded into the simulation framework. The calibrated model was subsequently employed to conduct a comprehensive sensitivity analysis, quantitatively delineating the influence of petrophysical, completion, and operational variables on production performance. Simulation results demonstrate that compared to conventional CO₂ huff-n-puff, the addition of surfactants increases the cumulative recovery factor by 3.5 percentage points over a 20-year production period. The enhancement mechanisms primarily include reducing CO₂–oil interfacial tension (IFT) and minimum miscibility pressure (MMP), improving reservoir wettability, and promoting CO₂ dissolution and diffusion in crude oil. Sensitivity analysis reveals that injection duration, injection pressure, and injection rate significantly influence recovery efficiency, while soaking time exhibits relatively limited impact. Moreover, an optimal surfactant concentration (0.0003 mole fraction) exists; excessive concentrations lead to diminished enhancement effects due to competitive adsorption and pore blockage. This study demonstrates that SA-CO₂-HnP technology offers favorable economic viability and operational feasibility, providing theoretical foundation and parameter optimization guidance for efficient tight conglomerate oil reservoir development. Full article

We report the fabrication of nanoscale MoS₂ (nMoS₂) via laser ablation in liquid and its application in electrochemical sensing. The laser ablation process fragments microscale MoS₂ sheets into ~5 nm dots with stable aqueous dispersibility. Electrochemical analysis reveals that nMoS₂ possesses multiple reversible redox states, enabling it to participate in redox cycling reactions that can amplify electrochemical signals. When the nMoS₂ is embedded in an electrochemically inert matrix, a chitosan layer, and subsequently incorporated within a nanostructured Au electrode, the nMoS₂-participating redox cycling reactions are further enhanced by the nanoconfinement effect, leading to synergistic signal amplification. As a model system, this hybrid nMoS₂-in-nanoporous Au electrode demonstrates a 9-fold increase in sensitivity for detecting pyocyanin, a biomarker of Pseudomonas aeruginosa infection, compared with a flat electrode without nMoS₂ loading. This study not only elucidates the redox characteristics of laser-fabricated zero-dimensional transition metal dichalcogenides but also presents a strategy to integrate semiconducting nanomaterials with metallic nanostructures for high-performance electrochemical sensing. Full article

For effective water purification, the combination of membrane separation and catalytic degradation technologies not only permits continuous pollutant degradation but also successfully reduces membrane fouling. In recent years, catalytic membranes (CMs) have garnered a lot of interest in the water treatment industry. The main benefits of CMs are methodically explained in this review, emphasizing the synergistic effect of membrane separation and catalysis. These benefits include stable catalyst loading achieved through membrane structure manipulation, nanoconfinement, and effective degradation of organic pollutants. The application of catalytic membranes in water treatment is then thoroughly summarized, and they are separated into five main groups based on their unique catalytic reaction mechanisms: ozone catalytic membranes, photocatalytic membranes, electrocatalytic membranes, Fenton-type catalytic membranes, and persulfate catalytic membranes. The mechanisms and performance characteristics of each kind of CM are looked at in greater detail. Finally, research directions and future prospects for water treatment using catalytic membranes are proposed. This review provides recommendations for future research and development to ensure the effective use of catalytic membranes in water treatment, in addition to providing a thorough examination of the advancements made in their application in the treatment of various wastewaters. Full article

This study presents a molecular dynamics (MD) investigation of water evaporation in copper nanochannels, with a focus on accurately modeling copper–water interactions through forcefield calibration. The TIP4P/2005 water model was coupled with the Modified Embedded Atom Method (MEAM) for copper, and the oxygen–copper Lennard–Jones (LJ) parameters were systematically tuned to match experimentally reported water contact angles (WCAs) on Cu (111) surfaces. Contact angles were extracted from simulation trajectories using a robust five-step protocol involving 2D kernel density estimation, adaptive thresholding, circle fitting, and mean squared error (MSE) validation. The optimized forcefield demonstrated strong agreement with experimental WCA values (50.2°–82.3°), enabling predictive control of wetting behavior by varying ε in the range 0.20–0.28 kcal/mol. Using this validated parameterization, we explored nanoscale evaporation in copper channels under varying thermal loads (300–600 K). The results reveal a clear temperature-dependent transition from interfacial-layer evaporation to bulk-phase vaporization, with evaporation onset and rate governed by the interplay between copper–water adhesion and thermal disruption of hydrogen bonding. These findings provide atomistically resolved insights into wetting and evaporation in metallic nanochannels, offering a calibrated framework for simulating phase-change heat transfer in advanced thermal management systems. Full article

Three-dimensionally ordered macroporous (3DOM) La₂O₃-supported Ni catalysts exhibit outstanding performance for methane dry reforming (DRM). The 5Ni/La₂O₃-3DOM catalyst achieves 79% CH₄ and 84% CO₂ conversions at 800 °C under the reaction conditions of atmospheric pressure, CH₄:CO₂ molar ratio of 1:1, and gas hourly space velocity (GHSV) = 36,000 mL·gcat⁻¹·h⁻¹, outperforming its counterparts (5Ni/La₂O₃-PP prepared by means of co-precipitation and 5Ni/La₂O₃-GNC prepared by means of glycine–nitrate combustion) by 15–20%. Long-term stability tests at 700 °C (same CH₄:CO₂ ratio and GHSV as above) show that the 5Ni/La₂O₃-3DOM catalyst maintains CH₄ and CO₂ conversions at approximately 80% and 85%, respectively, with zero deactivation over 50 h. Meanwhile, its carbon deposition rate plummets to 1.1 mg·g⁻¹·h⁻¹, which is 75% lower than that of the precipitation-derived 5Ni/La₂O₃-PP catalyst. This excellent performance stems from the synergy of nano-confined Ni particles (11.2 nm in crystallite size after reduction) and abundant surface oxygen species (38 μmol·g⁻¹), establishing 3DOM La₂O₃ as a superior anti-coking support platform for scalable H₂ production via DRM. Full article

The effect of molecule–surface interaction strength on water becomes pronounced when pore size shrinks to the nanoscale, leading to the spatially varying viscosity and water slip phenomena that break the theoretical basis of the classic Lucas–Washburn (L-W) equation for the spontaneous imbibition of water. With the purpose of fulfilling the knowledge gap, the viscosity of nanoconfined water is investigated in relation to surface contact angle, a critical parameter manifesting microscopic molecule–surface interaction strength. Then, the water slip length at the nanoscale is determined in accordance with the mechanical balance of the first-layer water molecules, which enlarges gradually with increasing contact angle, indicating a weaker surface–molecule interaction. After that, a novel model for the spontaneous imbibition of nanoconfined water incorporating spatially inhomogeneous water viscosity and water slip is developed for the first time, demonstrating that the conventional model yields overestimations of 16.7–103.2%. Hydrodynamics affected by pore geometry are considered as well. The results indicate the following: (a) Enhanced viscosity resulting from the nanopore surface action reduces the water imbibition distance, the absolute magnitude of which could be 3 times greater than the positive impact of water slip. (b) With increasing pore size, the impact of water slip declines much faster than the enhanced viscosity, leading to the ratio of the nanoconfined water imbibition distance to the result of the L-W equation dropping rapidly at first and then approaching unity. (c) Water imbibition performance in slit nanopores is superior to that in nanoscale capillaries, stemming from the fact that the effective water viscosity in nano-capillaries is greater than that in slit nanopores by 5.1–22.1%, suggesting stronger hydrodynamic resistance. This research is able to provide an accurate prediction of spontaneous imbibition of nanoconfined water with microscopic mechanisms well captured, sharing broad application potential in hydraulic fracturing water analysis and water-flooding-enhanced oil/gas recovery. Full article