There are many conventional techniques for assembling the layered nanocomposites,such as layer-by-layer (LbL),vacuumassisted filtration,and blade coating.The two-dimensional nanoplatelets,including clay,graphene oxide...There are many conventional techniques for assembling the layered nanocomposites,such as layer-by-layer (LbL),vacuumassisted filtration,and blade coating.The two-dimensional nanoplatelets,including clay,graphene oxide (GO),and MXene,are usually first dissolved into water,and then assembled into a lamellar structure after evaporation of water [1-3].However,these wet chemical methods usually inevitably undergo capillary contraction during the process of water evaporation.Capillary contraction results in the wrinkles of the nanoplatelets,inducing the voids and decreasing the orientation degree.Thus,the resultant nanocomposites usually show much lower performance than predicted.展开更多
Nanoscale confinement environments often affect the transport mechanisms of nanofluids.Understanding the dynamic behavior of molecules in two-dimensional(2D)confined channels is of great importance in the areas of sen...Nanoscale confinement environments often affect the transport mechanisms of nanofluids.Understanding the dynamic behavior of molecules in two-dimensional(2D)confined channels is of great importance in the areas of sensing,catalysis and energy storage.As a popular candidate for a new type of gas sensing material,MXenes have the problem of nonselectivity towards polar gases with slow responses,which severely limits their applications.Here,we report a study on regulating the confinement effect of 2D channels between MXene layers through annealing treatment and ion(Na^(+))intercalation for high-performance ammonia(NH_(3))sensing.Firstly,the annealing treatment accurately modulates the size of the 2D channels to effectively block the entry of large-size gas molecules and improve the selectivity for NH_(3).Ab initio molecular dynamics(AIMD)also confirms that the modulated channel size has a special"nano-pumping effect",which can accelerate the dynamic behavior of NH_(3) molecules in the 2D confined space.Moreover,the intercalation of Na+ions increases the adsorption capacity of NH_(3).Therefore,the"nano-pumping effect"and theintercalation of Na+ions effectively enhance the response speed and sensitivity of MXene to NH_(3),respectively.The experimental results show that the modified Ti_(3)C_(2) exhibits high sensitivity(0.17),rapid response(181 s),excellent selectivity and stability towards NH_(3).展开更多
Friction is ubiquitous and plays a key role in the functionality of many biological and engineering systems,from articular cartilage to machinery.While friction facilitates motion,it also causes wear and energy loss i...Friction is ubiquitous and plays a key role in the functionality of many biological and engineering systems,from articular cartilage to machinery.While friction facilitates motion,it also causes wear and energy loss in moving parts.Lubricants(particularly liquid lubricants)are essential to reduce the negative effects of friction,and their properties(e.g.,rheology and compatibility with friction materials)significantly influence lubrication performance and related mechanisms.The tribological phenomena between friction surfaces separated by a nanoconfined liquid film are governed by both external load and surface forces involved.Despite significant progress over the past few decades,the molecular and interfacial interaction mechanisms driving liquid-lubricated friction are not yet fully understood,and a comprehensive correlation between surface forces and tribological behaviors in nanoconfined liquids has not been fully established.In this review,we first summarize the latest understanding of fundamental concepts in surface forces,nano-rheology,and tribology in nanoconfined liquids.Representative tribological phenomena in nanoconfined liquids are analyzed and correlated with surface forces and liquid properties involved in specific cases.Additionally,advanced nanomechanical technologies(e.g.,surface forces apparatus(SFA)and atomic force microscopy(AFM)),which show great potential in the field of tribology,are introduced.The advantages and current limitations of these technologies are also discussed.Moreover,key findings from recent tribological studies involving different liquids(both aqueous solutions and nonpolar liquids)are reviewed,and the underlying mechanisms of lubrication performance are analyzed from the perspective of surface forces.The future directions of tribology in nanoconfined liquids are discussed,providing insights and inspirations for developing effective lubrication strategies.This review enhances the understanding of nanotribology and correlates tribological phenomena with surface forces and rheology in nanoconfined liquids,offering new insights for developing advanced lubricants and wear-resistance materials.展开更多
Single-atom catalysts are highly effective in catalyzing a wide range of reactions owing to their capacity to have precise coordination patterns and fully leverage the potential of metal atoms.Although several techniq...Single-atom catalysts are highly effective in catalyzing a wide range of reactions owing to their capacity to have precise coordination patterns and fully leverage the potential of metal atoms.Although several techniques have been reported for the preparation of single-atom catalysts,adopting a convenient method to construct them still has a challenge.In this work,we report a convenient method for the preparation of Zr-based single-atom catalyst that takes advantage of the nanoconfined environments between the template and silica wall in template-occupied silica SBA-15.After introducing Zr-containing precursor into the nanoconfined environments of the templateoccupied silica SBA-15 using solid-phase milling,Zrbased single-atom catalysts were produced via the following calcination step.Density functional theory calculations and experimental findings show that Zr atoms form Zr-O-Si structure in the silica walls.The Zr single-atom catalyst synthesized using the nanoconfined environments exhibited notably superior catalytic performance in the synthesis of benzyl acetate from the esterification reaction between acetic acid and benzyl alcohol(63.3%yield),outperforming the counterpart that synthesized without such nanoconfined environments(19.8%yield).展开更多
Iontronics based on nanoconfined effects exhibit enhanced ion dynamics and have become more important in the fields such as energy harvesting and storage,sensors,and human-machine communications,which maybe an alterna...Iontronics based on nanoconfined effects exhibit enhanced ion dynamics and have become more important in the fields such as energy harvesting and storage,sensors,and human-machine communications,which maybe an alternative or supplementary solution to electronics due to their biocompatibility and safety.The enhanced ion dynamics can be attributable to the strong interactions between ions and the electrical double layer(EDL)in the nanoconfined spaces.Therefore,in this review,an overview of the EDL is firstly provided,with its distinctive nanoconfined effects in governing ion dynamics highlighted.The primary material frameworks associated with nanoconfined spaces,including nanopores,nanochannels,and multidimensional nanostructures,are systematically classified.Strategies for modulating ion dynamics through external physical and chemical fields are explored,forming the basis for iontronic applications driven by nanoconfined effects.These applications are presented,encompassing iontronic power sources,sensors,logic components such as memristors,diodes,and transistors,as well as iontronic filter capacitors,with their unparalleled advantages in biosafety,flexibility,cost-effectiveness,and environmental adaptability emphasized.Finally,existing challenges in nanoconfined iontronics are addressed,with the expectation that advancements in nanoconfined iontronics will catalyze more efficient energy and information flow.展开更多
Heat conduction of nanoconfined liquid may differ from its bulk because of the effects of size,geometry,interface,temperature,etc.In this study,the roles of some critical factors for the heat conduction of nanoconfine...Heat conduction of nanoconfined liquid may differ from its bulk because of the effects of size,geometry,interface,temperature,etc.In this study,the roles of some critical factors for the heat conduction of nanoconfined water film are systematically analyzed by using the molecular dynamics method.With decreasing thickness,the normal thermal conductivity of nanoconfined water film between two copper plates decreases exponentially,while the thermal resistance,peak of the radial distribution function,and atomistic heat path increase exponentially.The average bond order,radial distribution function,mean squared displacement,and vibrational density of states are calculated to analyze the effects of structure,distribution,molecular diffusion,and vibration of water molecules on heat conduction especially in a region having no oxygen atoms(which is observed by the near-wall density profile).The results show that phonon scattering is dominant for determining the reduced thermal conductivity in this near-wall region.The thermal conductivity ratio of confined water film to bulk water has a roughly linear relationship with the logarithm of the proportion of the near-wall region.Moreover,the high interfacial thermal resistance is positively correlated to the film thickness,but it has a negligible impact on heat conduction.This work provides insights into the contribution of water molecules near the solid/liquid interface to the heat conduction of nanoconfined liquid for process intensification.展开更多
Poly(vinyl alcohol)(PVA)is biodegradable,recyclable,and has high tensile strength.Therefore,it is ideal for the development of environment-friendly sustainable bioplastics.However,at elevated humidity,the mechanical p...Poly(vinyl alcohol)(PVA)is biodegradable,recyclable,and has high tensile strength.Therefore,it is ideal for the development of environment-friendly sustainable bioplastics.However,at elevated humidity,the mechanical properties of PVA bioplastic films undergo degradation owing to their intrinsic hydrophilic and hygroscopic nature,hindering their applications.This study proposes a nanoconfined assembly strategy to produce humidity-adaptive,mechanically robust,and recyclable bioplastic film.The strong hydrogen bonds between PVA and cellulose nanofibrils inhibit the penetration of water molecules into the film to promote humidity resistance.Further,the robust coordination interactions between bentonite nanoplates,PVA,and cellulose nanofibrils restrict the slip of polymer chains during deformation,leading to enhanced mechanical properties.Benefiting from the nanoconfined assembly architecture in aggregated composites,the resulting reinforced PVA film simultaneously exhibits strength,stiffness,toughness,fracture energy,and tearing energy of 55.9 MPa,1,275.6 MPa,162.9 MJ m^(−3),630.9 kJ m^(−2),and 465.0 kJ m^(−2),respectively.Moreover,the film maintains a strength of approximately 48.7 MPa even at 80%relative humidity for 180 days.This efficient design strategy applies to diverse scales and structured cellulose biomacromolecules.Moreover,it facilitates the application of recyclable high-performance bioplastic films to settings that require high humidity tolerance.展开更多
Recently, we have found a reversible transition between the dispersion and aggregation states of solute molecules in aqueous solutions confined in nanoscale geometry, where solutes exhibit distinct behavior in a new a...Recently, we have found a reversible transition between the dispersion and aggregation states of solute molecules in aqueous solutions confined in nanoscale geometry, where solutes exhibit distinct behavior in a new association state from that in the dispersion and aggregation states observed usually in macroscopic systems. However, it remains unknown whether this new association state of solute molecules found in nanoconfined systems would vanish with the system size increasing and approaching the macroscopic scale. Here, we achieve the phase diagram of solute association states by making the analyses of Gibbs free energy of solutes in nanoconfined aqueous solutions in detail. In the phase diagram, we observe a closed regime with a finite system size of nanoconfined aqueous solutions and a solute concentration range, only in which there exists the new association state of solutes with the reversible transition between the aggregation and dispersion states, and there indeed exists an upper limit of the system size for the new association state, around several tens nanometers. These findings regarding the intimate connection between the system size and the solute association behavior provides the comprehensive understanding of the association dynamics of solutes in nanoconfined environment.展开更多
Nanoconfinement is a promising approach to simultaneously enhance the thermodynamics,kinetics,and cycling stability of hydrogen storage materials.The introduction of supporting scaffolds usually causes a reduction in ...Nanoconfinement is a promising approach to simultaneously enhance the thermodynamics,kinetics,and cycling stability of hydrogen storage materials.The introduction of supporting scaffolds usually causes a reduction in the total hydrogen storage capacity due to“dead weight.”Here,we synthesize an optimized N-doped porous carbon(rN-pC)without heavy metal as supporting scaffold to confine Mg/MgH_(2) nanoparticles(Mg/MgH_(2)@rN-pC).rN-pC with 60 wt%loading capacity of Mg(denoted as 60 Mg@rN-pC)can adsorb and desorb 0.62 wt%H_(2) on the rN-pC scaffold.The nanoconfined MgH_(2) can be chemically dehydrided at 175℃,providing~3.59 wt%H_(2) with fast kinetics(fully dehydrogenated at 300℃ within 15 min).This study presents the first realization of nanoconfined Mg-based system with adsorption-active scaffolds.Besides,the nanoconfined MgH_(2) formation enthalpy is reduced to~68 kJ mol^(−1) H_(2) from~75 kJ mol^(−1) H_(2) for pure MgH_(2).The composite can be also compressed to nanostructured pellets,with volumetric H_(2) density reaching 33.4 g L^(−1) after 500 MPa compression pressure,which surpasses the 24 g L^(−1) volumetric capacity of 350 bar compressed H_(2).Our approach can be implemented to the design of hybrid H_(2) storage materials with enhanced capacity and desorption rate.展开更多
Harvesting energy from humid air to generate electricity represents a promising strategy for sustainable power generation.However,achieving high output and long-term stability in moisture-driven power generators(MPGs)...Harvesting energy from humid air to generate electricity represents a promising strategy for sustainable power generation.However,achieving high output and long-term stability in moisture-driven power generators(MPGs)remains a significant challenge.Here,we develop an efficient MPG by incorporating polymerized ionic liquid(PIL)and MXene through in-situ polymerization of cationic long chains within the MXene layers.This structural design enhances the hydrophilicity and ion dynamics,ensuring stable and sustained electrical output.A single MPG device delivers an open-circuit voltage of 0.65 V and a power density of 14.87 mW·cm^(-2),operating continuously for over 36 h.Surface characterization and quantum chemistry calculations elucidate that the mobile anions within the MPG move directionally under moisture gradients,while polymerized cations remain stationary,driving power generation.The MPG exhibits exceptional long-term stability,retaining about 80%of its initial voltage output after 30 days.Moreover,these MPGs demonstrate scalability for practical applications,capable of efficiently charging capacitors and powering LEDs through simple series-parallel configurations.This work offers a promising strategy to simultaneously enhance the performance and operational stability of MPGs,offering a sustainable solution for the direct conversion of low-grade thermal energy from moisture into clean electricity.展开更多
Available online Further oxidation of NH3produced via photocatalytic N_(2)fixation represents a promising strategy to enhance the economic value of N_(2)fixation.This work employs first-principles density functional t...Available online Further oxidation of NH3produced via photocatalytic N_(2)fixation represents a promising strategy to enhance the economic value of N_(2)fixation.This work employs first-principles density functional theory(DFT)calculations to demonstrate that incorporating Co into Ni O improves both N_(2)adsorption and activation as well as M-N electron exchange intensity.Guided by these predictions,a novel Co single-atom photocatalyst supported by nanoconfined Ni O@C nanosheets was synthesized using a direct metal atomization method,achieving high HNO_(3)production(60.54%).NH_(4)^(+)and NO_(3)^(-)production rates during N_(2)photofixation reached 67.97μmol g_(cat)^(-1)h^(-1)and 104.28μmol g_(cat)^(-1)h^(-1),respectively.The overall N_(2)→NH_(3)→HNO_(3)photofixation pathway was validated through in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and^(15)N isotopic labeling.Mechanistic studies reveal that Co single-atom introduction serves as an electron trap,enhancing photogenerated electron accumulation with a five-fold increase in carrier density compared to Ni O@C,as observed via in-situ X-ray photoelectron spectroscopy(XPS).This synergistic effect between electron traps and N2adsorption/activation sites at Co single-atom centers supports rapid N_(2)reduction kinetics.Additionally,nanoconfined ink-bottle pores in the carbon layer impede NH_(3)desorption,further boosting NO_(3)-production.This work offers a comprehensive approach to optimizing N_(2)photofixation through electron regulation and surface reaction kinetics.展开更多
The characterization of kerogen nanopores is crucial for predicting the geostorage capacity and recoverability of natural gas in unconventional gas shale reservoirs.Towards this end,a powerful technique is presented w...The characterization of kerogen nanopores is crucial for predicting the geostorage capacity and recoverability of natural gas in unconventional gas shale reservoirs.Towards this end,a powerful technique is presented which integrates 2D NMR T_(1)-T_(2) relaxation measurements with molecular dynamics(MD)simulations of hydrocarbons confined in the nanopores of kerogen.The integrated NMR-MD technique is demonstrated using T_(1)-T_(2) measurements of kerogen isolates and organic-rich chalks saturated with heptane,together with MD simulations of heptane completely dissolved in a realistic kerogen model.The NMR-MD results are used to extract the swelling ratio and nanopore size distribution of kerogen as a function of depth in the reservoir.The effects of organic nanoconfinement on the T_(1) relaxation dispersion and T_(2) residual dipolar coupling of heptane are investigated,as well as the effect of downhole effective stress on the kerogen nanopore size as a function of depth and compaction.Potential applications in partially depleted gas shale reservoirs are discussed,including CO_(2) utilization/geostorage,geostorage of green H_(2),and integration of the NMR-MD technique with thermodynamic models for predicting the competitive sorption of gas mixtures in kerogen.展开更多
In modern chemical engineering processes, solid interface involvement is the most important component of process intensification techniques, such as nanoporous membrane separation and heterogeneous catalysis. The fund...In modern chemical engineering processes, solid interface involvement is the most important component of process intensification techniques, such as nanoporous membrane separation and heterogeneous catalysis. The fundamental mechanism underlying interfacial transport remains incompletely understood given the complexity of heterogeneous interfacial molecular interactions and the high nonideality of the fluid involved. Thus, understanding the effects of interface-induced fluid microstructures on flow resistance is the first step in further understanding interfacial transport. Molecular simulation has become an indispensable method for the investigation of fluid microstructure and flow resistance. Here, we reviewed the recent research progress of our group and the latest relevant works to elucidate the contribution of interface-induced fluid microstructures to flow resistance.We specifically focused on water, ionic aqueous solutions, and alcohol–water mixtures given the ubiquity of these fluid systems in modern chemical engineering processes. We discussed the effects of the interfaceinduced hydrogen bond networks of water molecules, the ionic hydration of ionic aqueous solutions, and the spatial distributions of alcohol and alcohol–water mixtures on flow resistance on the basis of the distinctive characteristics of different fluid systems.展开更多
MgH_(2) has attracted intensive interests as one of the most promising hydrogen storage materials.Nevertheless,the high desorption temperature,sluggish kinetics,and rapid capacity decay hamper its commercial applicati...MgH_(2) has attracted intensive interests as one of the most promising hydrogen storage materials.Nevertheless,the high desorption temperature,sluggish kinetics,and rapid capacity decay hamper its commercial application.Herein,2D TiO_(2) nanosheets with abundant oxygen vacancies are used to fabricate a flower-like MgH_(2)/TiO_(2) heterostructure with enhanced hydrogen storage performances.Particularly,the onset hydrogen desorption temperature of the MgH_(2)/TiO_(2) heterostructure is lowered down to 180℃(295℃ for blank MgH_(2)).The initial desorption rate of MgH_(2)/TiO_(2) reaches 2.116 wt% min^(-1) at 300℃,35 times of the blank MgH_(2) under the same conditions.Moreover,the capacity retention is as high as 98.5% after 100 cycles at 300℃,remarkably higher than those of the previously reported MgH_(2)-TiO_(2) composites.Both in situ HRTEM observations and ex situ XPS analyses confirm that the synergistic effects from multi-valance of Ti species,accelerated electron transportation caused by oxygen vacancies,formation of catalytic Mg-Ti oxides,and stabilized MgH_(2) NPs confined by TiO_(2) nanosheets contribute to the high stability and kinetically accelerated hydrogen storage performances of the composite.The strategy of using 2D substrates with abundant defects to support nano-sized energy storage materials to build heterostructure is therefore promising for the design of high-performance energy materials.展开更多
Unveiling the pore-size performance of metal organic frameworks(MOFs)is imperative for controllable design of sophisticated catalysts.Herein,UiO-66 with distinct macropores and mesopores were intentionally created and...Unveiling the pore-size performance of metal organic frameworks(MOFs)is imperative for controllable design of sophisticated catalysts.Herein,UiO-66 with distinct macropores and mesopores were intentionally created and served as substrates to create advanced CdS/UiO-66 catalysts.The pore size impacted the spatial distribution of CdS nanoparticles(NPs):CdS tended to deposit on the external surface of mesoporous UiO-66,but spontaneously penetrated into the large cavity of macroporous UiO-66 nanocage.Normalized to unit amount of CdS,the photocatalytic reaction constant of macroporous CdS/UiO-66 over 4-nitroaniline reduction was~3 folds of that of mesoporous counterpart,and outperformed many other reported state-of-art CdS-based catalysts.A confinement effect of CdS NPs within UiO-66 cage could respond for its high activity,which could shorten the electron-transport distance of NPs-MOFs-reactant,and protect the active CdS NPs from photocorrosion.The finding here provides a straightforward paradigm and mechanism to rationally fabricate advance NPs/MOFs for diverse applications.展开更多
Water scarcity is a global challenge,and solar evaporation technology offers a promising and eco-friendly solution for freshwater production.Photothermal conversion materials(PCMs)are crucial for solar evaporation.Imp...Water scarcity is a global challenge,and solar evaporation technology offers a promising and eco-friendly solution for freshwater production.Photothermal conversion materials(PCMs)are crucial for solar evaporation.Improving photothermal conversion efficiency and reducing water evaporation enthalpy are the two key strategies for the designing of PCMs.The desired PCMs that combine both of these properties remain a challenging task,even with the latest advancements in the field.Herein,we developed copper nanoparticles(NPs)with different conjugated nitrogen-doped microporous carbon coatings(Cu@C–N)as PCMs.The microporous carbon enveloping layer provides a highly efficient pathway for water transport and a nanoconfined environment that protects Cu NPs and facilitates the evaporation of water clusters,reducing the enthalpy of water evaporation.Meanwhile,the conjugated nitrogen nodes form strong metal-organic coordination bonds with the surface of copper NPs,acting as an energy bridge to achieve rapid energy transfer and provide high solar-to-vapor conversion efficiency.The Cu@C–N exhibited up to 89.4%solar-to-vapor conversion efficiency and an evaporation rate of 1.94 kgm^(−2) h^(−1) under one sun irradiation,outperforming conventional PCMs,including carbon-based materials and semiconductor materials.These findings offer an efficient design scheme for high-performance PCMs essential for solar evaporators to address global water scarcity.展开更多
Hydrogen is an ideal clean energy because of its high calorific value and abundance of sources.However,storing hydrogen in a compact,inexpensive,and safe manner is the main restriction on the extensive utilization of ...Hydrogen is an ideal clean energy because of its high calorific value and abundance of sources.However,storing hydrogen in a compact,inexpensive,and safe manner is the main restriction on the extensive utilization of hydrogen energy.Magnesium(Mg)-based hydrogen storage material is considered a reliable solid hydrogen storage material with the advantages of high hydrogen storage capacity(7.6wt%),good performance,and low cost.However,the high thermodynamic stability and slow kinetics of Mg-based hydrogen storage materials have to be overcome.In this paper,we will review the recent advances in the nanoconfinement of Mg-related hydrogen storage materials by loading Mg particles on different supporting materials,including carbons,metal-organic frameworks,and other materials.Perspectives are also provided for designing high-performance Mg-based materials using nanoconfinement.展开更多
Polymeric materials under nanoconfinements have substantially deviated physical properties with respect to the bulk,especially glass transition temperature,physical aging,and crystallization behavior.Here we highlight...Polymeric materials under nanoconfinements have substantially deviated physical properties with respect to the bulk,especially glass transition temperature,physical aging,and crystallization behavior.Here we highlight the leading methods for creating various confinement systems.Upon these systems,recent advances on hard and soft confinement effect for glass transition,physical aging,mechanical properties and crystallization of polymers are reviewed in details.Furthermore,as nanoconfined systems in extreme conditions are experimentally inaccessible,simulation results describing confinement effect on such systems are also discussed.展开更多
Owing to its favorable thermodynamics and high density,NaAlH_(4) has been widely regarded as a potential hydrogen storage material,but its practical application is hindered by the sluggish kinetics,high operating temp...Owing to its favorable thermodynamics and high density,NaAlH_(4) has been widely regarded as a potential hydrogen storage material,but its practical application is hindered by the sluggish kinetics,high operating temperature and poor cycling stability.Here,taking advantage of Co-doped nanoporous carbon scaffolds as structural host,we develop a new strategy to balance the synergistic effect between the catalytic role of Co nanoparticles and the nanoconfinement role of porous carbon scaffolds via the controllable etching of Co nanoparticles towards enhanced hydrogen storage performance of NaAlH_(4).The etching of Co nanoparticles creates extra void spaces nearby catalytically active Co nanoparticles,which not only exerts the catalytic effect of Co nanoparticles,but also improves the nanoconfinement role in maintaining the cycling stability towards increased loading ratio and hence high systematic capacity.Induced by this balanced synergistic effect,the peak temperature for the dehydrogenation of NaAlH_(4) could be reduced to 164°C,97°C lower than the bulk counterpart,even under an ultrahigh loading ratio of 67%,and more importantly,the reversible systematic hydrogen storage capacity could still reach 3.3 wt.%after 5 cycles.This work opens up a new avenue to improve the hydrogen storage performance of various complex hydrides.展开更多
文摘There are many conventional techniques for assembling the layered nanocomposites,such as layer-by-layer (LbL),vacuumassisted filtration,and blade coating.The two-dimensional nanoplatelets,including clay,graphene oxide (GO),and MXene,are usually first dissolved into water,and then assembled into a lamellar structure after evaporation of water [1-3].However,these wet chemical methods usually inevitably undergo capillary contraction during the process of water evaporation.Capillary contraction results in the wrinkles of the nanoplatelets,inducing the voids and decreasing the orientation degree.Thus,the resultant nanocomposites usually show much lower performance than predicted.
基金supported by the National Natural Science Foundation of China(Nos.52422505 and 12274124)the Innovative Research Group Project of the National Natural Science Foundation of China(No.52321002).
文摘Nanoscale confinement environments often affect the transport mechanisms of nanofluids.Understanding the dynamic behavior of molecules in two-dimensional(2D)confined channels is of great importance in the areas of sensing,catalysis and energy storage.As a popular candidate for a new type of gas sensing material,MXenes have the problem of nonselectivity towards polar gases with slow responses,which severely limits their applications.Here,we report a study on regulating the confinement effect of 2D channels between MXene layers through annealing treatment and ion(Na^(+))intercalation for high-performance ammonia(NH_(3))sensing.Firstly,the annealing treatment accurately modulates the size of the 2D channels to effectively block the entry of large-size gas molecules and improve the selectivity for NH_(3).Ab initio molecular dynamics(AIMD)also confirms that the modulated channel size has a special"nano-pumping effect",which can accelerate the dynamic behavior of NH_(3) molecules in the 2D confined space.Moreover,the intercalation of Na+ions increases the adsorption capacity of NH_(3).Therefore,the"nano-pumping effect"and theintercalation of Na+ions effectively enhance the response speed and sensitivity of MXene to NH_(3),respectively.The experimental results show that the modified Ti_(3)C_(2) exhibits high sensitivity(0.17),rapid response(181 s),excellent selectivity and stability towards NH_(3).
基金support from the Natural Sciences and Engineering Research Council of Canada(NSERC),the Canada Foundation for Innovation(CFI),the Research Capacity Program(RCP)of Alberta,the Canada Research Chairs Program(H.Zeng),and China Scholarship Council.
文摘Friction is ubiquitous and plays a key role in the functionality of many biological and engineering systems,from articular cartilage to machinery.While friction facilitates motion,it also causes wear and energy loss in moving parts.Lubricants(particularly liquid lubricants)are essential to reduce the negative effects of friction,and their properties(e.g.,rheology and compatibility with friction materials)significantly influence lubrication performance and related mechanisms.The tribological phenomena between friction surfaces separated by a nanoconfined liquid film are governed by both external load and surface forces involved.Despite significant progress over the past few decades,the molecular and interfacial interaction mechanisms driving liquid-lubricated friction are not yet fully understood,and a comprehensive correlation between surface forces and tribological behaviors in nanoconfined liquids has not been fully established.In this review,we first summarize the latest understanding of fundamental concepts in surface forces,nano-rheology,and tribology in nanoconfined liquids.Representative tribological phenomena in nanoconfined liquids are analyzed and correlated with surface forces and liquid properties involved in specific cases.Additionally,advanced nanomechanical technologies(e.g.,surface forces apparatus(SFA)and atomic force microscopy(AFM)),which show great potential in the field of tribology,are introduced.The advantages and current limitations of these technologies are also discussed.Moreover,key findings from recent tribological studies involving different liquids(both aqueous solutions and nonpolar liquids)are reviewed,and the underlying mechanisms of lubrication performance are analyzed from the perspective of surface forces.The future directions of tribology in nanoconfined liquids are discussed,providing insights and inspirations for developing effective lubrication strategies.This review enhances the understanding of nanotribology and correlates tribological phenomena with surface forces and rheology in nanoconfined liquids,offering new insights for developing advanced lubricants and wear-resistance materials.
基金support of this work by the National Science Fund for Distinguished Young Scholars(Grant No.22125804)the National Natural Science Foundation of China(Grant No.22078155)+1 种基金supporting the computational resourcesprovided by the BL11B beam station at the Shanghai Synchrotron Radiation Facility(SSRF).
文摘Single-atom catalysts are highly effective in catalyzing a wide range of reactions owing to their capacity to have precise coordination patterns and fully leverage the potential of metal atoms.Although several techniques have been reported for the preparation of single-atom catalysts,adopting a convenient method to construct them still has a challenge.In this work,we report a convenient method for the preparation of Zr-based single-atom catalyst that takes advantage of the nanoconfined environments between the template and silica wall in template-occupied silica SBA-15.After introducing Zr-containing precursor into the nanoconfined environments of the templateoccupied silica SBA-15 using solid-phase milling,Zrbased single-atom catalysts were produced via the following calcination step.Density functional theory calculations and experimental findings show that Zr atoms form Zr-O-Si structure in the silica walls.The Zr single-atom catalyst synthesized using the nanoconfined environments exhibited notably superior catalytic performance in the synthesis of benzyl acetate from the esterification reaction between acetic acid and benzyl alcohol(63.3%yield),outperforming the counterpart that synthesized without such nanoconfined environments(19.8%yield).
基金supported by the National Natural Science Foundation of China(No.22479016).
文摘Iontronics based on nanoconfined effects exhibit enhanced ion dynamics and have become more important in the fields such as energy harvesting and storage,sensors,and human-machine communications,which maybe an alternative or supplementary solution to electronics due to their biocompatibility and safety.The enhanced ion dynamics can be attributable to the strong interactions between ions and the electrical double layer(EDL)in the nanoconfined spaces.Therefore,in this review,an overview of the EDL is firstly provided,with its distinctive nanoconfined effects in governing ion dynamics highlighted.The primary material frameworks associated with nanoconfined spaces,including nanopores,nanochannels,and multidimensional nanostructures,are systematically classified.Strategies for modulating ion dynamics through external physical and chemical fields are explored,forming the basis for iontronic applications driven by nanoconfined effects.These applications are presented,encompassing iontronic power sources,sensors,logic components such as memristors,diodes,and transistors,as well as iontronic filter capacitors,with their unparalleled advantages in biosafety,flexibility,cost-effectiveness,and environmental adaptability emphasized.Finally,existing challenges in nanoconfined iontronics are addressed,with the expectation that advancements in nanoconfined iontronics will catalyze more efficient energy and information flow.
基金the National Natural Science Foundation of China(No.51876058)。
文摘Heat conduction of nanoconfined liquid may differ from its bulk because of the effects of size,geometry,interface,temperature,etc.In this study,the roles of some critical factors for the heat conduction of nanoconfined water film are systematically analyzed by using the molecular dynamics method.With decreasing thickness,the normal thermal conductivity of nanoconfined water film between two copper plates decreases exponentially,while the thermal resistance,peak of the radial distribution function,and atomistic heat path increase exponentially.The average bond order,radial distribution function,mean squared displacement,and vibrational density of states are calculated to analyze the effects of structure,distribution,molecular diffusion,and vibration of water molecules on heat conduction especially in a region having no oxygen atoms(which is observed by the near-wall density profile).The results show that phonon scattering is dominant for determining the reduced thermal conductivity in this near-wall region.The thermal conductivity ratio of confined water film to bulk water has a roughly linear relationship with the logarithm of the proportion of the near-wall region.Moreover,the high interfacial thermal resistance is positively correlated to the film thickness,but it has a negligible impact on heat conduction.This work provides insights into the contribution of water molecules near the solid/liquid interface to the heat conduction of nanoconfined liquid for process intensification.
基金National Natural Science Foundation of China,Grant/Award Number:31890774Forestry Science and Technology Innovation and Extension Project of Jiangsu Province,Grant/Award Number:LYKJ[2021]04。
文摘Poly(vinyl alcohol)(PVA)is biodegradable,recyclable,and has high tensile strength.Therefore,it is ideal for the development of environment-friendly sustainable bioplastics.However,at elevated humidity,the mechanical properties of PVA bioplastic films undergo degradation owing to their intrinsic hydrophilic and hygroscopic nature,hindering their applications.This study proposes a nanoconfined assembly strategy to produce humidity-adaptive,mechanically robust,and recyclable bioplastic film.The strong hydrogen bonds between PVA and cellulose nanofibrils inhibit the penetration of water molecules into the film to promote humidity resistance.Further,the robust coordination interactions between bentonite nanoplates,PVA,and cellulose nanofibrils restrict the slip of polymer chains during deformation,leading to enhanced mechanical properties.Benefiting from the nanoconfined assembly architecture in aggregated composites,the resulting reinforced PVA film simultaneously exhibits strength,stiffness,toughness,fracture energy,and tearing energy of 55.9 MPa,1,275.6 MPa,162.9 MJ m^(−3),630.9 kJ m^(−2),and 465.0 kJ m^(−2),respectively.Moreover,the film maintains a strength of approximately 48.7 MPa even at 80%relative humidity for 180 days.This efficient design strategy applies to diverse scales and structured cellulose biomacromolecules.Moreover,it facilitates the application of recyclable high-performance bioplastic films to settings that require high humidity tolerance.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11290164 and11574339)the National Science Fund for Outstanding Young Scholars (Grant No. 11422542)Shanghai Supercomputer Center of China and Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund (the second phase)
文摘Recently, we have found a reversible transition between the dispersion and aggregation states of solute molecules in aqueous solutions confined in nanoscale geometry, where solutes exhibit distinct behavior in a new association state from that in the dispersion and aggregation states observed usually in macroscopic systems. However, it remains unknown whether this new association state of solute molecules found in nanoconfined systems would vanish with the system size increasing and approaching the macroscopic scale. Here, we achieve the phase diagram of solute association states by making the analyses of Gibbs free energy of solutes in nanoconfined aqueous solutions in detail. In the phase diagram, we observe a closed regime with a finite system size of nanoconfined aqueous solutions and a solute concentration range, only in which there exists the new association state of solutes with the reversible transition between the aggregation and dispersion states, and there indeed exists an upper limit of the system size for the new association state, around several tens nanometers. These findings regarding the intimate connection between the system size and the solute association behavior provides the comprehensive understanding of the association dynamics of solutes in nanoconfined environment.
基金supported by the National Key R&D Program of China(2022YFB3803700)National Natural Science Foundation of China(52171186)+1 种基金Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)support from“Zhiyuan Honor Program”for doctoral students,Shanghai Jiao Tong University.
文摘Nanoconfinement is a promising approach to simultaneously enhance the thermodynamics,kinetics,and cycling stability of hydrogen storage materials.The introduction of supporting scaffolds usually causes a reduction in the total hydrogen storage capacity due to“dead weight.”Here,we synthesize an optimized N-doped porous carbon(rN-pC)without heavy metal as supporting scaffold to confine Mg/MgH_(2) nanoparticles(Mg/MgH_(2)@rN-pC).rN-pC with 60 wt%loading capacity of Mg(denoted as 60 Mg@rN-pC)can adsorb and desorb 0.62 wt%H_(2) on the rN-pC scaffold.The nanoconfined MgH_(2) can be chemically dehydrided at 175℃,providing~3.59 wt%H_(2) with fast kinetics(fully dehydrogenated at 300℃ within 15 min).This study presents the first realization of nanoconfined Mg-based system with adsorption-active scaffolds.Besides,the nanoconfined MgH_(2) formation enthalpy is reduced to~68 kJ mol^(−1) H_(2) from~75 kJ mol^(−1) H_(2) for pure MgH_(2).The composite can be also compressed to nanostructured pellets,with volumetric H_(2) density reaching 33.4 g L^(−1) after 500 MPa compression pressure,which surpasses the 24 g L^(−1) volumetric capacity of 350 bar compressed H_(2).Our approach can be implemented to the design of hybrid H_(2) storage materials with enhanced capacity and desorption rate.
基金the National Natural Science Foundation of China(22278401 and 92163209)the ANSO Collaborative Research Program(ANSO-CR-KP-2022-12)+2 种基金Beijing Natural Science Foundation(2252011 and JQ22004)Beijing Nova Program(20230484478)for financial supportsupported by Public Computing Cloud,Renmin University of China.
文摘Harvesting energy from humid air to generate electricity represents a promising strategy for sustainable power generation.However,achieving high output and long-term stability in moisture-driven power generators(MPGs)remains a significant challenge.Here,we develop an efficient MPG by incorporating polymerized ionic liquid(PIL)and MXene through in-situ polymerization of cationic long chains within the MXene layers.This structural design enhances the hydrophilicity and ion dynamics,ensuring stable and sustained electrical output.A single MPG device delivers an open-circuit voltage of 0.65 V and a power density of 14.87 mW·cm^(-2),operating continuously for over 36 h.Surface characterization and quantum chemistry calculations elucidate that the mobile anions within the MPG move directionally under moisture gradients,while polymerized cations remain stationary,driving power generation.The MPG exhibits exceptional long-term stability,retaining about 80%of its initial voltage output after 30 days.Moreover,these MPGs demonstrate scalability for practical applications,capable of efficiently charging capacitors and powering LEDs through simple series-parallel configurations.This work offers a promising strategy to simultaneously enhance the performance and operational stability of MPGs,offering a sustainable solution for the direct conversion of low-grade thermal energy from moisture into clean electricity.
基金supported by the National Natural Science Foundation of China(No.62004143)the Key Research and Development Program of Gansu Province-Industrial Project under Grant(No.25YFGA058)+4 种基金the Key Talent Project Foundation of Gansu Province(No.2025RCXM066)the Gansu Provincial Department of Education:Industrial Support Plan Project(No.2025CYZC-005)the Key R&D Program of Hubei Province(No.2022BAA084)the Science and Technology Project of Lanzhou(No.2024-3-42)the Fundamental Research Funds for the Central Universities(No.331920240059)。
文摘Available online Further oxidation of NH3produced via photocatalytic N_(2)fixation represents a promising strategy to enhance the economic value of N_(2)fixation.This work employs first-principles density functional theory(DFT)calculations to demonstrate that incorporating Co into Ni O improves both N_(2)adsorption and activation as well as M-N electron exchange intensity.Guided by these predictions,a novel Co single-atom photocatalyst supported by nanoconfined Ni O@C nanosheets was synthesized using a direct metal atomization method,achieving high HNO_(3)production(60.54%).NH_(4)^(+)and NO_(3)^(-)production rates during N_(2)photofixation reached 67.97μmol g_(cat)^(-1)h^(-1)and 104.28μmol g_(cat)^(-1)h^(-1),respectively.The overall N_(2)→NH_(3)→HNO_(3)photofixation pathway was validated through in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and^(15)N isotopic labeling.Mechanistic studies reveal that Co single-atom introduction serves as an electron trap,enhancing photogenerated electron accumulation with a five-fold increase in carrier density compared to Ni O@C,as observed via in-situ X-ray photoelectron spectroscopy(XPS).This synergistic effect between electron traps and N2adsorption/activation sites at Co single-atom centers supports rapid N_(2)reduction kinetics.Additionally,nanoconfined ink-bottle pores in the carbon layer impede NH_(3)desorption,further boosting NO_(3)-production.This work offers a comprehensive approach to optimizing N_(2)photofixation through electron regulation and surface reaction kinetics.
基金Vinegar Technologies LLC,Chevron Energy Technology Company,Rice University Consortium for Processes in Porous Media,and the American Chemical Society Petroleum Research Fund(No.ACS PRF 58859-ND6)for their financial support。
文摘The characterization of kerogen nanopores is crucial for predicting the geostorage capacity and recoverability of natural gas in unconventional gas shale reservoirs.Towards this end,a powerful technique is presented which integrates 2D NMR T_(1)-T_(2) relaxation measurements with molecular dynamics(MD)simulations of hydrocarbons confined in the nanopores of kerogen.The integrated NMR-MD technique is demonstrated using T_(1)-T_(2) measurements of kerogen isolates and organic-rich chalks saturated with heptane,together with MD simulations of heptane completely dissolved in a realistic kerogen model.The NMR-MD results are used to extract the swelling ratio and nanopore size distribution of kerogen as a function of depth in the reservoir.The effects of organic nanoconfinement on the T_(1) relaxation dispersion and T_(2) residual dipolar coupling of heptane are investigated,as well as the effect of downhole effective stress on the kerogen nanopore size as a function of depth and compaction.Potential applications in partially depleted gas shale reservoirs are discussed,including CO_(2) utilization/geostorage,geostorage of green H_(2),and integration of the NMR-MD technique with thermodynamic models for predicting the competitive sorption of gas mixtures in kerogen.
基金Supported by the National Natural Science Foundation of China(21878144,21576130,21490584 and 21838004)Project of Jiangsu Natural Science Foundation of China(BK20171464)+2 种基金Qing Lan ProjectJiangsu Overseas Visiting Scholar Program for University Prominent Young&Middle-aged Teachers and Presidentsthe Project of Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘In modern chemical engineering processes, solid interface involvement is the most important component of process intensification techniques, such as nanoporous membrane separation and heterogeneous catalysis. The fundamental mechanism underlying interfacial transport remains incompletely understood given the complexity of heterogeneous interfacial molecular interactions and the high nonideality of the fluid involved. Thus, understanding the effects of interface-induced fluid microstructures on flow resistance is the first step in further understanding interfacial transport. Molecular simulation has become an indispensable method for the investigation of fluid microstructure and flow resistance. Here, we reviewed the recent research progress of our group and the latest relevant works to elucidate the contribution of interface-induced fluid microstructures to flow resistance.We specifically focused on water, ionic aqueous solutions, and alcohol–water mixtures given the ubiquity of these fluid systems in modern chemical engineering processes. We discussed the effects of the interfaceinduced hydrogen bond networks of water molecules, the ionic hydration of ionic aqueous solutions, and the spatial distributions of alcohol and alcohol–water mixtures on flow resistance on the basis of the distinctive characteristics of different fluid systems.
基金the support from the National Natural Science Foundation (No. 52171186)the Science and Technology Commission of Shanghai Municipality under No. 19511108100+1 种基金Shanghai Education Commission “Shuguang” scholar Project (16SG08)the financial support from the Center of Hydrogen Science, Shanghai Jiao Tong University
文摘MgH_(2) has attracted intensive interests as one of the most promising hydrogen storage materials.Nevertheless,the high desorption temperature,sluggish kinetics,and rapid capacity decay hamper its commercial application.Herein,2D TiO_(2) nanosheets with abundant oxygen vacancies are used to fabricate a flower-like MgH_(2)/TiO_(2) heterostructure with enhanced hydrogen storage performances.Particularly,the onset hydrogen desorption temperature of the MgH_(2)/TiO_(2) heterostructure is lowered down to 180℃(295℃ for blank MgH_(2)).The initial desorption rate of MgH_(2)/TiO_(2) reaches 2.116 wt% min^(-1) at 300℃,35 times of the blank MgH_(2) under the same conditions.Moreover,the capacity retention is as high as 98.5% after 100 cycles at 300℃,remarkably higher than those of the previously reported MgH_(2)-TiO_(2) composites.Both in situ HRTEM observations and ex situ XPS analyses confirm that the synergistic effects from multi-valance of Ti species,accelerated electron transportation caused by oxygen vacancies,formation of catalytic Mg-Ti oxides,and stabilized MgH_(2) NPs confined by TiO_(2) nanosheets contribute to the high stability and kinetically accelerated hydrogen storage performances of the composite.The strategy of using 2D substrates with abundant defects to support nano-sized energy storage materials to build heterostructure is therefore promising for the design of high-performance energy materials.
文摘Unveiling the pore-size performance of metal organic frameworks(MOFs)is imperative for controllable design of sophisticated catalysts.Herein,UiO-66 with distinct macropores and mesopores were intentionally created and served as substrates to create advanced CdS/UiO-66 catalysts.The pore size impacted the spatial distribution of CdS nanoparticles(NPs):CdS tended to deposit on the external surface of mesoporous UiO-66,but spontaneously penetrated into the large cavity of macroporous UiO-66 nanocage.Normalized to unit amount of CdS,the photocatalytic reaction constant of macroporous CdS/UiO-66 over 4-nitroaniline reduction was~3 folds of that of mesoporous counterpart,and outperformed many other reported state-of-art CdS-based catalysts.A confinement effect of CdS NPs within UiO-66 cage could respond for its high activity,which could shorten the electron-transport distance of NPs-MOFs-reactant,and protect the active CdS NPs from photocorrosion.The finding here provides a straightforward paradigm and mechanism to rationally fabricate advance NPs/MOFs for diverse applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.52162012,52262014,22368019)Key Research and Development Project of Hainan Province(Grant Nos.ZDYF2022SHFZ053,ZDYF2021GXJS209)+1 种基金Science and Technology Innovation Talent Platform Fund for South China Sea New Star of Hainan Province(Grant No.NHXXRCXM202305)Open Research Project of State Key Laboratory of Marine Resource Utilization in South China Sea(Grant No.MRUKF2023020).
文摘Water scarcity is a global challenge,and solar evaporation technology offers a promising and eco-friendly solution for freshwater production.Photothermal conversion materials(PCMs)are crucial for solar evaporation.Improving photothermal conversion efficiency and reducing water evaporation enthalpy are the two key strategies for the designing of PCMs.The desired PCMs that combine both of these properties remain a challenging task,even with the latest advancements in the field.Herein,we developed copper nanoparticles(NPs)with different conjugated nitrogen-doped microporous carbon coatings(Cu@C–N)as PCMs.The microporous carbon enveloping layer provides a highly efficient pathway for water transport and a nanoconfined environment that protects Cu NPs and facilitates the evaporation of water clusters,reducing the enthalpy of water evaporation.Meanwhile,the conjugated nitrogen nodes form strong metal-organic coordination bonds with the surface of copper NPs,acting as an energy bridge to achieve rapid energy transfer and provide high solar-to-vapor conversion efficiency.The Cu@C–N exhibited up to 89.4%solar-to-vapor conversion efficiency and an evaporation rate of 1.94 kgm^(−2) h^(−1) under one sun irradiation,outperforming conventional PCMs,including carbon-based materials and semiconductor materials.These findings offer an efficient design scheme for high-performance PCMs essential for solar evaporators to address global water scarcity.
基金financially supported by the research programs of the National Natural Science Foundation of China (No. 52101274)the Natural Science Foundation of Shandong Province, China (No. ZR2020QE011)the Youth Top Talent Foundation of Yantai University, China (No. 2219008)
文摘Hydrogen is an ideal clean energy because of its high calorific value and abundance of sources.However,storing hydrogen in a compact,inexpensive,and safe manner is the main restriction on the extensive utilization of hydrogen energy.Magnesium(Mg)-based hydrogen storage material is considered a reliable solid hydrogen storage material with the advantages of high hydrogen storage capacity(7.6wt%),good performance,and low cost.However,the high thermodynamic stability and slow kinetics of Mg-based hydrogen storage materials have to be overcome.In this paper,we will review the recent advances in the nanoconfinement of Mg-related hydrogen storage materials by loading Mg particles on different supporting materials,including carbons,metal-organic frameworks,and other materials.Perspectives are also provided for designing high-performance Mg-based materials using nanoconfinement.
基金The authorsacknowledge the National Natural Science Foundation of China for financial support through the General Program No.2157408.Y.G.is very grateful to the National Youth 1000 Talent Program of China,the Shanghai 1000 Talent Plan,and the support by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry of China.The authors also acknowledge the start-up fund of Y.G.from both University of Michigan-Shanghai Jiao Tong University Joint Institute,and School of Materials Science and Engineering at SJTU.
文摘Polymeric materials under nanoconfinements have substantially deviated physical properties with respect to the bulk,especially glass transition temperature,physical aging,and crystallization behavior.Here we highlight the leading methods for creating various confinement systems.Upon these systems,recent advances on hard and soft confinement effect for glass transition,physical aging,mechanical properties and crystallization of polymers are reviewed in details.Furthermore,as nanoconfined systems in extreme conditions are experimentally inaccessible,simulation results describing confinement effect on such systems are also discussed.
基金This work was partially supported by the National Key R&D Program of China(No.2018YFB1502101)National Science Fund for Distinguished Young Scholars(51625102)+3 种基金the National Natural Science Foundation of China(51971065,51901045)the Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-07-E00028)the Open Fund of the Guangdong Provincial Key Laboratory of Advanced Energy Storage Materialsthe Programs for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning。
文摘Owing to its favorable thermodynamics and high density,NaAlH_(4) has been widely regarded as a potential hydrogen storage material,but its practical application is hindered by the sluggish kinetics,high operating temperature and poor cycling stability.Here,taking advantage of Co-doped nanoporous carbon scaffolds as structural host,we develop a new strategy to balance the synergistic effect between the catalytic role of Co nanoparticles and the nanoconfinement role of porous carbon scaffolds via the controllable etching of Co nanoparticles towards enhanced hydrogen storage performance of NaAlH_(4).The etching of Co nanoparticles creates extra void spaces nearby catalytically active Co nanoparticles,which not only exerts the catalytic effect of Co nanoparticles,but also improves the nanoconfinement role in maintaining the cycling stability towards increased loading ratio and hence high systematic capacity.Induced by this balanced synergistic effect,the peak temperature for the dehydrogenation of NaAlH_(4) could be reduced to 164°C,97°C lower than the bulk counterpart,even under an ultrahigh loading ratio of 67%,and more importantly,the reversible systematic hydrogen storage capacity could still reach 3.3 wt.%after 5 cycles.This work opens up a new avenue to improve the hydrogen storage performance of various complex hydrides.
基金the financial support from the National Natural Science Foundation of China(51878332,21976084,and 21925602)the Fundamental Research Funds for the Central Universities.
