Efficient bifunctional catalysts for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)are vital for rechargeable Zn-air batteries(ZABs).Herein,an oxygen-respirable sponge-like Co@C–O–Cs catalyst with ...Efficient bifunctional catalysts for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)are vital for rechargeable Zn-air batteries(ZABs).Herein,an oxygen-respirable sponge-like Co@C–O–Cs catalyst with oxygen-rich active sites was designed and constructed for both ORR and OER by a facile carbon dot-assisted strategy.The aerophilic triphase interface of Co@C–O–Cs cathode efficiently boosts oxygen diffusion and transfer.The theoretical calculations and experimental studies revealed that the Co–C–COC active sites can redistribute the local charge density and lower the reaction energy barrier.The Co@C–O–Cs catalyst displays superior bifunctional catalytic activities with a half-wave potential of 0.82 V for ORR and an ultralow overpotential of 294 mV at 10 mA cm^(−2) for OER.Moreover,it can drive the liquid ZABs with high peak power density(106.4 mW cm^(−2)),specific capacity(720.7 mAh g^(−1)),outstanding long-term cycle stability(over 750 cycles at 10 mA cm^(−2)),and exhibits excellent feasibility in flexible all-solid-state ZABs.These findings provide new insights into the rational design of efficient bifunctional oxygen catalysts in rechargeable metal-air batteries.展开更多
A series of novel catalysts was developed using cationic Gemini surfactants intercalated in natural montmorillonite (MMT) clay. These Gemini surfactant-MMT intercalates were used to study the kinetics of a nucleophili...A series of novel catalysts was developed using cationic Gemini surfactants intercalated in natural montmorillonite (MMT) clay. These Gemini surfactant-MMT intercalates were used to study the kinetics of a nucleophilic displacement reactions converting n-butyl bromide to n-butyl chloride in a triphase catalytic (TC) system. Most reaction rates compared favorably to those of biphase catalytic reactions where Gemini surfactants were used in the absence of MMT. Catalytic activity varied with Gemini surfactant structure, specifically with carbon spacer group and side chain length. In addition to the ease of catalyst separation that a triphase system affords, Gemini-MMT catalysts are stable and can be recycled and re-used several times.展开更多
A remarkable rate enhancement technique has been devised for a typical nucleophilic displacement reaction by using triphase catalytic materials based on tetraoctylammonium exchange forms of hectorite clay. Pseudo-firs...A remarkable rate enhancement technique has been devised for a typical nucleophilic displacement reaction by using triphase catalytic materials based on tetraoctylammonium exchange forms of hectorite clay. Pseudo-first order rate constants (kobs) for the conversion of 1-bromobutane to the corresponding chloride under triphase conditions using the clay catalyst in the presence of various polar cosolvents have been observed. The results here have shown that the addition of a cosolvent increases the catalytic activity of the triphase system by several fold. In addition, the results have demonstrated that each cosolvent has a unique concentration for achieving an optimum reaction rate.展开更多
The exothermic characteristic of the water-gas-shift(WGS)reaction,coupled with the thermodynamic constraints at elevated temperatures,has spurred a research inclination towards conducting the WGS reaction at reduced t...The exothermic characteristic of the water-gas-shift(WGS)reaction,coupled with the thermodynamic constraints at elevated temperatures,has spurred a research inclination towards conducting the WGS reaction at reduced temperatures.Nonetheless,the challenge of achieving efficient mass transfer between gaseous CO and liquid H_(2)O at the photocatalytic interface under mild reaction conditions hinders the advancement of the photocatalytic WGS reaction.In this study,we introduce a gas-liquid-solid triphase photocatalytic WGS reaction system.This system facilitates swift transportation of gaseous CO to the photocatalyst's surface while ensuring a consistent water supply.Among various metal-loaded TiO_(2) photocatalysts,Rh/TiO_(2) nanoparticles positioned at the triphase interface demonstrated an impressive H_(2) production rate of 27.60 mmol g^(-1) h^(-1).This rate is roughly 2 and 10 times greater than that observed in the liquid-solid and gas-solid diphase systems.Additionally,finite element simulations indicate that the concentrations of CO and H_(2)O at the gas-liquid-solid interface remain stable.This suggests that the triphase interface establishes a conducive microenvironment with sufficient CO and H_(2)O supply to the surface of photocatalysts.These insights offer a foundational approach to enhance the interfacial mass transfer of gaseous CO and liquid H_(2)O,thereby optimizing the photocatalytic WGS reaction's efficiency.展开更多
Multiphase catalysis is used in many industrial processes;however,the reaction rate can be restricted by the low accessibility of gaseous reactants to the catalysts in water,especially for oxygen-dependent biocatalyti...Multiphase catalysis is used in many industrial processes;however,the reaction rate can be restricted by the low accessibility of gaseous reactants to the catalysts in water,especially for oxygen-dependent biocatalytic reactions.Despite the fact that solubility and diffusion rates of oxygen in many liquids(such as perfluorocarbon)are much higher than in water,multiphase reactions with a second liquid phase are still difficult to conduct,because the interaction efficiency between immiscible phases is extremely low.Herein,we report an efficient triphase biocatalytic system using oil core-silica shell oxygen nanocarriers.Such design offers the biocatalytic system an extremely large water-solid-oil triphase interfacial area and a short path required for oxygen diffusion.Moreover,the silica shell stabilizes the oil nanodroplets in water and prevents their aggregation.Using oxygen-dependent oxidase enzymatic reaction as an example,we demonstrate this efficient biocatalytic system for the oxidation of glucose,choline,lactate,and sucrose by substituting their corresponding oxidase counterparts.A rate enhancement by a factor of 10-30 is observed when the oxygen nanocarriers are introduced into reaction system.This strategy offers the opportunity to enhance the efficiency of other gaseous reactants involved in multiphase catalytic reactions.展开更多
Heterogeneous structure and carbon coating are important ways to enhance the reaction kinetics and cycling stability of metal phosphides as anode materials for sodium-ion batteries.Therefore,nitrogen-doped carbon-capp...Heterogeneous structure and carbon coating are important ways to enhance the reaction kinetics and cycling stability of metal phosphides as anode materials for sodium-ion batteries.Therefore,nitrogen-doped carbon-capped triphasic heterostructure Cu_(3)P/Co_(2)P/CoP@NC stands for nitrogen doped carbon nanorods were designed and synthesized through a combination of phosphide and carbonization.Kinetic analyses(cyclic voltammetry,electrochemical impedance spectroscopy,and galvanostatic intermittent titration technique)and density functional theory calculations show that the three-phase heterostructure and carbon layer effectively improve Na adsorption and migration as well as the electrochemical reactivity of the electrode.Based on this,Cu_(3)P/Co_(2)P/CoP@NC demonstrated excellent rate performance(305.9 mAh g^(-1)at 0.3 A g^(-1)and 202.8 mAh g^(-1)even at 10 A g^(-1))and cycling stability(the capacity decay rate is only 0.12%from the 5th to 300th cycle)when it is used for sodium-ion battery anodes.The in situ X-ray diffraction,ex situ X-ray photoelectron spectroscopy,and high-resolution transmission electron microscopy tests showed that Cu_(3)P/Co_(2)P/CoP@NC is based on a conversion reaction mechanism for sodium-ion storage.In addition,the NVP@reduced graphene oxide(rGO)//Cu_(3)P/Co_(2)P/CoP@NC full-cell delivers a high capacity of 210.2 mAh g^(-1)after 50 cycles at 0.3 A g^(-1).This work can provide a reference for the design of high-performance sodium electrode anode materials.展开更多
As one of the most promising secondary batteries in large-scale energy storage,sodium ion batteries(SIBs) have attracted wide attention due to the abundant raw materials and low cost.Layered transition metal oxides ar...As one of the most promising secondary batteries in large-scale energy storage,sodium ion batteries(SIBs) have attracted wide attention due to the abundant raw materials and low cost.Layered transition metal oxides are one kind of popular cathode material candidates because of its easy synthesis and large theoretical specific capacity.Yet,the most common P2 and O3 phases show distinct structural characteristics respectively.O3 phase can serve as a sodium reservoir,but it usually suffers from serious phase transition and sluggish kinetics.For the P2 phase,it allows the fast sodium ion migration in the bulk and the structure can maintain stable,but it is lack of sodium,showing a great negative effect on Coulombic efficiency in full cell.Thus,single phase structure almost cannot achieve satisfied comprehensive sodium storage performances.Under these circumstances,exploiting novel multiphase cathodes showing synergetic effect may give solution to these problems.In this review,we summarize the recent development of multiphase layered transition metal oxide cathodes of SIBs,analyze the mechanism and prospect the future potential research directions.展开更多
The limited CO_(2)content in aqueous solution and low adsorption amount of CO_(2)on catalyst surface lead to poor photocatalytic CO_(2)reduction activity and selectivity.Herein,the design and fabrication of a novel ph...The limited CO_(2)content in aqueous solution and low adsorption amount of CO_(2)on catalyst surface lead to poor photocatalytic CO_(2)reduction activity and selectivity.Herein,the design and fabrication of a novel photocatalytic architecture is reported,accomplished via chemical vapor deposition of polymeric carbon nitride on carbon paper.The as-obtained samples with a hydrophobic surface exhibit excellent CO_(2)transport and adsorption ability,as well as the building of triphase air-liquid-solid(CO_(2)-H_(2)O-catalyst)joint interfaces,eventually resulting in the inhibition of H2 evolution and great promotion of CO_(2)reduction with a selectivity of 78.6%.The addition of phosphate to reaction environment makes further improvement of CO_(2)photoreduction into carbon fuels with a selectivity of 93.8%and an apparent quantum yield of 0.4%.This work provides new insight for constructing efficient photocatalytic architecture of CO_(2)photoreduction in aqueous solution and demonstrates that phosphate could play a key role in this process.展开更多
In this study was to investigate, by phase-transfer catalysis, the activity of single and mixed ammonium and phosphonium salts grafted on a 揼el-type?styrene-7% divinylbenzene copolymer in the oxidation of benzyl alco...In this study was to investigate, by phase-transfer catalysis, the activity of single and mixed ammonium and phosphonium salts grafted on a 揼el-type?styrene-7% divinylbenzene copolymer in the oxidation of benzyl alcohol with hydrogen peroxide. A wide variety of catalysts with different quaternary groups and different quaternary chain length substituents were examined. The activity of single 搊nium?salts increases as a consequence of the association of ammonium and phosphonium salts grafted on the same polymeric support. The activity of polymer-supported ammonium and phosphonium salts increases with the number of carbon atoms contained in the alkyl radicals of the onium and of the functionalization degree with phosphonium groups.展开更多
It is well known that subtle changes in structure and tissue composition of articular cartilage can lead to its degeneration. The present paper puts forward a modified layered inhomogeneous triphasic model with four p...It is well known that subtle changes in structure and tissue composition of articular cartilage can lead to its degeneration. The present paper puts forward a modified layered inhomogeneous triphasic model with four parameters based on the inhomogeneous triphasic model proposed by Narmoneva et al. Incorporating a piecewise fitting optimization criterion, the new model was used to obtain the uniaxial modulus Ha, and predict swelling pattern for the articular cartilage based on ultrasound-measured swelling strain data. The results show that the new method can be used to provide more accurate estimation on the uniaxial modulus than the inhomogeneous triphasic model with three parameters and the homogeneous mode, and predict effectively the swell- ing strains of highly nonuniform distribution of degenerated articular cartilages. This study can provide supplementary information for exploring mechanical and material properties of the cartilage, and thus be helpful for the diagnosis of osteoarthritis-related diseases.展开更多
The microgravity environment of a long-term space flight may induce acute changes in an astronaut＇s musculo-skeletal systems. This study explores the effects of simulated microgravity on the mechanical characteristic...The microgravity environment of a long-term space flight may induce acute changes in an astronaut＇s musculo-skeletal systems. This study explores the effects of simulated microgravity on the mechanical characteristics of articular cartilage. Six rats underwent tail suspension for 14 days and six additional rats were kept under normal earth gravity as controls. Swelling strains were measured using high-frequency ultrasound in all cartilage samples subject to osmotic loading. Site-specific swelling strain data were used in a triphasic theoretical model of cartilage swelling to determine the uniaxial modulus of the cartilage solid matrix. No severe surface irregularities were found in the cartilage samples obtained from the control or tail-suspended groups. For the tail-suspended group, the thickness of the cartilage at a specified site, as determined by ultrasound echo, showed a minor decrease. The uniaxial modulus of articular cartilage at the specified site decreased significantly, from （6.31 ± 3.37） MPa to （5.05 ± 2.98）MPa （p 〈 0.05）. The histology- stained image of a cartilage sample also showed a reduced number of chondrocytes and decreased degree of matrix staining. These results demonstrated that the 14 d simulated microgravity induced significant effects on the mechanical characteristics of articular cartilage. This study is the first attempt to explore the effects of simulated microgravity on the mechanical characteristics of articular cartilage using an osmotic loading method and a triphasic model. The conclusions may provide reference information for manned space flights and a better understanding of the effects of microgravity on the skeletal system.展开更多
Methyl methacrylate （MMA） was polymerized by using of benzoyl peroxide （BPO） and N, N-dimethylaniline （DMA） as an redox initiator in fluorous triphasic system at room temperature. The polymerization was occurred...Methyl methacrylate （MMA） was polymerized by using of benzoyl peroxide （BPO） and N, N-dimethylaniline （DMA） as an redox initiator in fluorous triphasic system at room temperature. The polymerization was occurred in both initiator layer and monomer layer in a U-tube. It was found that PMMA obtained from the initiator layer with relatively narrow polydispersity.（PDI = 1.38）展开更多
Visible-light-driven photocatalysis has great potential in environmental remediation and organic synthesis.Rational design and regulation of the reaction interfacial microenvironment is critical for photocatalytic per...Visible-light-driven photocatalysis has great potential in environmental remediation and organic synthesis.Rational design and regulation of the reaction interfacial microenvironment is critical for photocatalytic performance,yet challenging.We report here a highly efficient photocatalytic system based on hydrophobic TiO_(2) porous(H-OTP)film for visible-light-driven dye-sensitized photo-oxidation.Such interface architecture design enhances the adsorption capability of organic dyes and enables the formation of air trapped triphase reaction interface microenvironment as confirmed via three-dimensional(3D)laser scanning confocal microscopy.Based on this interface architecture,the concentrations of O_(2) and organic molecule at the local reaction zone are both significantly increased,which promotes the generation of reactive oxygen species(·O_(2)^(−)and·OH),and enhances the photocatalytic performance in terms of both kinetics and organic mineralization efficiency.This study highlights the importance of interface microenvironment design and reveals an effective way to develop highly efficient photocatalytic systems.展开更多
The exploration of high-efficiency transition metal-nitrogen-carbon(M-N-C)catalysts is crucial for accelerating the kinetics of oxygen reduction/oxygen evolution reactions(ORR/OER).Fine-tuning the distribution of acce...The exploration of high-efficiency transition metal-nitrogen-carbon(M-N-C)catalysts is crucial for accelerating the kinetics of oxygen reduction/oxygen evolution reactions(ORR/OER).Fine-tuning the distribution of accessible metal sites and the correlated triphase interfaces within the M-N-C catalysts holds significant promise.In this study,we present an integrated electrocatalyst comprised of tip-enriched NiFe nanoalloys encapsulated within N-doped carbon nanotubes(NiFe@CNTs),synthesized using an in-situ wet-electrochemistry mediated approach.The well-defined NiFe@CNTs catalyst possesses a porous heterostructure,synergistic M-N_(x)-C active sites,and intimate micro interfaces,facilitating accelerated redox kinetics.This leads to exceptional OER/ORR activities with a low overallΔE of 630 mV.Experimental results and density functional theory calculations unveil the predominant electronic interplay between the apical bimetallic sites and neighboring N-doped CNTs,thereby enhancing the binding of intermediates on NiFe@CNTs.Molecular dynamics simulations reveal that the local gas-liquid environment surrounding NiFe@CNTs favors the diffusion/adsorption of the OH-/O_(2)reactants.Consequently,NiFe@CNTs contribute to high-performance aqueous Zn-Air batteries(ZABs),exhibiting a high gravimetric energy den-sity(936 Wh kgZn-1)and superb cycling stability(>425 h)at 20 mA cm^(-2).Furthermore,solid-state ZABs based on NiFe@CNTs demonstrate impressive electrochemical performance(e.g.,peak power density of 108 mW cm-2,specific energy of 1003 Wh kgZn-1)and prominent flexibility.This work illuminates a viable strategy for constructing metal site-specific,cobalt-free,and integrated M-N-C electrocatalysts for multifunctional catalysis and advanced/flexible energy storage applications.展开更多
Photocatalysis is a promising green approach for water purification.The diversity of water pH values is a key factor that restricts its practical application since pH affects the adsorption of organic molecules,the st...Photocatalysis is a promising green approach for water purification.The diversity of water pH values is a key factor that restricts its practical application since pH affects the adsorption of organic molecules,the stability of catalysts and photocatalytic performance.Here,we report a pH–independent,efficient and stable photocatalytic system with a liquid(water)–liquid(oil)–solid(semiconductor)(L–L–S)triphase interface microenvironment.The system is fabricated by coating a thin layer of silicon oil on the surface of ZnO nanowire arrays,a model chemically unstable semiconductor in both acidic and alkaline solutions.We show that the unique interface makes the dye adsorption pH independent and prevents the semiconductor from being corroded by strong acidic/alkaline solutions,leading to a stable and efficient photocatalytic reaction over a wide pH range(1—14).These findings reveal a promising path for the development of high-performance catalysis systems applicable in complex water environments.展开更多
With exceptional capacity during high-voltage cycling,P3-type Nadeficient layered oxide cathodes have captured substantial attention.Nevertheless,they are plagued by severe capacity degradation over cycling.In this st...With exceptional capacity during high-voltage cycling,P3-type Nadeficient layered oxide cathodes have captured substantial attention.Nevertheless,they are plagued by severe capacity degradation over cycling.In this study,tuning and optimizing the phase composition in layered oxides through Li incorporation are proposed to enhance the high-voltage stability.The structural dependence of layered Na_(2/3)LixNi_(0.25)Mn_(0.75)O_(2)þδoxides on the lithium content(0.0≤x≤1.0)offered during synthesis is investigated systematically on an atomic scale.Surprisingly,increasing the Li content triggers the formation of mixed P2/O3-type or P3/P2/O3-type layered phases.As the voltage window is 1.5-4.5 V,P3-type Na2/3Ni_(0.25)Mn_(0.75)O_(2)(NL0.0NMO,R3m)material exhibits a sequence of phase transformations throughout the process of(de)sodiation,that is,O3⇌P3⇌O30⇌O3″.Such complicated phase transitions can be effectively suppressed in the Na2/3Li_(0.7)Ni_(0.25)Mn_(0.75)O_(2.4)(NL_(0.7)NMO)oxide with P2/P3/O3-type mixed phases.Consequently,cathodes made of NL0.7NMO exhibit a substantially enhanced cyclic performance at high voltages compared to that of the P3-type layered NL0.0NMO cathode.Specifically,NL0.7NMO demonstrates an outstanding capacity retention of 98%after 10 cycles at 1 C within 1.5-4.5 V,much higher than that of NL0.0NMO(83%).This work delves into the intricate realm of bolstering the high-voltage durability of layered oxide cathodes,paving the way for advanced sodium-ion battery technologies.展开更多
Developing photoelectrochemical(PEC)bioassays based on the principle of a photocathodic measurement of enzymatic product H_(2)O_(2) is highly attractive because it can naturally avoid interfering signals arising from ...Developing photoelectrochemical(PEC)bioassays based on the principle of a photocathodic measurement of enzymatic product H_(2)O_(2) is highly attractive because it can naturally avoid interfering signals arising from reductive species inherent to biofluids.However,fluctuant oxygen levels in the analyte solution can compromise the accuracy of photocathodic bioanalysis and restrict its application because oxygen reduction potential is similar to H_(2)O_(2).Herein,we addressed this restriction by constructing a triphase biophotocathode with air–liquid–solid joint interfaces by immobilizing an oxidase enzyme film on the tip part of superhydrophobic p-type semiconductor nanowire arrays.Such a triphase biophotocathode has a reaction zone with steady and air phasedependent oxygen concentration which stabilizes and increases the oxidase kinetics,and enables the photocathodic measurement principle in reliable PEC bioassay development with high selectivity,good accuracy,and a wide linear detection range.Moreover,the biophotocathode shows good stability during repeated testing under light illumination.This reliable PEC bioassay system has broad potential in the fields of disease diagnosis,medical research,and environmental monitoring.展开更多
Exploring cost-effective catalysts with high catalytic performance and long-term stability has always been a general concern for environment protection and energy conversion.Here,Au nanoparticles(NPs)embedded CuOx-CeO...Exploring cost-effective catalysts with high catalytic performance and long-term stability has always been a general concern for environment protection and energy conversion.Here,Au nanoparticles(NPs)embedded CuOx-CeO2 core/shell nanospheres(Au@CuOx-CeO2 CSNs)have been successfully prepared through a versatile one-pot method at ambient conditions.The spontaneous auto-redox reaction between HAuCl4 and Ce(OH)3 in aqueous solution triggered the self-assembly growth of micro-/nanostructural Au@CuOx-CeO2 CSNs.Meanwhile,the CuOx clusters in Au@CuOx-CeO2 CSNs are capable of improving the anti-sintering ability of Au NPs and providing synergistic catalysis benefits.As a result,the confined Au NPs exhibited extraordinary thermal stability even at a harsh thermal condition up to 700℃.In addition,before and after the severe calcination process,Au@CuOx-CeO2 CSNs can exhibit enhanced catalytic activity and excellent recyclability towards the hydrogenation of p-nitrophenol compared to previously reported nanocatalysts.The synergistic catalysis path between Au/CuOx/CeO2 triphasic interfaces was revealed by density functional theory(DFT)calculations.The CuOx clusters around the embedded Au NPs can provide moderate adsorption strength of p-nitrophenol,while the adjacent CeO2-supported Au NPs can facilitate the hydrogen dissociation to form H*species,which contributes to achieve the efficient reduction of p-nitrophenol.This study opens up new possibilities for developing high-efficient and sintering-resistant micro-/nanostructural nanocatalysts by exploiting multiphasic systems.展开更多
基金supported by the National Key Research and Development Program of China(No.2019YFC1907801)National Natural Science Foundation of China(No.52174286)+1 种基金the Science and Technology Innovation Program of Hunan Province(2021RC3014)Innovation-Driven Project of Central South University(No.2020CX007)。
文摘Efficient bifunctional catalysts for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)are vital for rechargeable Zn-air batteries(ZABs).Herein,an oxygen-respirable sponge-like Co@C–O–Cs catalyst with oxygen-rich active sites was designed and constructed for both ORR and OER by a facile carbon dot-assisted strategy.The aerophilic triphase interface of Co@C–O–Cs cathode efficiently boosts oxygen diffusion and transfer.The theoretical calculations and experimental studies revealed that the Co–C–COC active sites can redistribute the local charge density and lower the reaction energy barrier.The Co@C–O–Cs catalyst displays superior bifunctional catalytic activities with a half-wave potential of 0.82 V for ORR and an ultralow overpotential of 294 mV at 10 mA cm^(−2) for OER.Moreover,it can drive the liquid ZABs with high peak power density(106.4 mW cm^(−2)),specific capacity(720.7 mAh g^(−1)),outstanding long-term cycle stability(over 750 cycles at 10 mA cm^(−2)),and exhibits excellent feasibility in flexible all-solid-state ZABs.These findings provide new insights into the rational design of efficient bifunctional oxygen catalysts in rechargeable metal-air batteries.
文摘A series of novel catalysts was developed using cationic Gemini surfactants intercalated in natural montmorillonite (MMT) clay. These Gemini surfactant-MMT intercalates were used to study the kinetics of a nucleophilic displacement reactions converting n-butyl bromide to n-butyl chloride in a triphase catalytic (TC) system. Most reaction rates compared favorably to those of biphase catalytic reactions where Gemini surfactants were used in the absence of MMT. Catalytic activity varied with Gemini surfactant structure, specifically with carbon spacer group and side chain length. In addition to the ease of catalyst separation that a triphase system affords, Gemini-MMT catalysts are stable and can be recycled and re-used several times.
文摘A remarkable rate enhancement technique has been devised for a typical nucleophilic displacement reaction by using triphase catalytic materials based on tetraoctylammonium exchange forms of hectorite clay. Pseudo-first order rate constants (kobs) for the conversion of 1-bromobutane to the corresponding chloride under triphase conditions using the clay catalyst in the presence of various polar cosolvents have been observed. The results here have shown that the addition of a cosolvent increases the catalytic activity of the triphase system by several fold. In addition, the results have demonstrated that each cosolvent has a unique concentration for achieving an optimum reaction rate.
基金the National Key R&D Program of China(2021YFA1500803)the National Natural Science Foundation of China(51825205,52120105002,22272190,22209190,22088102)+5 种基金the Beijing Natural Science Foundation(2222035)the CAS Project for Young Scientists in Basic Research(YSBR-004)the DNL Cooperation Fund,CAS(DNL202016)the China Postdoctoral Science Foundation(2021M703288,2021T150665)the Young Elite Scientist Sponsorship Program by CAST(2021QNRC001)the Youth Innovation Promotion Association of the CAS.
文摘The exothermic characteristic of the water-gas-shift(WGS)reaction,coupled with the thermodynamic constraints at elevated temperatures,has spurred a research inclination towards conducting the WGS reaction at reduced temperatures.Nonetheless,the challenge of achieving efficient mass transfer between gaseous CO and liquid H_(2)O at the photocatalytic interface under mild reaction conditions hinders the advancement of the photocatalytic WGS reaction.In this study,we introduce a gas-liquid-solid triphase photocatalytic WGS reaction system.This system facilitates swift transportation of gaseous CO to the photocatalyst's surface while ensuring a consistent water supply.Among various metal-loaded TiO_(2) photocatalysts,Rh/TiO_(2) nanoparticles positioned at the triphase interface demonstrated an impressive H_(2) production rate of 27.60 mmol g^(-1) h^(-1).This rate is roughly 2 and 10 times greater than that observed in the liquid-solid and gas-solid diphase systems.Additionally,finite element simulations indicate that the concentrations of CO and H_(2)O at the gas-liquid-solid interface remain stable.This suggests that the triphase interface establishes a conducive microenvironment with sufficient CO and H_(2)O supply to the surface of photocatalysts.These insights offer a foundational approach to enhance the interfacial mass transfer of gaseous CO and liquid H_(2)O,thereby optimizing the photocatalytic WGS reaction's efficiency.
基金the National Key R&D Program of China(No.2019YFA0709200)the National Natural Science Foundation of China(Nos.21988102,51772198,21975171).
文摘Multiphase catalysis is used in many industrial processes;however,the reaction rate can be restricted by the low accessibility of gaseous reactants to the catalysts in water,especially for oxygen-dependent biocatalytic reactions.Despite the fact that solubility and diffusion rates of oxygen in many liquids(such as perfluorocarbon)are much higher than in water,multiphase reactions with a second liquid phase are still difficult to conduct,because the interaction efficiency between immiscible phases is extremely low.Herein,we report an efficient triphase biocatalytic system using oil core-silica shell oxygen nanocarriers.Such design offers the biocatalytic system an extremely large water-solid-oil triphase interfacial area and a short path required for oxygen diffusion.Moreover,the silica shell stabilizes the oil nanodroplets in water and prevents their aggregation.Using oxygen-dependent oxidase enzymatic reaction as an example,we demonstrate this efficient biocatalytic system for the oxidation of glucose,choline,lactate,and sucrose by substituting their corresponding oxidase counterparts.A rate enhancement by a factor of 10-30 is observed when the oxygen nanocarriers are introduced into reaction system.This strategy offers the opportunity to enhance the efficiency of other gaseous reactants involved in multiphase catalytic reactions.
基金supported by the National Natural Science Foundation of China (No. 22305210, 52371238 to C. D.)the Shandong Provincial Natural Science Foundation (No. ZR2020QB108)+1 种基金the Graduate Innovation Foundation of Yantai University (GIFYTU)the Shandong Laboratory of Advanced Materials and Green Manufacturing (Yantai, AMGM2024A01)
文摘Heterogeneous structure and carbon coating are important ways to enhance the reaction kinetics and cycling stability of metal phosphides as anode materials for sodium-ion batteries.Therefore,nitrogen-doped carbon-capped triphasic heterostructure Cu_(3)P/Co_(2)P/CoP@NC stands for nitrogen doped carbon nanorods were designed and synthesized through a combination of phosphide and carbonization.Kinetic analyses(cyclic voltammetry,electrochemical impedance spectroscopy,and galvanostatic intermittent titration technique)and density functional theory calculations show that the three-phase heterostructure and carbon layer effectively improve Na adsorption and migration as well as the electrochemical reactivity of the electrode.Based on this,Cu_(3)P/Co_(2)P/CoP@NC demonstrated excellent rate performance(305.9 mAh g^(-1)at 0.3 A g^(-1)and 202.8 mAh g^(-1)even at 10 A g^(-1))and cycling stability(the capacity decay rate is only 0.12%from the 5th to 300th cycle)when it is used for sodium-ion battery anodes.The in situ X-ray diffraction,ex situ X-ray photoelectron spectroscopy,and high-resolution transmission electron microscopy tests showed that Cu_(3)P/Co_(2)P/CoP@NC is based on a conversion reaction mechanism for sodium-ion storage.In addition,the NVP@reduced graphene oxide(rGO)//Cu_(3)P/Co_(2)P/CoP@NC full-cell delivers a high capacity of 210.2 mAh g^(-1)after 50 cycles at 0.3 A g^(-1).This work can provide a reference for the design of high-performance sodium electrode anode materials.
基金financial support from the National Key R&D Program of China(No.2018YFB0104300)National Natural Science Foundation of China(Nos.21633003,51802149 and U1801251)+1 种基金NSF of Jiangsu Province,China(No.BK20170630)the Fundamental Research Funds for the Central Universities(Nos.021314380141 and 021314380157)。
文摘As one of the most promising secondary batteries in large-scale energy storage,sodium ion batteries(SIBs) have attracted wide attention due to the abundant raw materials and low cost.Layered transition metal oxides are one kind of popular cathode material candidates because of its easy synthesis and large theoretical specific capacity.Yet,the most common P2 and O3 phases show distinct structural characteristics respectively.O3 phase can serve as a sodium reservoir,but it usually suffers from serious phase transition and sluggish kinetics.For the P2 phase,it allows the fast sodium ion migration in the bulk and the structure can maintain stable,but it is lack of sodium,showing a great negative effect on Coulombic efficiency in full cell.Thus,single phase structure almost cannot achieve satisfied comprehensive sodium storage performances.Under these circumstances,exploiting novel multiphase cathodes showing synergetic effect may give solution to these problems.In this review,we summarize the recent development of multiphase layered transition metal oxide cathodes of SIBs,analyze the mechanism and prospect the future potential research directions.
文摘The limited CO_(2)content in aqueous solution and low adsorption amount of CO_(2)on catalyst surface lead to poor photocatalytic CO_(2)reduction activity and selectivity.Herein,the design and fabrication of a novel photocatalytic architecture is reported,accomplished via chemical vapor deposition of polymeric carbon nitride on carbon paper.The as-obtained samples with a hydrophobic surface exhibit excellent CO_(2)transport and adsorption ability,as well as the building of triphase air-liquid-solid(CO_(2)-H_(2)O-catalyst)joint interfaces,eventually resulting in the inhibition of H2 evolution and great promotion of CO_(2)reduction with a selectivity of 78.6%.The addition of phosphate to reaction environment makes further improvement of CO_(2)photoreduction into carbon fuels with a selectivity of 93.8%and an apparent quantum yield of 0.4%.This work provides new insight for constructing efficient photocatalytic architecture of CO_(2)photoreduction in aqueous solution and demonstrates that phosphate could play a key role in this process.
文摘In this study was to investigate, by phase-transfer catalysis, the activity of single and mixed ammonium and phosphonium salts grafted on a 揼el-type?styrene-7% divinylbenzene copolymer in the oxidation of benzyl alcohol with hydrogen peroxide. A wide variety of catalysts with different quaternary groups and different quaternary chain length substituents were examined. The activity of single 搊nium?salts increases as a consequence of the association of ammonium and phosphonium salts grafted on the same polymeric support. The activity of polymer-supported ammonium and phosphonium salts increases with the number of carbon atoms contained in the alkyl radicals of the onium and of the functionalization degree with phosphonium groups.
基金supported by the National Natural Science Foundation of China(10772018,30872720)
文摘It is well known that subtle changes in structure and tissue composition of articular cartilage can lead to its degeneration. The present paper puts forward a modified layered inhomogeneous triphasic model with four parameters based on the inhomogeneous triphasic model proposed by Narmoneva et al. Incorporating a piecewise fitting optimization criterion, the new model was used to obtain the uniaxial modulus Ha, and predict swelling pattern for the articular cartilage based on ultrasound-measured swelling strain data. The results show that the new method can be used to provide more accurate estimation on the uniaxial modulus than the inhomogeneous triphasic model with three parameters and the homogeneous mode, and predict effectively the swell- ing strains of highly nonuniform distribution of degenerated articular cartilages. This study can provide supplementary information for exploring mechanical and material properties of the cartilage, and thus be helpful for the diagnosis of osteoarthritis-related diseases.
基金supported by the National Natural Science Foundation of China (31170896)State Key Laboratory of Software Development Environment (SKLSDE-2011ZX-11)
文摘The microgravity environment of a long-term space flight may induce acute changes in an astronaut＇s musculo-skeletal systems. This study explores the effects of simulated microgravity on the mechanical characteristics of articular cartilage. Six rats underwent tail suspension for 14 days and six additional rats were kept under normal earth gravity as controls. Swelling strains were measured using high-frequency ultrasound in all cartilage samples subject to osmotic loading. Site-specific swelling strain data were used in a triphasic theoretical model of cartilage swelling to determine the uniaxial modulus of the cartilage solid matrix. No severe surface irregularities were found in the cartilage samples obtained from the control or tail-suspended groups. For the tail-suspended group, the thickness of the cartilage at a specified site, as determined by ultrasound echo, showed a minor decrease. The uniaxial modulus of articular cartilage at the specified site decreased significantly, from （6.31 ± 3.37） MPa to （5.05 ± 2.98）MPa （p 〈 0.05）. The histology- stained image of a cartilage sample also showed a reduced number of chondrocytes and decreased degree of matrix staining. These results demonstrated that the 14 d simulated microgravity induced significant effects on the mechanical characteristics of articular cartilage. This study is the first attempt to explore the effects of simulated microgravity on the mechanical characteristics of articular cartilage using an osmotic loading method and a triphasic model. The conclusions may provide reference information for manned space flights and a better understanding of the effects of microgravity on the skeletal system.
文摘Methyl methacrylate （MMA） was polymerized by using of benzoyl peroxide （BPO） and N, N-dimethylaniline （DMA） as an redox initiator in fluorous triphasic system at room temperature. The polymerization was occurred in both initiator layer and monomer layer in a U-tube. It was found that PMMA obtained from the initiator layer with relatively narrow polydispersity.（PDI = 1.38）
基金supported by the National Key R&D Program of China(2019YFA0709200)the National Natural Science Foundation of China(21988102,51772198,21975171)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Visible-light-driven photocatalysis has great potential in environmental remediation and organic synthesis.Rational design and regulation of the reaction interfacial microenvironment is critical for photocatalytic performance,yet challenging.We report here a highly efficient photocatalytic system based on hydrophobic TiO_(2) porous(H-OTP)film for visible-light-driven dye-sensitized photo-oxidation.Such interface architecture design enhances the adsorption capability of organic dyes and enables the formation of air trapped triphase reaction interface microenvironment as confirmed via three-dimensional(3D)laser scanning confocal microscopy.Based on this interface architecture,the concentrations of O_(2) and organic molecule at the local reaction zone are both significantly increased,which promotes the generation of reactive oxygen species(·O_(2)^(−)and·OH),and enhances the photocatalytic performance in terms of both kinetics and organic mineralization efficiency.This study highlights the importance of interface microenvironment design and reveals an effective way to develop highly efficient photocatalytic systems.
基金supported by the Natural Science Foundation of Guangdong Province(No.2023A1515030131,2022A1515010476)the National Natural Science Foundation of China(22078118).
文摘The exploration of high-efficiency transition metal-nitrogen-carbon(M-N-C)catalysts is crucial for accelerating the kinetics of oxygen reduction/oxygen evolution reactions(ORR/OER).Fine-tuning the distribution of accessible metal sites and the correlated triphase interfaces within the M-N-C catalysts holds significant promise.In this study,we present an integrated electrocatalyst comprised of tip-enriched NiFe nanoalloys encapsulated within N-doped carbon nanotubes(NiFe@CNTs),synthesized using an in-situ wet-electrochemistry mediated approach.The well-defined NiFe@CNTs catalyst possesses a porous heterostructure,synergistic M-N_(x)-C active sites,and intimate micro interfaces,facilitating accelerated redox kinetics.This leads to exceptional OER/ORR activities with a low overallΔE of 630 mV.Experimental results and density functional theory calculations unveil the predominant electronic interplay between the apical bimetallic sites and neighboring N-doped CNTs,thereby enhancing the binding of intermediates on NiFe@CNTs.Molecular dynamics simulations reveal that the local gas-liquid environment surrounding NiFe@CNTs favors the diffusion/adsorption of the OH-/O_(2)reactants.Consequently,NiFe@CNTs contribute to high-performance aqueous Zn-Air batteries(ZABs),exhibiting a high gravimetric energy den-sity(936 Wh kgZn-1)and superb cycling stability(>425 h)at 20 mA cm^(-2).Furthermore,solid-state ZABs based on NiFe@CNTs demonstrate impressive electrochemical performance(e.g.,peak power density of 108 mW cm-2,specific energy of 1003 Wh kgZn-1)and prominent flexibility.This work illuminates a viable strategy for constructing metal site-specific,cobalt-free,and integrated M-N-C electrocatalysts for multifunctional catalysis and advanced/flexible energy storage applications.
基金financially supported by the National Key R&D Program of China(2019YFA0709200)the National Natural Science Foundation of China(21988102,51772198,21975171)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
基金supported by the National Key R&D Program of China(2019YFA0709200)the National Natural Science Foundation of China(21988102,51772198,21975171)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Photocatalysis is a promising green approach for water purification.The diversity of water pH values is a key factor that restricts its practical application since pH affects the adsorption of organic molecules,the stability of catalysts and photocatalytic performance.Here,we report a pH–independent,efficient and stable photocatalytic system with a liquid(water)–liquid(oil)–solid(semiconductor)(L–L–S)triphase interface microenvironment.The system is fabricated by coating a thin layer of silicon oil on the surface of ZnO nanowire arrays,a model chemically unstable semiconductor in both acidic and alkaline solutions.We show that the unique interface makes the dye adsorption pH independent and prevents the semiconductor from being corroded by strong acidic/alkaline solutions,leading to a stable and efficient photocatalytic reaction over a wide pH range(1—14).These findings reveal a promising path for the development of high-performance catalysis systems applicable in complex water environments.
基金Distinguished Young Foundation of Sichuan Province,Grant/Award Number:2020JDJQ0027National Natural Science Foundation of China,Grant/Award Numbers:22108218,20A20145,21878195+2 种基金German Research Foundation,Grant/Award Number:390874152“Young Talent Support Plan”of Xi'an Jiaotong University,Grant/Award Number:HG6J016Qinchuangyuan Innovative Talent Project,Grant/Award Number:QCYRCXM-2022-137。
文摘With exceptional capacity during high-voltage cycling,P3-type Nadeficient layered oxide cathodes have captured substantial attention.Nevertheless,they are plagued by severe capacity degradation over cycling.In this study,tuning and optimizing the phase composition in layered oxides through Li incorporation are proposed to enhance the high-voltage stability.The structural dependence of layered Na_(2/3)LixNi_(0.25)Mn_(0.75)O_(2)þδoxides on the lithium content(0.0≤x≤1.0)offered during synthesis is investigated systematically on an atomic scale.Surprisingly,increasing the Li content triggers the formation of mixed P2/O3-type or P3/P2/O3-type layered phases.As the voltage window is 1.5-4.5 V,P3-type Na2/3Ni_(0.25)Mn_(0.75)O_(2)(NL0.0NMO,R3m)material exhibits a sequence of phase transformations throughout the process of(de)sodiation,that is,O3⇌P3⇌O30⇌O3″.Such complicated phase transitions can be effectively suppressed in the Na2/3Li_(0.7)Ni_(0.25)Mn_(0.75)O_(2.4)(NL_(0.7)NMO)oxide with P2/P3/O3-type mixed phases.Consequently,cathodes made of NL0.7NMO exhibit a substantially enhanced cyclic performance at high voltages compared to that of the P3-type layered NL0.0NMO cathode.Specifically,NL0.7NMO demonstrates an outstanding capacity retention of 98%after 10 cycles at 1 C within 1.5-4.5 V,much higher than that of NL0.0NMO(83%).This work delves into the intricate realm of bolstering the high-voltage durability of layered oxide cathodes,paving the way for advanced sodium-ion battery technologies.
基金supported by the National Key R&D Program of China(no.2019YFA0709200)National Natural Science Foundation of China(nos.21988102,51772198,and 22002101).
文摘Developing photoelectrochemical(PEC)bioassays based on the principle of a photocathodic measurement of enzymatic product H_(2)O_(2) is highly attractive because it can naturally avoid interfering signals arising from reductive species inherent to biofluids.However,fluctuant oxygen levels in the analyte solution can compromise the accuracy of photocathodic bioanalysis and restrict its application because oxygen reduction potential is similar to H_(2)O_(2).Herein,we addressed this restriction by constructing a triphase biophotocathode with air–liquid–solid joint interfaces by immobilizing an oxidase enzyme film on the tip part of superhydrophobic p-type semiconductor nanowire arrays.Such a triphase biophotocathode has a reaction zone with steady and air phasedependent oxygen concentration which stabilizes and increases the oxidase kinetics,and enables the photocathodic measurement principle in reliable PEC bioassay development with high selectivity,good accuracy,and a wide linear detection range.Moreover,the biophotocathode shows good stability during repeated testing under light illumination.This reliable PEC bioassay system has broad potential in the fields of disease diagnosis,medical research,and environmental monitoring.
基金The authors are grateful for the financial support of the National Natural Science Foundation of China(Nos.21590791,21771005,21931001,and 21927901)Ministry of Science and Technology(MOST)of China(Nos.2014CB643803,2017YFA0205101,and 2017YFA0205104)+1 种基金The computational work was supported by the High-performance Computing Platform of Peking University.K.W.specifically thanks the National Postdoctoral Program for Innovative Talents under grant No.BX20190005the China Postdoctoral Science Foundation(No.2019M660293).
文摘Exploring cost-effective catalysts with high catalytic performance and long-term stability has always been a general concern for environment protection and energy conversion.Here,Au nanoparticles(NPs)embedded CuOx-CeO2 core/shell nanospheres(Au@CuOx-CeO2 CSNs)have been successfully prepared through a versatile one-pot method at ambient conditions.The spontaneous auto-redox reaction between HAuCl4 and Ce(OH)3 in aqueous solution triggered the self-assembly growth of micro-/nanostructural Au@CuOx-CeO2 CSNs.Meanwhile,the CuOx clusters in Au@CuOx-CeO2 CSNs are capable of improving the anti-sintering ability of Au NPs and providing synergistic catalysis benefits.As a result,the confined Au NPs exhibited extraordinary thermal stability even at a harsh thermal condition up to 700℃.In addition,before and after the severe calcination process,Au@CuOx-CeO2 CSNs can exhibit enhanced catalytic activity and excellent recyclability towards the hydrogenation of p-nitrophenol compared to previously reported nanocatalysts.The synergistic catalysis path between Au/CuOx/CeO2 triphasic interfaces was revealed by density functional theory(DFT)calculations.The CuOx clusters around the embedded Au NPs can provide moderate adsorption strength of p-nitrophenol,while the adjacent CeO2-supported Au NPs can facilitate the hydrogen dissociation to form H*species,which contributes to achieve the efficient reduction of p-nitrophenol.This study opens up new possibilities for developing high-efficient and sintering-resistant micro-/nanostructural nanocatalysts by exploiting multiphasic systems.
