Rechargeable magnesium-ion(Mg-ion)batteries have attracted wide attention for energy storage.However,magnesium anode is still limited by the irreversible Mg plating/stripping procedure.Herein,a well-designed binary Bi...Rechargeable magnesium-ion(Mg-ion)batteries have attracted wide attention for energy storage.However,magnesium anode is still limited by the irreversible Mg plating/stripping procedure.Herein,a well-designed binary Bi_(2)O_(3)-Bi_(2)S_(3)(BO-BS)heterostructure is fulfilled by virtue of the cooperative interface and energy band engineering targeted fast Mg-ion storage.The built-in electronic field resulting from the asymmetrical electron distribution at the interface of electron-rich S center at Bi_(2)S_(3) side and electron-poor O center at Bi_(2)O_(3) side effectively accelerates the electrochemical reaction kinetics in the Mg-ion battery system.Moreover,the as-designed heterogenous interface also benefits to maintaining the electrode integrity.With these advantages,the BO-BS electrode displays a remarkable capacity of 150.36 mAh g^(−1) at 0.67 A g^(-1) and a superior cycling stability.This investigation would offer novel insights into the rational design of functional heterogenous electrode materials targeted the fast reaction kinetics for energy storage systems.展开更多
Based on ab initio theory, the interracial spin polarization of a benzene-dithiolate molecule vertically adsorbed on a nickel surface is investigated by adopting different microscopic con- tact configurations. The res...Based on ab initio theory, the interracial spin polarization of a benzene-dithiolate molecule vertically adsorbed on a nickel surface is investigated by adopting different microscopic con- tact configurations. The results demonstrate a strong dependence of the interfacial spin polarization on the contact configuration, where the sign of spin polarization may vary from positive to negative with the change of contact configuration. By analyzing the projected density of states, an interracial orbital hybridization between the 3d orbital of the nickel atom and the sp3 hybridized orbital of the sulfur atom is observed. We also simulated the interracial adsorption in mechanically controllable break junction experiments. The magne- toresistance obtained from Julliere model is about 27% based on the calculated interracial spin polarization, which is consistent with experimental measurement.展开更多
Security risks of flammability and explosion represent major problems with the use of conventional lithium rechargeable batteries using a liquid electrolyte.The application of solid-state electrolytes could effectivel...Security risks of flammability and explosion represent major problems with the use of conventional lithium rechargeable batteries using a liquid electrolyte.The application of solid-state electrolytes could effectively help to avoid these safety concerns.However,integrating the solid-state electrolytes into the all-solid-state lithium batteries is still a huge challenge mainly due to the high interfacial resistance present in the entire battery,especially at the interface between the cathode and the solid-state electrolyte pellet and the interfaces inside the cathode.Herein,recent progress made from investigations of cathode/solid-state electrolyte interfacial behaviors including the contact problem,the interlayer diffusion issue,the space-charge layer effect,and electrochemical compatibility is presented according to the classification of oxide-,sulfide-,and polymer-based solid-state electrolytes.We also propose strategies for the construction of ideal next-generation cathode/solid-state electrolyte interfaces with high room-temperature ionic conductivity,stable interfacial contact during long cycling,free formation of the space-charge region,and good compatibility with high-voltage cathodes.展开更多
Ammonia borane(AB)is an excellent candidate for the chemical storage of hydrogen.However,its practical utilization for hydrogen production is hindered by the need for expensive noble-metal-based catalysts.Herein,we re...Ammonia borane(AB)is an excellent candidate for the chemical storage of hydrogen.However,its practical utilization for hydrogen production is hindered by the need for expensive noble-metal-based catalysts.Herein,we report Co-Co3O4 nanoparticles(NPs)facilely deposited on carbon dots(CDs)as a highly efficient,robust,and noble-metal-free catalyst for the hydrolysis of AB.The incorporation of the multiinterfaces between Co,Co3O4 NPs,and CDs endows this hybrid material with excellent catalytic activity(rB=6816 mLH2 min^-1 gCo^-1)exceeding that of previous non-noble-metal NP systems and even that of some noble-metal NP systems.A further mechanistic study suggests that these interfacial interactions can affect the electronic structures of interfacial atoms and provide abundant adsorption sites for AB and water molecules,resulting in a low energy barrier for the activation of reactive molecules and thus substantial improvement of the catalytic rate.展开更多
There has been much interest in developing multilayered or nanolayered physical vapor deposition（PVD） coatings identified as a group of promising protective coatings for their excellent mechanical properties and cor...There has been much interest in developing multilayered or nanolayered physical vapor deposition（PVD） coatings identified as a group of promising protective coatings for their excellent mechanical properties and corrosion resistance. In this study, the multilayered Cr N/Cr2O3 coatings with different bilayer periods（L） were synthesized on the polished high speed steel substrates from a Cr target with the alternative atmosphere of pure nitrogen and pure oxygen by arc ion plating（AIP） technique. The results revealed that the microstructure,morphologies and properties of the multilayered coatings were strongly influenced by the bilayer period（L）.There were two kinds of interfaces in the multilayered Cr N/Cr2O3coatings： the sharp ones and the blurry ones. With reducing the value of L, the macro-particles densities decreased gradually, whereas the coating microhardness, adhesive strength and wear resistance first increased, and then decreased slightly or remained stable as the bilayer period L 〈 590 nm. The multilayered Cr N/Cr2O3 coating with the bilayer period L of 590 nm possessed the best comprehensive properties, namely the highest microhardness, the strongest adhesion, and the lowest wear rate.展开更多
Herein,a bottom-down design is presented to successfully fabricate ZIF-derived Co3O4,grown in situ on a one-dimensional(1D)α-MnO2 material,denoted as α-MnO2@Co3O4.The synergistic effect derived from the coupled inte...Herein,a bottom-down design is presented to successfully fabricate ZIF-derived Co3O4,grown in situ on a one-dimensional(1D)α-MnO2 material,denoted as α-MnO2@Co3O4.The synergistic effect derived from the coupled interface constructed betweenα-MnO2 and Co3O4 is responsible for the enhanced catalytic activity.The resultantα-MnO2@Co3O4 catalyst exhibits excellent catalytic activity at a T90%(temperature required to achieve a toluene conversion of 90%)of approximately 229℃,which is 47 and 28℃ lower than those of the pureα-MnO2 nanowire and Co3O4-b obtained via pyrolysis of ZIF-67,respectively.This activity is attributed to the increase in the number of surface-adsorbed oxygen species,which accelerate the oxygen mobility and enhance the redox pairs of Mn^4+/Mn^3+ and Co^2+/Co^3+.Moreover,the result of in situ diffuse reflectance infrared Fourier transform spectroscopy suggests that the gaseous oxygen could be more easily activated to adsorbed oxygen species on the surface of α-MnO2@Co3O4 than on that of α-MnO2.The catalytic reaction route of toluene oxidation over theα-MnO2@Co3O4 catalyst is as follows:toluene→benzoate species→alkanes containing oxygen functional group→CO2 and H2O.In addition,the α-MnO2@Co3O4 catalyst shows excellent stability and good water resistance for toluene oxidation.Furthermore,the preparation method can be extended to other 1D MnO2 materials.A new strategy for the development of high-performance catalysts of practical significance is provided.展开更多
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
The microstructural characteristic of 1070AI matrix composites reinforced by 0.15 祄 AI2O3 particles whose volume fraction was 40% was investigated by TEM and HREM. The results showed that the interface between the ma...The microstructural characteristic of 1070AI matrix composites reinforced by 0.15 祄 AI2O3 particles whose volume fraction was 40% was investigated by TEM and HREM. The results showed that the interface between the matrix and reinforcements was clean and bonded well, without any interfacial reaction products. There were some preferential crystallographic orientation relationships between Al matrix and AI2O3 particle because of the lattice imperfection on the surface of Al2O3 particles.展开更多
The correlation between surface complexation at the SiO_(2)H_(2)O interface and quartz notation behavior was studied.Computer assisted calculations,using the programs SOLGASWATER,were adapted in order to con-struct di...The correlation between surface complexation at the SiO_(2)H_(2)O interface and quartz notation behavior was studied.Computer assisted calculations,using the programs SOLGASWATER,were adapted in order to con-struct distribution diagrams of surface speciation in the SiO_(2)-metal ion-H^(+) system in aqueous solutions.Equilib-rium constants for both surface and solution reactions were introduced in the composition matrix.Surface complexation,surface charge as well as notation results were compared and a good agreement was obtained.Furthermore,flotation mechanisms of quartz activation by common metal ions like Ca^(2+),Mg^(2+),Fe^(2+) are quantitatively discussed based on the surface reaction equilibrium constants.展开更多
Intrinsic hydrogenated amorphous silicon（a-Si：H） film is deposited on n-type crystalline silicon（c-Si） wafer by hotwire chemical vapor deposition（HWCVD） to analyze the amorphous/crystalline heterointerface pass...Intrinsic hydrogenated amorphous silicon（a-Si：H） film is deposited on n-type crystalline silicon（c-Si） wafer by hotwire chemical vapor deposition（HWCVD） to analyze the amorphous/crystalline heterointerface passivation properties.The minority carrier lifetime of symmetric heterostructure is measured by using Sinton Consulting WCT-120 lifetime tester system,and a simple method of determining the interface state density（D_（it）） from lifetime measurement is proposed.The interface state density（D_（it）） measurement is also performed by using deep-level transient spectroscopy（DLTS） to prove the validity of the simple method.The microstructures and hydrogen bonding configurations of a-Si：H films with different hydrogen dilutions are investigated by using spectroscopic ellipsometry（SE） and Fourier transform infrared spectroscopy（FTIR） respectively.Lower values of interface state density（D_（it）） are obtained by using a-Si：H film with more uniform,compact microstructures and fewer bulk defects on crystalline silicon deposited by HWCVD.展开更多
Interfacial structures and interactions of two-dimensional(2D)materials on solid substrates are of fundamental importance for fabrications and applications of 2D materials.However,selection of a suitable solid substra...Interfacial structures and interactions of two-dimensional(2D)materials on solid substrates are of fundamental importance for fabrications and applications of 2D materials.However,selection of a suitable solid substrate to grow a 2D material,determination and control of 2D material-substrate interface remain a big challenge due to the large diversity of possible configurations.Here,we propose a computational framework to select an appropriate substrate for epitaxial growth of 2D material and to predict possible 2D material-substrate interface structures and orientations using density functional theory calculations performed for all non-equivalent atomic structures satisfying the symmetry constraints.The approach is validated by the correct prediction of three experimentally reported 2D material-substrate interface systems with only the given information of two parent materials.Several possible interface configurations are also proposed based on this approach.We therefore construct a database that contains these interface systems and has been continuously expanding.This database serves as preliminary guidance for epitaxial growth and stabilization of new materials in experiments.展开更多
The film forming behavior on the interface between air and hydrosol of Fe2O3 nanoparticles was investigated by the surface pressure-time isotherms, the surface pressure-trough area isotherms, Brewster angle microscopy...The film forming behavior on the interface between air and hydrosol of Fe2O3 nanoparticles was investigated by the surface pressure-time isotherms, the surface pressure-trough area isotherms, Brewster angle microscopy and transmission electron microscopy. It is found that the freshly prepared hydrosol of Fe2O3 nanoparticles is not stable. The surface pressure increases with the aging time and finally approaches a constant, and the smaller the concentration is, the smaller the surface pressure is stabilized at and the shorter the time the hydrosol reaching stable needs. The surface pressure also increases with compression until collapsed, and the longer the hydrosol is aged, the higher the collapsing pressure is. A uniform and compact film composed of nanoparticles with an average diameter of about 2-3 nm on the air-hydrosol interface is observed by Brewster angle microscope and transmission electron microscope.展开更多
Frequency dependent conductance measurements are implemented to investigate the interface states in Al2O3/A1GaN/GaN metal-oxide-semiconductor （MOS） structures. Two types of device structures, namely, the recessed ga...Frequency dependent conductance measurements are implemented to investigate the interface states in Al2O3/A1GaN/GaN metal-oxide-semiconductor （MOS） structures. Two types of device structures, namely, the recessed gate structure （RGS） and the normal gate structure （NGS）, are studied in the experiment. Interface trap parameters includ-ing trap density Dit, trap time constant ιit, and trap state energy ET in both devices have been determined. Furthermore, the obtained results demonstrate that the gate recess process can induce extra traps with shallower energy levels at the Al2O3/AlGaN interface due to the damage on the surface of the AlGaN barrier layer resulting from reactive ion etching （RIE）.展开更多
Solar-driven H_(2)O_(2) production through artificial photosynthesis presents a promising alternative to anthraquinone,given its lower energy consumption and eco-friendly nature[1-3].However,its catalytic performance ...Solar-driven H_(2)O_(2) production through artificial photosynthesis presents a promising alternative to anthraquinone,given its lower energy consumption and eco-friendly nature[1-3].However,its catalytic performance is severely restricted by the inefficient separation of photogenerated carriers and interface reactions[4,5].展开更多
The distributions of traps and electron density in the interfaces between polyimide （PI） matrix and Al2O3 nanoparticles are researched using the isothermal decay current and the small-angle x-ray scattering （SAXS）...The distributions of traps and electron density in the interfaces between polyimide （PI） matrix and Al2O3 nanoparticles are researched using the isothermal decay current and the small-angle x-ray scattering （SAXS） tests. According to the electron density distribution for quasi two-phase mixture doped by spherical nanoparticles, the electron densities in the interfaces of PI/Al2O3 nanocomposite films are evaluated. The trap level density and carrier mobility in the interface are studied. The experimental results show that the distribution and the change rate of the electron density in the three layers of interface are different, indicating different trap distributions in the interface layers. There is a maximum trap level density in the second layer, where the maximum trap level density for the nanocomposite film doped by 25 wt% is 1.054 × 10^22 eV·m^-3 at 1.324eV, resulting in the carrier mobility reducing. In addition, both the thickness and the electron density of the nanocomposite film interface increase with the addition of the doped Al2O3 contents. Through the study on the trap level distribution in the interface, it is possible to further analyze the insulation mechanism and to improve the performance of nano-dielectric materials.展开更多
The ineluctable introduction of lithium salt to polymer solid-state electrolytes incurs a compromise between strength,ionic conductivity,and thickness.Here,we propose Al_(2)O_(3)-coated polyimide(AO/PI)porous film as ...The ineluctable introduction of lithium salt to polymer solid-state electrolytes incurs a compromise between strength,ionic conductivity,and thickness.Here,we propose Al_(2)O_(3)-coated polyimide(AO/PI)porous film as a high-strength substrate to support fast-ion-conducting polymer-in-salt(PIS)solid-state electrolytes,aiming to suppress lithium dendrite growth and improve full-cell performance.The Al_(2)O_(3)coating layer not only refines the wettability of polyimide porous film to PIS,but also performs as a high modulus protective layer to suppress the growth of lithium dendrites.The resulting PI/AO@PIS exhibits a small thickness of only 35μm with an outstanding tensile strength of 11.3 MPa and Young's modulus of 537.6 MPa.In addition,the PI/AO@PIS delivers a high ionic conductivity of 0.1 m S/cm at 25°C.As a result,the PI/AO@PIS enables symmetric Li cells to achieve exceptional cyclability for over 1000 h at 0.1 m A/cm2without noticeable lithium dendrite formation.Moreover,the PI/AO@PIS-based LiFePO4||Li full cells demonstrate outstanding rate performance(125.7 m Ah/g at 5 C)and impressive cycling stability(96.1%capacity retention at 1 C after 200 cycles).This work highlights the efficacy of enhancing the mechanical properties of polymer matrices and extending cell performance through the incorporation of a dense inorganic interface layer.展开更多
Degrading volatile organic compounds at low temperatures and active sites aggregation are still challenging.In this study,a novel mesoporous zeolite silicalite-1(S-1–meso)enveloped Pt–Ni bimetallic catalysts(noted a...Degrading volatile organic compounds at low temperatures and active sites aggregation are still challenging.In this study,a novel mesoporous zeolite silicalite-1(S-1–meso)enveloped Pt–Ni bimetallic catalysts(noted as Pt1Ni1@S-1–meso)were synthesized via a facile in situ mesoporous template-free method.The Pt–Ni bimetallic nanoparticles were uniformly distributed and displayed a large specific surface area and enriched mesopores to facilitate the deep oxidation of toluene.The presence of the Pt–Ni O interface both increased the dispersion of the catalyst and improved its catalytic performance,thereby reducing the consumption of Pt.The Mars-van Krevelen mechanism and density function theory(DFT)calculations revealed that the Pt–Ni O interface effect changed the electronic structure of Pt and Ni species,reduced the activation potential for oxygen,formed reactive oxygen species,and facilitated the adsorption and activation of reactants in the direction favorable to the toluene oxidation.This study provides a guideline for minimizing the proportion of precious metals used in practical applications and a promising method for toluene elimination at low temperatures.展开更多
ZnO with good lithiophilicity has widely been employed to modify the lithiophobic substrates and facilitate uniform lithium(Li)deposition.The overpotential of ZnO-derived Li anode during cycling depends on the lithiop...ZnO with good lithiophilicity has widely been employed to modify the lithiophobic substrates and facilitate uniform lithium(Li)deposition.The overpotential of ZnO-derived Li anode during cycling depends on the lithiophilicity of both LiZn and Li_(2)O products upon lithiation of ZnO.However,the striking differences in the lithiophilicity between Li_(2)O and LiZn would result in a high overpotential during cycling.In this research,the Al_(2)O_(3)/nZnO(n≥1)hybrid layers were precisely fabricated by atomic layer deposition(ALD)to regulate the lithiophilicity of ZnO phase and Li_(2)O/LiZn configuration—determining the actual Li loading amount and Li plating/stripping processes.Theoretically,the Li adsorption energy(E_(a))values of LiZn and Li_(2)O in the LiZn/Li_(2)O configuration are separately predicted as-2.789 and-3.447 eV.In comparison,the E_(a) values of LiZn,LiAlO_(2),and Li_(2)O in the LiZn/LiAlO_(2)/Li_(2)O configuration upon lithiation of Al_(2)O_(3)/8ZnO layer are calculated as-2.899,-3.089,and-3.208 eV,respectively.Importantly,a novel introduction of LiAlO_(2)into the LiZn/Li_(2)O configuration could enable the hierarchical Li plating/stripping and reduce the overpotentials during cycling.Consequently,the Al_(2)O_(3)/8ZnO-derived hybrid Li-metal anode could exhibit electrochemical performances superior to these of ZnO-derived Li anode in both symmetrical and full cells paired with a LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cathode.展开更多
The transfer of Sr^2+ and Ba^2+ ion,facilitated by 18-crown-6 present in the aqueous phase,and of succinylcholine ion at w/nb interface were investigated by semi-differeniial cyclic voltammetry.A good polarographic cu...The transfer of Sr^2+ and Ba^2+ ion,facilitated by 18-crown-6 present in the aqueous phase,and of succinylcholine ion at w/nb interface were investigated by semi-differeniial cyclic voltammetry.A good polarographic curve of succinylcholine ion dissolved in water was obtained in the system of 0.01 mol/l LiCl(w)-0.01mol/l TBATPB(nb).The peak current is directly proportional to the concentration of SC^2+ ion.It can be used for the determination of SC and the detection limit is 1.05×10^-5mol/l,The apparent D^m and D^mb have been estimated.The transfer of Sr^2+ and of Ba^2+ at the interface are facilitated by 18-Crown-6 present in the aqueous phase and the peak current is directly proportional to the concentration of 18-Crown-6 in water.This method can be used for the determination of the complexing agent and for the stability constant of the complex formed in the aqueous phase.All the experimental results are in keeping with the theoretical.展开更多
基金supported by the National Natural Science Foundation of China(52172239)Project of State Key Laboratory of Environment-Friendly Energy Materials(SWUST,Grant Nos.22fksy23 and 18ZD320304)+3 种基金the Frontier Project of Chengdu Tianfu New Area Institute(SWUST,Grand No.2022ZY017)Chongqing Talents:Exceptional Young Talents Project(Grant No.CQYC201905041)Natural Science Foundation of Chongqing China(Grant No.cstc2021jcyj-jqX0031)Interdiscipline Team Project under auspices of“Light of West”Program in Chinese Academy of Sciences(Grant No.xbzg-zdsys-202106).
文摘Rechargeable magnesium-ion(Mg-ion)batteries have attracted wide attention for energy storage.However,magnesium anode is still limited by the irreversible Mg plating/stripping procedure.Herein,a well-designed binary Bi_(2)O_(3)-Bi_(2)S_(3)(BO-BS)heterostructure is fulfilled by virtue of the cooperative interface and energy band engineering targeted fast Mg-ion storage.The built-in electronic field resulting from the asymmetrical electron distribution at the interface of electron-rich S center at Bi_(2)S_(3) side and electron-poor O center at Bi_(2)O_(3) side effectively accelerates the electrochemical reaction kinetics in the Mg-ion battery system.Moreover,the as-designed heterogenous interface also benefits to maintaining the electrode integrity.With these advantages,the BO-BS electrode displays a remarkable capacity of 150.36 mAh g^(−1) at 0.67 A g^(-1) and a superior cycling stability.This investigation would offer novel insights into the rational design of functional heterogenous electrode materials targeted the fast reaction kinetics for energy storage systems.
文摘Based on ab initio theory, the interracial spin polarization of a benzene-dithiolate molecule vertically adsorbed on a nickel surface is investigated by adopting different microscopic con- tact configurations. The results demonstrate a strong dependence of the interfacial spin polarization on the contact configuration, where the sign of spin polarization may vary from positive to negative with the change of contact configuration. By analyzing the projected density of states, an interracial orbital hybridization between the 3d orbital of the nickel atom and the sp3 hybridized orbital of the sulfur atom is observed. We also simulated the interracial adsorption in mechanically controllable break junction experiments. The magne- toresistance obtained from Julliere model is about 27% based on the calculated interracial spin polarization, which is consistent with experimental measurement.
基金National Natural Science Foundation of China(U2001220)the Local Innovative Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01N111)+1 种基金the Shenzhen Technical Plan Project(Nos.JCYJ20180508152210821,JCYJ20170817161221958,and JCYJ20180508152135822)the Shenzhen All-Solid-State Lithium Battery Electrolyte Engineering Research Center(XMHT20200203006).
文摘Security risks of flammability and explosion represent major problems with the use of conventional lithium rechargeable batteries using a liquid electrolyte.The application of solid-state electrolytes could effectively help to avoid these safety concerns.However,integrating the solid-state electrolytes into the all-solid-state lithium batteries is still a huge challenge mainly due to the high interfacial resistance present in the entire battery,especially at the interface between the cathode and the solid-state electrolyte pellet and the interfaces inside the cathode.Herein,recent progress made from investigations of cathode/solid-state electrolyte interfacial behaviors including the contact problem,the interlayer diffusion issue,the space-charge layer effect,and electrochemical compatibility is presented according to the classification of oxide-,sulfide-,and polymer-based solid-state electrolytes.We also propose strategies for the construction of ideal next-generation cathode/solid-state electrolyte interfaces with high room-temperature ionic conductivity,stable interfacial contact during long cycling,free formation of the space-charge region,and good compatibility with high-voltage cathodes.
基金financially supported by the National Natural Science Foundation of China(21774041 and 51433003)the China Postdoctoral Science Foundation(2018M640681 and 2019T120632)。
文摘Ammonia borane(AB)is an excellent candidate for the chemical storage of hydrogen.However,its practical utilization for hydrogen production is hindered by the need for expensive noble-metal-based catalysts.Herein,we report Co-Co3O4 nanoparticles(NPs)facilely deposited on carbon dots(CDs)as a highly efficient,robust,and noble-metal-free catalyst for the hydrolysis of AB.The incorporation of the multiinterfaces between Co,Co3O4 NPs,and CDs endows this hybrid material with excellent catalytic activity(rB=6816 mLH2 min^-1 gCo^-1)exceeding that of previous non-noble-metal NP systems and even that of some noble-metal NP systems.A further mechanistic study suggests that these interfacial interactions can affect the electronic structures of interfacial atoms and provide abundant adsorption sites for AB and water molecules,resulting in a low energy barrier for the activation of reactive molecules and thus substantial improvement of the catalytic rate.
基金financial supports from the National Key Basic Research Program of China (973 Program, No. 2012CB625100)the National Natural Science Foundation of China (Nos. 51001106 and 51301181)the Doctoral Starting up Foundation of Liaoning Province Science and Technology Agency, China (No. 20131118)
文摘There has been much interest in developing multilayered or nanolayered physical vapor deposition（PVD） coatings identified as a group of promising protective coatings for their excellent mechanical properties and corrosion resistance. In this study, the multilayered Cr N/Cr2O3 coatings with different bilayer periods（L） were synthesized on the polished high speed steel substrates from a Cr target with the alternative atmosphere of pure nitrogen and pure oxygen by arc ion plating（AIP） technique. The results revealed that the microstructure,morphologies and properties of the multilayered coatings were strongly influenced by the bilayer period（L）.There were two kinds of interfaces in the multilayered Cr N/Cr2O3coatings： the sharp ones and the blurry ones. With reducing the value of L, the macro-particles densities decreased gradually, whereas the coating microhardness, adhesive strength and wear resistance first increased, and then decreased slightly or remained stable as the bilayer period L 〈 590 nm. The multilayered Cr N/Cr2O3 coating with the bilayer period L of 590 nm possessed the best comprehensive properties, namely the highest microhardness, the strongest adhesion, and the lowest wear rate.
文摘Herein,a bottom-down design is presented to successfully fabricate ZIF-derived Co3O4,grown in situ on a one-dimensional(1D)α-MnO2 material,denoted as α-MnO2@Co3O4.The synergistic effect derived from the coupled interface constructed betweenα-MnO2 and Co3O4 is responsible for the enhanced catalytic activity.The resultantα-MnO2@Co3O4 catalyst exhibits excellent catalytic activity at a T90%(temperature required to achieve a toluene conversion of 90%)of approximately 229℃,which is 47 and 28℃ lower than those of the pureα-MnO2 nanowire and Co3O4-b obtained via pyrolysis of ZIF-67,respectively.This activity is attributed to the increase in the number of surface-adsorbed oxygen species,which accelerate the oxygen mobility and enhance the redox pairs of Mn^4+/Mn^3+ and Co^2+/Co^3+.Moreover,the result of in situ diffuse reflectance infrared Fourier transform spectroscopy suggests that the gaseous oxygen could be more easily activated to adsorbed oxygen species on the surface of α-MnO2@Co3O4 than on that of α-MnO2.The catalytic reaction route of toluene oxidation over theα-MnO2@Co3O4 catalyst is as follows:toluene→benzoate species→alkanes containing oxygen functional group→CO2 and H2O.In addition,the α-MnO2@Co3O4 catalyst shows excellent stability and good water resistance for toluene oxidation.Furthermore,the preparation method can be extended to other 1D MnO2 materials.A new strategy for the development of high-performance catalysts of practical significance is provided.
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.
基金This research is supported by the National Natural Science Foundation of China (under Grant No.59771014 and No.50071019). The help of the National Advanced Material Open Research Lab of Tsinghua University is gratefully acknowledged.
文摘The microstructural characteristic of 1070AI matrix composites reinforced by 0.15 祄 AI2O3 particles whose volume fraction was 40% was investigated by TEM and HREM. The results showed that the interface between the matrix and reinforcements was clean and bonded well, without any interfacial reaction products. There were some preferential crystallographic orientation relationships between Al matrix and AI2O3 particle because of the lattice imperfection on the surface of Al2O3 particles.
文摘The correlation between surface complexation at the SiO_(2)H_(2)O interface and quartz notation behavior was studied.Computer assisted calculations,using the programs SOLGASWATER,were adapted in order to con-struct distribution diagrams of surface speciation in the SiO_(2)-metal ion-H^(+) system in aqueous solutions.Equilib-rium constants for both surface and solution reactions were introduced in the composition matrix.Surface complexation,surface charge as well as notation results were compared and a good agreement was obtained.Furthermore,flotation mechanisms of quartz activation by common metal ions like Ca^(2+),Mg^(2+),Fe^(2+) are quantitatively discussed based on the surface reaction equilibrium constants.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51361022 and 61574072)the Postdoctoral Science Foundation of Jiangxi Province,China(Grant No.2015KY12)
文摘Intrinsic hydrogenated amorphous silicon（a-Si：H） film is deposited on n-type crystalline silicon（c-Si） wafer by hotwire chemical vapor deposition（HWCVD） to analyze the amorphous/crystalline heterointerface passivation properties.The minority carrier lifetime of symmetric heterostructure is measured by using Sinton Consulting WCT-120 lifetime tester system,and a simple method of determining the interface state density（D_（it）） from lifetime measurement is proposed.The interface state density（D_（it）） measurement is also performed by using deep-level transient spectroscopy（DLTS） to prove the validity of the simple method.The microstructures and hydrogen bonding configurations of a-Si：H films with different hydrogen dilutions are investigated by using spectroscopic ellipsometry（SE） and Fourier transform infrared spectroscopy（FTIR） respectively.Lower values of interface state density（D_（it）） are obtained by using a-Si：H film with more uniform,compact microstructures and fewer bulk defects on crystalline silicon deposited by HWCVD.
基金Supported by the National Key R&D program of China(Grant Nos.2019YFA0308500,2020YFA0308800,and 2016YFA0202300)the National Natural Science Foundation of China(Grant Nos.51922011,61888102,and 11974045)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDB30000000 and XDB28000000)Beijing Institute of Technology Research Fund Program for Young Scholarsthe Fundamental Research Funds for the Central Universities。
文摘Interfacial structures and interactions of two-dimensional(2D)materials on solid substrates are of fundamental importance for fabrications and applications of 2D materials.However,selection of a suitable solid substrate to grow a 2D material,determination and control of 2D material-substrate interface remain a big challenge due to the large diversity of possible configurations.Here,we propose a computational framework to select an appropriate substrate for epitaxial growth of 2D material and to predict possible 2D material-substrate interface structures and orientations using density functional theory calculations performed for all non-equivalent atomic structures satisfying the symmetry constraints.The approach is validated by the correct prediction of three experimentally reported 2D material-substrate interface systems with only the given information of two parent materials.Several possible interface configurations are also proposed based on this approach.We therefore construct a database that contains these interface systems and has been continuously expanding.This database serves as preliminary guidance for epitaxial growth and stabilization of new materials in experiments.
基金Funded by the National Natural Science Foundation of China (50672089)the Encouraging Foundation for the Scientific Research of the Excellent Young and Middleaged Scientists in Shandong Province(2006BS04034)
文摘The film forming behavior on the interface between air and hydrosol of Fe2O3 nanoparticles was investigated by the surface pressure-time isotherms, the surface pressure-trough area isotherms, Brewster angle microscopy and transmission electron microscopy. It is found that the freshly prepared hydrosol of Fe2O3 nanoparticles is not stable. The surface pressure increases with the aging time and finally approaches a constant, and the smaller the concentration is, the smaller the surface pressure is stabilized at and the shorter the time the hydrosol reaching stable needs. The surface pressure also increases with compression until collapsed, and the longer the hydrosol is aged, the higher the collapsing pressure is. A uniform and compact film composed of nanoparticles with an average diameter of about 2-3 nm on the air-hydrosol interface is observed by Brewster angle microscope and transmission electron microscope.
基金Project supported by the National Basic Research Program of China(Grant No.2011CBA00606)
文摘Frequency dependent conductance measurements are implemented to investigate the interface states in Al2O3/A1GaN/GaN metal-oxide-semiconductor （MOS） structures. Two types of device structures, namely, the recessed gate structure （RGS） and the normal gate structure （NGS）, are studied in the experiment. Interface trap parameters includ-ing trap density Dit, trap time constant ιit, and trap state energy ET in both devices have been determined. Furthermore, the obtained results demonstrate that the gate recess process can induce extra traps with shallower energy levels at the Al2O3/AlGaN interface due to the damage on the surface of the AlGaN barrier layer resulting from reactive ion etching （RIE）.
文摘Solar-driven H_(2)O_(2) production through artificial photosynthesis presents a promising alternative to anthraquinone,given its lower energy consumption and eco-friendly nature[1-3].However,its catalytic performance is severely restricted by the inefficient separation of photogenerated carriers and interface reactions[4,5].
基金Supported by the National Natural Science Foundation of China under Grant Nos 51337002,51077028,51502063 and 51307046the Foundation of Harbin Science and Technology Bureau of Heilongjiang Province under Grant No RC2014QN017034
文摘The distributions of traps and electron density in the interfaces between polyimide （PI） matrix and Al2O3 nanoparticles are researched using the isothermal decay current and the small-angle x-ray scattering （SAXS） tests. According to the electron density distribution for quasi two-phase mixture doped by spherical nanoparticles, the electron densities in the interfaces of PI/Al2O3 nanocomposite films are evaluated. The trap level density and carrier mobility in the interface are studied. The experimental results show that the distribution and the change rate of the electron density in the three layers of interface are different, indicating different trap distributions in the interface layers. There is a maximum trap level density in the second layer, where the maximum trap level density for the nanocomposite film doped by 25 wt% is 1.054 × 10^22 eV·m^-3 at 1.324eV, resulting in the carrier mobility reducing. In addition, both the thickness and the electron density of the nanocomposite film interface increase with the addition of the doped Al2O3 contents. Through the study on the trap level distribution in the interface, it is possible to further analyze the insulation mechanism and to improve the performance of nano-dielectric materials.
基金the financial support from the 261Project of MIIT and Natural Science Foundation of Jiangsu Province(No.BK20240179)。
文摘The ineluctable introduction of lithium salt to polymer solid-state electrolytes incurs a compromise between strength,ionic conductivity,and thickness.Here,we propose Al_(2)O_(3)-coated polyimide(AO/PI)porous film as a high-strength substrate to support fast-ion-conducting polymer-in-salt(PIS)solid-state electrolytes,aiming to suppress lithium dendrite growth and improve full-cell performance.The Al_(2)O_(3)coating layer not only refines the wettability of polyimide porous film to PIS,but also performs as a high modulus protective layer to suppress the growth of lithium dendrites.The resulting PI/AO@PIS exhibits a small thickness of only 35μm with an outstanding tensile strength of 11.3 MPa and Young's modulus of 537.6 MPa.In addition,the PI/AO@PIS delivers a high ionic conductivity of 0.1 m S/cm at 25°C.As a result,the PI/AO@PIS enables symmetric Li cells to achieve exceptional cyclability for over 1000 h at 0.1 m A/cm2without noticeable lithium dendrite formation.Moreover,the PI/AO@PIS-based LiFePO4||Li full cells demonstrate outstanding rate performance(125.7 m Ah/g at 5 C)and impressive cycling stability(96.1%capacity retention at 1 C after 200 cycles).This work highlights the efficacy of enhancing the mechanical properties of polymer matrices and extending cell performance through the incorporation of a dense inorganic interface layer.
基金supported by the National Natural Science Foundation of China(Nos.22276086,21976078)the Natural Science Foundation of Jiangxi Province(Nos.20202ACB213001,20232BCJ22003)。
文摘Degrading volatile organic compounds at low temperatures and active sites aggregation are still challenging.In this study,a novel mesoporous zeolite silicalite-1(S-1–meso)enveloped Pt–Ni bimetallic catalysts(noted as Pt1Ni1@S-1–meso)were synthesized via a facile in situ mesoporous template-free method.The Pt–Ni bimetallic nanoparticles were uniformly distributed and displayed a large specific surface area and enriched mesopores to facilitate the deep oxidation of toluene.The presence of the Pt–Ni O interface both increased the dispersion of the catalyst and improved its catalytic performance,thereby reducing the consumption of Pt.The Mars-van Krevelen mechanism and density function theory(DFT)calculations revealed that the Pt–Ni O interface effect changed the electronic structure of Pt and Ni species,reduced the activation potential for oxygen,formed reactive oxygen species,and facilitated the adsorption and activation of reactants in the direction favorable to the toluene oxidation.This study provides a guideline for minimizing the proportion of precious metals used in practical applications and a promising method for toluene elimination at low temperatures.
基金supported by the National Key Research and Development Program of China(2021YFB2400202)the National Natural Science Foundation of China(52104313)+1 种基金the Key Research and Development Plan of Shaanxi(2024GH-YBXM-11)the Foshan Science and Technology Innovation Team Project(1920001004098).
文摘ZnO with good lithiophilicity has widely been employed to modify the lithiophobic substrates and facilitate uniform lithium(Li)deposition.The overpotential of ZnO-derived Li anode during cycling depends on the lithiophilicity of both LiZn and Li_(2)O products upon lithiation of ZnO.However,the striking differences in the lithiophilicity between Li_(2)O and LiZn would result in a high overpotential during cycling.In this research,the Al_(2)O_(3)/nZnO(n≥1)hybrid layers were precisely fabricated by atomic layer deposition(ALD)to regulate the lithiophilicity of ZnO phase and Li_(2)O/LiZn configuration—determining the actual Li loading amount and Li plating/stripping processes.Theoretically,the Li adsorption energy(E_(a))values of LiZn and Li_(2)O in the LiZn/Li_(2)O configuration are separately predicted as-2.789 and-3.447 eV.In comparison,the E_(a) values of LiZn,LiAlO_(2),and Li_(2)O in the LiZn/LiAlO_(2)/Li_(2)O configuration upon lithiation of Al_(2)O_(3)/8ZnO layer are calculated as-2.899,-3.089,and-3.208 eV,respectively.Importantly,a novel introduction of LiAlO_(2)into the LiZn/Li_(2)O configuration could enable the hierarchical Li plating/stripping and reduce the overpotentials during cycling.Consequently,the Al_(2)O_(3)/8ZnO-derived hybrid Li-metal anode could exhibit electrochemical performances superior to these of ZnO-derived Li anode in both symmetrical and full cells paired with a LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cathode.
文摘The transfer of Sr^2+ and Ba^2+ ion,facilitated by 18-crown-6 present in the aqueous phase,and of succinylcholine ion at w/nb interface were investigated by semi-differeniial cyclic voltammetry.A good polarographic curve of succinylcholine ion dissolved in water was obtained in the system of 0.01 mol/l LiCl(w)-0.01mol/l TBATPB(nb).The peak current is directly proportional to the concentration of SC^2+ ion.It can be used for the determination of SC and the detection limit is 1.05×10^-5mol/l,The apparent D^m and D^mb have been estimated.The transfer of Sr^2+ and of Ba^2+ at the interface are facilitated by 18-Crown-6 present in the aqueous phase and the peak current is directly proportional to the concentration of 18-Crown-6 in water.This method can be used for the determination of the complexing agent and for the stability constant of the complex formed in the aqueous phase.All the experimental results are in keeping with the theoretical.
