Zero-dimensional environmentally friendly carbon quantum dots(CQDs)combined with two-di-mensional materials have a wide range of applications in optoelec-tronic devices.We combined steady-state and transient absorp-ti...Zero-dimensional environmentally friendly carbon quantum dots(CQDs)combined with two-di-mensional materials have a wide range of applications in optoelec-tronic devices.We combined steady-state and transient absorp-tion spectroscopies to study the energy transfer dynamics between CQDs and molybdenum disulfide(MoS_(2)).Transient absorption plots showed photoinduced absorption and stimulated emission features,which involved the intrinsic and defect states of CQDs.Adding MoS_(2)to CQDs solution,the lowest unoccupied molecular orbital of CQDs transferred energy to MoS_(2),which quenched the intrinsic emission at 390 nm.With addition of MoS_(2),CQD-MoS_(2)composites quenched defect emission at 490 nm and upward absorption,which originated from another energy transfer from the defect state.Two energy transfer paths between CQDs and MoS_(2)were efficiently manipulated by changing the concentration of MoS_(2),which laid a foundation for improving device performance.展开更多
The properties of a metal-oxide-semiconductor device on a single layer MoS_(2)(molybdenum disulfide)semiconductor are determined theoretically utilizing the concept of physics that the carrier effective masses in mate...The properties of a metal-oxide-semiconductor device on a single layer MoS_(2)(molybdenum disulfide)semiconductor are determined theoretically utilizing the concept of physics that the carrier effective masses in materials are related to the intrinsic Fermi energy levels in materials by the universal mass-energy equivalence equation given as dE/E=dm/m,where E is the energy and m is the mass of the free electron.The known parameters of electron effective mass of 0.48 m and the direct bandgap of 1.8 eV for monolayer MoS_(2) semiconductor are utilized to determine the properties of the MOS(metal-oxide-semiconductor)device,with the given previous research consequence that the threshold for electron heating in SiO_(2) is 2 MV/cm-eV.展开更多
Nitrogen electro-reduction under mild conditions is one promising alternative approach of the energyconsuming Haber-Bosch process for the artificial ammonia synthesis.One critical aspect to unlocking this technology i...Nitrogen electro-reduction under mild conditions is one promising alternative approach of the energyconsuming Haber-Bosch process for the artificial ammonia synthesis.One critical aspect to unlocking this technology is to discover the catalysts with high selectivity and efficiency.In this work,the N_(2)-to-NH_(3)conversion on the functional MoS_(2)is fully investigated by density functional theory calculations since the layered MoS_(2)provides the ideal platform for the elaborating copies of the nitrogenase found in nature,wherein the functionalization is achieved via basal-adsorption,basal-substitution or edge-substitution of transition metal elements.Our results reveal that the edge-functionalization is a feasible strategy for the activity promotion;however,the basal-adsorption and basal-substitution separately suffer from the electrochemical instability and the NRR inefficiency.Specifically,MoS_(2)functionalized via edge W-substitution exhibits an exceptional activity.The energetically favored reaction pathway is through the distal pathway and a limiting potential is less than 0.20 V.Overall,this work escalates the rational design of the high-effective catalysts for nitrogen fixation and provides the explanation why the predicated catalyst have a good performance,paving the guidance for the experiments.展开更多
Electrocatalytic water splitting is crucial for H2generation via hydrogen evolution reaction(HER)but subject to the sluggish dynamics of oxygen evolution reaction(OER).In this work,single Fe atomdoped MoS_(2)nanosheet...Electrocatalytic water splitting is crucial for H2generation via hydrogen evolution reaction(HER)but subject to the sluggish dynamics of oxygen evolution reaction(OER).In this work,single Fe atomdoped MoS_(2)nanosheets(SFe-DMNs)were prepared based on the high-throughput density functional theory(DFT)calculation screening.Due to the synergistic effect between Fe atom and MoS_(2)and optimized intermediate binding energy,the SFe-DMNs could deliver outstanding activity for both HER and OER.When assembled into a two-electrode electrolytic cell,the SFe-DMNs could achieve the current density of 50 mA cm^(-2)at a low cell voltage of 1.55 V under neutral condition.These results not only confirmed the effectiveness of high-throughput screening,but also revealed the excellent activity and thus the potential applications in fuel cells of SFe-DMNs.展开更多
The hierarchical structure of molybdenum disulfide(MoS2)nanosheet arrays stemmed from nickelcobalt layered double hydroxide(NiCo-LDH)/carbon cloth was prepared by growing the MoS_(2) nanosheet arrays onto the NiCo-LDH...The hierarchical structure of molybdenum disulfide(MoS2)nanosheet arrays stemmed from nickelcobalt layered double hydroxide(NiCo-LDH)/carbon cloth was prepared by growing the MoS_(2) nanosheet arrays onto the NiCo-LDH template which was pre-deposited onto the carbon cloth substrate.In this electrode configuration,carbon cloth is the three dimensional and conductive skeleton;NiCo-LDH nanosheets,as the template,ensure the oriented growth of MoS2 nanosheet arrays.Therefore,more MoS_(2) active sites are exposed and the catalyst exhibits good hydrogen evolution reaction activity.展开更多
Epoxy resin powder coating has been successfully applied on the corrosion protection of magnesium lithium alloys.However,poor wear resistance and microcracks formed during the solidification have limited it extensive ...Epoxy resin powder coating has been successfully applied on the corrosion protection of magnesium lithium alloys.However,poor wear resistance and microcracks formed during the solidification have limited it extensive application.There are limited approaches to exploit such anti-corrosion and mechanical properties of magnesium lithium alloys.Herein,the epoxy resin powder coating with polydopamine modified molybdenum disulfide(MoS_(2)@PDA-EP powder coating with 0,0.1,0.2,0.5,1.0 wt.%loading)was well prepared by melt extrusion to investigate its anticorrosion performance and wear resistance.The results revealed that the addition of MoS_(2)@PDA enhanced the adhesion strength between coatings and alloys,wear resistance and corrosion protection of the powder coatings.Among them,the optimum was obtained by 0.2 wt.%MoS_(2)@PDA-EP powder coating which could be attributed to well dispersion and efficient adhesion with coating matrix.To conclude,MoS_(2)@PDA-EP powder coating is meaningfully beneficial for the anticorrosive and wear performance improvement of magnesium lithium alloys.展开更多
Molybdenum disulfide(MoS_(2))-based materials as the non-noble metal catalysts have displayed the potential capability to drive electrocatalytic hydrogen evolution reaction(HER)for green hydrogen production along with...Molybdenum disulfide(MoS_(2))-based materials as the non-noble metal catalysts have displayed the potential capability to drive electrocatalytic hydrogen evolution reaction(HER)for green hydrogen production along with their intrinsic activity,tunable electronic properties,low cost,and abundance reserves,which have attracted intensive attention as alternatives to the low-abundance and high-cost platinum-based catalysts.However,their insufficient catalytic HER activities and stability are the major challenges for them to become practically applicable.Hereby,the MoS_(2)-based electrocatalysts for HER are comprehensively reviewed to explain the fundamental science behind the manipulations of the crystal structure,microstructure,surface,and interface of MoS_(2) in order to enhance its catalytic performance through changing the electrical conductivity,the number of active sites,surface wettability,and the Gibbs free energy for hydrogen adsorption(ΔGH).Recent studies in surface/interface engineering,such as phase engineering,defect engineering,morphology design,and heterostructure construction,are analyzed to reveal the state-of-the-art strategies for designing and preparing the cost-effective and highperformance MoS_(2)-based catalysts through optimizing the charge transfer,surface-active sites,ΔGH,and surface hydrophilicity.Lastly,the perspectives,challenges,and future research directions of HER electrocatalysis are also given to facilitate the further research and development of HER catalysts.展开更多
Two-dimensional materials(2DMs) have attracted substantial attention due to their abundant active sites and their ultrahigh surface area for different catalytic applications due to the high lateral-longitudinal ratio....Two-dimensional materials(2DMs) have attracted substantial attention due to their abundant active sites and their ultrahigh surface area for different catalytic applications due to the high lateral-longitudinal ratio. Transition metal dichalcogenides(TMDs), especially MoS2, as one of the 2DMs most often studied, have shown superior activity in electrochemical applications. Recently, combinations of different 2DMs have been widely studied, and they appear to be the most promising strategy available to develop state of the art catalysts for different reactions.In this article, we review the interactions between MoS2 and other materials as well as the novel assembly induced phase transitions of TMDs and their underlying mechanisms. Several methods for inducing the phase transition of TMDs by building MoS2-based heterostructures have been introduced. The electronic coupling between these counterparts has significantly enhanced their conductivity and optimized the energy states of the materials, thus introducing enhanced activity as compared to their original counterparts. The ideas summarized in this article may shed new light on and help to develop next-generation green energy materials by designing and constructing highly active two-dimensional catalysts for efficient water splitting.展开更多
The acoustic-phonon emission from monolayer molybdenum disulfide(ML-MoS_(2))driven by a direct-current electric field is studied theoretically using the Boltzmann equation method.It is found that the Cerenkov emission...The acoustic-phonon emission from monolayer molybdenum disulfide(ML-MoS_(2))driven by a direct-current electric field is studied theoretically using the Boltzmann equation method.It is found that the Cerenkov emission of terahertz acoustic-phonons can be generated when a very weak electric field is applied to ML-MoS_(2).The physical mechanisms of acoustic-phonon emission are analyzed from the perspective of condensed matter physics.The acoustic-phonon emission from ML-MoS_(2)is also compared with those from graphene and GaAs.The results reveal that the frequencies of acousticphonons generated by ML-MoS_(2)are between the frequencies of those generated from GaAs and graphene.The results of this work suggest that the ML-MoS_(2)can make up for graphene and GaAs in respect of acoustic-phonon emission and be used in tunable hypersonic devices such as terahertz sound sources.展开更多
As an outstanding representative of layered materials,molybdenum disulfide(MoS_(2))has excellent physical properties,such as high carrier mobility,stability,and abundance on earth.Moreover,its reasonable band gap and ...As an outstanding representative of layered materials,molybdenum disulfide(MoS_(2))has excellent physical properties,such as high carrier mobility,stability,and abundance on earth.Moreover,its reasonable band gap and microelectronic compatible fabrication characteristics makes it the most promising candidate in future advanced integrated circuits such as logical electronics,flexible electronics,and focal-plane photodetector.However,to realize the all-aspects application of MoS_(2),the research on obtaining high-quality and large-area films need to be continuously explored to promote its industrialization.Although the MoS_(2)grain size has already improved from several micrometers to sub-millimeters,the high-quality growth of wafer-scale MoS_(2)is still of great challenge.Herein,this review mainly focuses on the evolution of MoS_(2)by including chemical vapor deposition,metal–organic chemical vapor deposition,physical vapor deposition,and thermal conversion technology methods.The state-of-the-art research on the growth and optimization mechanism,including nucleation,orientation,grain,and defect engineering,is systematically summarized.Then,this review summarizes the wafer-scale application of MoS_(2)in a transistor,inverter,electronics,and photodetectors.Finally,the current challenges and future perspectives are outlined for the wafer-scale growth and application of MoS_(2).展开更多
The rational synergy of chemical composition and spatial nanostructures of electrode materials play important roles in high-performance energy storage devices.Here,we designed pea-like MoS_(2)@NiS_(1.03)-carbon hollow...The rational synergy of chemical composition and spatial nanostructures of electrode materials play important roles in high-performance energy storage devices.Here,we designed pea-like MoS_(2)@NiS_(1.03)-carbon hollow nanofibers using a simple electrospinning and thermal treatment method.The hierarchical hollow nanofiber is composed of a nitrogen-doped carbon-coated NiS_(1.03) tube wall,in which pea-like uniformly discrete MoS_(2) nanoparticles are enclosed.As a sodium-ion battery electrode material,the MoS_(2)@NiS_(1.03)-carbon hollow nanofibers have abundant diphasic heterointerfaces,a conductive network,and appropriate volume variation-buffering spaces,which can facilitate ion diffusion kinetics,shorten the diffusion path of electrons/ion,and buffer volume expansion during Na^(+)insertion/extraction.It shows outstanding rate capacity and long-cycle performance in a sodium-ion battery.This heterogeneous hollow nanoarchitectures designing enlightens an efficacious strategy to boost the capacity and long-life stability of sodium storage performance of electrode materials.展开更多
Metal-ion capacitors(including Li^(+),Na^(+),and K^(+))effectively combine a battery negative electrode capable of reversibly intercalating metal cations,together with an electrical double-layer positive electrode.How...Metal-ion capacitors(including Li^(+),Na^(+),and K^(+))effectively combine a battery negative electrode capable of reversibly intercalating metal cations,together with an electrical double-layer positive electrode.However,such novel cell design has a birth defect,namely kinetics mismatch between sluggish negative electrode and fast positive electrode,thus limiting the energy-power performance.Herein,we design a MoS_(2)-carbon composite anode with the ordered macroporous architecture and interlayer-expanded feature,exhibiting the fast and reversible Na^(+)redox processes.This kinetically favored anode is coupled with a homemade activated carbon cathode that allows for the excellent electrochemical performance of sodiumion capacitor with respect to large specific capacity,high-rate capability,and robust cycling.Through quantification of the potential swings of anode and cathode via a three-electrode Swagelok cell,we for the first time observe the abnormal variation law of potential swings and thus directly providing the evidence that the kinetics gap has been filled up by this kinetically favored anode.Our results represent a crucial step toward understanding the key issues of kinetics mismatch for hybrid cell,thus propelling the development of design of kinetically favored anode materials for high-performance metalion capacitors.展开更多
MoS2 was used as an efficient catalyst for hydropyrolysis (Hypy) of three samples of sedimentary organic matter with different maturities. Through comparison with Soxhlet extraction (SE), it was found that MoS2 ca...MoS2 was used as an efficient catalyst for hydropyrolysis (Hypy) of three samples of sedimentary organic matter with different maturities. Through comparison with Soxhlet extraction (SE), it was found that MoS2 catalytic Hypy can remarkably promote the yields of total chloroform extracts, saturates, aromatics, hopanes and steranes. In addition, the difference of biomarker parameters indicated that isomerization of covalently-bound biomarkers is much more difficult than their free counterparts. Meanwhile, the high conversion of total organic carbon (TOC) in MoS2 catalytic Hypy of organic matter proved that the presence of dispersed molybdenum sulfide accelerated the breaking of C-C bonds and the release of hydrocarbons. To address the catalytic mechanism, a series of control experiments based on free Hypy and catalytic Hypy were conducted. The results showed that the calculated atomic ratio of carbon conversion/hydrogen conversion for catalytic Hypy was much larger than the presumed value of 1/2, indicating that intensive hydrogenation took place and significantly influenced the distribution of liquid products. Analysis of stable hydrogen isotope data, infrared spectra and m/z 83 ion chromatograph of the saturate fraction further confirmed this hypothesis. The difference of S content changing (AS) between catalyst-free Hypy and catalytic Hypy, and the thermal characteristics of the catalyst, indicated that active H2S was definitely generated and it probably initiated free radical reactions in the early stage of hydropyrolysis of organic matter.展开更多
The optical properties of four kinds of lubricating greases (urea, lithium, extreme pressure lithium, molybdenum disulfide lithium greases) with different NLGL (National Lubricant Grease Institute of America) numb...The optical properties of four kinds of lubricating greases (urea, lithium, extreme pressure lithium, molybdenum disulfide lithium greases) with different NLGL (National Lubricant Grease Institute of America) numbers were investigated using terahertz time-domain spectroscopy. Greases with different NLGL grades have unique spectral features in the terahertz range. Comparison of the experimental data with predictions based on Lorentz Lorenz theory exhibited that the refractive indices of each kind of lubricating grease were dependent on the their consistency. In addition, molybdenum disullfide (MoS2) aa a libricant additive shows strong absorption from 0.2 to 1.4 THz, leading to higher absorption of MoS2-1ithium grease than that of lithium grease.展开更多
High performance supercapacitors coupled with mechanical flexibility are needed to drive flexible and wearable electronics that have anesthetic appeal and multi-functionality. Two dimensional(2D) materials have attr...High performance supercapacitors coupled with mechanical flexibility are needed to drive flexible and wearable electronics that have anesthetic appeal and multi-functionality. Two dimensional(2D) materials have attracted attention owing to their unique physicochemical and electrochemical properties, in addition to their ability to form hetero-structures with other nanomaterials further improving mechanical and electrochemical properties. After a brief introduction of supercapacitors and 2D materials, recent progress on flexible supercapacitors using 2D materials is reviewed. Here we provide insights into the structure–property relationships of flexible electrodes, in particular free-standing films. We also present our perspectives on the development of flexible supercapacitors.展开更多
A controllable approach that combines surface plasmon resonance and twodimensional(2D)graphene/MoS2 heterojunction has not been implemented despite its potential for efficient photoelectrochemical(PEC)water splitting....A controllable approach that combines surface plasmon resonance and twodimensional(2D)graphene/MoS2 heterojunction has not been implemented despite its potential for efficient photoelectrochemical(PEC)water splitting.In this study,plasmonic Ag-decorated 2D MoS2 nanosheets were vertically grown on graphene substrates in a practical large-scale manner through metalorganic chemical vapor deposition of MoS2 and thermal evaporation of Ag.The plasmonic Ag-decorated MoS2 nanosheets on graphene yielded up to 10 times higher photo-to-dark current ratio than MoS2 nanosheets on indium tin oxide.The significantly enhanced PEC activity could be attributed to the synergetic effects of SPR and favorable graphene/2D MoS2 heterojunction.Plasmonic Ag nanoparticles not only increased visible-light and near-infrared absorption of 2D MoS2,but also induced highly amplified local electric field intensity in 2D MoS2.In addition,the vertically aligned 2D MoS2 on graphene acted as a desirable heterostructure for efficient separation and transportation of photo-generated carriers.This study provides a promising path for exploiting the full potential of 2D MoS2 for practical large-scale and efficient PEC water-splitting applications.展开更多
The catalytic performance of Molybdenum disulfide(MoS_(2)) has been still far from that of Pt-based catalysts for inadequate active sites and sluggish electron transfer kinetics. Through engineering the interface betw...The catalytic performance of Molybdenum disulfide(MoS_(2)) has been still far from that of Pt-based catalysts for inadequate active sites and sluggish electron transfer kinetics. Through engineering the interface between MoS_(2)-based materials and supported substrates, hybrid Ru-doped MoS_(2) on carbonized lignin(CL) is designed and prepared as efficient catalyst for hydrogen evolution reaction(HER). The CL substrate not only facilitates the growth of MoS_(2) nanoflowers, but also promotes the electron transfer. Ru doping increases active sites greatly for HER. The hybrid catalyst achieves a low onset overpotential of 25 mV and a low Tafel slope of 46 m V dec^(-1). The favorable HER activity ascribes to the interfacial interaction between MoS_(2) and CL. Density functional theory calculations further confirm the improved HER performance with doped Ru atoms. This study presents a prototype application to design electrocatalysts with enhanced carrier mobility and high-density active sites based on interface effect.展开更多
Replacing platinum for catalyzing hydrogen evolution reaction (HER) in acidic medium remains great chal- lenges. Herein, we prepared few-layered MoS2 by ball milling as an efficient catalyst for HER in acidic medium...Replacing platinum for catalyzing hydrogen evolution reaction (HER) in acidic medium remains great chal- lenges. Herein, we prepared few-layered MoS2 by ball milling as an efficient catalyst for HER in acidic medium, The activity of as-prepared MoS2 had a strong dependence on the ball milling time, Furthermore, Ketjen Black EC 300J was added into the ball-milled MoS2 followed by a second ball milling, and the resultant MoS2/carbon black hybrid material showed a much higher HER activity than MoS2 and carbon black alone. The enhanced activity of the MoS2/carbon black hybrid material was attributed to the increased abundance of catalytic edge sites of MoS) and excellent electrical coupling to the underlving carbon network.展开更多
Direct visualization of the structural defects in two-dimensional(2D)semiconductors at a large scale plays a significant role in understanding their electrical/optical/magnetic properties,but is challenging.Although t...Direct visualization of the structural defects in two-dimensional(2D)semiconductors at a large scale plays a significant role in understanding their electrical/optical/magnetic properties,but is challenging.Although traditional atomic resolution imaging techniques,such as transmission electron microscopy and scanning tunneling microscopy,can directly image the structural defects,they provide only local-scale information and require complex setups.Here,we develop a simple,non-invasive wet etching method to directly visualize the structural defects in 2D semiconductors at a large scale,including both point defects and grain boundaries.Utilizing this method,we extract successfully the defects density in several different types of monolayer molybdenum disulfide samples,providing key insights into the device functions.Furthermore,the etching method we developed is anisotropic and tunable,opening up opportunities to obtain exotic edge states on demand.展开更多
Ti_(3)C_(2)T_(x)MXene fiber has shown extraordinary potential for supercapacitor electrode in wearable elec-tronics and textile energy storage,but realizing high energy density and practical-powered applications remai...Ti_(3)C_(2)T_(x)MXene fiber has shown extraordinary potential for supercapacitor electrode in wearable elec-tronics and textile energy storage,but realizing high energy density and practical-powered applications remains a great challenge.Here,we report a covalent-architected molybdenum disulfide-Ti_(3)C_(2)T_(x)(MoS_(2)-Ti_(3)C_(2)T_(x))core-shell fiber for high-performance supercapacitor.Benefiting from the microfluidic and micro-reaction strategies,the ordered MoS_(2)arrays are strongly bridged on Ti_(3)C_(2)T_(x)fiber via Ti-O-Mo bond,re-sulting in large exposed surface,enhanced porosity and excellent interfacial conduction for charges high diffusion and faradaic transfer.The MoS_(2)-Ti_(3)C_(2)T_(x)fiber exhibits ultra-large capacitance of 2028 F cm^(-3)and admirable reversibility in 1 M H_(2)SO_(4)aqueous electrolyte.Meanwhile,MoS_(2)-Ti_(3)C_(2)T_(x)fiber-based solid-state supercapacitor presents high energy density of 23.86 mWh cm^(-3),capacitance of 1073.6 F cm^(-3)and superior cycling ability of 92.13%retention after 20,000 cycles,which can realize stable energy supply for wearable watch,LEDs,electric fans,toy ship and self-powered devices.Our work may provide an insight-ful guidance for the advanced design of structural fiber towards robust new energy and next-generation wearable industry.展开更多
基金supported by the National Natural Science Foundation of China(No.61805134 and No.11974229)Applied Basic Research Program in Shanxi Province,China(No.201801D221016 and No.202103021223254)+2 种基金Scientific and Technological Innovation Pro-grams of Higher Education Institutions in Shanxi(No.2020L0235 and No.2021L257)Linfen Key Re-search and Development Program(No.2028)Graduate Innovation Project in Shanxi Province(No.2022Y498).
文摘Zero-dimensional environmentally friendly carbon quantum dots(CQDs)combined with two-di-mensional materials have a wide range of applications in optoelec-tronic devices.We combined steady-state and transient absorp-tion spectroscopies to study the energy transfer dynamics between CQDs and molybdenum disulfide(MoS_(2)).Transient absorption plots showed photoinduced absorption and stimulated emission features,which involved the intrinsic and defect states of CQDs.Adding MoS_(2)to CQDs solution,the lowest unoccupied molecular orbital of CQDs transferred energy to MoS_(2),which quenched the intrinsic emission at 390 nm.With addition of MoS_(2),CQD-MoS_(2)composites quenched defect emission at 490 nm and upward absorption,which originated from another energy transfer from the defect state.Two energy transfer paths between CQDs and MoS_(2)were efficiently manipulated by changing the concentration of MoS_(2),which laid a foundation for improving device performance.
文摘The properties of a metal-oxide-semiconductor device on a single layer MoS_(2)(molybdenum disulfide)semiconductor are determined theoretically utilizing the concept of physics that the carrier effective masses in materials are related to the intrinsic Fermi energy levels in materials by the universal mass-energy equivalence equation given as dE/E=dm/m,where E is the energy and m is the mass of the free electron.The known parameters of electron effective mass of 0.48 m and the direct bandgap of 1.8 eV for monolayer MoS_(2) semiconductor are utilized to determine the properties of the MOS(metal-oxide-semiconductor)device,with the given previous research consequence that the threshold for electron heating in SiO_(2) is 2 MV/cm-eV.
基金financial support from the National Natural Science Foundation of China(21503097,52130101,51701152,21806023,and 51702345)China Scholarship Council(202008320215).
文摘Nitrogen electro-reduction under mild conditions is one promising alternative approach of the energyconsuming Haber-Bosch process for the artificial ammonia synthesis.One critical aspect to unlocking this technology is to discover the catalysts with high selectivity and efficiency.In this work,the N_(2)-to-NH_(3)conversion on the functional MoS_(2)is fully investigated by density functional theory calculations since the layered MoS_(2)provides the ideal platform for the elaborating copies of the nitrogenase found in nature,wherein the functionalization is achieved via basal-adsorption,basal-substitution or edge-substitution of transition metal elements.Our results reveal that the edge-functionalization is a feasible strategy for the activity promotion;however,the basal-adsorption and basal-substitution separately suffer from the electrochemical instability and the NRR inefficiency.Specifically,MoS_(2)functionalized via edge W-substitution exhibits an exceptional activity.The energetically favored reaction pathway is through the distal pathway and a limiting potential is less than 0.20 V.Overall,this work escalates the rational design of the high-effective catalysts for nitrogen fixation and provides the explanation why the predicated catalyst have a good performance,paving the guidance for the experiments.
基金supported by the Research Funds of Institute of Zhejiang University-Quzhou(IZQ2023RCZX032)the Natural Science Foundation of Guangdong Province(2022A1515010185)+1 种基金the Fundamental Research Funds for the Central Universities(FRF-TP-20-005A3)partially supported by the Special Funds for Postdoctoral Research at Tsinghua University(100415017)。
文摘Electrocatalytic water splitting is crucial for H2generation via hydrogen evolution reaction(HER)but subject to the sluggish dynamics of oxygen evolution reaction(OER).In this work,single Fe atomdoped MoS_(2)nanosheets(SFe-DMNs)were prepared based on the high-throughput density functional theory(DFT)calculation screening.Due to the synergistic effect between Fe atom and MoS_(2)and optimized intermediate binding energy,the SFe-DMNs could deliver outstanding activity for both HER and OER.When assembled into a two-electrode electrolytic cell,the SFe-DMNs could achieve the current density of 50 mA cm^(-2)at a low cell voltage of 1.55 V under neutral condition.These results not only confirmed the effectiveness of high-throughput screening,but also revealed the excellent activity and thus the potential applications in fuel cells of SFe-DMNs.
基金financial support for this work from the Strategic Priority Research Program of CAS(XDB36030000)the National Natural Science Foundation of China(21422303,21573049,21872043,22002028)+3 种基金the National Basic Research Plan of China(2016YFA0201600)the Beijing Natural Science Foundation(2142036)the Youth Innovation Promotion Associationthe Special Program of “One Belt One Road”of CAS。
文摘The hierarchical structure of molybdenum disulfide(MoS2)nanosheet arrays stemmed from nickelcobalt layered double hydroxide(NiCo-LDH)/carbon cloth was prepared by growing the MoS_(2) nanosheet arrays onto the NiCo-LDH template which was pre-deposited onto the carbon cloth substrate.In this electrode configuration,carbon cloth is the three dimensional and conductive skeleton;NiCo-LDH nanosheets,as the template,ensure the oriented growth of MoS2 nanosheet arrays.Therefore,more MoS_(2) active sites are exposed and the catalyst exhibits good hydrogen evolution reaction activity.
基金financial support provided by the National Natural Science Foundation of China(Grant No.U1806225)the National Natural Science Foundation of China(Grant No.51908092)the Joint Funds of the National Natural Science Foundation of China-Guangdong(Grant No.U1801254)。
文摘Epoxy resin powder coating has been successfully applied on the corrosion protection of magnesium lithium alloys.However,poor wear resistance and microcracks formed during the solidification have limited it extensive application.There are limited approaches to exploit such anti-corrosion and mechanical properties of magnesium lithium alloys.Herein,the epoxy resin powder coating with polydopamine modified molybdenum disulfide(MoS_(2)@PDA-EP powder coating with 0,0.1,0.2,0.5,1.0 wt.%loading)was well prepared by melt extrusion to investigate its anticorrosion performance and wear resistance.The results revealed that the addition of MoS_(2)@PDA enhanced the adhesion strength between coatings and alloys,wear resistance and corrosion protection of the powder coatings.Among them,the optimum was obtained by 0.2 wt.%MoS_(2)@PDA-EP powder coating which could be attributed to well dispersion and efficient adhesion with coating matrix.To conclude,MoS_(2)@PDA-EP powder coating is meaningfully beneficial for the anticorrosive and wear performance improvement of magnesium lithium alloys.
基金financially supported by the National Natural Science Foundation of China(Grant No.51572166)the China Postdoctoral Science Foundation(Grant No.2021M702073)+1 种基金the Rare and Precious Metals Material Genetic Engineering Project of Yunnan Province(Grant No.202002AB080001-1)support from the Program for Professors with Special Appointments(Eastern Scholar:TP2014041)at Shanghai Institutions of Higher Learning。
文摘Molybdenum disulfide(MoS_(2))-based materials as the non-noble metal catalysts have displayed the potential capability to drive electrocatalytic hydrogen evolution reaction(HER)for green hydrogen production along with their intrinsic activity,tunable electronic properties,low cost,and abundance reserves,which have attracted intensive attention as alternatives to the low-abundance and high-cost platinum-based catalysts.However,their insufficient catalytic HER activities and stability are the major challenges for them to become practically applicable.Hereby,the MoS_(2)-based electrocatalysts for HER are comprehensively reviewed to explain the fundamental science behind the manipulations of the crystal structure,microstructure,surface,and interface of MoS_(2) in order to enhance its catalytic performance through changing the electrical conductivity,the number of active sites,surface wettability,and the Gibbs free energy for hydrogen adsorption(ΔGH).Recent studies in surface/interface engineering,such as phase engineering,defect engineering,morphology design,and heterostructure construction,are analyzed to reveal the state-of-the-art strategies for designing and preparing the cost-effective and highperformance MoS_(2)-based catalysts through optimizing the charge transfer,surface-active sites,ΔGH,and surface hydrophilicity.Lastly,the perspectives,challenges,and future research directions of HER electrocatalysis are also given to facilitate the further research and development of HER catalysts.
基金supported by the National Key Research and Development Program of China (2016YFFA0200400)the Natural Science Foundation of China (51571100, 51872116, and 51602305)+3 种基金the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT, 2017TD-09)the Fundamental Research Funds for the Central Universitiessupport from the Australian Research Council (ARC, FT150100450 and IH150100006)the ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET, CE170100039)
文摘Two-dimensional materials(2DMs) have attracted substantial attention due to their abundant active sites and their ultrahigh surface area for different catalytic applications due to the high lateral-longitudinal ratio. Transition metal dichalcogenides(TMDs), especially MoS2, as one of the 2DMs most often studied, have shown superior activity in electrochemical applications. Recently, combinations of different 2DMs have been widely studied, and they appear to be the most promising strategy available to develop state of the art catalysts for different reactions.In this article, we review the interactions between MoS2 and other materials as well as the novel assembly induced phase transitions of TMDs and their underlying mechanisms. Several methods for inducing the phase transition of TMDs by building MoS2-based heterostructures have been introduced. The electronic coupling between these counterparts has significantly enhanced their conductivity and optimized the energy states of the materials, thus introducing enhanced activity as compared to their original counterparts. The ideas summarized in this article may shed new light on and help to develop next-generation green energy materials by designing and constructing highly active two-dimensional catalysts for efficient water splitting.
基金Project supported by the National Natural Science Foundation of China(Grant No.11604192)the Fundamental Research Program of Shanxi Province,China(Grant No.202103021224250)+1 种基金the Science and Technology Innovation Project of Colleges and Universities of Shanxi Province of China(Grant No.2020L0242)the Start-up funding from Shanxi Normal University(Grant No.0505/02070351)
文摘The acoustic-phonon emission from monolayer molybdenum disulfide(ML-MoS_(2))driven by a direct-current electric field is studied theoretically using the Boltzmann equation method.It is found that the Cerenkov emission of terahertz acoustic-phonons can be generated when a very weak electric field is applied to ML-MoS_(2).The physical mechanisms of acoustic-phonon emission are analyzed from the perspective of condensed matter physics.The acoustic-phonon emission from ML-MoS_(2)is also compared with those from graphene and GaAs.The results reveal that the frequencies of acousticphonons generated by ML-MoS_(2)are between the frequencies of those generated from GaAs and graphene.The results of this work suggest that the ML-MoS_(2)can make up for graphene and GaAs in respect of acoustic-phonon emission and be used in tunable hypersonic devices such as terahertz sound sources.
基金financially the National Natural Science Foundation of China(52002254,52272160)Sichuan Science and Technology Foundation(2020YJ0262,2021YFH0127,2022YFSY0045,2022YFH0083 and 23SYSX0060)+3 种基金the Chunhui plan of Ministry of Education,Fundamental Research Funds for the Central Universities,China(YJ201893)the Open-Foundation of Key Laboratory of Laser Device Technology,China North Industries Group Corporation Limited(Grant No.KLLDT202104)the foundation of the State Key Laboratory of Solidification Processing in NWPU(No.SKLSP202210)the 2035-Plan of Sichuan University。
文摘As an outstanding representative of layered materials,molybdenum disulfide(MoS_(2))has excellent physical properties,such as high carrier mobility,stability,and abundance on earth.Moreover,its reasonable band gap and microelectronic compatible fabrication characteristics makes it the most promising candidate in future advanced integrated circuits such as logical electronics,flexible electronics,and focal-plane photodetector.However,to realize the all-aspects application of MoS_(2),the research on obtaining high-quality and large-area films need to be continuously explored to promote its industrialization.Although the MoS_(2)grain size has already improved from several micrometers to sub-millimeters,the high-quality growth of wafer-scale MoS_(2)is still of great challenge.Herein,this review mainly focuses on the evolution of MoS_(2)by including chemical vapor deposition,metal–organic chemical vapor deposition,physical vapor deposition,and thermal conversion technology methods.The state-of-the-art research on the growth and optimization mechanism,including nucleation,orientation,grain,and defect engineering,is systematically summarized.Then,this review summarizes the wafer-scale application of MoS_(2)in a transistor,inverter,electronics,and photodetectors.Finally,the current challenges and future perspectives are outlined for the wafer-scale growth and application of MoS_(2).
基金financially supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.22175007,21975007,52172080,and 22005012)the National Natural Science Foundation for Outstanding Youth Foundation,the Fundamental Research Funds for the Central Universities,the National Program for Support of Top-notch Young Professionalsthe 111 project(Grant No.B14009).
文摘The rational synergy of chemical composition and spatial nanostructures of electrode materials play important roles in high-performance energy storage devices.Here,we designed pea-like MoS_(2)@NiS_(1.03)-carbon hollow nanofibers using a simple electrospinning and thermal treatment method.The hierarchical hollow nanofiber is composed of a nitrogen-doped carbon-coated NiS_(1.03) tube wall,in which pea-like uniformly discrete MoS_(2) nanoparticles are enclosed.As a sodium-ion battery electrode material,the MoS_(2)@NiS_(1.03)-carbon hollow nanofibers have abundant diphasic heterointerfaces,a conductive network,and appropriate volume variation-buffering spaces,which can facilitate ion diffusion kinetics,shorten the diffusion path of electrons/ion,and buffer volume expansion during Na^(+)insertion/extraction.It shows outstanding rate capacity and long-cycle performance in a sodium-ion battery.This heterogeneous hollow nanoarchitectures designing enlightens an efficacious strategy to boost the capacity and long-life stability of sodium storage performance of electrode materials.
基金supported by National Natural Science Foundation of China(No.51902188)Natural Science Foundation of Jiangsu Province(No.BK20190207)+1 种基金Natural Science Doctoral Foundation of Shandong Province(No.ZR2019BB057)the CAS Key Laboratory of Carbon Materials(No.KLCMKFJJ2006).
文摘Metal-ion capacitors(including Li^(+),Na^(+),and K^(+))effectively combine a battery negative electrode capable of reversibly intercalating metal cations,together with an electrical double-layer positive electrode.However,such novel cell design has a birth defect,namely kinetics mismatch between sluggish negative electrode and fast positive electrode,thus limiting the energy-power performance.Herein,we design a MoS_(2)-carbon composite anode with the ordered macroporous architecture and interlayer-expanded feature,exhibiting the fast and reversible Na^(+)redox processes.This kinetically favored anode is coupled with a homemade activated carbon cathode that allows for the excellent electrochemical performance of sodiumion capacitor with respect to large specific capacity,high-rate capability,and robust cycling.Through quantification of the potential swings of anode and cathode via a three-electrode Swagelok cell,we for the first time observe the abnormal variation law of potential swings and thus directly providing the evidence that the kinetics gap has been filled up by this kinetically favored anode.Our results represent a crucial step toward understanding the key issues of kinetics mismatch for hybrid cell,thus propelling the development of design of kinetically favored anode materials for high-performance metalion capacitors.
基金supported by the Science and Technology Major roject (2008A-0600) from CNPC
文摘MoS2 was used as an efficient catalyst for hydropyrolysis (Hypy) of three samples of sedimentary organic matter with different maturities. Through comparison with Soxhlet extraction (SE), it was found that MoS2 catalytic Hypy can remarkably promote the yields of total chloroform extracts, saturates, aromatics, hopanes and steranes. In addition, the difference of biomarker parameters indicated that isomerization of covalently-bound biomarkers is much more difficult than their free counterparts. Meanwhile, the high conversion of total organic carbon (TOC) in MoS2 catalytic Hypy of organic matter proved that the presence of dispersed molybdenum sulfide accelerated the breaking of C-C bonds and the release of hydrocarbons. To address the catalytic mechanism, a series of control experiments based on free Hypy and catalytic Hypy were conducted. The results showed that the calculated atomic ratio of carbon conversion/hydrogen conversion for catalytic Hypy was much larger than the presumed value of 1/2, indicating that intensive hydrogenation took place and significantly influenced the distribution of liquid products. Analysis of stable hydrogen isotope data, infrared spectra and m/z 83 ion chromatograph of the saturate fraction further confirmed this hypothesis. The difference of S content changing (AS) between catalyst-free Hypy and catalytic Hypy, and the thermal characteristics of the catalyst, indicated that active H2S was definitely generated and it probably initiated free radical reactions in the early stage of hydropyrolysis of organic matter.
基金Project supported by the New Century Excellent Talents in University(Grant No.NCET-08-0841)the National Natural Science Foundation of China(Grant Nos.60778034,60877038,and10804077)+2 种基金the Beijng Natural Science Foundation(Grant No.4082026)the Research Fund for the Doctoral Program of Higher Education(Grant No.200804250006)the State KeyLaboratory of Heavy Oil Processing,China University of Petroleum(Grant No.2008-14)
文摘The optical properties of four kinds of lubricating greases (urea, lithium, extreme pressure lithium, molybdenum disulfide lithium greases) with different NLGL (National Lubricant Grease Institute of America) numbers were investigated using terahertz time-domain spectroscopy. Greases with different NLGL grades have unique spectral features in the terahertz range. Comparison of the experimental data with predictions based on Lorentz Lorenz theory exhibited that the refractive indices of each kind of lubricating grease were dependent on the their consistency. In addition, molybdenum disullfide (MoS2) aa a libricant additive shows strong absorption from 0.2 to 1.4 THz, leading to higher absorption of MoS2-1ithium grease than that of lithium grease.
基金Funding from the Australian Research Council Centre of Excellence Scheme(CE 140100012)the funding from National Natural Science Foundation of China(51502206)+1 种基金the CSC scholarship from the Ministry of Education of PR Chinathe support of the CSC scholarship from the Ministry of Education of PR China
文摘High performance supercapacitors coupled with mechanical flexibility are needed to drive flexible and wearable electronics that have anesthetic appeal and multi-functionality. Two dimensional(2D) materials have attracted attention owing to their unique physicochemical and electrochemical properties, in addition to their ability to form hetero-structures with other nanomaterials further improving mechanical and electrochemical properties. After a brief introduction of supercapacitors and 2D materials, recent progress on flexible supercapacitors using 2D materials is reviewed. Here we provide insights into the structure–property relationships of flexible electrodes, in particular free-standing films. We also present our perspectives on the development of flexible supercapacitors.
基金This work was supported by the National Research Foundation of Korea(NRF)grants funded by the Ministry of Education(2020R1I1A3A04037241 and 2019R1A6A3A13095792)and the Korea Government(MSIT)(2020R1A4A4079397).
文摘A controllable approach that combines surface plasmon resonance and twodimensional(2D)graphene/MoS2 heterojunction has not been implemented despite its potential for efficient photoelectrochemical(PEC)water splitting.In this study,plasmonic Ag-decorated 2D MoS2 nanosheets were vertically grown on graphene substrates in a practical large-scale manner through metalorganic chemical vapor deposition of MoS2 and thermal evaporation of Ag.The plasmonic Ag-decorated MoS2 nanosheets on graphene yielded up to 10 times higher photo-to-dark current ratio than MoS2 nanosheets on indium tin oxide.The significantly enhanced PEC activity could be attributed to the synergetic effects of SPR and favorable graphene/2D MoS2 heterojunction.Plasmonic Ag nanoparticles not only increased visible-light and near-infrared absorption of 2D MoS2,but also induced highly amplified local electric field intensity in 2D MoS2.In addition,the vertically aligned 2D MoS2 on graphene acted as a desirable heterostructure for efficient separation and transportation of photo-generated carriers.This study provides a promising path for exploiting the full potential of 2D MoS2 for practical large-scale and efficient PEC water-splitting applications.
基金supported by National Natural Science Foundation of China (21705036, 21975067, 11974105, and 11634001)National Basic Research Programs of China (2016YFA0300901)+3 种基金Natural Science Foundation of Hunan Province, China (2018JJ3035)Fundamental Research Funds for the Central Universities from Hunan Universityfinancially supported by the fund of Prof. Hong from University of Macao (SRG201600092-IAPME, MYRG2018-00079-IAPME, MYRG2019-00115-IAPME)the Science and Technology Development Fund, Macao SAR (FDCT081/2017/A2, FDCT0059/2018/A2, FDCT009/2017/AMJ)
文摘The catalytic performance of Molybdenum disulfide(MoS_(2)) has been still far from that of Pt-based catalysts for inadequate active sites and sluggish electron transfer kinetics. Through engineering the interface between MoS_(2)-based materials and supported substrates, hybrid Ru-doped MoS_(2) on carbonized lignin(CL) is designed and prepared as efficient catalyst for hydrogen evolution reaction(HER). The CL substrate not only facilitates the growth of MoS_(2) nanoflowers, but also promotes the electron transfer. Ru doping increases active sites greatly for HER. The hybrid catalyst achieves a low onset overpotential of 25 mV and a low Tafel slope of 46 m V dec^(-1). The favorable HER activity ascribes to the interfacial interaction between MoS_(2) and CL. Density functional theory calculations further confirm the improved HER performance with doped Ru atoms. This study presents a prototype application to design electrocatalysts with enhanced carrier mobility and high-density active sites based on interface effect.
基金the financial support from the Ministry of Science and Technology of China (grants 2012CB215500 and 2013CB933100)the National Natural Science Foundation of China (grants 21573222 and 21103178)
文摘Replacing platinum for catalyzing hydrogen evolution reaction (HER) in acidic medium remains great chal- lenges. Herein, we prepared few-layered MoS2 by ball milling as an efficient catalyst for HER in acidic medium, The activity of as-prepared MoS2 had a strong dependence on the ball milling time, Furthermore, Ketjen Black EC 300J was added into the ball-milled MoS2 followed by a second ball milling, and the resultant MoS2/carbon black hybrid material showed a much higher HER activity than MoS2 and carbon black alone. The enhanced activity of the MoS2/carbon black hybrid material was attributed to the increased abundance of catalytic edge sites of MoS) and excellent electrical coupling to the underlving carbon network.
基金the Key-Area Research and Development Program of Guangdong Province,China(Grant No.2020B0101340001)the Strategic Priority Research Program of Chinese Academy of Sciences(CAS)(Grant No.XDB30000000)the National Natural Science Foundation of China(Grant Nos.61888102 and 11834017)。
文摘Direct visualization of the structural defects in two-dimensional(2D)semiconductors at a large scale plays a significant role in understanding their electrical/optical/magnetic properties,but is challenging.Although traditional atomic resolution imaging techniques,such as transmission electron microscopy and scanning tunneling microscopy,can directly image the structural defects,they provide only local-scale information and require complex setups.Here,we develop a simple,non-invasive wet etching method to directly visualize the structural defects in 2D semiconductors at a large scale,including both point defects and grain boundaries.Utilizing this method,we extract successfully the defects density in several different types of monolayer molybdenum disulfide samples,providing key insights into the device functions.Furthermore,the etching method we developed is anisotropic and tunable,opening up opportunities to obtain exotic edge states on demand.
基金This work was financially supported by the National Natu-ral Science Foundation of China(Nos.22278378,22208190,and 21706120)the Natural Science Foundation of Jiangsu Province(No.BK20211592)+2 种基金the National Postdoctoral Program for Innovative Tal-ents(No.BX2021146)the Shuimu Tsinghua Scholar Program(No.2021SM055)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Ti_(3)C_(2)T_(x)MXene fiber has shown extraordinary potential for supercapacitor electrode in wearable elec-tronics and textile energy storage,but realizing high energy density and practical-powered applications remains a great challenge.Here,we report a covalent-architected molybdenum disulfide-Ti_(3)C_(2)T_(x)(MoS_(2)-Ti_(3)C_(2)T_(x))core-shell fiber for high-performance supercapacitor.Benefiting from the microfluidic and micro-reaction strategies,the ordered MoS_(2)arrays are strongly bridged on Ti_(3)C_(2)T_(x)fiber via Ti-O-Mo bond,re-sulting in large exposed surface,enhanced porosity and excellent interfacial conduction for charges high diffusion and faradaic transfer.The MoS_(2)-Ti_(3)C_(2)T_(x)fiber exhibits ultra-large capacitance of 2028 F cm^(-3)and admirable reversibility in 1 M H_(2)SO_(4)aqueous electrolyte.Meanwhile,MoS_(2)-Ti_(3)C_(2)T_(x)fiber-based solid-state supercapacitor presents high energy density of 23.86 mWh cm^(-3),capacitance of 1073.6 F cm^(-3)and superior cycling ability of 92.13%retention after 20,000 cycles,which can realize stable energy supply for wearable watch,LEDs,electric fans,toy ship and self-powered devices.Our work may provide an insight-ful guidance for the advanced design of structural fiber towards robust new energy and next-generation wearable industry.