Through using mineral oil and synthetic oil to deploy the semisynthesis base oil, modifying the surfaces of ultrafine tungsten disulfide grains by surface chemical embellishment and adsorption embellishment to make th...Through using mineral oil and synthetic oil to deploy the semisynthesis base oil, modifying the surfaces of ultrafine tungsten disulfide grains by surface chemical embellishment and adsorption embellishment to make them suspended steadily in the base oil as solid lubricating additive, and adding some function additives, the tungsten disulfide motor oil was prepared. The tribological characteristics of this kind motor oil and the well-known motor oils in our country and overseas were studied. The results show that the oil film strength of this kind of motor oil is respectively 1.06 and 1.38 times of that of shell helix ultra motor oil and great wall motor oil, and its sintering load is 1.75 and 2.33 times of that of them, and when tested under 392 N, 1 450 r/rain and 30 min, the friction coefficients of friction pairs lubricated by the tungsten disulfide motor oil decrease with the increase of time, meanwhile, the diameter of worn spot is small, and the surface of worn spot is smooth, and no obvious furrows appear. The experiments indicate that the tungsten disulfide motor oil has the better antiwear, antifriction and extreme pressure properties than the well-known motor oils.展开更多
二硫化钨由于具有独特的层状结构、大的层间距等优点,已经成为一种非常有潜力的钠离子电池负极材料,但是其导电性差、充放电过程中易发生体积膨胀的不足限制了它进一步的广泛应用.本文以六氯化钨、硫代乙酰胺以及自制的空心碳壳为原料,...二硫化钨由于具有独特的层状结构、大的层间距等优点,已经成为一种非常有潜力的钠离子电池负极材料,但是其导电性差、充放电过程中易发生体积膨胀的不足限制了它进一步的广泛应用.本文以六氯化钨、硫代乙酰胺以及自制的空心碳壳为原料,采用溶剂热法合成了一种中空杆状结构的C/WS_(2)复合材料,将其用于钠离子电池来改善其上述存在的问题.结果表明,在2 A g^(-1)的电流密度下,循环90圈后,C/WS_(2)电极的比容量仍能达到417.1 mAh g^(-1);在10.0 A g^(-1)的大电流密度下,还具有343.3 mAh g^(^(-1))的比容量.因此,中空杆状C/WS2复合材料具有优异的储钠性能.展开更多
Paper-based devices have attracted extensive attention due to the growing demand for disposable flexible electronics.Herein,we integrate semiconducting devices on cellulose paper substrate through a simple abrasion te...Paper-based devices have attracted extensive attention due to the growing demand for disposable flexible electronics.Herein,we integrate semiconducting devices on cellulose paper substrate through a simple abrasion technique that yields high-performance photodetectors.A solvent-free WS_(2) film deposited on paper favors an effective electron-hole separation and hampers recombination.The as-prepared paper-based WS2 photodetectors exhibit a sensitive photoresponse over a wide spectral range spanning from ultraviolet(365 nm)to near-infrared(940 nm).Their responsivity value reaches up to~270 mA W^(−1) at 35 V under a power density of 35 mW cm^(−2).A high performance photodetector was achieved by controlling the environmental exposure as the ambient oxygen molecules were found to decrease the photoresponse and stability of the WS_(2) photodetector.Furthermore,we have built a spectrometer using such a paperbased WS_(2) device as the photodetecting component to illustrate its potential application.The present work could promote the development of cost-effective disposable photodetection devices.展开更多
The basal planes of transition metal dichalcogenides are basically inert for catalysis due to the absence of adsorption and activation sites,which substantially limit their catalytic application.Herein,a facile strate...The basal planes of transition metal dichalcogenides are basically inert for catalysis due to the absence of adsorption and activation sites,which substantially limit their catalytic application.Herein,a facile strategy to activate the basal plane of WS_(2) for hydrogen evolution reaction(HER)catalysis by phosphorous-induced electron density modulation is demonstrated.The optimized P doped WS_(2)(P-WS_(2))nanowires arrays deliver a low overpotential of 88 mV at 10 mA·cm^(-2)with a Tafel slope of 62 mV·dec^(-1)for HER,which is substantially better than the pristine counterpart.X-ray photoelectron spectroscopy confirms the surface electron densities of WS_(2) have been availably manipulated by P doping.Moreover,density functional theory(DFT)studies further prove P doping can redistribute the density of states(DOS)around EF,which endow the inert basal plane of PWS_(2) with edge-like catalytic activity toward hydrogen evolution catalysis.Our work offers a facile and effective approach to modulate the catalytic surface of WS_(2) toward highly efficient HER catalysis.展开更多
We describe a direct atomic layer deposition method to grow lubricant tungsten disulfide （WS2） films. The WS2 films were deposited on a Si （100） substrate and a zinc sulfide （ZnS） film coated the Si （100） subs...We describe a direct atomic layer deposition method to grow lubricant tungsten disulfide （WS2） films. The WS2 films were deposited on a Si （100） substrate and a zinc sulfide （ZnS） film coated the Si （100） substrate using tungsten hexacarbonyl and hydrogen sulfide as precursors. The ZnS film served as an intermediate layer to facilitate the nucleation and growth of the WS2 films. The thickness of the WS2 films was measured via scanning electron microscope, the microstructure was probed with an X-ray diffractometer and a transmission electron microscope. The friction coefficient was measured with a ball-on-disk tester under dry nitrogen. The results reveal that the WS2 films deposited on both substrates are N175 nm and have （002） and （101） crystal orientations. The WS2 film deposited on the ZnS coated Si substrate exhibits a stronger （002） orientation and a denser crystal structure than that deposited on the Si substrate. The WS2 films on both substrates have low friction coefficients. How- ever, due to the stronger （002） orientation and denser crystal structure, the friction coefficient of the WS2 film deposited on ZnS coated Si substrate is smaller with longer wear life.展开更多
Recently,two-dimensional transition metal dichalcogenides,particularly WS_(2),raised extensive interest due to its extraordi-nary physicochemical properties.With the merits of low costs and prominent properties such a...Recently,two-dimensional transition metal dichalcogenides,particularly WS_(2),raised extensive interest due to its extraordi-nary physicochemical properties.With the merits of low costs and prominent properties such as high anisotropy and distinct crystal structure,WS_(2) is regarded as a competent substitute in the construction of next-generation environmentally benign energy storage and conversion devices.In this review,we begin with the fundamental studies of the structure,properties and preparation of WS_(2),followed by detailed discussions on the development of various WS_(2) and WS_(2)-based composites for electrochemical energy storage and conversion applications.In the end,some prospective prospects and promising develop-ments of WS_(2) in these fields are proposed.展开更多
Energy and environmental issues received widespread attentions due to the fast growth of world population and rapid development of social economy.As a transition metal dichalcogenide,tungsten disulfide(WS_(2))nanomate...Energy and environmental issues received widespread attentions due to the fast growth of world population and rapid development of social economy.As a transition metal dichalcogenide,tungsten disulfide(WS_(2))nanomaterials make important research progress in the field of energy conversion and storage.In view of the versatile and rich microstructure of these mate-rials,the modification and controllable synthesis of WS_(2) nanomaterials also inspire a research interest.This review mainly focuses on WS_(2)-based nanomaterials in the application of energy conversion and storage as well as discusses some basic characteristics and modification strategies of them.Finally,the research progress of WS_(2)-based nanomaterials is reviewed and some prospects for future research directions are proposed.This review is expected to be beneficial to the future study of WS_(2) nanomaterials used in the field of energy conversion and storage.展开更多
Inorganic nanotubes of tungsten disulfide （INTs-WS2） are insoluble in common solvents and practically inert, hindering their usefulness in both research and commercial applications. The covalent attachment of functi...Inorganic nanotubes of tungsten disulfide （INTs-WS2） are insoluble in common solvents and practically inert, hindering their usefulness in both research and commercial applications. The covalent attachment of functional species onto the surface of INT-WS2 is a critical first step in realizing the potential that INT-WS2 offer for high-performance materials and products. Although a few attempts have been reported regarding preparing modified nanotubes, only a limited range of surface functionalities is possible with these methods. We have developed a versatile method, based on a modified, highly electrophilic acidic Vilsmeier- Haack reagent, to produce covalently bonded, polycarboxylated functional WS2 nanotubes that are dispersible in polar liquids, including water. The surface polycarboxylated shell provides a means for additional derivatization, enabling matching compatibility of derivatized nanotubes to both hydrophobic and hydrophilic materials. Nanocomposites incorporating derivatized INT-WS2 are expected to show improved properties as a result of enhanced interfacial compatibility, made possible by the large number of classes of functionalization available through the initial polycarboxylation step.展开更多
Tungsten disulfide （WS2）, as a representative layered transition metal dichalcogenide （TMDC） material, possesses important potential for applications in highly sensitive sensors. Here, a sensitivity-enhanced surfa...Tungsten disulfide （WS2）, as a representative layered transition metal dichalcogenide （TMDC） material, possesses important potential for applications in highly sensitive sensors. Here, a sensitivity-enhanced surface plasmon resonance （SPR） sensor with a metal film modified by an overlayer of WS2 nanosheets is proposed and demo onstrated. The SPR sensitivity is related to the thickness of the WS2 overlayer, which can be tailored by coating a WS2 ethanol suspension with different concentrations or by the number of times of repeated post-coating. Benefitting from its large surface area, high refractive index, and unique optoelectronic properties, the WS2 nanosheet overlayer coated on the gold film significantly improves the sensing sensitivity. The highest sensitivity （up to 2459.3 nm/RIU） in the experiment is achieved by coating the WS2 suspension once. Compared to the case without a WS2 overlayer, this result shows a sensitivity enhancement of 26.6%. The influence of the WS2 nano- sheet overlayer on the sensing performance improvement is analyzed and discussed. Moreover, the proposed WS2 SPR sensor has a linear correlation coefficient of 99.76% in refractive index range of 1.333 to 1.360. Besides sensitivity enhancement, the WS2 nanosheet overlayer is able to show additional advantages, such as protection of metal film from oxidation, tunability of the resonance wavelength region, biocompatibility, capability of vapor, and gas sensing.展开更多
文摘Through using mineral oil and synthetic oil to deploy the semisynthesis base oil, modifying the surfaces of ultrafine tungsten disulfide grains by surface chemical embellishment and adsorption embellishment to make them suspended steadily in the base oil as solid lubricating additive, and adding some function additives, the tungsten disulfide motor oil was prepared. The tribological characteristics of this kind motor oil and the well-known motor oils in our country and overseas were studied. The results show that the oil film strength of this kind of motor oil is respectively 1.06 and 1.38 times of that of shell helix ultra motor oil and great wall motor oil, and its sintering load is 1.75 and 2.33 times of that of them, and when tested under 392 N, 1 450 r/rain and 30 min, the friction coefficients of friction pairs lubricated by the tungsten disulfide motor oil decrease with the increase of time, meanwhile, the diameter of worn spot is small, and the surface of worn spot is smooth, and no obvious furrows appear. The experiments indicate that the tungsten disulfide motor oil has the better antiwear, antifriction and extreme pressure properties than the well-known motor oils.
文摘二硫化钨由于具有独特的层状结构、大的层间距等优点,已经成为一种非常有潜力的钠离子电池负极材料,但是其导电性差、充放电过程中易发生体积膨胀的不足限制了它进一步的广泛应用.本文以六氯化钨、硫代乙酰胺以及自制的空心碳壳为原料,采用溶剂热法合成了一种中空杆状结构的C/WS_(2)复合材料,将其用于钠离子电池来改善其上述存在的问题.结果表明,在2 A g^(-1)的电流密度下,循环90圈后,C/WS_(2)电极的比容量仍能达到417.1 mAh g^(-1);在10.0 A g^(-1)的大电流密度下,还具有343.3 mAh g^(^(-1))的比容量.因此,中空杆状C/WS2复合材料具有优异的储钠性能.
基金Felix Carrascoso (ICMM-CSIC) for support with the metal evaporationfunding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement n°755655,ERC-StG 2017 project2D-TOPSENSE)+5 种基金the Ministry of Science and Innovation (Spain) through the project PID2020-115566RB-I00support from the National Natural Science Foundation of China under grant No.61704129 and No.62011530438the Key Research and Development Program of Shaanxi (Program No.2021KW-02)Fundamental Research Funds for the Central Universities (JB211409)the grant from China Scholarship Council (CSC) under No.201908610178the support from European Union’s Horizon 2020 research and innovation program under the grant agreement 956813 (2Exciting)。
文摘Paper-based devices have attracted extensive attention due to the growing demand for disposable flexible electronics.Herein,we integrate semiconducting devices on cellulose paper substrate through a simple abrasion technique that yields high-performance photodetectors.A solvent-free WS_(2) film deposited on paper favors an effective electron-hole separation and hampers recombination.The as-prepared paper-based WS2 photodetectors exhibit a sensitive photoresponse over a wide spectral range spanning from ultraviolet(365 nm)to near-infrared(940 nm).Their responsivity value reaches up to~270 mA W^(−1) at 35 V under a power density of 35 mW cm^(−2).A high performance photodetector was achieved by controlling the environmental exposure as the ambient oxygen molecules were found to decrease the photoresponse and stability of the WS_(2) photodetector.Furthermore,we have built a spectrometer using such a paperbased WS_(2) device as the photodetecting component to illustrate its potential application.The present work could promote the development of cost-effective disposable photodetection devices.
基金This work is supported by the National Natural Science Foundation of China(No.52122702)Natural Science Foundation of Heilongjiang Province of China(No.JQ2021E005)Fundamental Research Foundation for Universities of Heilongjiang Province(No.LGYC2018JQ006).
文摘The basal planes of transition metal dichalcogenides are basically inert for catalysis due to the absence of adsorption and activation sites,which substantially limit their catalytic application.Herein,a facile strategy to activate the basal plane of WS_(2) for hydrogen evolution reaction(HER)catalysis by phosphorous-induced electron density modulation is demonstrated.The optimized P doped WS_(2)(P-WS_(2))nanowires arrays deliver a low overpotential of 88 mV at 10 mA·cm^(-2)with a Tafel slope of 62 mV·dec^(-1)for HER,which is substantially better than the pristine counterpart.X-ray photoelectron spectroscopy confirms the surface electron densities of WS_(2) have been availably manipulated by P doping.Moreover,density functional theory(DFT)studies further prove P doping can redistribute the density of states(DOS)around EF,which endow the inert basal plane of PWS_(2) with edge-like catalytic activity toward hydrogen evolution catalysis.Our work offers a facile and effective approach to modulate the catalytic surface of WS_(2) toward highly efficient HER catalysis.
基金supported by the National Natural Science Fundation of China(Grant Nos.50825501,51321092&51335005)the National Science and Technology Major Project(Grant No.2008ZX02104-001)
文摘We describe a direct atomic layer deposition method to grow lubricant tungsten disulfide （WS2） films. The WS2 films were deposited on a Si （100） substrate and a zinc sulfide （ZnS） film coated the Si （100） substrate using tungsten hexacarbonyl and hydrogen sulfide as precursors. The ZnS film served as an intermediate layer to facilitate the nucleation and growth of the WS2 films. The thickness of the WS2 films was measured via scanning electron microscope, the microstructure was probed with an X-ray diffractometer and a transmission electron microscope. The friction coefficient was measured with a ball-on-disk tester under dry nitrogen. The results reveal that the WS2 films deposited on both substrates are N175 nm and have （002） and （101） crystal orientations. The WS2 film deposited on the ZnS coated Si substrate exhibits a stronger （002） orientation and a denser crystal structure than that deposited on the Si substrate. The WS2 films on both substrates have low friction coefficients. How- ever, due to the stronger （002） orientation and denser crystal structure, the friction coefficient of the WS2 film deposited on ZnS coated Si substrate is smaller with longer wear life.
基金This work was financially supported by the National Natural Science Foundation of China(Grant Nos.51672194 and 51702241)Program for Innovative Teams of Outstanding Young and Middle-aged Researchers in the Higher Education Institutions of Hubei Province(Grant No.T201602)+1 种基金Key Program of Natural Science Foundation of Hubei Province,China(Contract No.2017CFA004)the Special Project of Central Government for Local Science and Technology Development of Hubei Province(Grant No.2019ZYYD076).
文摘Recently,two-dimensional transition metal dichalcogenides,particularly WS_(2),raised extensive interest due to its extraordi-nary physicochemical properties.With the merits of low costs and prominent properties such as high anisotropy and distinct crystal structure,WS_(2) is regarded as a competent substitute in the construction of next-generation environmentally benign energy storage and conversion devices.In this review,we begin with the fundamental studies of the structure,properties and preparation of WS_(2),followed by detailed discussions on the development of various WS_(2) and WS_(2)-based composites for electrochemical energy storage and conversion applications.In the end,some prospective prospects and promising develop-ments of WS_(2) in these fields are proposed.
基金This work was financially supported by the National Science Foundation for Excellent Young Scholar(Grant No.51722403)Tianjin Natural Science Foundation(Grant No.18JCJQJC46500)+1 种基金National Natural Science Foundation of China and Guangdong Province(Grant No.U1601216)the National Youth Talent Support Program.
文摘Energy and environmental issues received widespread attentions due to the fast growth of world population and rapid development of social economy.As a transition metal dichalcogenide,tungsten disulfide(WS_(2))nanomaterials make important research progress in the field of energy conversion and storage.In view of the versatile and rich microstructure of these mate-rials,the modification and controllable synthesis of WS_(2) nanomaterials also inspire a research interest.This review mainly focuses on WS_(2)-based nanomaterials in the application of energy conversion and storage as well as discusses some basic characteristics and modification strategies of them.Finally,the research progress of WS_(2)-based nanomaterials is reviewed and some prospects for future research directions are proposed.This review is expected to be beneficial to the future study of WS_(2) nanomaterials used in the field of energy conversion and storage.
文摘Inorganic nanotubes of tungsten disulfide （INTs-WS2） are insoluble in common solvents and practically inert, hindering their usefulness in both research and commercial applications. The covalent attachment of functional species onto the surface of INT-WS2 is a critical first step in realizing the potential that INT-WS2 offer for high-performance materials and products. Although a few attempts have been reported regarding preparing modified nanotubes, only a limited range of surface functionalities is possible with these methods. We have developed a versatile method, based on a modified, highly electrophilic acidic Vilsmeier- Haack reagent, to produce covalently bonded, polycarboxylated functional WS2 nanotubes that are dispersible in polar liquids, including water. The surface polycarboxylated shell provides a means for additional derivatization, enabling matching compatibility of derivatized nanotubes to both hydrophobic and hydrophilic materials. Nanocomposites incorporating derivatized INT-WS2 are expected to show improved properties as a result of enhanced interfacial compatibility, made possible by the large number of classes of functionalization available through the initial polycarboxylation step.
基金National Natural Science Foundation of China(NSFC)(61575084,61705087,61705046,61361166006,61401176,61405075,61475066,61505069)Natural Science Foundation of Guangdong Province(2015A030313320,S2013050014606,2014A030313377,2014A030310205,2015A030306046,2016A030311019,2016A030313079,2016A030310098)+2 种基金Science and Technology Projects of Guangdong Province(2017A010101013,2012A032300016,2014B010120002,2014B010117002,2015A020213006,2015B010125007,2016B010111003,2016A010101017)Science and Technology Project of Guangzhou(201707010500,201506010046,201607010134,201605030002,201610010026,201604040005)China Postdoctoral Science Foundation(2017M612608)
文摘Tungsten disulfide （WS2）, as a representative layered transition metal dichalcogenide （TMDC） material, possesses important potential for applications in highly sensitive sensors. Here, a sensitivity-enhanced surface plasmon resonance （SPR） sensor with a metal film modified by an overlayer of WS2 nanosheets is proposed and demo onstrated. The SPR sensitivity is related to the thickness of the WS2 overlayer, which can be tailored by coating a WS2 ethanol suspension with different concentrations or by the number of times of repeated post-coating. Benefitting from its large surface area, high refractive index, and unique optoelectronic properties, the WS2 nanosheet overlayer coated on the gold film significantly improves the sensing sensitivity. The highest sensitivity （up to 2459.3 nm/RIU） in the experiment is achieved by coating the WS2 suspension once. Compared to the case without a WS2 overlayer, this result shows a sensitivity enhancement of 26.6%. The influence of the WS2 nano- sheet overlayer on the sensing performance improvement is analyzed and discussed. Moreover, the proposed WS2 SPR sensor has a linear correlation coefficient of 99.76% in refractive index range of 1.333 to 1.360. Besides sensitivity enhancement, the WS2 nanosheet overlayer is able to show additional advantages, such as protection of metal film from oxidation, tunability of the resonance wavelength region, biocompatibility, capability of vapor, and gas sensing.
