以辉钼矿(MoS_(2))、褐铁矿和无烟煤为原料,通过碳热还原法制备了MoS_(x)@ZVI复合材料。研究了MoS_(2)用量、焙烧温度、无烟煤用量和焙烧时间对MoS_(x)@ZVI去除酸性橙G(OG)的影响,并确定了制备MoS_(x)@ZVI的较优制备条件为焙烧温度1000...以辉钼矿(MoS_(2))、褐铁矿和无烟煤为原料,通过碳热还原法制备了MoS_(x)@ZVI复合材料。研究了MoS_(2)用量、焙烧温度、无烟煤用量和焙烧时间对MoS_(x)@ZVI去除酸性橙G(OG)的影响,并确定了制备MoS_(x)@ZVI的较优制备条件为焙烧温度1000℃、MoS_(2)用量6%、焙烧时间60 min和无烟煤用量25%。通过X射线衍射、扫描电子显微镜和能谱仪对较优条件制备的MoS_(x)@ZVI进行表征,结果表明,材料中生成了大量核壳结构的硫化零价铁,内核为Fe-Mo-C合金,外壳可能由硫化钼、FeS、C、钼氧化物和铁氧化物组成。降解实验结果表明,将较优条件制备的MoS_(x)@ZVI碎磨至粒径<0.1 mm,用0.6 g MoS_(x)@ZVI处理400 mL 200 mg/L OG模拟废水,在初始pH=3.0~10.0范围处理150 min,OG的去除率均在90%以上。展开更多
The design of anode materials with a high specific capacity,high cyclic stability,and superior rate performance is required for the practical applications of sodium-ion batteries(SIBs).In this regard,we introduce in t...The design of anode materials with a high specific capacity,high cyclic stability,and superior rate performance is required for the practical applications of sodium-ion batteries(SIBs).In this regard,we introduce in this work a facile,low-cost and scalable method for the synthesis of nanocomposites of amorphous molybdenum sulfide(a-MoS_(x))and hierarchical porous carbon and have systematically investigated their performance for sodium ion storage.In the synthesis,ammonium molybdate tetrahydrate and thioacetamide are used as molybdenum and sulfur sources,respectively,with abundant corn starch as the carbon source and KOH as an activation agent.A simple pyrolysis of their mixtures leads to the formation of nanocomposites with a-MoS_(x)embedded within a hierarchical porous carbon(MoS_(x)@HPC),which are featured with a high surface area of up to 518.4 m^(2) g^(-1)and hierarchical pores ranging from micropores to macropores.It has also been shown that the annealing of MoS_(x)@HPC results in the formation of crystalline MoS_(2)nanosheets anchored in the hierarchical porous carbon matrix(MoS_(2)@HPC).The as-prepared nanocomposite MoS_(x)@HPC1 at an optimum carbon content of 32 wt%delivers a high specific sodium storage capacity of 599 mAh g^(-1)at 0.2 A g^(-1)and a high-rate performa nce with a retained capacity of 289 mAh g^(-1)at 5 A g^(-1).A comparison of the electrochemical performances of MoS_(x)@HPC and MoS_(2)@HPC demonstrates the superior specific capacity,rate performance,and charge transfer kinetics of the former,highlighting the unique advantageous role of amorphous MoS_(x)relative to crystalline MoS_(2).展开更多
Precise design and synthesis of sub-nano scale catalysts with controllable electronic and geometric structures are pivotal for enhancing the hydrogen evolution reaction(HER)performance of molybdenum sulfide(MoS_(2))an...Precise design and synthesis of sub-nano scale catalysts with controllable electronic and geometric structures are pivotal for enhancing the hydrogen evolution reaction(HER)performance of molybdenum sulfide(MoS_(2))and unraveling its structure−activity relationship.By leveraging transition molybdenum polysulfide clusters as functional units for multi-level ordering,we successfully designed and synthesized MoS_(x)nanowire networks derived from[Mo_(3)S_(13)]^(2−) clusters via evaporationinduced self-assembly,which exhibit enhanced HER activity attributed to a high density of active sites and dynamic evolution behavior under cathodic potentials.MoS_(x) nanowire networks electrode yields a current density of 100 mA·cm^(−2) at 142 mV in 0.5 M H_(2)SO_(4).This work provides an attractive prospect for optimizing catalysts at the sub-nano scale and offers insights into a strategy for designing catalysts in various gas evolution reactions.展开更多
Traditional bulk MoS_(2) as an effective H_(2)-evolution cocatalyst is mainly subjected to the weak hydrogen-adsorption ability of highporpotion saturated S,resulting in a slow interfacial H_(2)-evolution reaction.In ...Traditional bulk MoS_(2) as an effective H_(2)-evolution cocatalyst is mainly subjected to the weak hydrogen-adsorption ability of highporpotion saturated S,resulting in a slow interfacial H_(2)-evolution reaction.In this paper,an efficient strategy for enhancing hydrogen adsorption of saturated S by manipulating electron density through O atoms is proposed to boost photocatalytic performance of CdS.Simultaneously,amorphization of MoS_(2) can further increase the unsaturated active S sites.Herein,oxygencontained amorphous MoS_(x)(a-MoOS_(x))nanoparticles(10-30 nm)were tightly loaded on the CdS surface through a mild photoinduced deposition method by using(NH_(4))_(2)[MoO(S_(4))_(2)]solution as the precursor at room temperature.The photocatalytic H_(2)-evolution result showed that the a-MoOS_(x)/CdS performed the superior H_(2)-production activity(382μmol·h^(-1),apparent quantum efficiencies(AQE)=11.83%)with a lot of visual H_(2)bubbles,which was 54.6,2.5,and 5.1 times as high as that of CdS,MoS_(x)/CdS,and annealed a-MoOS_(x)/CdS,respectively.Characterizations and density functional theory(DFT)calculations revealed the mechanism of improved H_(2)-evolution activity is that the O heteroatom in amorphous MoOS_(x) can enhance the atomic H-adsorption ability by manipulating the electron density to form electron-deficient S^((2-δ)-)sites.This study provides a new idea to improve the efficiency and number of H_(2)-evolution active sites for developing efficient cocatalysts in the field of photocatalytic hydrogen evolution.展开更多
Renewable energy powered electrocatalytic water splitting is a promising strategy for hydrogen generation,and the design and development of high-efficiency and earth-abundant electrocatalysts for hydrogen evolution re...Renewable energy powered electrocatalytic water splitting is a promising strategy for hydrogen generation,and the design and development of high-efficiency and earth-abundant electrocatalysts for hydrogen evolution reaction(HER)are highly desirable.Herein,MoS2 nanoflowers decorated two-dimensional carbonitride-based MXene Ti3CN(OH)x hybrids have been constructed by etching and post-hydrothermal methods.The electrochemical performance of the as-obtained Ti_(3)CN(OH)_(x)@MoS_(2)hybrids having a quasi core-shell structure is fascinating:An overpotential of 120 mV and a Tafel slope of 64 mV∙dec^(−1)can be delivered at a current density of 10 mA∙cm^(−2).And after 3,000 cyclic voltammetry cycles,it can be seen that there is no apparent attenuation.Both the experimental results and density functional theory(DFT)calculations indicate that the synergetic effects between Ti_(3)CN(OH)x and MoS_(2)are responsible for the robust electrochemical HER performance.The electrons of-OH group in Ti_(3)CN(OH)x are transferred to MoS_(2),making the adsorption energy of the composite for H almost vanish.The metallic Ti_(3)CN(OH)x is also beneficial to the fast charge transfer kinetics.The construction of MXene-based hybrids with optimal electronic structure and unique morphology tailored to the applications can be further used in other promising energy storage and conversion devices.展开更多
Aqueous zinc-ion batteries(ZIBs)have attracted increasing attention due to their low cost and high safety.MoS_(2) is a promising cathode material for aqueous ZIBs due to its favorable Zn^(2+)accommodation ability.Howe...Aqueous zinc-ion batteries(ZIBs)have attracted increasing attention due to their low cost and high safety.MoS_(2) is a promising cathode material for aqueous ZIBs due to its favorable Zn^(2+)accommodation ability.However,the structural strain and large volume changes during intercalation/deintercalation lead to exfoliation of active materials from substrate and cause irreversible capacity fading.In this work,a highly stable cathode was developed by designing a hierarchical carbon nanosheet-confined defective MoS_(x)material(CNS@MoS_(x)).This cathode material exhibits an excellent cycling stability with high capacity retention of 88.3%and~100%Coulombic efficiency after 400 cycles at 1.2 A·g^(-1),much superior compared to bare MoS_(2).Density functional theory(DFT)calculations combined with experiments illustrate that the promising electrochemical properties of CNS@MoS_(x)are due to the unique porous conductive structure of CNS with abundant active sites to anchor MoS_(x)via strong chemical bonding,enabling MoS_(x)to be firmly confined on the substrate.Moreover,this unique hierarchical complex structure ensures the fast migration of Zn^(2+)within MoS_(x)interlayer.展开更多
Surface and interface engineering plays a crucial role in modulating the properties of materials,especially two-dimensional(2D)materials.Hence,a strategy,forming heterostructures with MoS_(2),is proposed to overcome t...Surface and interface engineering plays a crucial role in modulating the properties of materials,especially two-dimensional(2D)materials.Hence,a strategy,forming heterostructures with MoS_(2),is proposed to overcome the natural agglomeration of Ti_(3)C_(2)T_(x) MXene nanosheets.Most importantly,the interactions between Ti_(3)C_(2)Tx and MoS_(2) were elaborately investigated by first-principles calculations based on density functional theory(DFT)for the first time.The calculations demonstrate that van der Waals forces dominate the interface interactions of Ti_(3)C_(2)T_(x) and MoS_(2),rendering Ti_(3)C_(2)T_(x)@MoS_(2) heterostructures favorable stability.The Ti_(3)C_(2)T_(x)@MoS_(2) heterostructure composites were synthesized through a facile one-step hydrothermal method and exhibit a 2D hierarchical structure.Furthermore,the corrosion and tribological properties of epoxy composite coatings with varying proportions of Ti_(3)C_(2)T_(x)@MoS_(2) composites were studied in detail.As a result,the epoxy composite coating with 0.1 wt.%Ti_(3)C_(2)T_(x)@MoS_(2) composites(Ti_(3)C_(2)T_(x)@MoS_(2)-0.1)exhibits excellent corrosion protection and antiwear performances.The Ti_(3)C_(2)T_(x)@MoS_(2)-0.1 keeps the largest low-frequency impedance modulus(|Z|_(0.)01 Hz)and coating resistance(R_(c))during the whole immersion period.Its wear rate is 0.09μm^(3)/(Nμm)under the load of 10 N,one half of that of pure epoxy coating(EP).This work further broadens the application of MXene-based heterostructure composites.展开更多
In order to prevent the microwave leakage and mutual interference,more and more microwave absorbing devices are added into the design of electronic products to ensure its routine operation.In this work,we have success...In order to prevent the microwave leakage and mutual interference,more and more microwave absorbing devices are added into the design of electronic products to ensure its routine operation.In this work,we have successfully prepared MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) hierarchical composites by one-pot hydrothermal method and focused on the relationship between structures and electromagnetic absorbing properties.Supported by comprehensive characterizations,M0S_(2) nanosheets were proved to be anchored on the surface and interlayer of Ti_(3)C_(2)T_(x) through a hydrothermal process.Additionally,TiO_(2) nanoparticles were obtained in situ.Due to these hierarchical structures,the MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) composites showed greatly enhanced microwave absorbing performance.The MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) composites exhibit a maximum reflection loss value of -33.5 dB at 10.24 GHz and the effective absorption bandwidth covers 3.1GHz(13.9-17 GHz)at the thickness of 1.0 mm,implying the features of wide frequency and light weight.This work in the hierarchical structure of MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) composites opens a promising door to the exploration of constructing extraordinary electromagnetic wave absorbents.展开更多
The few-layer Ti_(3)C_(2)T_(x)/MoS_(2) heterostructure was successfully prepared via vertically growing of MoS_(2) nanosheets on the few-layer Ti3C2Tx matrix using hydrothermal method.The tribological properties as ad...The few-layer Ti_(3)C_(2)T_(x)/MoS_(2) heterostructure was successfully prepared via vertically growing of MoS_(2) nanosheets on the few-layer Ti3C2Tx matrix using hydrothermal method.The tribological properties as additive in mineral oil(150N)were evaluated in detail.The 0.3 wt% of few-layer Ti_(3)C_(2)T_(x)/MoS_(2) heterostructure addition amount can reduce the friction and wear of 150N by 39% and 85%,respectively.Moreover,the enhancement effect of few-layer Ti_(3)C_(2)T_(x)/MoS_(2) on tribological properties of 150N is superior to that of few-layer Ti_(3)C_(2)T_(x),MoS_(2) nanosheets,and their mechanical mixture.Based on the characterization and analysis of wear debris and wear track,such excellent tribological properties of the few-layer Ti_(3)C_(2)T_(x)/MoS_(2) heterostructure derive from its structural advantage toward good dispersion,the synergistic lubrication of Ti_(3)C_(2)T_(x) and MoS_(2) nanosheets during the rubbing process,and the formation of tribo-film.展开更多
Photocatalytic hydrogen generation from water-splitting holds huge promise for resolving the current energy shortage and environmental issues.Nevertheless,it is still challenging so far to develop non-noble-metal phot...Photocatalytic hydrogen generation from water-splitting holds huge promise for resolving the current energy shortage and environmental issues.Nevertheless,it is still challenging so far to develop non-noble-metal photocatalysts which are efficient toward solar-powered hydrogen evolution reaction(HER).In this work,through an ultrasonic water-bath strategy combined with solvothermal and electrostatic assembly processes,we obtain homogeneous Cd_(1-x)Zn_(x)S–Ni_(2)P–MoS_(2) hybrid nano-spheres consisting of Cd_(1-x)Zn_(x)S solid solutions decorated by Ni_(2)P and 1 T/2 H MoS_(2) cocatalysts,which demonstrate excellent activity and stability for visible-light-responsive(λ>420 nm)H_(2) production.Specifically,the Cd_(1-x)Zn_(x)S-Ni_(2)P-MoS_(2) nano-spheres with 2 wt%Ni_(2)P and 0.2 wt%MoS_(2)(CZ_(0.7)S–2 N–0.2 M)exhibit the optimal HER activity of 55.77 mmol·g^(-1)·h^(-1),about 47 and 32 times more than that of CZ_(0.7)S and Pt–CZ_(0.7)S,respectively.The outstanding HER performance of Cd_(1-x)Zn_(x)S–Ni_(2)P–MoS_(2) can be ascribed to the presence of abundant HER active sites in Ni2 P nanoparticles and 1 T/2 H MoS_(2) nanosheets as well as the effective transfer and separation of charge carriers.Moreover,the coupling sequence of cocatalysts in Cd_(1-x)Zn_(x)S–Ni_(2)P–MoS_(2) is found to be critical in the regulation of charge transfer pathways and thus the resultant photocatalytic efficiency.The results displayed here could facilitate the engineering of high-performance photocatalysts employing multi-component cocatalysts for sustainable solar-to-fuel conversion.展开更多
文摘以辉钼矿(MoS_(2))、褐铁矿和无烟煤为原料,通过碳热还原法制备了MoS_(x)@ZVI复合材料。研究了MoS_(2)用量、焙烧温度、无烟煤用量和焙烧时间对MoS_(x)@ZVI去除酸性橙G(OG)的影响,并确定了制备MoS_(x)@ZVI的较优制备条件为焙烧温度1000℃、MoS_(2)用量6%、焙烧时间60 min和无烟煤用量25%。通过X射线衍射、扫描电子显微镜和能谱仪对较优条件制备的MoS_(x)@ZVI进行表征,结果表明,材料中生成了大量核壳结构的硫化零价铁,内核为Fe-Mo-C合金,外壳可能由硫化钼、FeS、C、钼氧化物和铁氧化物组成。降解实验结果表明,将较优条件制备的MoS_(x)@ZVI碎磨至粒径<0.1 mm,用0.6 g MoS_(x)@ZVI处理400 mL 200 mg/L OG模拟废水,在初始pH=3.0~10.0范围处理150 min,OG的去除率均在90%以上。
基金financially supported by grants from the Natural Science and Engineering Research Council of Canada(Grant#RGPIN-2020-05546)。
文摘The design of anode materials with a high specific capacity,high cyclic stability,and superior rate performance is required for the practical applications of sodium-ion batteries(SIBs).In this regard,we introduce in this work a facile,low-cost and scalable method for the synthesis of nanocomposites of amorphous molybdenum sulfide(a-MoS_(x))and hierarchical porous carbon and have systematically investigated their performance for sodium ion storage.In the synthesis,ammonium molybdate tetrahydrate and thioacetamide are used as molybdenum and sulfur sources,respectively,with abundant corn starch as the carbon source and KOH as an activation agent.A simple pyrolysis of their mixtures leads to the formation of nanocomposites with a-MoS_(x)embedded within a hierarchical porous carbon(MoS_(x)@HPC),which are featured with a high surface area of up to 518.4 m^(2) g^(-1)and hierarchical pores ranging from micropores to macropores.It has also been shown that the annealing of MoS_(x)@HPC results in the formation of crystalline MoS_(2)nanosheets anchored in the hierarchical porous carbon matrix(MoS_(2)@HPC).The as-prepared nanocomposite MoS_(x)@HPC1 at an optimum carbon content of 32 wt%delivers a high specific sodium storage capacity of 599 mAh g^(-1)at 0.2 A g^(-1)and a high-rate performa nce with a retained capacity of 289 mAh g^(-1)at 5 A g^(-1).A comparison of the electrochemical performances of MoS_(x)@HPC and MoS_(2)@HPC demonstrates the superior specific capacity,rate performance,and charge transfer kinetics of the former,highlighting the unique advantageous role of amorphous MoS_(x)relative to crystalline MoS_(2).
基金supported by Innovation Support Programme(Soft Science Research)Project Achievements of Jiangsu Province(No.BK20231514)the National College Student Innovation and Entrepreneurship Training Program(NO.202310293173K).
文摘Precise design and synthesis of sub-nano scale catalysts with controllable electronic and geometric structures are pivotal for enhancing the hydrogen evolution reaction(HER)performance of molybdenum sulfide(MoS_(2))and unraveling its structure−activity relationship.By leveraging transition molybdenum polysulfide clusters as functional units for multi-level ordering,we successfully designed and synthesized MoS_(x)nanowire networks derived from[Mo_(3)S_(13)]^(2−) clusters via evaporationinduced self-assembly,which exhibit enhanced HER activity attributed to a high density of active sites and dynamic evolution behavior under cathodic potentials.MoS_(x) nanowire networks electrode yields a current density of 100 mA·cm^(−2) at 142 mV in 0.5 M H_(2)SO_(4).This work provides an attractive prospect for optimizing catalysts at the sub-nano scale and offers insights into a strategy for designing catalysts in various gas evolution reactions.
基金This work was supported by the National Natural Science Foundation of China(No.22178275)the Natural Science Foundation of Hubei Province of China(No.2022CFA001).
文摘Traditional bulk MoS_(2) as an effective H_(2)-evolution cocatalyst is mainly subjected to the weak hydrogen-adsorption ability of highporpotion saturated S,resulting in a slow interfacial H_(2)-evolution reaction.In this paper,an efficient strategy for enhancing hydrogen adsorption of saturated S by manipulating electron density through O atoms is proposed to boost photocatalytic performance of CdS.Simultaneously,amorphization of MoS_(2) can further increase the unsaturated active S sites.Herein,oxygencontained amorphous MoS_(x)(a-MoOS_(x))nanoparticles(10-30 nm)were tightly loaded on the CdS surface through a mild photoinduced deposition method by using(NH_(4))_(2)[MoO(S_(4))_(2)]solution as the precursor at room temperature.The photocatalytic H_(2)-evolution result showed that the a-MoOS_(x)/CdS performed the superior H_(2)-production activity(382μmol·h^(-1),apparent quantum efficiencies(AQE)=11.83%)with a lot of visual H_(2)bubbles,which was 54.6,2.5,and 5.1 times as high as that of CdS,MoS_(x)/CdS,and annealed a-MoOS_(x)/CdS,respectively.Characterizations and density functional theory(DFT)calculations revealed the mechanism of improved H_(2)-evolution activity is that the O heteroatom in amorphous MoOS_(x) can enhance the atomic H-adsorption ability by manipulating the electron density to form electron-deficient S^((2-δ)-)sites.This study provides a new idea to improve the efficiency and number of H_(2)-evolution active sites for developing efficient cocatalysts in the field of photocatalytic hydrogen evolution.
基金supported by the National Natural Science Foundation of China(Nos.62004143 and 21902108)the Key Research and Development(R&D)Program of Hubei Province(No.2022BAA084)+1 种基金the Central Government Guided Local Science and Technology Development Special Fund Project(No.2020ZYYD033),the Natural Science Foundation of Hubei Province(No.2021CFB133)the Knowledge Innovation Program of Wuhan-Shuguang Project(No.2022010801020355).
文摘Renewable energy powered electrocatalytic water splitting is a promising strategy for hydrogen generation,and the design and development of high-efficiency and earth-abundant electrocatalysts for hydrogen evolution reaction(HER)are highly desirable.Herein,MoS2 nanoflowers decorated two-dimensional carbonitride-based MXene Ti3CN(OH)x hybrids have been constructed by etching and post-hydrothermal methods.The electrochemical performance of the as-obtained Ti_(3)CN(OH)_(x)@MoS_(2)hybrids having a quasi core-shell structure is fascinating:An overpotential of 120 mV and a Tafel slope of 64 mV∙dec^(−1)can be delivered at a current density of 10 mA∙cm^(−2).And after 3,000 cyclic voltammetry cycles,it can be seen that there is no apparent attenuation.Both the experimental results and density functional theory(DFT)calculations indicate that the synergetic effects between Ti_(3)CN(OH)x and MoS_(2)are responsible for the robust electrochemical HER performance.The electrons of-OH group in Ti_(3)CN(OH)x are transferred to MoS_(2),making the adsorption energy of the composite for H almost vanish.The metallic Ti_(3)CN(OH)x is also beneficial to the fast charge transfer kinetics.The construction of MXene-based hybrids with optimal electronic structure and unique morphology tailored to the applications can be further used in other promising energy storage and conversion devices.
基金The authors acknowledge the financial support by the National Natural Science Foundation of China(Nos.21922501,21625102,and 21471018)the China National Petroleum Corporation Research Fund Program,and the Research Institute of Petroleum Exploration and Development Research Fund Program.
文摘Aqueous zinc-ion batteries(ZIBs)have attracted increasing attention due to their low cost and high safety.MoS_(2) is a promising cathode material for aqueous ZIBs due to its favorable Zn^(2+)accommodation ability.However,the structural strain and large volume changes during intercalation/deintercalation lead to exfoliation of active materials from substrate and cause irreversible capacity fading.In this work,a highly stable cathode was developed by designing a hierarchical carbon nanosheet-confined defective MoS_(x)material(CNS@MoS_(x)).This cathode material exhibits an excellent cycling stability with high capacity retention of 88.3%and~100%Coulombic efficiency after 400 cycles at 1.2 A·g^(-1),much superior compared to bare MoS_(2).Density functional theory(DFT)calculations combined with experiments illustrate that the promising electrochemical properties of CNS@MoS_(x)are due to the unique porous conductive structure of CNS with abundant active sites to anchor MoS_(x)via strong chemical bonding,enabling MoS_(x)to be firmly confined on the substrate.Moreover,this unique hierarchical complex structure ensures the fast migration of Zn^(2+)within MoS_(x)interlayer.
基金financially supported by the National Natural Science Foundation of China(No.52075458)the Sichuan Science and Technology Program(No.2021JDRC0094)。
文摘Surface and interface engineering plays a crucial role in modulating the properties of materials,especially two-dimensional(2D)materials.Hence,a strategy,forming heterostructures with MoS_(2),is proposed to overcome the natural agglomeration of Ti_(3)C_(2)T_(x) MXene nanosheets.Most importantly,the interactions between Ti_(3)C_(2)Tx and MoS_(2) were elaborately investigated by first-principles calculations based on density functional theory(DFT)for the first time.The calculations demonstrate that van der Waals forces dominate the interface interactions of Ti_(3)C_(2)T_(x) and MoS_(2),rendering Ti_(3)C_(2)T_(x)@MoS_(2) heterostructures favorable stability.The Ti_(3)C_(2)T_(x)@MoS_(2) heterostructure composites were synthesized through a facile one-step hydrothermal method and exhibit a 2D hierarchical structure.Furthermore,the corrosion and tribological properties of epoxy composite coatings with varying proportions of Ti_(3)C_(2)T_(x)@MoS_(2) composites were studied in detail.As a result,the epoxy composite coating with 0.1 wt.%Ti_(3)C_(2)T_(x)@MoS_(2) composites(Ti_(3)C_(2)T_(x)@MoS_(2)-0.1)exhibits excellent corrosion protection and antiwear performances.The Ti_(3)C_(2)T_(x)@MoS_(2)-0.1 keeps the largest low-frequency impedance modulus(|Z|_(0.)01 Hz)and coating resistance(R_(c))during the whole immersion period.Its wear rate is 0.09μm^(3)/(Nμm)under the load of 10 N,one half of that of pure epoxy coating(EP).This work further broadens the application of MXene-based heterostructure composites.
基金financially supported by the National Natural Science Foundation of China(No.U2004177)Outstanding Youth Fund of Henan Province(No.212300410081)Natural Science Research Project of Henan Educational Committee(No.20A43001).
文摘In order to prevent the microwave leakage and mutual interference,more and more microwave absorbing devices are added into the design of electronic products to ensure its routine operation.In this work,we have successfully prepared MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) hierarchical composites by one-pot hydrothermal method and focused on the relationship between structures and electromagnetic absorbing properties.Supported by comprehensive characterizations,M0S_(2) nanosheets were proved to be anchored on the surface and interlayer of Ti_(3)C_(2)T_(x) through a hydrothermal process.Additionally,TiO_(2) nanoparticles were obtained in situ.Due to these hierarchical structures,the MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) composites showed greatly enhanced microwave absorbing performance.The MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) composites exhibit a maximum reflection loss value of -33.5 dB at 10.24 GHz and the effective absorption bandwidth covers 3.1GHz(13.9-17 GHz)at the thickness of 1.0 mm,implying the features of wide frequency and light weight.This work in the hierarchical structure of MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) composites opens a promising door to the exploration of constructing extraordinary electromagnetic wave absorbents.
基金The authors gratefully acknowledge the financial support provided by National Natural Science Foundation of China(No.52075458)Sichuan Science and Technology Program(No.2021JDRC0094).
文摘The few-layer Ti_(3)C_(2)T_(x)/MoS_(2) heterostructure was successfully prepared via vertically growing of MoS_(2) nanosheets on the few-layer Ti3C2Tx matrix using hydrothermal method.The tribological properties as additive in mineral oil(150N)were evaluated in detail.The 0.3 wt% of few-layer Ti_(3)C_(2)T_(x)/MoS_(2) heterostructure addition amount can reduce the friction and wear of 150N by 39% and 85%,respectively.Moreover,the enhancement effect of few-layer Ti_(3)C_(2)T_(x)/MoS_(2) on tribological properties of 150N is superior to that of few-layer Ti_(3)C_(2)T_(x),MoS_(2) nanosheets,and their mechanical mixture.Based on the characterization and analysis of wear debris and wear track,such excellent tribological properties of the few-layer Ti_(3)C_(2)T_(x)/MoS_(2) heterostructure derive from its structural advantage toward good dispersion,the synergistic lubrication of Ti_(3)C_(2)T_(x) and MoS_(2) nanosheets during the rubbing process,and the formation of tribo-film.
基金supported by the Foundation of State Key Laboratory of Structural Chemistry(20190021)the National Natural Science Foundation of China(51802170,21801150,51772162)+1 种基金the Natural Science Foundation of Shandong Province(ZR2018BEM014,ZR2019JQ14,ZR2019MB001)the Taishan Scholar Project of Shandong Province。
文摘Photocatalytic hydrogen generation from water-splitting holds huge promise for resolving the current energy shortage and environmental issues.Nevertheless,it is still challenging so far to develop non-noble-metal photocatalysts which are efficient toward solar-powered hydrogen evolution reaction(HER).In this work,through an ultrasonic water-bath strategy combined with solvothermal and electrostatic assembly processes,we obtain homogeneous Cd_(1-x)Zn_(x)S–Ni_(2)P–MoS_(2) hybrid nano-spheres consisting of Cd_(1-x)Zn_(x)S solid solutions decorated by Ni_(2)P and 1 T/2 H MoS_(2) cocatalysts,which demonstrate excellent activity and stability for visible-light-responsive(λ>420 nm)H_(2) production.Specifically,the Cd_(1-x)Zn_(x)S-Ni_(2)P-MoS_(2) nano-spheres with 2 wt%Ni_(2)P and 0.2 wt%MoS_(2)(CZ_(0.7)S–2 N–0.2 M)exhibit the optimal HER activity of 55.77 mmol·g^(-1)·h^(-1),about 47 and 32 times more than that of CZ_(0.7)S and Pt–CZ_(0.7)S,respectively.The outstanding HER performance of Cd_(1-x)Zn_(x)S–Ni_(2)P–MoS_(2) can be ascribed to the presence of abundant HER active sites in Ni2 P nanoparticles and 1 T/2 H MoS_(2) nanosheets as well as the effective transfer and separation of charge carriers.Moreover,the coupling sequence of cocatalysts in Cd_(1-x)Zn_(x)S–Ni_(2)P–MoS_(2) is found to be critical in the regulation of charge transfer pathways and thus the resultant photocatalytic efficiency.The results displayed here could facilitate the engineering of high-performance photocatalysts employing multi-component cocatalysts for sustainable solar-to-fuel conversion.
