Fiber-based material systems are emerging as key elements for next-generation wearable devices due to their remarkable advantages,including large mechanical deformability,breathability,and high durability.Recently,gre...Fiber-based material systems are emerging as key elements for next-generation wearable devices due to their remarkable advantages,including large mechanical deformability,breathability,and high durability.Recently,greatly improved mechani-cal stability has been established in functional fiber systems by introducing atomic-thick two-dimensional(2D)materials.Further development of intelligent fibers that can respond to various external stimuli is strongly needed for versatile applica-tions.In this work,helical-shaped semiconductive fibers capable of multifunctional sensing are obtained by wet-spinning MoS2 liquid crystal(LC)dispersions.The mechanical properties of the MoS2 fibers were improved by exploiting high-purity LC dispersions consisting of uniformly-sized MoS2 nanoflakes.Notably,three-dimensional(3D)helical fibers with structural chirality were successfully constructed by controlling the wet-spinning process parameters.The helical fibers exhibited multifunctional sensing characteristics,including(1)photodetection,(2)pH monitoring,(3)gas detection,and(4)3D strain sensing.2D materials with semiconducting properties as well as abundant surface reactive sites enable smart multifunctionalities in one-dimensional(1D)and helical fiber geometry,which is potentially useful for diverse applications such as wearable internet of things(IoT)devices and soft robotics.展开更多
Due to their unique characteristics,two-dimensional(2D)materials have drawn great attention as promising candidates for the next generation of integrated circuits,which generate a calculation unit with a new working m...Due to their unique characteristics,two-dimensional(2D)materials have drawn great attention as promising candidates for the next generation of integrated circuits,which generate a calculation unit with a new working mechanism,called a logic transistor.To figure out the application prospects of logic transistors,exploring the temperature dependence of logic characteristics is important.In this work,we explore the temperature effect on the electrical characteristic of a logic transistor,finding that changes in temperature cause transformation in the calculation:logical output converts from‘AND’at 10 K to‘OR’at 250 K.The transformation phenomenon of temperature regulation in logical output is caused by energy band which decreases with increasing temperature.In the experiment,the indirect band gap of MoS2 shows an obvious decrease from 1.581 eV to 1.535 eV as the temperature increases from 10 K to 250 K.The change of threshold voltage with temperature is consistent with the energy band,which confirms the theoretical analysis.Therefore,as a promising material for future integrated circuits,the demonstrated characteristic of 2D transistors suggests possible application for future functional devices.展开更多
The MoS_2 catalysts were prepared from various molybdate precursors including inorganic and organic molybdate compounds. The sulfidation degree and morphology of active phases of MoS_2 activated by various molybdate p...The MoS_2 catalysts were prepared from various molybdate precursors including inorganic and organic molybdate compounds. The sulfidation degree and morphology of active phases of MoS_2 activated by various molybdate precursors in H_2S/H_2 stream at different temperatures were studied by X-ray photoelectron spectroscopy(XPS) and high-resolution transmission electron microscopy(HRTEM). The organic molybdate precursors lead to MoS_2 catalysts with higher sulfidation degree and smaller active phases to demonstrate higher catalytic activity during hydrodesulfurizaiton(HDS) of 4,6-DMDBT.展开更多
Molybdenum disulfide(MoS_(2)),a typical two-dimensional transition metallic layered material,attracts tremendous attentions in the electrochemical energy storage due to its excellent physicochemical properties.However...Molybdenum disulfide(MoS_(2)),a typical two-dimensional transition metallic layered material,attracts tremendous attentions in the electrochemical energy storage due to its excellent physicochemical properties.However,with the deepening of the research and exploration of the lithium storage mechanism of these advanced MoS_(2)-based anode materials,the complex reaction process influenced by internal and external factors hinders the exhaustive understanding of the lithium storage process.To design stable anode material with high performance,it is urgent to review the mechanisms of reported anode materials and summarize the related factors that influence the reaction processes.This review aims to dissect all possible side reactions during charging and discharging process,uncover internal and external factors inducing various anode reactions and finally put forward strategies of controlling high cycling capacity and super-stable lithium storage capability of MoS_(2).This review will be helpful to the design of MoS_(2)-based lithium-ion batteries(LIBs) with excellent cycle performance to enlarge the application fields of these advanced electrochemical energy storage devices.展开更多
Recently, two-dimensional monolayer molybdenum disulfide(MoS_2), a transition metal dichalcogenide, has received considerable attention due to its direct bandgap, which does not exist in its bulk form, enabling applic...Recently, two-dimensional monolayer molybdenum disulfide(MoS_2), a transition metal dichalcogenide, has received considerable attention due to its direct bandgap, which does not exist in its bulk form, enabling applications in optoelectronics and also thanks to its enhanced catalytic activity which allows it to be used for energy harvesting. However,growth of controllable and high-quality monolayers is still a matter of research and the parameters determining growth mechanism are not completely clear. In this work, chemical vapor deposition is utilized to grow monolayer MoS_2 flakes while deposition duration and temperature effect have been systematically varied to develop a better understanding of the MoS_2 film formation and the influence of these parameters on the quality of the monolayer flakes. Different from previous studies, SEM results show that single-layer MoS_2 flakes do not necessarily grow flat on the surface, but rather they can stay erect and inclined at different angles on the surface, indicating possible gas-phase reactions allowing for monolayer film formation. We have also revealed that process duration influences the amount of MoO_3/MoO_2 within the film network. The homogeneity and the number of layers depend on the change in the desorption–adsorption of radicals together with sulfurization rates, and, inasmuch, a careful optimization of parameters is crucial. Therefore, distinct from the general trend of MoS_2 monolayer formation, our films are rough and heterogeneous with monolayer MoS_2 nanowalls. Despite this roughness and the heterogeneity, we observe a strong photoluminescence located around 675 nm.展开更多
Molybdenum disulfide (MoS2) holds great promise as atomically thin two-dimensional (2D) semiconductor for future electronics and opto-electronics. In this report, we study the magnetoresistance (MR) of MoS2 field-effe...Molybdenum disulfide (MoS2) holds great promise as atomically thin two-dimensional (2D) semiconductor for future electronics and opto-electronics. In this report, we study the magnetoresistance (MR) of MoS2 field-effect transistors (FETs) with graphene insertion layer at the contact interface. Owing to the unique device structure and high-quality contact interface, a gate-tunable linear MR up to 67% is observed at 2 K. By comparing with the MRs of graphene FETs and MoS2 FETs with conventional metal contact, it is found that this unusual MR is most likely to be originated from the contact interfaces between graphene and MoS2, and can be explained by the classical linear MR model caused by spatial fluctuation of carrier mobility. Our study demonstrates large MR responses in MoS2-based systems through heterojunction design, shedding lights for the future magneto-electronics and van der Waals heterostructures.展开更多
Density functional theory (DFT) and coupled cluster theory (CCSD(T)) calcula-tions were employed to investigate the geometric and electronic structures of a range of dinuclearmolybdenum sulfide clusters, Mo2S,- ...Density functional theory (DFT) and coupled cluster theory (CCSD(T)) calcula-tions were employed to investigate the geometric and electronic structures of a range of dinuclearmolybdenum sulfide clusters, Mo2S,- and Mo2S,^-/0(n = 4-8). The results showed that the sulfuratoms tended to occupy the terminal sites of the clusters continuously in the process of sequentialsulfidation. After the oxidation state of Mo atoms reached the maximum of +6, diverse disulfurligands emerged in the sulfur-rich Mo2S^-/0 (n = 7,8) clusters. The driving forces of removing asulfur atom from different S ligands in Mo2S^-/0 (n = 4-8) clusters, especially from those disulfurunits, were evaluated. The corresponding order may provide insight into the pretreatment of freshMoS2 catalysts. Vertical detachment energies (VDEs) were predicted according to the GeneralizedKoopmans' theorem, and then the photoelectron spectra (PES) were simulated. Molecular orbitaland spin density values were analyzed to elucidate the chemical bonding and the evolutionarybehavior in the dinuclear molvbdenum sulfide clusters.展开更多
We study molybdenum disulfide (MoS2) structures generated by folding single-layer and bilayer MoS2 flakes. We find that this modified layer stacking leads to a decrease in the interlayer coupling and an enhancement ...We study molybdenum disulfide (MoS2) structures generated by folding single-layer and bilayer MoS2 flakes. We find that this modified layer stacking leads to a decrease in the interlayer coupling and an enhancement of the photoluminescence emission yield. We additionally find that folded single-layer MoS2 structures show a contribution to photoluminescence spectra of both neutral and charged excitons, which is a characteristic feature of single-layer MoS2 that has not been observed in multilayer MoS2. The results presented here open the door to fabrication of multilayered MoS2 samples with high optical absorption while maintaining the advantageous enhanced photoluminescence emission of single-layer MoS2 by controllably twisting the MoS2 layers.展开更多
Designing efficient electrocatalysts for the hydrogen evolution reaction (HER) has attracted substantial attention owing to the urgent demand for clean energy to face the energy crisis and subsequent environmental i...Designing efficient electrocatalysts for the hydrogen evolution reaction (HER) has attracted substantial attention owing to the urgent demand for clean energy to face the energy crisis and subsequent environmental issues in the near future. Among the large variety of HER catalysts, molybdenum disulfide (MoS2) has been regarded as the most famous catalyst owing to its abundance, low price, high efficiency, and definite catalytic mechanism. In this study, defect-engineered MoS2 nanowall (NW) catalysts with controllable thickness were fabricated and exhibited a significantly enhanced HER performance. Benefiting from the highly exposed active edge sites and the rough surface accompanied by the robust NW structure, the defect-rich MoS2 NW catalyst with an optimized thickness showed an ultralow onset overpotential of 85 mV, a high current density of 310.6 mA·cm^-2 at η = 300 mV, and a low potential of 95 mV to drive a 10 mA·cm^-2 cathodic current. Additionally, excellent electrochemical stability was realized, making this freestanding NW catalyst a promising candidate for practical water splitting and hydrogen production.展开更多
In the past few years, two-dimensional (2D) transition metal dichalcogenide (TMDC) materials have attracted increasing attention of the research community, owing to their unique electronic and optical properties, ...In the past few years, two-dimensional (2D) transition metal dichalcogenide (TMDC) materials have attracted increasing attention of the research community, owing to their unique electronic and optical properties, ranging from the valley-spin coupling to the indirect-to-direct bandgap transition when scaling the materials from multi-layer to monolayer. These properties are appealing for the development of novel electronic and optoelectronic devices with important applications in the broad fields of communication, computation, and healthcare. One of the key features of the TMDC family is the indirect-to-direct bandgap transition that occurs when the material thickness decreases from multilayer to monolayer, which is favorable for many photonic applications. TMDCs have also demonstrated unprecedented flexibility and versatility for constructing a wide range of heterostructures with atomic-level control over their layer thickness that is also free of lattice mismatch issues. As a result, layered TMDCs in combination with other 2D materials have the potential for realizing novel high-performance optoelectronic devices over a broad operating spectral range. In this article, we review the recent progress in the synthesis of 2D TMDCs and optoelectronic devices research. We also discuss the challenges facing the scalable applications of the family of 2D materials and provide our perspective on the opportunities offered by these materials for future generations of nanophotonics technology.展开更多
Semiconductoremetal nanocomposites have been widely investigated to modify the intrinsic properties of materials used for optoelectronic devices and sensing applications.In this study,a method for rapid synthesis of M...Semiconductoremetal nanocomposites have been widely investigated to modify the intrinsic properties of materials used for optoelectronic devices and sensing applications.In this study,a method for rapid synthesis of MoS_(2)-Ag nanocomposites via laser-assisted photoreduction was proposed.For the photoreduction process,we used AgNO_(3)solution as a metal source.Under laser irradiation,Ag ions were easily reduced on MoS_(2)by photo-generated electrons from MoS_(2).The optical properties of MoS_(2)-Ag nanocomposites were easily controlled by simple adjustment of the photoreduction time.To investigate the surface-enhanced Raman scattering(SERS)effect of the MoS_(2)-Ag nanocomposites,the SERS spectra of methylene blue(MB)on MoS_(2)-Ag nanocomposites were measured,and the nanocomposites were found to enhance the Raman scattering intensity of MB up to~106.Therefore,the laser-assisted photoreduction method has great potential for rapid synthesis and optical tuning of semiconductoremetal nanocomposites.展开更多
基金supported by the National Creative Research Initiative(CRI)Center for Multi-Dimensional Directed Nanoscale Assembly(2015R1A3A2033061)through the National Research Foundation of Korea(NRF)funded by the Ministry of Educationsupported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2022M3H4A1A02046445)+2 种基金This work was supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.RS-2024-00406240)This work was supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.RS-2024-00347619)This research was supported by the National Research Council of Science&Technology(NST)grant by the Korea government(MSIT)(No.CAP22071-000).
文摘Fiber-based material systems are emerging as key elements for next-generation wearable devices due to their remarkable advantages,including large mechanical deformability,breathability,and high durability.Recently,greatly improved mechani-cal stability has been established in functional fiber systems by introducing atomic-thick two-dimensional(2D)materials.Further development of intelligent fibers that can respond to various external stimuli is strongly needed for versatile applica-tions.In this work,helical-shaped semiconductive fibers capable of multifunctional sensing are obtained by wet-spinning MoS2 liquid crystal(LC)dispersions.The mechanical properties of the MoS2 fibers were improved by exploiting high-purity LC dispersions consisting of uniformly-sized MoS2 nanoflakes.Notably,three-dimensional(3D)helical fibers with structural chirality were successfully constructed by controlling the wet-spinning process parameters.The helical fibers exhibited multifunctional sensing characteristics,including(1)photodetection,(2)pH monitoring,(3)gas detection,and(4)3D strain sensing.2D materials with semiconducting properties as well as abundant surface reactive sites enable smart multifunctionalities in one-dimensional(1D)and helical fiber geometry,which is potentially useful for diverse applications such as wearable internet of things(IoT)devices and soft robotics.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61925402,61851402,and 61734003)Science and Technology Commission of Shanghai Municipality,China(Grant No.19JC1416600)+1 种基金National Key Research and Development Program of China(Grant No.2017YFB0405600)Shanghai Education Development Foundation and Shanghai Municipal Education Commission Shuguang Program,China(Grant No.18SG01).
文摘Due to their unique characteristics,two-dimensional(2D)materials have drawn great attention as promising candidates for the next generation of integrated circuits,which generate a calculation unit with a new working mechanism,called a logic transistor.To figure out the application prospects of logic transistors,exploring the temperature dependence of logic characteristics is important.In this work,we explore the temperature effect on the electrical characteristic of a logic transistor,finding that changes in temperature cause transformation in the calculation:logical output converts from‘AND’at 10 K to‘OR’at 250 K.The transformation phenomenon of temperature regulation in logical output is caused by energy band which decreases with increasing temperature.In the experiment,the indirect band gap of MoS2 shows an obvious decrease from 1.581 eV to 1.535 eV as the temperature increases from 10 K to 250 K.The change of threshold voltage with temperature is consistent with the energy band,which confirms the theoretical analysis.Therefore,as a promising material for future integrated circuits,the demonstrated characteristic of 2D transistors suggests possible application for future functional devices.
基金the financial support by the National Key Basic Research Development Program "973" Project (2012CB224800) of China
文摘The MoS_2 catalysts were prepared from various molybdate precursors including inorganic and organic molybdate compounds. The sulfidation degree and morphology of active phases of MoS_2 activated by various molybdate precursors in H_2S/H_2 stream at different temperatures were studied by X-ray photoelectron spectroscopy(XPS) and high-resolution transmission electron microscopy(HRTEM). The organic molybdate precursors lead to MoS_2 catalysts with higher sulfidation degree and smaller active phases to demonstrate higher catalytic activity during hydrodesulfurizaiton(HDS) of 4,6-DMDBT.
基金financially supported by the National Funds for Distinguished Young Scientists (No. 61825503)the National Natural Science Foundation of China (Nos. 51902101, 61775101,61804082)+3 种基金the Youth Natural Science Foundation of Hunan Province (No. 2019JJ50044)Natural Science Foundation of Jiangsu Province (No. BK20201381)Science Foundation of Nanjing University of Posts and Telecommunications (No. NY219144)China Postdoctoral Science Foundation (Nos. 2020TQ0202, 2021M692161)。
文摘Molybdenum disulfide(MoS_(2)),a typical two-dimensional transition metallic layered material,attracts tremendous attentions in the electrochemical energy storage due to its excellent physicochemical properties.However,with the deepening of the research and exploration of the lithium storage mechanism of these advanced MoS_(2)-based anode materials,the complex reaction process influenced by internal and external factors hinders the exhaustive understanding of the lithium storage process.To design stable anode material with high performance,it is urgent to review the mechanisms of reported anode materials and summarize the related factors that influence the reaction processes.This review aims to dissect all possible side reactions during charging and discharging process,uncover internal and external factors inducing various anode reactions and finally put forward strategies of controlling high cycling capacity and super-stable lithium storage capability of MoS_(2).This review will be helpful to the design of MoS_(2)-based lithium-ion batteries(LIBs) with excellent cycle performance to enlarge the application fields of these advanced electrochemical energy storage devices.
基金supported by Anadolu University BAP 1407F335 and BAP 1505F271 Projects
文摘Recently, two-dimensional monolayer molybdenum disulfide(MoS_2), a transition metal dichalcogenide, has received considerable attention due to its direct bandgap, which does not exist in its bulk form, enabling applications in optoelectronics and also thanks to its enhanced catalytic activity which allows it to be used for energy harvesting. However,growth of controllable and high-quality monolayers is still a matter of research and the parameters determining growth mechanism are not completely clear. In this work, chemical vapor deposition is utilized to grow monolayer MoS_2 flakes while deposition duration and temperature effect have been systematically varied to develop a better understanding of the MoS_2 film formation and the influence of these parameters on the quality of the monolayer flakes. Different from previous studies, SEM results show that single-layer MoS_2 flakes do not necessarily grow flat on the surface, but rather they can stay erect and inclined at different angles on the surface, indicating possible gas-phase reactions allowing for monolayer film formation. We have also revealed that process duration influences the amount of MoO_3/MoO_2 within the film network. The homogeneity and the number of layers depend on the change in the desorption–adsorption of radicals together with sulfurization rates, and, inasmuch, a careful optimization of parameters is crucial. Therefore, distinct from the general trend of MoS_2 monolayer formation, our films are rough and heterogeneous with monolayer MoS_2 nanowalls. Despite this roughness and the heterogeneity, we observe a strong photoluminescence located around 675 nm.
基金the National Key Research and Development Program of China(No.2018YFB0406603)the National Natural Science Foundation of China(Nos.61574006,61522401,61927806,61521004,11634002,and U1632156)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB30000000).
文摘Molybdenum disulfide (MoS2) holds great promise as atomically thin two-dimensional (2D) semiconductor for future electronics and opto-electronics. In this report, we study the magnetoresistance (MR) of MoS2 field-effect transistors (FETs) with graphene insertion layer at the contact interface. Owing to the unique device structure and high-quality contact interface, a gate-tunable linear MR up to 67% is observed at 2 K. By comparing with the MRs of graphene FETs and MoS2 FETs with conventional metal contact, it is found that this unusual MR is most likely to be originated from the contact interfaces between graphene and MoS2, and can be explained by the classical linear MR model caused by spatial fluctuation of carrier mobility. Our study demonstrates large MR responses in MoS2-based systems through heterojunction design, shedding lights for the future magneto-electronics and van der Waals heterostructures.
基金supported by the National Natural Science Foundation of China(21301030 and 21371034)the Science and Technology Development Fund of Fuzhou University(XRC-1017 and 2012-XY-6)
文摘Density functional theory (DFT) and coupled cluster theory (CCSD(T)) calcula-tions were employed to investigate the geometric and electronic structures of a range of dinuclearmolybdenum sulfide clusters, Mo2S,- and Mo2S,^-/0(n = 4-8). The results showed that the sulfuratoms tended to occupy the terminal sites of the clusters continuously in the process of sequentialsulfidation. After the oxidation state of Mo atoms reached the maximum of +6, diverse disulfurligands emerged in the sulfur-rich Mo2S^-/0 (n = 7,8) clusters. The driving forces of removing asulfur atom from different S ligands in Mo2S^-/0 (n = 4-8) clusters, especially from those disulfurunits, were evaluated. The corresponding order may provide insight into the pretreatment of freshMoS2 catalysts. Vertical detachment energies (VDEs) were predicted according to the GeneralizedKoopmans' theorem, and then the photoelectron spectra (PES) were simulated. Molecular orbitaland spin density values were analyzed to elucidate the chemical bonding and the evolutionarybehavior in the dinuclear molvbdenum sulfide clusters.
文摘We study molybdenum disulfide (MoS2) structures generated by folding single-layer and bilayer MoS2 flakes. We find that this modified layer stacking leads to a decrease in the interlayer coupling and an enhancement of the photoluminescence emission yield. We additionally find that folded single-layer MoS2 structures show a contribution to photoluminescence spectra of both neutral and charged excitons, which is a characteristic feature of single-layer MoS2 that has not been observed in multilayer MoS2. The results presented here open the door to fabrication of multilayered MoS2 samples with high optical absorption while maintaining the advantageous enhanced photoluminescence emission of single-layer MoS2 by controllably twisting the MoS2 layers.
基金Acknowledgements This work was financially supported by the National Basic Research Program of China (No. 2015CB932302), the National Natural Science Foundation of China (Nos. 21501112, 21331005, 21401181, U1532265, U1632149, 91422303, and 11321503), and Natural Science Foundation of Shandong Province (No. ZR2014BQ007).
文摘Designing efficient electrocatalysts for the hydrogen evolution reaction (HER) has attracted substantial attention owing to the urgent demand for clean energy to face the energy crisis and subsequent environmental issues in the near future. Among the large variety of HER catalysts, molybdenum disulfide (MoS2) has been regarded as the most famous catalyst owing to its abundance, low price, high efficiency, and definite catalytic mechanism. In this study, defect-engineered MoS2 nanowall (NW) catalysts with controllable thickness were fabricated and exhibited a significantly enhanced HER performance. Benefiting from the highly exposed active edge sites and the rough surface accompanied by the robust NW structure, the defect-rich MoS2 NW catalyst with an optimized thickness showed an ultralow onset overpotential of 85 mV, a high current density of 310.6 mA·cm^-2 at η = 300 mV, and a low potential of 95 mV to drive a 10 mA·cm^-2 cathodic current. Additionally, excellent electrochemical stability was realized, making this freestanding NW catalyst a promising candidate for practical water splitting and hydrogen production.
文摘In the past few years, two-dimensional (2D) transition metal dichalcogenide (TMDC) materials have attracted increasing attention of the research community, owing to their unique electronic and optical properties, ranging from the valley-spin coupling to the indirect-to-direct bandgap transition when scaling the materials from multi-layer to monolayer. These properties are appealing for the development of novel electronic and optoelectronic devices with important applications in the broad fields of communication, computation, and healthcare. One of the key features of the TMDC family is the indirect-to-direct bandgap transition that occurs when the material thickness decreases from multilayer to monolayer, which is favorable for many photonic applications. TMDCs have also demonstrated unprecedented flexibility and versatility for constructing a wide range of heterostructures with atomic-level control over their layer thickness that is also free of lattice mismatch issues. As a result, layered TMDCs in combination with other 2D materials have the potential for realizing novel high-performance optoelectronic devices over a broad operating spectral range. In this article, we review the recent progress in the synthesis of 2D TMDCs and optoelectronic devices research. We also discuss the challenges facing the scalable applications of the family of 2D materials and provide our perspective on the opportunities offered by these materials for future generations of nanophotonics technology.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT).(NRF-2020R1A2C4002557)It was also supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education.(NRF-2021R1A6A3A13045573)Miri Choi at the KBSI(Chuncheon)is thanked for technical assistance with the FE-TEM analysis.
文摘Semiconductoremetal nanocomposites have been widely investigated to modify the intrinsic properties of materials used for optoelectronic devices and sensing applications.In this study,a method for rapid synthesis of MoS_(2)-Ag nanocomposites via laser-assisted photoreduction was proposed.For the photoreduction process,we used AgNO_(3)solution as a metal source.Under laser irradiation,Ag ions were easily reduced on MoS_(2)by photo-generated electrons from MoS_(2).The optical properties of MoS_(2)-Ag nanocomposites were easily controlled by simple adjustment of the photoreduction time.To investigate the surface-enhanced Raman scattering(SERS)effect of the MoS_(2)-Ag nanocomposites,the SERS spectra of methylene blue(MB)on MoS_(2)-Ag nanocomposites were measured,and the nanocomposites were found to enhance the Raman scattering intensity of MB up to~106.Therefore,the laser-assisted photoreduction method has great potential for rapid synthesis and optical tuning of semiconductoremetal nanocomposites.