Electrocatalytic nitric oxide(NO)reduction reaction(NORR)is a promising and sustainable process that can simultaneously realize green ammonia(NH3)synthesis and hazardous NO removal.However,current NORR performances ar...Electrocatalytic nitric oxide(NO)reduction reaction(NORR)is a promising and sustainable process that can simultaneously realize green ammonia(NH3)synthesis and hazardous NO removal.However,current NORR performances are far from practical needs due to the lack of efficient electrocatalysts.Engineering the lattice of metal-based nanomaterials via phase control has emerged as an effective strategy to modulate their intrinsic electrocatalytic properties.Herein,we realize boron(B)-insertion-induced phase regulation of rhodium(Rh)nanocrystals to obtain amorphous Rh_(4)B nanoparticles(NPs)and hexagonal close-packed(hcp)RhB NPs through a facile wet-chemical method.A high Faradaic efficiency(92.1±1.2%)and NH_(3) yield rate(629.5±11.0μmol h^(−1) cm^(−2))are achieved over hcp RhB NPs,far superior to those of most reported NORR nanocatalysts.In situ spectro-electrochemical analysis and density functional theory simulations reveal that the excellent electrocatalytic performances of hcp RhB NPs are attributed to the upshift of d-band center,enhanced NO adsorption/activation profile,and greatly reduced energy barrier of the rate-determining step.A demonstrative Zn-NO battery is assembled using hcp RhB NPs as the cathode and delivers a peak power density of 4.33 mW cm−2,realizing simultaneous NO removal,NH3 synthesis,and electricity output.展开更多
Van der Waals heterostructures(vdWHs) are showing considerable potential in both fundamental exploration and practical applications. Built upon the synthetic successes of(two-dimensional) 2D materials, several synthet...Van der Waals heterostructures(vdWHs) are showing considerable potential in both fundamental exploration and practical applications. Built upon the synthetic successes of(two-dimensional) 2D materials, several synthetic strategies of vdWHs have been developed,allowing the convenient fabrication of diverse vdWHs with decent controllability, quality, and scalability. This review first summarizes the current state of the art in synthetic strategies of vdWHs, including physical combination, deposition, solvothermal synthesis, and synchronous evolution. Then three major applications and their representative vdWH devices have been reviewed, including electronics(tunneling field effect transistors and 2D contact),optoelectronics(photodetector), and energy conversion(electrocatalysts and metal ion batteries), to unveil the potentials of vdWHs in practical applications and provide the general design principles of functional vdWHs for different applications. Besides, moiré superlattices based on vdWHs are discussed to showcase the importance of vdWHs as a platform for novel condensed matter physics. Finally, the crucial challenges towards ideal vdWHs with high performance are discussed, and the outlook for future development is presented. By the systematical integration of synthetic strategies and applications, we hope this review can further light up the rational designs of vdWHs for emerging applications.展开更多
Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since ...Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief backgroundintroduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials(PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.展开更多
A fundamental understanding of the charge transport mechanism in two-dimensional semiconductors(e.g., MoS2) is crucial for fully exploring their potential in electronic and optoelectronic devices. By using monolayer g...A fundamental understanding of the charge transport mechanism in two-dimensional semiconductors(e.g., MoS2) is crucial for fully exploring their potential in electronic and optoelectronic devices. By using monolayer graphene as the barrier-free contact to MoS2, we show that the field-modulated conductivity can be used to probe the electronic structure of the localized states. A series of regularly distributed plateaus were observed in the gate-dependent transfer curves. Calculations based on the variable-range hopping theory indicate that such plateaus can be attributed to the discrete localized states near mobility edge. This method provides an effective approach to directly profiling the localized states in conduction channel with an ultrahigh resolution up to 1 meV.展开更多
Transition metal sulfides demonstrate attractive potential for sodium storage owing to their high theoretical specific capacity and high reserve.However,the low conductivity and volume expansion deteriorate their high...Transition metal sulfides demonstrate attractive potential for sodium storage owing to their high theoretical specific capacity and high reserve.However,the low conductivity and volume expansion deteriorate their high-rate performance and cycling stability.In this work,we construct NiS_(2)/FeS heterostructure by growing Ni-based layered double hydroxide nanosheets on Fe-based Prussian Blue nanocrystals followed by gaseous sulfurization,giving rise to flower-like NiS_(2)/FeS nanoparticles.The as-prepared nanocomposite exhibits good rate performance of 156 mAh g^(−1) at 50 A g^(-1) and long cycle life of 606 mAh g^(−1) at 5 A g^(−1) after 1,000 cycles,which are superior to the heterostructure-free counterpart of NiS_(2) and FeS.Density functional theory calculation further verifies that the enhanced electrochemical performance of NiS_(2)/FeS is due to the existence of interface derived from the heterostructure.展开更多
demonstrated to hydrogenate dangling bonds on the surface of crystalline silicon(c-Si),which reduces the interface defect density,thus enabling an outstanding passivation effect[1–3].However,like many other industria...demonstrated to hydrogenate dangling bonds on the surface of crystalline silicon(c-Si),which reduces the interface defect density,thus enabling an outstanding passivation effect[1–3].However,like many other industrial c-Si solar cells that suffer from light-induced degradation and light and elevated temperature induced degradation(LeTID)[4,5],the decay of electrical properties has also been found in thin-film a-Si:H solar cells[6–8],as well as samples of c-Si coated with intrinsic a-Si:H films after light soaking[9].A significant observation reported by Plagwitz et al.[10]suggested that illumination induced an increase in surface recombination velocities for both a-Si:H coated p-type and n-type c-Si substrates.The degradation of performance is generally attributed to the generation of deeplevel defects acting as recombination centers,most likely as single dangling bonds[11,12],which is considered to be related to the Staebler-Wronski effect(SWE)[13].展开更多
The remarkable successes of graphene have sparked increasing interest in elemental two‐dimensional(2D)materials,also referred to as Xenes.Due to their chemical simplicity and appealing physiochemical properties,Xenes...The remarkable successes of graphene have sparked increasing interest in elemental two‐dimensional(2D)materials,also referred to as Xenes.Due to their chemical simplicity and appealing physiochemical properties,Xenes have shown particular potential for numerous(opto)electronic,iontronic,and energy applications.Among them,layeredα‐phase tellurene has demonstrated the most promise,thanks to the recent successes in the chemical synthesis of highly crystalline 2D tellurene.However,the general electronic and electrochemical properties of tellurene in electrolyte systems remain ambiguous,hindering their further development.In this work,we studied the electrostatic gating,electrocatalysis,and electrochemical stability of tellurene in electrolyte systems.Our results show that tellurene obtained from both hydrothermal and chemical vapor deposition methods,two mainstream synthetic approaches for Xenes,demonstrates thickness‐dependent ambipolar transport with high hole mobility and stability in both aqueous electrolytes and ionic liquids.More importantly,the electrochemical properties of tellurene are investigated via the emerging on‐chip electrochemistry.Pristine tellurene demonstrates hydrogen evolution reaction with low Tafel slopes and remarkable electrochemical stability in acidic electrolytes over a large potential window.Our study provides a comprehensive understanding of the iontronic and electrochemical properties of tellurene,paving the way for the broad adoption of Xenes in sensors,synaptic devices,and electrocatalysis.展开更多
Cost-effective, rapid, and accurate virus detection technologies play key roles in reducing viral transmission. Prompt and accurate virus detection enables timely treatment and effective quarantine of virus carrier, a...Cost-effective, rapid, and accurate virus detection technologies play key roles in reducing viral transmission. Prompt and accurate virus detection enables timely treatment and effective quarantine of virus carrier, and therefore effectively reduces the possibility of large-scale spread. However, conventional virus detection techniques often suffer from slow response, high cost or sophisticated procedures. Recently, two-dimensional(2D) materials have been used as promising sensing platforms for the highperformance detection of a variety of chemical and biological substances. The unique properties of 2D materials, such as large specific area, active surface interaction with biomolecules and facile surface functionalization, provide advantages in developing novel virus detection technologies with fast response and high sensitivity. Furthermore, 2D materials possess versatile and tunable electronic, electrochemical and optical properties, making them ideal platforms to demonstrate conceptual sensing techniques and explore complex sensing mechanisms in next-generation biosensors. In this review, we first briefly summarize the virus detection techniques with an emphasis on the current efforts in fighting again COVID-19. Then, we introduce the preparation methods and properties of 2D materials utilized in biosensors, including graphene, transition metal dichalcogenides(TMDs) and other 2D materials. Furthermore, we discuss the working principles of various virus detection technologies based on emerging 2D materials, such as field-effect transistor-based virus detection, electrochemical virus detection, optical virus detection and other virus detection techniques. Then, we elaborate on the essential works in 2D material-based high-performance virus detection. Finally, our perspective on the challenges and future research direction in this field is discussed.展开更多
Layered van der Waals(vdW)materials,consisting of atomically thin layers,are of paramount importance in physics,chemistry,and materials science owing to their unique properties and various promising applications.Howev...Layered van der Waals(vdW)materials,consisting of atomically thin layers,are of paramount importance in physics,chemistry,and materials science owing to their unique properties and various promising applications.However,their fast and large‐scale growth via a general approach is still a big challenge,severely limiting their practical implementations.Here,we report a universal method for rapid(~60 min)and large‐scale(gram scale)growth of phase‐pure,high‐crystalline layered vdW materials from their elementary powders via microwave plasma heating in sealed ampoules.This method can be used for growth of 30 compounds with different components(binary,ternary,and quaternary)and properties.The ferroelectric and transport properties of mechanically exfoliated flakes validate the high crystal quality of the grown materials.Our study provides a general strategy for the fast and large‐scale growth of layered vdW materials with appealing physiochemical properties,which could be used for various promising applications.展开更多
Direct far-field visualization and characterization of surface plasmon polaritons(SPPs)are of great importance for fundamental studies and technological applications.To probe the evanescently confined plasmon fields,o...Direct far-field visualization and characterization of surface plasmon polaritons(SPPs)are of great importance for fundamental studies and technological applications.To probe the evanescently confined plasmon fields,one usually requires advanced near-field techniques,which is typically not applicable for real-time,high-throughput detecting or mapping of SPPs in complicated environments.Here,we report the utilization of rare-earth-doped nanoparticles to quantitatively upconvert invisible,evanescently confined SPPs into visible photoluminescence emissions for direct far-field visualization of SPPs in a complicated environment.The observed interference fringes between the SPPs and the coherent incident light at the metal surface provide a quantitative measurement of the SPP wavelength and the SPP propagating length and the local dielectric environments.It thus creates a new signaling pathway to sensitively transduce the local dielectric environment change into interference periodicity variation,enabling a new design of directly measurable,spectrometer-free optical rulers for rapid,ultrasensitive label-free detection of various biomolecules,including streptavidin and prostate-specific antigen,down to the femtomolar level.展开更多
Theπ-πstacking is a well-recognized intermolecular interaction that is responsible for the construction of electron hopping channels in numerous conducting frameworks/aggregates.However,the exact role ofπ-to-πchan...Theπ-πstacking is a well-recognized intermolecular interaction that is responsible for the construction of electron hopping channels in numerous conducting frameworks/aggregates.However,the exact role ofπ-to-πchannels within typical single crystalline organic semiconductors remains unclear as the orientations of these molecules are diverse,and their control usually requires additional side chain groups that misrepresent the intrinsic properties of the original semiconducting molecules.Therefore,the construction of conduction channels with intrinsicπ-πstacking in the molecule-based device is crucial for the utilization of their unique transport characteristics and understanding of the transport mechanism.To this end,we present a molecular intercalation strategy that integrates two-dimensional layered materials with functional organic semiconductor molecules for functional molecule-based electronics.Various organic semiconductor molecules can be effectively intercalated into the van der Waals gaps of semi-metallic TaS_(2) withπ-πstacking configuration and controlled intercalant content.Our results show that the vertical charge transport in the stacking direction shows a tunneling-dominated mechanism that strongly depends on the molecular structures.Furthermore,we demonstrated a new type of molecule-based vertical transistor in which TaS_(2) andπ-πstacked organic molecules function as the electrical contact and the active channel,respectively.On/off ratios as high as 447 are achieved under electrostatic modulation in ionic liquid,comparable to the current state-of-the-art molecular transistors.Our study provides an ideal platform for probing intrinsic charge transport acrossπ-πstacked conjugated molecules and also a feasible approach for the construction of high-performance molecule-based electronic devices.展开更多
As an important category of porous crystalline materials,metal-organic frameworks(MOFs)have attracted extensive research interests owing to their unique structural features such as tunable pore structure and enormous ...As an important category of porous crystalline materials,metal-organic frameworks(MOFs)have attracted extensive research interests owing to their unique structural features such as tunable pore structure and enormous surface area.Besides controlling the size,dimensionality,and composition of MOFs,further exploring the crystal-phase-dependent physicochemical properties is essential to improve their performances in various applications.Recently,great progress has been achieved in the phase engineering of nanomaterials(PEN),which provides an effective strategy to tune the functional properties of nanomaterials by modulating the arrangement of atoms.In this review,we adopt“phase”instead of“topology”to describe the crystal structure of MOFs and summarize the recent advances in phase engineering of MOFs.The two main strategies used to control the phase of MOFs,that is,phasecontrolled synthesis and phase transformation of MOFs,will be highlighted.The roles of various reaction parameters in controlling the crystal phase of MOFs are discussed.Then,the phase dependence of MOFs in various applications including luminescence,adsorption,and catalysis are introduced.Finally,some personal perspectives about the challenges and opportunities in this emerging field are presented.展开更多
基金funding support from General Research Fund[Project No.14300525]from the Research Grants Council(RGC)of Hong Kong SAR,Chinafunding support from Natural Science Foundation of China(NSFC)Young Scientists Fund(Project No.22305203)+2 种基金NSFC Projects Nos.22309123,22422303,22303011,22033002,92261112 and U21A20328support from the Hong Kong Branch of National Precious Metals Material Engineering Research Center(NPMM)at City University of Hong Kongsupport from Young Collaborative Research Grant[Project No.C1003-23Y]support from RGC of Hong Kong SAR,China.
文摘Electrocatalytic nitric oxide(NO)reduction reaction(NORR)is a promising and sustainable process that can simultaneously realize green ammonia(NH3)synthesis and hazardous NO removal.However,current NORR performances are far from practical needs due to the lack of efficient electrocatalysts.Engineering the lattice of metal-based nanomaterials via phase control has emerged as an effective strategy to modulate their intrinsic electrocatalytic properties.Herein,we realize boron(B)-insertion-induced phase regulation of rhodium(Rh)nanocrystals to obtain amorphous Rh_(4)B nanoparticles(NPs)and hexagonal close-packed(hcp)RhB NPs through a facile wet-chemical method.A high Faradaic efficiency(92.1±1.2%)and NH_(3) yield rate(629.5±11.0μmol h^(−1) cm^(−2))are achieved over hcp RhB NPs,far superior to those of most reported NORR nanocatalysts.In situ spectro-electrochemical analysis and density functional theory simulations reveal that the excellent electrocatalytic performances of hcp RhB NPs are attributed to the upshift of d-band center,enhanced NO adsorption/activation profile,and greatly reduced energy barrier of the rate-determining step.A demonstrative Zn-NO battery is assembled using hcp RhB NPs as the cathode and delivers a peak power density of 4.33 mW cm−2,realizing simultaneous NO removal,NH3 synthesis,and electricity output.
基金support from the Grants (9229079, 9610482,7005468) from City University of Hong KongEarly Career Scheme Project 21302821 from Research Grants Council。
文摘Van der Waals heterostructures(vdWHs) are showing considerable potential in both fundamental exploration and practical applications. Built upon the synthetic successes of(two-dimensional) 2D materials, several synthetic strategies of vdWHs have been developed,allowing the convenient fabrication of diverse vdWHs with decent controllability, quality, and scalability. This review first summarizes the current state of the art in synthetic strategies of vdWHs, including physical combination, deposition, solvothermal synthesis, and synchronous evolution. Then three major applications and their representative vdWH devices have been reviewed, including electronics(tunneling field effect transistors and 2D contact),optoelectronics(photodetector), and energy conversion(electrocatalysts and metal ion batteries), to unveil the potentials of vdWHs in practical applications and provide the general design principles of functional vdWHs for different applications. Besides, moiré superlattices based on vdWHs are discussed to showcase the importance of vdWHs as a platform for novel condensed matter physics. Finally, the crucial challenges towards ideal vdWHs with high performance are discussed, and the outlook for future development is presented. By the systematical integration of synthetic strategies and applications, we hope this review can further light up the rational designs of vdWHs for emerging applications.
文摘Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief backgroundintroduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials(PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.
基金the support by the National Science Foundation(DMR1508144)the financial support from the National Science Foundation(EFRI-1433541)
文摘A fundamental understanding of the charge transport mechanism in two-dimensional semiconductors(e.g., MoS2) is crucial for fully exploring their potential in electronic and optoelectronic devices. By using monolayer graphene as the barrier-free contact to MoS2, we show that the field-modulated conductivity can be used to probe the electronic structure of the localized states. A series of regularly distributed plateaus were observed in the gate-dependent transfer curves. Calculations based on the variable-range hopping theory indicate that such plateaus can be attributed to the discrete localized states near mobility edge. This method provides an effective approach to directly profiling the localized states in conduction channel with an ultrahigh resolution up to 1 meV.
基金National Key R&D Program of China(No.2021YFB2401900).
文摘Transition metal sulfides demonstrate attractive potential for sodium storage owing to their high theoretical specific capacity and high reserve.However,the low conductivity and volume expansion deteriorate their high-rate performance and cycling stability.In this work,we construct NiS_(2)/FeS heterostructure by growing Ni-based layered double hydroxide nanosheets on Fe-based Prussian Blue nanocrystals followed by gaseous sulfurization,giving rise to flower-like NiS_(2)/FeS nanoparticles.The as-prepared nanocomposite exhibits good rate performance of 156 mAh g^(−1) at 50 A g^(-1) and long cycle life of 606 mAh g^(−1) at 5 A g^(−1) after 1,000 cycles,which are superior to the heterostructure-free counterpart of NiS_(2) and FeS.Density functional theory calculation further verifies that the enhanced electrochemical performance of NiS_(2)/FeS is due to the existence of interface derived from the heterostructure.
基金the National Natural Science Foundation of China(61974129,62025403,and 61721005)the Natural Science Foundation of Zhejiang Province(LD22E020001)Lingyan Research and Development Project of Zhejiang Province(022C01215).
文摘demonstrated to hydrogenate dangling bonds on the surface of crystalline silicon(c-Si),which reduces the interface defect density,thus enabling an outstanding passivation effect[1–3].However,like many other industrial c-Si solar cells that suffer from light-induced degradation and light and elevated temperature induced degradation(LeTID)[4,5],the decay of electrical properties has also been found in thin-film a-Si:H solar cells[6–8],as well as samples of c-Si coated with intrinsic a-Si:H films after light soaking[9].A significant observation reported by Plagwitz et al.[10]suggested that illumination induced an increase in surface recombination velocities for both a-Si:H coated p-type and n-type c-Si substrates.The degradation of performance is generally attributed to the generation of deeplevel defects acting as recombination centers,most likely as single dangling bonds[11,12],which is considered to be related to the Staebler-Wronski effect(SWE)[13].
基金support from the Grants(Nos.9229079,9610482,and 7005468)the City University of Hong Kong and Early Career Scheme Project(No.21302821)General Research Fund Project(No.11314322)from the University Grants Committee of Hong Kong.
文摘The remarkable successes of graphene have sparked increasing interest in elemental two‐dimensional(2D)materials,also referred to as Xenes.Due to their chemical simplicity and appealing physiochemical properties,Xenes have shown particular potential for numerous(opto)electronic,iontronic,and energy applications.Among them,layeredα‐phase tellurene has demonstrated the most promise,thanks to the recent successes in the chemical synthesis of highly crystalline 2D tellurene.However,the general electronic and electrochemical properties of tellurene in electrolyte systems remain ambiguous,hindering their further development.In this work,we studied the electrostatic gating,electrocatalysis,and electrochemical stability of tellurene in electrolyte systems.Our results show that tellurene obtained from both hydrothermal and chemical vapor deposition methods,two mainstream synthetic approaches for Xenes,demonstrates thickness‐dependent ambipolar transport with high hole mobility and stability in both aqueous electrolytes and ionic liquids.More importantly,the electrochemical properties of tellurene are investigated via the emerging on‐chip electrochemistry.Pristine tellurene demonstrates hydrogen evolution reaction with low Tafel slopes and remarkable electrochemical stability in acidic electrolytes over a large potential window.Our study provides a comprehensive understanding of the iontronic and electrochemical properties of tellurene,paving the way for the broad adoption of Xenes in sensors,synaptic devices,and electrocatalysis.
基金support from ITC via the Hong Kong Branch of National Precious Metals Material Engineering Research Center (NPMM)the Research Grants Council of Hong Kong (AoE/P-701/ 20)+4 种基金the Start-Up Grant (9380100)the grants from the City University of Hong Kong (9610478, 9680314, 7020013, 1886921)the Science Technology and Innovation Committee of Shenzhen Municipality (JCYJ20200109143412311, SGDX2020110309300301, “Preparation of single atoms on transition metal chalcogenides for electrolytic hydrogen evolution”, City U)funding support from the StartUp Grant (7200656, 9610482)Grant from the City University of Hong Kong (7020013)。
文摘Cost-effective, rapid, and accurate virus detection technologies play key roles in reducing viral transmission. Prompt and accurate virus detection enables timely treatment and effective quarantine of virus carrier, and therefore effectively reduces the possibility of large-scale spread. However, conventional virus detection techniques often suffer from slow response, high cost or sophisticated procedures. Recently, two-dimensional(2D) materials have been used as promising sensing platforms for the highperformance detection of a variety of chemical and biological substances. The unique properties of 2D materials, such as large specific area, active surface interaction with biomolecules and facile surface functionalization, provide advantages in developing novel virus detection technologies with fast response and high sensitivity. Furthermore, 2D materials possess versatile and tunable electronic, electrochemical and optical properties, making them ideal platforms to demonstrate conceptual sensing techniques and explore complex sensing mechanisms in next-generation biosensors. In this review, we first briefly summarize the virus detection techniques with an emphasis on the current efforts in fighting again COVID-19. Then, we introduce the preparation methods and properties of 2D materials utilized in biosensors, including graphene, transition metal dichalcogenides(TMDs) and other 2D materials. Furthermore, we discuss the working principles of various virus detection technologies based on emerging 2D materials, such as field-effect transistor-based virus detection, electrochemical virus detection, optical virus detection and other virus detection techniques. Then, we elaborate on the essential works in 2D material-based high-performance virus detection. Finally, our perspective on the challenges and future research direction in this field is discussed.
文摘Layered van der Waals(vdW)materials,consisting of atomically thin layers,are of paramount importance in physics,chemistry,and materials science owing to their unique properties and various promising applications.However,their fast and large‐scale growth via a general approach is still a big challenge,severely limiting their practical implementations.Here,we report a universal method for rapid(~60 min)and large‐scale(gram scale)growth of phase‐pure,high‐crystalline layered vdW materials from their elementary powders via microwave plasma heating in sealed ampoules.This method can be used for growth of 30 compounds with different components(binary,ternary,and quaternary)and properties.The ferroelectric and transport properties of mechanically exfoliated flakes validate the high crystal quality of the grown materials.Our study provides a general strategy for the fast and large‐scale growth of layered vdW materials with appealing physiochemical properties,which could be used for various promising applications.
基金X.D.acknowledge the financial support from the National Science Foundation through grant No.1610361.
文摘Direct far-field visualization and characterization of surface plasmon polaritons(SPPs)are of great importance for fundamental studies and technological applications.To probe the evanescently confined plasmon fields,one usually requires advanced near-field techniques,which is typically not applicable for real-time,high-throughput detecting or mapping of SPPs in complicated environments.Here,we report the utilization of rare-earth-doped nanoparticles to quantitatively upconvert invisible,evanescently confined SPPs into visible photoluminescence emissions for direct far-field visualization of SPPs in a complicated environment.The observed interference fringes between the SPPs and the coherent incident light at the metal surface provide a quantitative measurement of the SPP wavelength and the SPP propagating length and the local dielectric environments.It thus creates a new signaling pathway to sensitively transduce the local dielectric environment change into interference periodicity variation,enabling a new design of directly measurable,spectrometer-free optical rulers for rapid,ultrasensitive label-free detection of various biomolecules,including streptavidin and prostate-specific antigen,down to the femtomolar level.
基金support by the National Natural Science Foundation of China(Nos.22172075,92156024)the Fundamental Research Funds for the Central Universities in China(Nos.0210/14380174,14380273)+4 种基金Beijing National Laboratory for Molecular Sciences(No.BNLMS202107)Thousand Talents Plan of Jiangxi Province(No.jxsq2019102002)support by the National Natural Science Foundation of China(No.22033004)support from Early Career Scheme Project(No.21302821)General Research Fund Project(No.11314322)from the University Grants Committee of Hong Kong.
文摘Theπ-πstacking is a well-recognized intermolecular interaction that is responsible for the construction of electron hopping channels in numerous conducting frameworks/aggregates.However,the exact role ofπ-to-πchannels within typical single crystalline organic semiconductors remains unclear as the orientations of these molecules are diverse,and their control usually requires additional side chain groups that misrepresent the intrinsic properties of the original semiconducting molecules.Therefore,the construction of conduction channels with intrinsicπ-πstacking in the molecule-based device is crucial for the utilization of their unique transport characteristics and understanding of the transport mechanism.To this end,we present a molecular intercalation strategy that integrates two-dimensional layered materials with functional organic semiconductor molecules for functional molecule-based electronics.Various organic semiconductor molecules can be effectively intercalated into the van der Waals gaps of semi-metallic TaS_(2) withπ-πstacking configuration and controlled intercalant content.Our results show that the vertical charge transport in the stacking direction shows a tunneling-dominated mechanism that strongly depends on the molecular structures.Furthermore,we demonstrated a new type of molecule-based vertical transistor in which TaS_(2) andπ-πstacked organic molecules function as the electrical contact and the active channel,respectively.On/off ratios as high as 447 are achieved under electrostatic modulation in ionic liquid,comparable to the current state-of-the-art molecular transistors.Our study provides an ideal platform for probing intrinsic charge transport acrossπ-πstacked conjugated molecules and also a feasible approach for the construction of high-performance molecule-based electronic devices.
基金The Chinese University of Hong Kong:Start-up,Grant/Award Number:4930977Direct Grant for Research,Grant/Award Number:4053444+1 种基金City University of Hong Kong,Grant/Award Numbers:9610478,9680314,7020013,1886921Start-Up,Grant/Award Number:9380100。
文摘As an important category of porous crystalline materials,metal-organic frameworks(MOFs)have attracted extensive research interests owing to their unique structural features such as tunable pore structure and enormous surface area.Besides controlling the size,dimensionality,and composition of MOFs,further exploring the crystal-phase-dependent physicochemical properties is essential to improve their performances in various applications.Recently,great progress has been achieved in the phase engineering of nanomaterials(PEN),which provides an effective strategy to tune the functional properties of nanomaterials by modulating the arrangement of atoms.In this review,we adopt“phase”instead of“topology”to describe the crystal structure of MOFs and summarize the recent advances in phase engineering of MOFs.The two main strategies used to control the phase of MOFs,that is,phasecontrolled synthesis and phase transformation of MOFs,will be highlighted.The roles of various reaction parameters in controlling the crystal phase of MOFs are discussed.Then,the phase dependence of MOFs in various applications including luminescence,adsorption,and catalysis are introduced.Finally,some personal perspectives about the challenges and opportunities in this emerging field are presented.
