Two-dimensional(2D)materials have attracted tremendous interest in view of the outstanding optoelectronic properties,showing new possibilities for future photovoltaic devices toward high performance,high specific powe...Two-dimensional(2D)materials have attracted tremendous interest in view of the outstanding optoelectronic properties,showing new possibilities for future photovoltaic devices toward high performance,high specific power and flexibility.In recent years,substantial works have focused on 2D photovoltaic devices,and great progress has been achieved.Here,we present the review of recent advances in 2D photovoltaic devices,focusing on 2D-material-based Schottky junctions,homojunctions,2D−2D heterojunctions,2D−3D heterojunctions,and bulk photovoltaic effect devices.Furthermore,advanced strategies for improving the photovoltaic performances are demonstrated in detail.Finally,conclusions and outlooks are delivered,providing a guideline for the further development of 2D photovoltaic devices.展开更多
Among the alloying-type anodes,elemental Sb possesses the suitable yet safe plateau,simple lithiation pathway,small voltage polarization,high conductivity,and superior cycle stability.However,challenge is that its int...Among the alloying-type anodes,elemental Sb possesses the suitable yet safe plateau,simple lithiation pathway,small voltage polarization,high conductivity,and superior cycle stability.However,challenge is that its intrinsic capacity is rather low(660 mAh g^(-1)),<1/6 of silicon.Herein,we propose a seamless integration strategy by merging the voltage and capacity of phosphorus and antimony into a solid solution alloy.Interestingly,the enlistment of P is found greatly enlarge the capacity from 660 to 993 mAh g^(-1) for such Sb_(30)P_(30) solid solution,while maintaining a single and stable discharge plateau(~0.79 V)similar to elemental Sb.Various experimental characterizations including XPS,PDF,Raman,and EDS mapping reveal that in such a material the P and Sb atoms have interacted with each other to form a homogenous solid solution alloy,rather than a simple mixing of the two substances.Thus,the Sb_(30)P_(30) exhibits superior rate performances(807 mAh g^(-1) at 5000 mA g^(-1))and cyclability(821 mAh g^(-1) remained after 300 cycles).Furthermore,such Sb_(60-x)P_(x) alloys can even deliver 621 mAh g^(-1) at30℃,which can be served as the alternative anode materials for high-energy and low-temperature batteries.This unique seamless integration strategy based on solid solution chemistry can be easily leveraged to manipulate the capacity of other electrode materials at similar voltage.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
Water electrolysis at high current density(1000 mA cm-2 level)with excellent durability especially in neutral electrolyte is the pivotal issue for green hydrogen from experiment to industrialization.In addition to the...Water electrolysis at high current density(1000 mA cm-2 level)with excellent durability especially in neutral electrolyte is the pivotal issue for green hydrogen from experiment to industrialization.In addition to the high intrinsic activity determined by the electronic structure,electrocatalysts are also required to be capable of fast mass transfer(electrolyte recharge and bubble overflow)and high mechanical stability.Herein,the 2D CoOOH sheet-encapsulated Ni2P into tubular arrays electrocatalytic system was proposed and realized 1000 mA cm-2-levelcurrent-density hydrogen evolution over 100 h in neutral water.In designed catalysts,2D stack structure as an adaptive material can buffer the shock of electrolyte convection,hydrogen bubble rupture,and evolution through the release of stress,which insure the long cycle stability.Meanwhile,the rich porosity between stacked units contributed the good infiltration of electrolyte and slippage of hydrogen bubbles,guaranteeing electrolyte fast recharge and bubble evolution at the high-current catalysis.Beyond that,the electron structure modulation induced by interfacial charge transfer is also beneficial to enhance the intrinsic activity.Profoundly,the multiscale coordinated regulation will provide a guide to design high-efficiency industrial electrocatalysts.展开更多
Self-powered devices are widely used in the detection and sensing fields.Asymmetric metal contacts provide an effective way to obtain self-powered devices.Finding two stable metallic electrode materials with large wor...Self-powered devices are widely used in the detection and sensing fields.Asymmetric metal contacts provide an effective way to obtain self-powered devices.Finding two stable metallic electrode materials with large work function differences is the key to obtain highly efficient asymmetric metal contacts structures.However,common metal electrode materials have similar and high work functions,making it difficult to form an asymmetric contacts structure with a large work function difference.Herein,Mo2C crystals with low work function(3.8 eV) was obtained by chemical vapor deposition(CVD) method.The large work function difference between Mo2C and Au allowed us to synthesize an efficient Mo2C/MoS2/Au photodetector with asymmetric metal contact structure,which enables light detection without external electric power.We believe that this novel device provides a new direcfor the design of miniature self-powered photodetectors.These results also highlight the great potential of ultrathin Mo2C prepared by CVD in heterojunction device applications.展开更多
Nonlayered two-dimensional(2D)materials have attracted increasing attention,due to novel physical properties,unique surface structure,and high compatibility with microfabrication technique.However,owing to the inheren...Nonlayered two-dimensional(2D)materials have attracted increasing attention,due to novel physical properties,unique surface structure,and high compatibility with microfabrication technique.However,owing to the inherent strong covalent bonds,the direct synthesis of 2D planar structure from nonlayered materials,especially for the realization of large-size ultrathin 2D nonlayered materials,is still a huge challenge.Here,a general atomic substitution conversion strategy is proposed to synthesize large-size,ultrathin nonlayered 2D materials.Taking nonlayered CdS as a typical example,large-size ultrathin nonlayered CdS single-crystalline flakes are successfully achieved via a facile low-temperature chemical sulfurization method,where pre-grown layered CdI2 flakes are employed as the precursor via a simple hot plate assisted vertical vapor deposition method.The size and thickness of CdS flakes can be controlled by the CdI2 precursor.The growth mechanism is ascribed to the chemical substitution reaction from I to S atoms between CdI2 and CdS,which has been evidenced by experiments and theoretical calculations.The atomic substitution conversion strategy demonstrates that the existing 2D layered materials can serve as the precursor for difficult-to-synthesize nonlayered 2D materials,providing a bridge between layered and nonlayered materials,meanwhile realizing the fabrication of large-size ultrathin nonlayered 2D materials.展开更多
Poly(ethylene oxide)(PEO)-based solid polymer electrolyte is always the most promising candidate for preparing thinner, lighter and safer lithium-ion batteries. However, the lithium dendrites growth of lithium anode a...Poly(ethylene oxide)(PEO)-based solid polymer electrolyte is always the most promising candidate for preparing thinner, lighter and safer lithium-ion batteries. However, the lithium dendrites growth of lithium anode and the high-voltage oxidation of cathode are easy to cause the PEO-based battery failure.The way to deal with the different challenges on both sides of the anode and cathode is pursued all the time. In this study, we reported a new strategy to construct the PVDF/PEO/PVDF three-layer structure for solid polymer electrolyte(marked as PVDF@PEO) using PVDF as the functional “skin”. The PVDF@PEO electrolyte can effectively prevent from the lithium dendrites, and shows a stable cycling life over1000 h in the Li/PVDF@PEO/Li cell. In addition, the PVDF@PEO electrolyte exhibits higher oxidation resistance and can be matched with high-voltage LiCoO_(2) cathode. The Li/PVDF@PEO/LiCoO_(2) cell delivered a specific capacity of about 150 m Ah g^(-1) over 150 cycles and maintained good cycling stability. Our research provides insights that the polymer electrolytes constructed with PVDF functional “skin” can simultaneously meet the challenges of both anode and cathode in solid-state lithium-ion batteries(SSLIBs).展开更多
Two-dimensional metal chalcogenides have garnered significant attention as promising candidates for novel neuromorphic synaptic devices due to their exceptional structural and optoelectronic properties.However,achievi...Two-dimensional metal chalcogenides have garnered significant attention as promising candidates for novel neuromorphic synaptic devices due to their exceptional structural and optoelectronic properties.However,achieving large-scale integration and practical applications of synaptic chips has proven to be challenging due to significant hurdles in materials preparation and the absence of effective nanofabrication techniques.In a recent breakthrough,we introduced a revolutionary allopatric defect-modulated Fe_(7)S_(8)@MoS_(2)synaptic heterostructure,which demonstrated remarkable optoelectronic synaptic response capabilities.Building upon this achievement,our current study takes a step further by presenting a sulfurization-seeding synergetic growth strategy,enabling the large-scale and arrayed preparation of Fe_(7)S_(8)@MoS_(2)heterostructures.Moreover,a three-dimensional vertical integration technique was developed for the fabrication of arrayed optoelectronic synaptic chips.Notably,we have successfully simulated the visual persistence function of the human eye with the adoption of the arrayed chip.Our synaptic devices exhibit a remarkable ability to replicate the preprocessing functions of the human visual system,resulting in significantly improved noise reduction and image recognition efficiency.This study might mark an important milestone in advancing the field of optoelectronic synaptic devices,which significantly prompts the development of mature integrated visual perception chips.展开更多
Nickel-iron layered double hydroxides(NiFe LDHs)represent a promising candidate for oxygen evolution reaction(OER),however,are still confronted with insufficient activity,due to the slow kinetics of electrooxidation o...Nickel-iron layered double hydroxides(NiFe LDHs)represent a promising candidate for oxygen evolution reaction(OER),however,are still confronted with insufficient activity,due to the slow kinetics of electrooxidation of Ni^(2+)cations for the high-valent active sites.Herein,nanopore-rich NiFe LDH(PR-NiFe LDH)nanosheets were proposed for enhancing the OER activity together with stability.In the designed catalyst,the confined nanopores create abundant unsaturated Ni sites at edges,and decrease the migration distance of protons down to the scale of their mean free path,thus promoting the formation of high-valent Ni^(3+)/^(4+)active sites.The unique configuration further improves the OER stability by releasing the lattice stress and accelerating the neutralization of the local acidity during the phase transformation.Thus,the optimized PR-NiFe LDH catalysts exhibit an ultralow overpotential of 278 mV at 10 mA∙cm^(−2)and a small Tafel slope of 75 mV∙dec^(−1),which are competitive among the advanced LDHs based catalysts.Moreover,the RP-NiFe LDH catalyst was implemented in anion exchange membrane(AEM)water electrolyzer devices and operated steadily at a high catalytic current of 2 A over 80 h.These results demonstrated that PR-NiFe LDH could be a viable candidate for the practical electrolyzer.This concept also provides valuable insights into the design of other catalysts for OER and beyond.展开更多
Li_(2)C_(2)O_(4),with a high theoretical capacity of 525 mAh·g^(−1)and good air stability,is regarded as a more attractive cathode prelithiation additive in contrast to the reported typical inorganic pre-lithiati...Li_(2)C_(2)O_(4),with a high theoretical capacity of 525 mAh·g^(−1)and good air stability,is regarded as a more attractive cathode prelithiation additive in contrast to the reported typical inorganic pre-lithiation compounds which are quite air sensitive.However,its obtained capacity is much lower than the theoretical value and its delithiation potential(>4.7 V)is too high to match with the most commercial cathode materials,which greatly impedes its practical application.Herein,we greatly improve the pre-lithiation performance of Li_(2)C_(2)O_(4)as cathode additive with fulfilled capacity at a much-reduced delithiation voltage,enabling its wide applicability for typical commercial cathodes.We increase the capacity of Li_(2)C_(2)O_(4)from 436 to 525 mAh·g^(−1)by reducing its particle size.Through optimizing the types of conductive additives,introducing nano-morphological NiO,MnO2,etc.as catalysts,and innovatively designing a bilayer electrode,the delithiation potential of Li_(2)C_(2)O_(4)is successfully reduced from 4.778 to 4.288 V.We systematically study different particle size,conductive additives,and catalysts on the delithiation behavior of Li_(2)C_(2)O_(4).Finally,it is applied to pre-lithiate the hard carbon anode,and it is found that Li_(2)C_(2)O_(4)could effectively increase the capacity of the full cell from 79.0 to 140.0 mAh·g^(−1)in the first cycle.In conclusion,our study proves that improving the reactivity is an effective strategy to boost the pre-lithiation of Li_(2)C_(2)O_(4).展开更多
Two-dimensional(2D)transition metal dichalcogenides(TMDs)have proved to possess exceptional catalytic performance for hydrogen evolution and are considered to be an appropriate substitute for commercial Pt-based catal...Two-dimensional(2D)transition metal dichalcogenides(TMDs)have proved to possess exceptional catalytic performance for hydrogen evolution and are considered to be an appropriate substitute for commercial Pt-based catalysts.Experimentally,chemical vapor deposition(CVD)is an extremely important technique for acquiring controllable and high-purity TMDs for electrocatalysis and modern electronic devices.Recently,researchers have made significant achievements in synthesizing TMDs used for electrocatalytic hydrogen evolution by CVD ranging from dynamic mechanism exploration to performance optimization.In this review,we present the recent progress based on electrocatalytic hydrogen evolution implemented by CVDgrowth TMDs nanosheets and unveil the structural–activity correlation.Firstly,in synthesis,diverse factors covering precursor,substrate,temperature settings,and atmosphere will affect the quality and surface morphology of TMDs.Then,we present the current research status of the CVD-grown 2D TMDs for engineering electrocatalytic hydrogen evolution,including intrinsic performance exploring,morphology engineering,composition adjusting,phase engineering,and vertically-oriented structure constructing.Finally,the future prospects and challenges of CVD in 2D TMDs electrocatalysis are provided.展开更多
Comprehensive Summary 2D materials have attracted intensive attention due to their unique electrical and optical properties associated with their strictly defined low dimensionalities.They provide a wide range of basi...Comprehensive Summary 2D materials have attracted intensive attention due to their unique electrical and optical properties associated with their strictly defined low dimensionalities.They provide a wide range of basic building blocks for future electronics and optoelectronics.The chemical vapor deposition(CVD)has been proposed to be efficient to realize the controllable thickness,scalable size,which are necessary for both industrial applications and fundamental researches.Herein,we share our research works to realize the controllable growth of 2D materials.We found that stable growth microenvironment can regulate the growth of 2D materials.Thus,we developed near-steady source supply,space-confined,and additive-assisted passivated growth methods to solve the problem of unstable growth environment caused by uneven source and mass transfer.Then,we developed several strategies to precisely control the parity,separation,and transport of the carriers in 2D materials including fabricating defect-free interface via van der Waals dielectrics,modulating the parity of carriers via ferroelectric-field,and the separation of carriers via band engineering.Toward future development,we highlight the opportunities and challenges inthis field.展开更多
2D van der Waals(vdW)magnets have opened intriguing prospects for next-generation spintronic nanodevices.Machine learning techniques and density functional theory calculations enable the discovery of 2D vdW magnets to...2D van der Waals(vdW)magnets have opened intriguing prospects for next-generation spintronic nanodevices.Machine learning techniques and density functional theory calculations enable the discovery of 2D vdW magnets to be accelerated;however,current computational frameworks based on these state-ofthe-art approaches cannot offer probability analysis on whether a 2D vdW magnet can be experimentally demonstrated.Herein,a new framework can be established to overcome this challenge.Via the framework,2D vdW magnets with high probability for experimental demonstration are captured from materials science literature.The key to the successful establishment is the introduction of the theory of mutual information.Historical validation of predictions substantiates the high reliability of the framework.For example,half of the 302D vdW magnets discovered in the literature published prior to 2017 have been experimentally demonstrated in the subsequent years.This framework has the potential to become a revolutionary force for progressing experimental discovery of 2D vdW magnets.展开更多
WS2/carbon nanofibers （WS2/CNFs） are obtained by a simple electrospinning method in which few-/ single-layer WS2 is uniformly embedded in carbon fibers. When used as the active anode material for Li-ion cells, these...WS2/carbon nanofibers （WS2/CNFs） are obtained by a simple electrospinning method in which few-/ single-layer WS2 is uniformly embedded in carbon fibers. When used as the active anode material for Li-ion cells, these nanofibers exhibit a first-cycle discharge/charge capacity of 941/756 mAh/g at 100 mAJg and maintain a capacity of 458 mAh/g after 100 cycles at 1 A/g. The evolution of size and crystallinity of WS2 with heating treatment are system- atically studied, which are found to strongly influence the final electrochemical performance. Interestingly, the WS2 samples of lowest crystallinity show the highest performance among all studied samples, which could result from the large interfacial capacity for Li ions due to their large specific surface area. More interestingly, the inherent flexible attribute of electrospun nanofibers renders them a great potential in the utilization of binder-flee anodes. Similar high discharge/charge capacity of 761/604 mAh/g with a first coulombic efficiency of 79.4 % has been achieved in these binder-flee anodes. Considering the universal of such simple and scalable preparation strategy, it is very likely to extend this method to other similar two-dimensional layered materials besides WS2 and provides a promising candidate elec- trode for developing flexible battery devices.展开更多
Two-dimensional(2D) materials with atomic thickness are promising candidates for the applications in future semiconductor devices, owing to their fascinating physical properties and superlative optoelectronic performa...Two-dimensional(2D) materials with atomic thickness are promising candidates for the applications in future semiconductor devices, owing to their fascinating physical properties and superlative optoelectronic performance. Chemical vapor deposition(CVD) is considered to be an efficient method for large-scale preparation of 2D materials toward practical applications.However, the high melting points of metal precursors and the thermodynamics instabilities of metastable phases limit the direct CVD synthesis of plenty of 2D materials. The salt has recently been introduced into the CVD process, which proved to be effective to address these issues. In this review, we highlighted the latest progress in the salt-assisted CVD growth of 2D materials, including layered and non-layered crystals. Firstly, strategies of adding salts are summarized. Then, the salt-assisted growth of various layered materials is presented, emphasizing on the transition metal chalcogenides of stable and metastable phases. Furthermore, strategies to grow ultrathin non-layered materials are discussed. We provide viewpoints into the techniques of using salt, the effects of salt, and the growth mechanisms of 2D crystals. Finally, we offer the challenges to be overcome and further research directions of this emerging salt-assisted CVD technique.展开更多
Two-dimensional(2D) PbI_2 flakes have been attracting intensive attention as one potential candidate for the modern optoelectronics. However, suffered from the instability of kinetics-driven growth, the fabricated 2D ...Two-dimensional(2D) PbI_2 flakes have been attracting intensive attention as one potential candidate for the modern optoelectronics. However, suffered from the instability of kinetics-driven growth, the fabricated 2D PbI_2 flakes have a wide dimensional distribution even under the same conditions. Herein, a novel facile space confined physical vapor deposition(PVD) process is provided to synthesize uniform triangle PbI_2 flakes with high quality. The confined space provides a relatively stable growth environment that renders more control on the growth kinetics, leading to highly uniform triangle PbI_2 flakes with the average size of 5 mm and thickness of 17 nm. Moreover, as-fabricated PbI_2-based photodetectors show promising stable and flexible optoelectronic performances to 470 nm light, including high responsivity(0.72 AW^(-1)), large on/off ratio up to 900, fast photoresponse speed(rise time of 13.5 ms and decay time of 20 ms) and high detectivity(1.04×10^(10) Jones). The well-controllable growth of the uniform triangle PbI_2 flakes and the detailed exploration of their optoelectronic properties are particularly valuable for their further practical applications.展开更多
基金supported by the National Natural Science Foundation of China(52322210,52172144,22375069,21825103,and U21A2069)National Key R&D Program of China(2021YFA1200501)+1 种基金Shenzhen Science and Technology Program(JCYJ20220818102215033,JCYJ20200109105422876)the Innovation Project of Optics Valley Laboratory(OVL2023PY007).
文摘Two-dimensional(2D)materials have attracted tremendous interest in view of the outstanding optoelectronic properties,showing new possibilities for future photovoltaic devices toward high performance,high specific power and flexibility.In recent years,substantial works have focused on 2D photovoltaic devices,and great progress has been achieved.Here,we present the review of recent advances in 2D photovoltaic devices,focusing on 2D-material-based Schottky junctions,homojunctions,2D−2D heterojunctions,2D−3D heterojunctions,and bulk photovoltaic effect devices.Furthermore,advanced strategies for improving the photovoltaic performances are demonstrated in detail.Finally,conclusions and outlooks are delivered,providing a guideline for the further development of 2D photovoltaic devices.
基金the National Natural Science Foundation of China(Grant No.52072138,21571073,51772115)National Key Research and Development Program of China(Grant No.2018YFE0206900)Hubei Provincial Natural Science Foundation of China(Grant No.2019CFA002)。
文摘Among the alloying-type anodes,elemental Sb possesses the suitable yet safe plateau,simple lithiation pathway,small voltage polarization,high conductivity,and superior cycle stability.However,challenge is that its intrinsic capacity is rather low(660 mAh g^(-1)),<1/6 of silicon.Herein,we propose a seamless integration strategy by merging the voltage and capacity of phosphorus and antimony into a solid solution alloy.Interestingly,the enlistment of P is found greatly enlarge the capacity from 660 to 993 mAh g^(-1) for such Sb_(30)P_(30) solid solution,while maintaining a single and stable discharge plateau(~0.79 V)similar to elemental Sb.Various experimental characterizations including XPS,PDF,Raman,and EDS mapping reveal that in such a material the P and Sb atoms have interacted with each other to form a homogenous solid solution alloy,rather than a simple mixing of the two substances.Thus,the Sb_(30)P_(30) exhibits superior rate performances(807 mAh g^(-1) at 5000 mA g^(-1))and cyclability(821 mAh g^(-1) remained after 300 cycles).Furthermore,such Sb_(60-x)P_(x) alloys can even deliver 621 mAh g^(-1) at30℃,which can be served as the alternative anode materials for high-energy and low-temperature batteries.This unique seamless integration strategy based on solid solution chemistry can be easily leveraged to manipulate the capacity of other electrode materials at similar voltage.
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financially supported by the National Natural Science Foundation of China(21761004,21805102,21701035 and 21825103)the Hubei Provincial Natural Science Foundation of China(2019CFA002)+2 种基金the specific research project of Guangxi for research bases and talents(AD18126005)the Fundamental Research Funds for the Central University(Grant No.2019kfyXMBZ018)the training program for thousands of backbone young teachers in Guangxi universities。
文摘Water electrolysis at high current density(1000 mA cm-2 level)with excellent durability especially in neutral electrolyte is the pivotal issue for green hydrogen from experiment to industrialization.In addition to the high intrinsic activity determined by the electronic structure,electrocatalysts are also required to be capable of fast mass transfer(electrolyte recharge and bubble overflow)and high mechanical stability.Herein,the 2D CoOOH sheet-encapsulated Ni2P into tubular arrays electrocatalytic system was proposed and realized 1000 mA cm-2-levelcurrent-density hydrogen evolution over 100 h in neutral water.In designed catalysts,2D stack structure as an adaptive material can buffer the shock of electrolyte convection,hydrogen bubble rupture,and evolution through the release of stress,which insure the long cycle stability.Meanwhile,the rich porosity between stacked units contributed the good infiltration of electrolyte and slippage of hydrogen bubbles,guaranteeing electrolyte fast recharge and bubble evolution at the high-current catalysis.Beyond that,the electron structure modulation induced by interfacial charge transfer is also beneficial to enhance the intrinsic activity.Profoundly,the multiscale coordinated regulation will provide a guide to design high-efficiency industrial electrocatalysts.
基金supported by the National Natural Science Foundation of China(11674113,U1765105)the support of experimental facilities in WNLO of HUSTAnalysis and Testing Center of HUST for support
文摘Self-powered devices are widely used in the detection and sensing fields.Asymmetric metal contacts provide an effective way to obtain self-powered devices.Finding two stable metallic electrode materials with large work function differences is the key to obtain highly efficient asymmetric metal contacts structures.However,common metal electrode materials have similar and high work functions,making it difficult to form an asymmetric contacts structure with a large work function difference.Herein,Mo2C crystals with low work function(3.8 eV) was obtained by chemical vapor deposition(CVD) method.The large work function difference between Mo2C and Au allowed us to synthesize an efficient Mo2C/MoS2/Au photodetector with asymmetric metal contact structure,which enables light detection without external electric power.We believe that this novel device provides a new direcfor the design of miniature self-powered photodetectors.These results also highlight the great potential of ultrathin Mo2C prepared by CVD in heterojunction device applications.
基金This work was supported by National Natural Science Foundation of China(21825103,11774044,52072059)the Hubei Provincial Natural Science Foundation of China(2019CFA002)+1 种基金the Fundamental Research Funds for the Central Universities(2019kfyXMBZ018 and 2020kfyXJJS050)We also thank the technical support from Analytical and Testing Center in Huazhong University of Science and Technology.
文摘Nonlayered two-dimensional(2D)materials have attracted increasing attention,due to novel physical properties,unique surface structure,and high compatibility with microfabrication technique.However,owing to the inherent strong covalent bonds,the direct synthesis of 2D planar structure from nonlayered materials,especially for the realization of large-size ultrathin 2D nonlayered materials,is still a huge challenge.Here,a general atomic substitution conversion strategy is proposed to synthesize large-size,ultrathin nonlayered 2D materials.Taking nonlayered CdS as a typical example,large-size ultrathin nonlayered CdS single-crystalline flakes are successfully achieved via a facile low-temperature chemical sulfurization method,where pre-grown layered CdI2 flakes are employed as the precursor via a simple hot plate assisted vertical vapor deposition method.The size and thickness of CdS flakes can be controlled by the CdI2 precursor.The growth mechanism is ascribed to the chemical substitution reaction from I to S atoms between CdI2 and CdS,which has been evidenced by experiments and theoretical calculations.The atomic substitution conversion strategy demonstrates that the existing 2D layered materials can serve as the precursor for difficult-to-synthesize nonlayered 2D materials,providing a bridge between layered and nonlayered materials,meanwhile realizing the fabrication of large-size ultrathin nonlayered 2D materials.
基金supported by the National Key Research and Development Program of China(2021YFB3800300,2018YFE0206900)the National Natural Science Foundation of China(52072138)the technical support from the Analytical and Testing Center of Huazhong University of Science and Technology(HUST)。
文摘Poly(ethylene oxide)(PEO)-based solid polymer electrolyte is always the most promising candidate for preparing thinner, lighter and safer lithium-ion batteries. However, the lithium dendrites growth of lithium anode and the high-voltage oxidation of cathode are easy to cause the PEO-based battery failure.The way to deal with the different challenges on both sides of the anode and cathode is pursued all the time. In this study, we reported a new strategy to construct the PVDF/PEO/PVDF three-layer structure for solid polymer electrolyte(marked as PVDF@PEO) using PVDF as the functional “skin”. The PVDF@PEO electrolyte can effectively prevent from the lithium dendrites, and shows a stable cycling life over1000 h in the Li/PVDF@PEO/Li cell. In addition, the PVDF@PEO electrolyte exhibits higher oxidation resistance and can be matched with high-voltage LiCoO_(2) cathode. The Li/PVDF@PEO/LiCoO_(2) cell delivered a specific capacity of about 150 m Ah g^(-1) over 150 cycles and maintained good cycling stability. Our research provides insights that the polymer electrolytes constructed with PVDF functional “skin” can simultaneously meet the challenges of both anode and cathode in solid-state lithium-ion batteries(SSLIBs).
基金supported by the National Natural Science Foundation of China(U22A20140,52072138)Shenzhen Science and Technology Program(JCYJ20220818100418040 and JCYJ20220530160816038)。
基金supported by the National Key R&D Program of China(2021YFA1200501)National Natural Science Foundation of China(U22A20137,U21A2069,62202350)Shenzhen Science and Technology Innovation Program(JCYJ20220818102215033,GJHZ20210705142542015,JCYJ20220530160811027).
文摘Two-dimensional metal chalcogenides have garnered significant attention as promising candidates for novel neuromorphic synaptic devices due to their exceptional structural and optoelectronic properties.However,achieving large-scale integration and practical applications of synaptic chips has proven to be challenging due to significant hurdles in materials preparation and the absence of effective nanofabrication techniques.In a recent breakthrough,we introduced a revolutionary allopatric defect-modulated Fe_(7)S_(8)@MoS_(2)synaptic heterostructure,which demonstrated remarkable optoelectronic synaptic response capabilities.Building upon this achievement,our current study takes a step further by presenting a sulfurization-seeding synergetic growth strategy,enabling the large-scale and arrayed preparation of Fe_(7)S_(8)@MoS_(2)heterostructures.Moreover,a three-dimensional vertical integration technique was developed for the fabrication of arrayed optoelectronic synaptic chips.Notably,we have successfully simulated the visual persistence function of the human eye with the adoption of the arrayed chip.Our synaptic devices exhibit a remarkable ability to replicate the preprocessing functions of the human visual system,resulting in significantly improved noise reduction and image recognition efficiency.This study might mark an important milestone in advancing the field of optoelectronic synaptic devices,which significantly prompts the development of mature integrated visual perception chips.
基金supported by the National Natural Science Foundation of China(No.22071069).
文摘Nickel-iron layered double hydroxides(NiFe LDHs)represent a promising candidate for oxygen evolution reaction(OER),however,are still confronted with insufficient activity,due to the slow kinetics of electrooxidation of Ni^(2+)cations for the high-valent active sites.Herein,nanopore-rich NiFe LDH(PR-NiFe LDH)nanosheets were proposed for enhancing the OER activity together with stability.In the designed catalyst,the confined nanopores create abundant unsaturated Ni sites at edges,and decrease the migration distance of protons down to the scale of their mean free path,thus promoting the formation of high-valent Ni^(3+)/^(4+)active sites.The unique configuration further improves the OER stability by releasing the lattice stress and accelerating the neutralization of the local acidity during the phase transformation.Thus,the optimized PR-NiFe LDH catalysts exhibit an ultralow overpotential of 278 mV at 10 mA∙cm^(−2)and a small Tafel slope of 75 mV∙dec^(−1),which are competitive among the advanced LDHs based catalysts.Moreover,the RP-NiFe LDH catalyst was implemented in anion exchange membrane(AEM)water electrolyzer devices and operated steadily at a high catalytic current of 2 A over 80 h.These results demonstrated that PR-NiFe LDH could be a viable candidate for the practical electrolyzer.This concept also provides valuable insights into the design of other catalysts for OER and beyond.
基金supported by the National Natural Science Foundation of China (52072138 and 51772115)the National Key Research and Development Program of China (2018YFE0206900)Australian Research Council (ARC) through the Discovery Project (DP180102297)。
基金the financial support provided by the National Natural Science Foundation of China(No.52072138)the National Key Research and Development Program of China(No.2018YFE0206900)+1 种基金the Shenzhen Science and Technology Program(No.JCYJ20220530160816038)the Australian Research Council(ARC)through the Discovery Project(No.DP180102297).
文摘Li_(2)C_(2)O_(4),with a high theoretical capacity of 525 mAh·g^(−1)and good air stability,is regarded as a more attractive cathode prelithiation additive in contrast to the reported typical inorganic pre-lithiation compounds which are quite air sensitive.However,its obtained capacity is much lower than the theoretical value and its delithiation potential(>4.7 V)is too high to match with the most commercial cathode materials,which greatly impedes its practical application.Herein,we greatly improve the pre-lithiation performance of Li_(2)C_(2)O_(4)as cathode additive with fulfilled capacity at a much-reduced delithiation voltage,enabling its wide applicability for typical commercial cathodes.We increase the capacity of Li_(2)C_(2)O_(4)from 436 to 525 mAh·g^(−1)by reducing its particle size.Through optimizing the types of conductive additives,introducing nano-morphological NiO,MnO2,etc.as catalysts,and innovatively designing a bilayer electrode,the delithiation potential of Li_(2)C_(2)O_(4)is successfully reduced from 4.778 to 4.288 V.We systematically study different particle size,conductive additives,and catalysts on the delithiation behavior of Li_(2)C_(2)O_(4).Finally,it is applied to pre-lithiate the hard carbon anode,and it is found that Li_(2)C_(2)O_(4)could effectively increase the capacity of the full cell from 79.0 to 140.0 mAh·g^(−1)in the first cycle.In conclusion,our study proves that improving the reactivity is an effective strategy to boost the pre-lithiation of Li_(2)C_(2)O_(4).
文摘Two-dimensional(2D)transition metal dichalcogenides(TMDs)have proved to possess exceptional catalytic performance for hydrogen evolution and are considered to be an appropriate substitute for commercial Pt-based catalysts.Experimentally,chemical vapor deposition(CVD)is an extremely important technique for acquiring controllable and high-purity TMDs for electrocatalysis and modern electronic devices.Recently,researchers have made significant achievements in synthesizing TMDs used for electrocatalytic hydrogen evolution by CVD ranging from dynamic mechanism exploration to performance optimization.In this review,we present the recent progress based on electrocatalytic hydrogen evolution implemented by CVDgrowth TMDs nanosheets and unveil the structural–activity correlation.Firstly,in synthesis,diverse factors covering precursor,substrate,temperature settings,and atmosphere will affect the quality and surface morphology of TMDs.Then,we present the current research status of the CVD-grown 2D TMDs for engineering electrocatalytic hydrogen evolution,including intrinsic performance exploring,morphology engineering,composition adjusting,phase engineering,and vertically-oriented structure constructing.Finally,the future prospects and challenges of CVD in 2D TMDs electrocatalysis are provided.
基金financially supported by the National Natural Science Foundation of China (22071069 and 22275060)technical support from the Analytical and Testing Center at Huazhong University of Science and Technology。
基金supported by the National Natural Science Foundation of China(Grant Nos.21825103,52172144,and U21A2069)the Ministry of Science and Technology of China(2021YFA1200500).
文摘Comprehensive Summary 2D materials have attracted intensive attention due to their unique electrical and optical properties associated with their strictly defined low dimensionalities.They provide a wide range of basic building blocks for future electronics and optoelectronics.The chemical vapor deposition(CVD)has been proposed to be efficient to realize the controllable thickness,scalable size,which are necessary for both industrial applications and fundamental researches.Herein,we share our research works to realize the controllable growth of 2D materials.We found that stable growth microenvironment can regulate the growth of 2D materials.Thus,we developed near-steady source supply,space-confined,and additive-assisted passivated growth methods to solve the problem of unstable growth environment caused by uneven source and mass transfer.Then,we developed several strategies to precisely control the parity,separation,and transport of the carriers in 2D materials including fabricating defect-free interface via van der Waals dielectrics,modulating the parity of carriers via ferroelectric-field,and the separation of carriers via band engineering.Toward future development,we highlight the opportunities and challenges inthis field.
基金supported by the National Natural Science Foundation of China(21825103,22103026,and U21A2069)the Fundamental Research Funds for the Central Universities(2020kfyXJJS050).
文摘2D van der Waals(vdW)magnets have opened intriguing prospects for next-generation spintronic nanodevices.Machine learning techniques and density functional theory calculations enable the discovery of 2D vdW magnets to be accelerated;however,current computational frameworks based on these state-ofthe-art approaches cannot offer probability analysis on whether a 2D vdW magnet can be experimentally demonstrated.Herein,a new framework can be established to overcome this challenge.Via the framework,2D vdW magnets with high probability for experimental demonstration are captured from materials science literature.The key to the successful establishment is the introduction of the theory of mutual information.Historical validation of predictions substantiates the high reliability of the framework.For example,half of the 302D vdW magnets discovered in the literature published prior to 2017 have been experimentally demonstrated in the subsequent years.This framework has the potential to become a revolutionary force for progressing experimental discovery of 2D vdW magnets.
文摘WS2/carbon nanofibers （WS2/CNFs） are obtained by a simple electrospinning method in which few-/ single-layer WS2 is uniformly embedded in carbon fibers. When used as the active anode material for Li-ion cells, these nanofibers exhibit a first-cycle discharge/charge capacity of 941/756 mAh/g at 100 mAJg and maintain a capacity of 458 mAh/g after 100 cycles at 1 A/g. The evolution of size and crystallinity of WS2 with heating treatment are system- atically studied, which are found to strongly influence the final electrochemical performance. Interestingly, the WS2 samples of lowest crystallinity show the highest performance among all studied samples, which could result from the large interfacial capacity for Li ions due to their large specific surface area. More interestingly, the inherent flexible attribute of electrospun nanofibers renders them a great potential in the utilization of binder-flee anodes. Similar high discharge/charge capacity of 761/604 mAh/g with a first coulombic efficiency of 79.4 % has been achieved in these binder-flee anodes. Considering the universal of such simple and scalable preparation strategy, it is very likely to extend this method to other similar two-dimensional layered materials besides WS2 and provides a promising candidate elec- trode for developing flexible battery devices.
基金supported by the National Natural Science Foundation of China (21825103, 51727809)the Fundamental Research Funds for the Central University (2019kfy XMBZ018)the project funded by China Postdoctoral Science Foundation (2018M642832)
文摘Two-dimensional(2D) materials with atomic thickness are promising candidates for the applications in future semiconductor devices, owing to their fascinating physical properties and superlative optoelectronic performance. Chemical vapor deposition(CVD) is considered to be an efficient method for large-scale preparation of 2D materials toward practical applications.However, the high melting points of metal precursors and the thermodynamics instabilities of metastable phases limit the direct CVD synthesis of plenty of 2D materials. The salt has recently been introduced into the CVD process, which proved to be effective to address these issues. In this review, we highlighted the latest progress in the salt-assisted CVD growth of 2D materials, including layered and non-layered crystals. Firstly, strategies of adding salts are summarized. Then, the salt-assisted growth of various layered materials is presented, emphasizing on the transition metal chalcogenides of stable and metastable phases. Furthermore, strategies to grow ultrathin non-layered materials are discussed. We provide viewpoints into the techniques of using salt, the effects of salt, and the growth mechanisms of 2D crystals. Finally, we offer the challenges to be overcome and further research directions of this emerging salt-assisted CVD technique.
基金supported by the National Natural Science Foundation of China (51472097, 91622117, 21501060, and 51727809)the National Key Research and Development Program (2016YFB0401100)+1 种基金the National Basic Research Program of China (2015CB932600)the Fundamental Research Funds for the Central University (2017KFKJXX007, 2015ZDTD038)
文摘Two-dimensional(2D) PbI_2 flakes have been attracting intensive attention as one potential candidate for the modern optoelectronics. However, suffered from the instability of kinetics-driven growth, the fabricated 2D PbI_2 flakes have a wide dimensional distribution even under the same conditions. Herein, a novel facile space confined physical vapor deposition(PVD) process is provided to synthesize uniform triangle PbI_2 flakes with high quality. The confined space provides a relatively stable growth environment that renders more control on the growth kinetics, leading to highly uniform triangle PbI_2 flakes with the average size of 5 mm and thickness of 17 nm. Moreover, as-fabricated PbI_2-based photodetectors show promising stable and flexible optoelectronic performances to 470 nm light, including high responsivity(0.72 AW^(-1)), large on/off ratio up to 900, fast photoresponse speed(rise time of 13.5 ms and decay time of 20 ms) and high detectivity(1.04×10^(10) Jones). The well-controllable growth of the uniform triangle PbI_2 flakes and the detailed exploration of their optoelectronic properties are particularly valuable for their further practical applications.
