Domain nucleation kinetics and polarization-texture-dependent electronic properties in two-dimensional α-In2Se3 ferroelectrics.

Two-dimensional (2D) ferroelectric semiconductors, such as α-In2Se3 with switchable spontaneous polarization and superior optoelectronic properties, exhibit large potential for functional device applications. The electric transport properties and device performance of 2D α-In2Se3 are strongly sensitive to the ferroelectric domain structures and polarization textures, but they are rarely explored at the atomic scale. Herein, by a combination of first-principles calculations and a developed domain switching theory, we report the domain nucleation kinetics and polarization-texture dependent electronic properties in α-In2Se3 ferroelectrics. Our calculated results reveal that the reversed domains characterized by armchair boundaries tend to form triangular or stripped shape. The energy barrier for propagating domain boundaries is ∼1.42 eV and can be reduced by loading external electric field, which is responsible for driving the evolution of domain structures. Moreover, the domain switching leads to notable changes in the band gap and carrier spatial distribution of α-In2Se3 monolayer, resulting in higher electric resistance of multi-polarization domain structures than that of single-polarization state. The domain structures of multilayer α-In2Se3 follow a layer-by-layer switching mechanism, which causes the transition of electronic structures from self-doped p-n junctions to type-II semiconductor homojunctions. This study not only provides an in-depth insight into the domain switching mechanisms of α-In2Se3 but also opens up the possibility to tailor their electronic and transport properties.

High-Throughput Computational Screening of All-MXene Metal-Semiconductor Junctions for Schottky-Barrier-Free Contacts with Weak Fermi-Level Pinning.

Van der Waals (vdW) metal-semiconductor junctions (MSJs) exhibit huge potential to reduce the contact resistance and suppress the Fermi-level pinning (FLP) for improving the device performance, but they are limited by optional (2D) metals with a wide range of work functions. Here a new class of vdW MSJs entirely composed of atomically thin MXenes is reported. Using high-throughput first-principles calculations, highly stable 80 metals and 13 semiconductors are screened from 2256 MXene structures. The selected MXenes cover a broad range of work functions (1.8-7.4 eV) and bandgaps (0.8-3 eV), providing a versatile material platform for constructing all-MXene vdW MSJs. The contact type of 1040 all-MXene vdW MSJs based on Schottky barrier heights (SBHs) is identified. Unlike conventional 2D vdW MSJs, the formation of all-MXene vdW MSJs leads to interfacial polarization, which is responsible for the FLP and deviation of SBHs from the prediction of Schottky-Mott rule. Based on a set of screening criteria, six Schottky-barrier-free MSJs with weak FLP and high carrier tunneling probability (>50%) are identified. This work offers a new way to realize vdW contacts for the development of high-performance electronic and optoelectronic devices.

One-step cladding metal oxide nanowires with a carbon-dots-embedded ZnO amorphous layer toward boosted photoelectrochemical water oxidation.

An effective method was proposed for constructing carbon dots (CDs)-sensitized multijunction composite photoelectrodes via one-step cladding a CDs-embedded ZnO amorphous overlayer on vertically aligned metal oxide nanowires. This strategy involved the double role of hexamethylenetetramine (HMTA) in the ethylene glycol (EG) solvent mixed with a controllable trace amount of water. In the water-deficient synthetic system, a limited portion of HMTA served as the pH buffer and hydroxyl source to force the hydrolytic process of zinc ions for the production of ZnO. The precipitated ZnO clusters were instantly capped by EG molecules through the activated alkoxidation reaction, and further crosslinked into an amorphous network surrounding the individual nanowires. Meanwhile, the excess HMTA was simultaneously depleted as the precursor for producing CDs in the EG solution through thermal condensation, which were packed in the gradually formed aggregates. We revealed that a CDs-embedded amorphous ZnO overlayer with an appropriate proportion of ingredient could be tailored through an optimal tradeoff between hydrolysis and condensation of HMTA. Benefiting from the synergy of the amorphous ZnO layer and the embedded CDs, the multijunction composite photoanodes exhibited significantly improved PEC performance and stability for water oxidation.

Phase-Controllable Growth of Air-Stable SnS Nanostructures for High-Performance Photodetectors with Ultralow Dark Current.

The epitaxial growth of low-dimensional tin chalcogenides SnX (X = S, Se) with a controlled crystal phase is of particular interest since it can be utilized to tune optoelectronic properties and exploit potential applications. However, it still remains a great challenge to synthesize SnX nanostructures with the same composition but different crystal phases and morphologies. Herein, we report a phase-controlled growth of SnS nanostructures via physical vapor deposition on mica substrates. The phase transition from α-SnS (Pbnm) nanosheets to ß-SnS (Cmcm) nanowires can be tailored by the reduction of growth temperature and precursor concentration, which originates from a delicate competition between SnS-mica interfacial coupling and phase cohesive energy. The phase transition from the α to ß phase not only greatly improves the ambient stability of SnS nanostructures but also leads to the band gap reduction from 1.03 to 0.93 eV, which is responsible for fabricated ß-SnS devices with an ultralow dark current of 21 pA at 1 V, an ultrafast response speed of ≤14 µs, and broadband spectra response from the visible to near-infrared range under ambient condition. A maximum detectivity of the ß-SnS photodetector arrives at 2.01 × 108 Jones, which is about 1 or 2 orders of magnitude larger than that of α-SnS devices. This work provides a new strategy for the phase-controlled growth of SnX nanomaterials for the development of highly stable and high-performance optoelectronic devices.

Molecular sieving of semiconductive NTU-9 coatings on titanium dioxide nanowire arrays: Augmented yet selective photoelectrochemical response enabled by boosting charge separation and transfer in confined space.

Radial heterostructures with titanium dioxide (TiO2) nanowire as core and NTU-9 as shell are synthesized via a surfactant-free approach based on the favorable bonding of linkers with TiO2 nanowire. Relative to the traditional growth strategy of surface modification, the thin NTU-9 shell with ordered arrangement of two-dimensional networks is uniformly formed on the sidewalls of TiO2 nanowire through the orientational growth process. Using the core-shell nanowire arrays as photoanodes, wide-range light absorption and high charge carrier separation efficiency are achieved due to the conjugation of NTU-9, leading to enhanced water oxidation performance in photoelectrochemical (PEC) water splitting. Under appropriately low applied potentials, the photogenerated holes are preferable to accumulate at TiO2/NTU-9/electrolyte three-phase interface and thus the long-range ordered NTU-9 shell can also serve as a size-exclusion filter to improve selectivity toward molecules of different sizes. Consequently, the TiO2/NTU-9 core-shell nanowire array exhibits an augmented and selective PEC response for small size molecules (e.g.,H2O2) at a very low potential (-0.25 V vs Ag/AgCl), outperforming the pure TiO2 nanowire array and the counterpart with a grain-boundary-rich NTU-9 shell that is prepared by pretreatment of the TiO2 nanowires with PVP functionalization.

Strong intrinsic room-temperature ferromagnetism in freestanding non-van der Waals ultrathin 2D crystals.

Control of ferromagnetism is of critical importance for a variety of proposed spintronic and topological quantum technologies. Inducing long-range ferromagnetic order in ultrathin 2D crystals will provide more functional possibility to combine their unique electronic, optical and mechanical properties to develop new multifunctional coupled applications. Recently discovered intrinsic 2D ferromagnetic crystals such as Cr2Ge2Te6, CrI3 and Fe3GeTe2 are intrinsically ferromagnetic only below room temperature, mostly far below room temperature (Curie temperature, ~20-207 K). Here we develop a scalable method to prepare freestanding non-van der Waals ultrathin 2D crystals down to mono- and few unit cells (UC) and report unexpected strong, intrinsic, ambient-air-robust, room-temperature ferromagnetism with TC up to ~367 K in freestanding non-van der Waals 2D CrTe crystals. Freestanding 2D CrTe crystals show comparable or better ferromagnetic properties to widely-used Fe, Co, Ni and BaFe12O19, promising as new platforms for room-temperature intrinsically-ferromagnetic 2D crystals and integrated 2D devices.

2D-VN2 MXene as a novel anode material for Li, Na and K ion batteries: Insights from the first-principles calculations.

Developing two-dimensional (2D) materials as anode materials have been proved a promising approach to significantly improve the charge storage performances of alkali metal ion. Herein, we investigate mono-layered VN2 as an anode material in Li, Na and K ion batteries. Firstly, the high stability of 2D-VN2 has been demonstrated via calculating the phonon spectra. 2D-VN2 is capable of delivering high capacities of 678.8, 339.4 and 1357.6 mAh g-1 in Li+, K+ and Na+ storage, respectively. In addition, the metallic properties and corresponding high electrical conductivity and low diffusion barriers of 201.1 meV for Li atoms, 34.7 meV for K atoms and 84.1 meV for Na atoms on VN2 surface, indicating good capacity and the superior rate performances of alkali metal atoms migration on VN2. The calculated average voltage of Li, Na and K are respectively 0.81 V, 0.29 V and 0.77 V, suggesting a promising voltage behavior compared with other 2D materials.

Intrinsic Polarization-Induced Enhanced Ferromagnetism and Self-Doped p-n Junctions in CrBr3/GaN van der Waals Heterostructures.

Two-dimensional (2D) ferromagnetic (FM) semiconductors with a high Curie temperature and tunable electronic properties are a long-term pursuing target for the development of high-performance spin-dependent optoelectronic devices. Herein, on the basis of density functional theory calculations, we report a new strategy to tune the Curie temperature and electronic structures of a ferromagnetic CrBr3 monolayer through the formation of CrBr3/GaN van der Waals heterostructures. Our calculated results demonstrate that the Curie temperature and band alignment of CrBr3/GaN heterostructures strongly depend on the thickness and polarization direction of the GaN layer. The combination of the CrBr3 monolayer with N-terminated GaN nanosheets leads to enhanced FM coupling via superexchange interactions between the Cr-t2g and Cr-eg orbitals, consequently resulting in a Curie temperature of CrBr3 of up to 67 K. Moreover, self-doped p-n junctions can be naturally formed in the heterostructures without additional modulation of external fields. The enhanced FM coupling and self-doping effect in the heterostructures are associated with the intrinsic polarization of the GaN layer that drives interfacial electron transfers from GaN to CrBr3. Therefore, this work not only offers an efficient scheme to boost the Curie temperature of the CrBr3 monolayer but also opens up a new route to realize nonvolatile van der Waals p-n junctions.

Synergistic enhancement effect of MoO3@Ag hybrid nanostructures for boosting selective detection sensitivity.

An ex situ method was used to synthesize noble metals and metal oxide composite materials, due to the selective adsorption properties of metal oxides, the adsorption of different probe molecules by this composite structure had been studied. In the ex situ approach, we use (3-aminopropyl) diethoxy methylsilane (ATES) as a coupling agent which is easy for noble metal nanoparticles deposited on metallic oxide nanomaterials. The Raman scattering (SERS) substrate of 1D MoO3 nanowires (MoO3-NWs) @Ag nanoparticles (Ag-NPs) hybrid surface had been fabricated. Several parameters are presented in the following which influences the morphology of self-assembly and SERS activity: (i) coupling agent of ATES, (ii) ATES content (iii) Ag-NPs content. The finite difference time domain (FDTD) method is to explain the enhancement mechanism distribution of the hybrid substrate. Different probe molecules (R6G, Methylene Blue, Crystal Violet, and 4-ATP) have been adsorbed for SERS tests. Improved principle component analysis (PCA) is adopted to obtain the minimum detection limit of probe molecules. Through the DFT calculation, different absorption strengths between the target molecules and the MoO3(010) surface have been illustrated, which is also the main reason for the selective enhancement effect of MoO3@Ag hybrid nanostructures. This paper might propose a method to prepare such enhancement substrate based on the selective absorption properties of oxide semiconductors.

Ultrafast nucleation and growth of high-quality monolayer MoSe2 crystals via vapor-liquid-solid mechanism.

The controlled production of two-dimensional atomically thin transition metal dichalcogenides (TMDs) is fundamentally important for their device applications. However, the synthesis of large-area and high-quality TMD monolayers remains a challenge due to the lack of sufficient understanding of growth mechanisms, especially for the chemical vapor deposition (CVD). Here we report molten-salt assisted CVD growth of highly crystalline MoSe2 monolayers via a novel vapor-liquid-solid (VLS) mechanism. Our results show that the growth rate of the VLS-grown monolayer MoSe2 is about 40 times faster than that of MoSe2 grown via the vapor-solid (VS) mechanism, which makes the fabrication of 100 µm domains for ∼2 min and a uniform monolayer film within 5 min. The ultrafast growth of monolayer MoSe2 crystals benefits from the synergic effect of one-dimensional VLS growth and two-dimensional VS edge expansion. Moreover, these MoSe2 monolayers exhibit high crystal quality and enhanced photoluminescence due to efficient Se-vacancy repairing by the doping of halogen atoms. These findings provide a new understanding of MoSe2 growth and open up an opportunity for the rapid synthesis of high-quality TMD monolayers and heterostructures.

Defect Passivation and Photoluminescence Enhancement of Monolayer MoS2 Crystals through Sodium Halide-Assisted Chemical Vapor Deposition Growth.

Recent success in the chemical vapor deposition (CVD) growth of atomically thin transition metal dichalcogenide (TMD) crystals opens up prospects for exploiting these materials in nanoelectronic and optoelectronic devices. However, CVD-grown TMDs often suffer from weak crystal quality because of the formation of defects during the growth, which makes a large impact on their electrical and optical properties. Here, we report a facile synthesis of high-quality MoS2 monolayers through a sodium halide-assisted CVD method. Our results show that the addition of sodium halides into MoO3 precursors leads to the rapid growth of highly crystalline MoS2 monolayers. Moreover, the overall photoluminescence (PL) intensity of MoS2 monolayers can be greatly enhanced by up to 2 orders of magnitude. The PL enhancement originates from that the deep trap states induced by sulfur vacancies are passivated by the substitution doping of halogen atoms, which promotes the emission of excitons and trions. Density functional theory calculations indicate that the band gaps of halogen-doped MoS2 monolayers are slightly smaller than those of pristine MoS2 monolayer, which is responsible for the small red shift of PL peaks (∼30 meV). These findings provide a new route toward engineering electronic and optical properties of MoS2 and other TMD monolayers.

Semiconducting edges and flake-shape evolution of monolayer GaSe: role of edge reconstructions.

Group-III metal monochalcogenides have emerged as a new class of two-dimensional (2D) semiconductor materials. For the integration of 2D materials for various potential device applications, there is an inevitable need to reduce their dimensionality into specific sized nanostructures with edges. Owing to the properties of finite-sized 2D nanostructures strongly related to the edge configurations, the precise understanding of the edge geometric structures at an atomic level is of particular importance. By means of first-principles calculations, the geometric structures and electronic properties of stable zigzag and armchair edges in a prototype example GaSe monolayer have been identified. Our results demonstrate that both Ga- and Se-terminated zigzag edges prefer to the (3 × 1) reconstructions, and the armchair edges with the perfect flat configuration are energetically favorable. It is unexpectedly found that both zigzag and armchair GaSe nanoribbons with reconstructed edges are semiconductors, which is different from previous recognition where the zigzag edges are metallic. Moreover, the edge-dependent flake shape in GaSe has been plotted using the Wulff construction theory, and the shape evolution with chemical potentials can be applied to explain broad experimental observations on the morphologies of GaSe flakes. Importantly, similar reconstructions and electronic properties also appeared at InSe edges, suggesting that the reconstruction induced semiconducting edges are a fundamental phenomenon for 2D group-III metal monochalcogenides.

Intriguing electronic and optical properties of two-dimensional Janus transition metal dichalcogenides.

Atomically thin Janus transition metal dichalcogenides (JTMDs) with an asymmetric structure have emerged as a new class of intriguing two-dimensional (2D) semiconductor materials. Using state-of-the-art density functional theory (DFT) calculations, we systematically investigate the structural, electronic, and optical properties of JTMD monolayers and heterostructures. Our calculated results indicate that the JTMD monolayers suffer from a bending strain but present high thermodynamic stability. All of them are semiconductors with a band-gap range from 1.37 to 1.96 eV. They possess pronounced optical absorption in the visible-light region and cover a large range of carrier mobilities from 28 to 606 cm2 V-1 s-1, indicating strong anisotropic characteristics. Significantly, some monolayer JTMDs (e.g., WSSe and WSeTe) exhibit superior mobilities than conventional TMD monolayers, such as MoS2. Moreover, the absolute band-edge positions of the JTMD monolayers are higher than the water redox potential, and most JTMD heterostructures have a type-II band alignment that contributes to the separation of carriers. Our work suggests that the 2D JTMD monolayers are promising for nanoelectronic, optoelectronic, and photocatalytic applications.

Hierarchical MoO3/SnS2 core-shell nanowires with enhanced electrochemical performance for lithium-ion batteries.

Two-dimensional (2D) tin disulfide (SnS2) is a promising anode material for lithium-ion batteries (LIBs) because of its high theoretical capacity. The main challenges associated with the SnS2 electrodes are the poor cycling stability and low rate capability due to structural degradation in the discharge/charge process. Here, a facile two-step synthesis method is developed to fabricate hierarchical MoO3/SnS2 core-shell nanowires, where ultrathin SnS2 nanosheets are vertically anchored on MoO3 nanobelts to induce a heterointerface. Benefiting from the unique structural and compositional characteristics, the hierarchical MoO3/SnS2 core-shell nanowires exhibit excellent electrochemical performance and deliver a high reversible capacity of 504 mA h g-1 after 100 stable cycles at a current density of 100 mA g-1, which is far superior to the MoO3 and SnS2 electrodes. An analysis of lithiation dynamics based on ab initio molecular dynamics simulations demonstrates that the formation of a hierarchical MoO3/SnS2 core-shell heterostructure can effectively suppress the rapid dissociation of shell-layer SnS2 nanosheets via the interfacial coupling effect and the central MoO3 backbone can trap and support the polysulfide in the discharge/charge process. The results are responsible for the high storage capacity and rate capability of MoO3/SnS2 electrode materials. This work provides a novel design strategy for constructing high-performance electrodes for LIBs.

Nonstoichiometry induced broadband tunable photoluminescence of monolayer WSe2.

A nonstoichiometric process by modulating the W/Se atomic ratio was employed to tune the excitonic PL band of monolayer WSe2 from 810 nm to 690 nm. DFT calculations indicate that Se-rich conditions reduce the band gap, while Se-deficient conditions facilitate the increasing band gap and decreasing excitionic binding energy, which finally induces such broadband tuning of the PL band.

Enhanced Electrocatalytic Hydrogen Evolution from Large-Scale, Facile-Prepared, Highly Crystalline WTe2 Nanoribbons with Weyl Semimetallic Phase.

Tungsten ditellurium (WTe2) is one of most important layered transition metal dichalcogenides (TMDs) and exhibits various prominent physical properties. All the present methods for WTe2 preparation need strict conditions such as high temperature or cannot be applied in large scale, which limits its practical applications. In addition, most studies on WTe2 focus on its physical properties, whereas its electrochemical properties are still illusive with little investigation. Here, we develop a facile and scalable two-step method to synthesize high-quality WTe2 nanoribbon crystals with 1T' Weyl semimetal phase for the first time. Highly crystalline 1T'-WTe2 nanoribbons can be obtained on a large scale through this two-step method. In addition, the electrochemical tests show that WTe2 nanoribbons exhibit smaller overpotential and much better hydrogen evolution reaction catalytic performance than other tungsten-based sulfide and selenide (WS2, WSe2) nanoribbons of same morphology and under same preparation conditions. WTe2 nanoribbons show a Tafel slope of 57 mV/dec, which is one of best values for TMD catalysts and about 2 and 4 times smaller than that for 2H-WS2 nanoribbons (135 mV/dec) and 2H-WSe2 nanoribbons (213 mV/dec), respectively. 1T'-WTe2 nanoribbons also show ultrahigh stability in 5000 cycles and 20 h at 10 mA/cm2. The better performance is attributed to high conductivity of semimetallic 1T'-phase-stable WTe2 nanoribbons with one or two order higher charge-transfer rate than normally semiconducting 2H-stable WS2 and WSe2 nanoribbons. These results open the door for electrochemical applications of Weyl semimetallic TMDs.

Defect Engineering in MoSe2 for the Hydrogen Evolution Reaction: From Point Defects to Edges.

Superior catalytic activity and high chemical stability of inexpensive electrocatalysts for the hydrogen evolution reaction (HER) are crucial to the large-scale production of hydrogen from water. The nonprecious two-dimensional MoSe2 materials emerge as a potential candidate, and the improvement of their catalytic activity depends on the optimization of active reaction sites at both the edges and the basal plane. Herein, the structural stability, electrocatalytic activity, and HER mechanisms on a series of MoSe2 catalytic structures including of point defects, holes, and edges have been explored by using first-principles calculations. Our calculated results demonstrate that thermodynamically stable defects (e.g., VSe, VSe2, SeMo, and VMo3Se2) and edges (e.g., Mo-R and Se-R) in MoSe2 are very similar to the case of MoS2, but their HER activity is higher than that of the corresponding structures in MoS2, which is in good agreement with experimental observations. Furthermore, a Fermi-abundance model is proposed to explain the fundamental correlation between the HER activity of various MoSe2 catalysts and their intrinsic electronic structures, and this model is also applicable for assessing the HER activity of other types of catalysts, such as MoS2 and Pt. Moreover, two different HER mechanisms have been revealed in the MoSe2 catalytic structures: the Volmer-Tafel mechanism is preferred for the VSe and VSe2 structures, whereas the Volmer-Heyrovsky mechanism is more favorable for other MoSe2 catalytic structures. The present work suggests that MoSe2 with appropriate defects and edges is able to compete against the Pt-based catalysts and also opens a route to design highly active electrocatalysts for the HER.

Design of a silver nanoparticle for sensitive surface enhanced Raman spectroscopy detection of carmine dye.

Flower-shaped silver nanoparticles have been successfully synthesized by a simple aqueous phase silver nitrate reduction by ascorbic acid in the presence of polyvinylpyrrolidone (PVP) surfactant. The nanoparticles diameters were adjusted from 450 to 1000nm with surface protrusions up to 10-25nm. The growth direction of silver nuclei is controlled by their degree of coating by PVP. The flower-shaped silver nanostructures obtained were used as stable Surface Enhanced Raman Scattering (SERS) substrates with high SERS activity for detecting Rhodamine 6G (R6G), at a concentration of only 10-9M, where the SERS signal is still clear. SERS spectra of the dye carmine was analysed and the characteristic bands were identified. An improved principle component analysis (PCA) was used for carmine detection, at concentrations down to 10-8M. The characteristic peaks of the carmine (1019, 1360, and 1573cm-1) remained at 10-8M. This indicated that the minimum detection limit of AgNP-based substrate for carmine is about 10-8M.

Unveiling the atomic structure and electronic properties of atomically thin boron sheets on an Ag(111) surface.

Two-dimensional (2D) boron sheets (i.e., borophene) have a huge potential as a basic building block in nanoelectronics and optoelectronics; such a situation is greatly promoted by recent experiments on fabrication of borophene on silver substrates. However, the fundamental atomic structure of borophene on the Ag substrate is still under debate, which greatly impedes further exploration of its properties. Herein, the atomic structure and electronic properties of borophene on an Ag(111) surface have been studied using first-principles calculations and ab initio molecular dynamics simulations. Our results reveal that there exist three energetically favorable borophene structures (ß5, χ1, and χ2) on the Ag(111) surface and their simulated STM images are in good agreement with experimental results, suggesting the coexistence of boron phases during the growth. All these stable borophene structures have a planar structure with slight surface buckling (∼0.15 Å) and relatively high hexagonal vacancy density (1/6 and 1/5) and exhibit typical metallic conductivity. These findings not only can be applied to solve the experimental controversies about the atomic structure of borophene on the Ag substrate but also provide a theoretical basis for exploring the fundamental properties and applications of 2D boron sheets.

The capacity fading mechanism and improvement of cycling stability in MoS2-based anode materials for lithium-ion batteries.

Two-dimensional (2D) layered MoS2 nanosheets possess great potential as anode materials for lithium ion batteries (LIBs), but they still suffer from poor cycling performance. Improving the cycling stability of electrode materials depends on a deep understanding of their dynamic structural evolution and reaction kinetics in the lithiation process. Herein, thermodynamic phase diagrams and the lithiation dynamics of MoS2-based nanostructures with the intercalation of lithium ions are studied by using first-principles calculations and ab initio molecular dynamics simulations. Our results demonstrate that the continuous intercalation of Li ions induces structural destruction of 2H phase MoS2 nanosheets in the discharge process that follows a layer-by-layer dissociation mechanism. Meanwhile, the intercalation of Li ions leads to a structural transition of MoS2 nanosheets from the 2H to the 1T phase due to the ultralow transition barriers (∼0.1 eV). We find that the phase transition can slow down the dissociation of MoS2 nanosheets during lithiation. The result can be applied to explain extensive experimental observation of the fast capacity fading of MoS2-based anode materials between the first and the subsequent discharges. To suppress the dissociation of MoS2 nanosheets in the lithiation process, we propose a strategy by constructing a sandwich-like graphene/MoS2/graphene structure that indicates high chemical stability, superior conductivity, and high Li-ion mobility in the charge/discharge process, implying the possibility to induce an improvement in the anode cycling performance. This work opens a new route to rational design layered transition-metal disulfide (TMD) anode materials for LIBs with superior cycling stability and electrochemical performance.