Formation Of Heterostructures Research Articles

Atomically Sharp 1D Interfaces in 2D Lateral Heterostructures of VSe2─NbSe2 Monolayers.

van der Waals heterostructures have emerged as an ideal platform for creating engineered artificial electronic states. While vertical heterostructures have been extensively studied, realizing high-quality lateral heterostructures with atomically sharp interfaces remains a major experimental challenge. Here, we advance a one-pot two-step molecular beam lateral epitaxy approach and successfully synthesize atomically well-defined 1T-VSe2─1H-NbSe2 lateral heterostructures. We demonstrate the formation of defect-free lateral heterostructures and characterize their electronic structure by using scanning tunneling microscopy and spectroscopy together with density functional theory calculations. We find additional electronic states at the 1D interface as well as signatures of Kondo resonances in a side-coupled geometry. Our experiments explored the full potential of lateral heterostructures for realizing exotic electronic states in low-dimensional systems for further studies of artificial designer quantum materials.

Design of heterostructure photocatalysts based on layered perovskite-like bismuth silicate

Heterostructure photocatalysts attract a lot of attention of researchers thanks to their enhanced photocatalytic performance. Herein, we focus on the formation of the p-n type heterojunction based on bismuth metasilicate Bi2SiO5 and β-Bi2O3. To date, there are some publications dedicated to these objects, however, the monitoring of the phase composition in the Bi2O3-Bi2SiO5 system and strong evidence of the heterostructure formation in the composite material have not been provided together. At first, we show with quantum-chemical calculations that such interface is possible to design. After that, using XRD in situ we clearly show the pathway of formation of Bi2SiO5 by consuming β-Bi2O3 phase with increasing of temperature. Such results allow monitoring the phase content of the composite material. Finally, we choose two calcination modes to prepare the samples. Based on the results of HRTEM, DRS, XRD, IR and Raman data we clearly show the difference between the mechanical mixture of the semiconductors and generated heterostructure material. Photocatalytic properties of the samples are tested in photodegradation of Rhodamine B under different wavelength of LEDS. Under visible light (470 nm) the heterostructure demonstrates better catalytic activity. Additionally, using air flow and trapping agents it is demonstrated that the holes h+ mainly take part in deethylation of the dye.

Hierarchical Flower Array NiCoOOH@CoLa‐LDH Nanosheets for High‐Performance Supercapacitor and Alkaline Zn Battery

AbstractNickel oxyhydroxide based energy storage materials have been largely confined by insufficient exposure of active sites which results in low energy efficiency and poor stability. In order to resolve the problems, hierarchical flower array heterostructure NiCoOOH@CoLa‐LDH (denoted as NC@CL) nanosheets are designed with NiCo oxyhydroxide (NiCoOOH, denoted as NC) being tightly covered on CoLa layered double hydroxide (CoLa‐LDH, denoted as CL) nanosheet. This rational design creates more active sites, enlarges the electrode‐electrolyte contact area, improves electron conductivity, and prevents agglomeration during the cycling charge–discharge processes. Density functional theory calculations and differential charges concurrently illustrate that heterostructure formation optimizes the reaction kinetics and promotes electron redistribution. Benefiting from the heterogeneous structure and rich electro‐active sites caused by NC, NC@CL displays outstanding reversible specific capacitance (3228 F g−1 at 1 A g−1). The aqueous rechargeable alkaline Zn battery NC@CL//Zn exhibits a high capacity of 381.1 mA h g−1 at 0.5 A g−1 and cycling durability (98% capacity retention after cycling at 5 A g−1 for 2000 cycles). The excellent electrochemical performances indicate that NC@CL has great application potential as electrode material for aqueous energy storage device.

Recent Advances in Electronic Structure Modifications of Layered Double Hydroxide (LDH) for the Water Splitting Application

AbstractElectrocatalytic water splitting is a feasible method for large‐scale hydrogen production. Recently, layered double hydroxides (LDH) have been identified as a possible candidate for accelerating the water splitting process. Nevertheless, certain structural alterations are necessary for immaculate LDH because of their weak electrocatalytic activity. These structural changes alter the local reaction environment by modulating the electronic structure of the metal center present in the LDH. This electronic structure tailoring is accomplished by a variety of processes, including heteroatom doping, single atom inclusion, cationic defect, oxygen vacancy creation, and heterostructure formation. Recently, there has been an uptick of advancement in this field, and it is necessary to summarize these developments. This review provides a concise summary of the current reports on the electronic structure manipulation of layered double hydroxide. The review begins by examining the local environmental changes of LDH resulting from the insertion of single atoms. Subsequently, we explore the charge transfer that occurs at the interface between LDH and other transition metal heterostructures. In addition, we explored the impact on the metal center near the vacancies on the basal plane of LDH. Finally, we presented a future perspective and guidance for advancing this field in electrocatalysis.

S-scheme3D/3D Bi0/BiOBr/P Doped g-C3 N4 with Oxygen Vacancies (Ov) for Photodegradation of Pharmaceuticals: In-situ H2O2 Production and Plasmon Induced Stability.

Complications accompanying photocatalyst stability and recombination of exciton charges in pollutants degradation has been addressed through the construction of heterojunctions, especially S-scheme heterojunction with strong and distinctive redox centres. Herein, an S-scheme BiOBr (BOR) and g-C3N4PO4 (CNPO) catalyst (BORCNPO) with oxygen vacancy (Ov) was synthesized for levofloxacin (LVX) and oxytetracycline (OTC) photodegradation under visible light. The 3D/3D BORCNPO catalyst possessed C-O-Br bridging bonds for efficient charge transfer during the fabrication of S-scheme heterojunction. In-situ H2O2 formation affirmed by potassium titanium (IV) oxalate spectrophotometric method improved the mineralization ability of BORCNPO7.5 catalyst. Bi0 surface plasmon resonance (SPR) enhanced formation and involvement of ⋅O2 - and the stability of the catalyst which increased reaction rate with increasing cycling experiments. XPS and radical trapping experiments supported the S-scheme charge transfer mechanism formation with high degradation rate of LVX which was 3 times higher than OTC degradation rate. Mineralization of pollutants and their intermediates were demonstrated with florescence excitation and emission matrix (FEEM) and quadruple time of flight high performance liquid chromatography (QTOF-HPLC). This work advances development of highly stable and efficient catalysts for photodegradation of pollutants through the formation of S-scheme heterostructure.

Near-Ideal Copper Oxide Heterostructure Design for Photoelectrochemical Water Splitting.

In recent years, photoelectrochemical (PEC) hydrogen generation through water splitting has gained significant attention as a carbon-free solar-to-energy conversion strategy. Among various materials, copper oxides, specifically cupric oxide (CuO) and cuprous oxide (Cu2O), have been extensively investigated for their suitable band positions and prominent performance, particularly in heterostructures. However, previously reported heterostructures, such as CuO layers on Cu2O, are not ideal configurations in terms of photoelectrical properties. In this study, we introduce the fabrication approach for an ideal heterostructure consisting of Cu2O nanowires on a CuO/Cu2O mixed-phase film, fabricated by a straightforward electrochemical/thermal method. The Cu2O nanowire with Cr layer (CNwC) shows potential for solar energy harvesting due to its suitable band positions and narrow bandgap, enabling enhanced photoabsorption across the entire visible spectrum. A thin chromium (Cr) layer underlying the nanostructure contributes to the formation of the ideal copper oxide heterostructure, acting as an adhesive and protective layer. The Cr layer is oxidized during the fabrication process of the CNwC and supports the hydrogen evolution reaction for water splitting. Moreover, the anodization time critically influences the phase composition, size, and density of the nanowires. Under optimal conditions, collective and slanted Cu2O nanowires can absorb incident light, maximizing both photon absorption and photon-to-energy conversion efficiency.

All-optical broadband terahertz modulator based on CdS NWs/Si heterojunction and interface photoconductivity analysis

A high-performance, low-cost terahertz modulator is fabricated by spin-coating CdS nanowires onto silicon. This all-optical modulator achieves broadband modulation (0.4–1.6 THz) with a significant depth of 85% at a low power density (2 W cm−2), exceeding bare silicon by fourfold. THz-TDS confirms its terahertz amplitude modulation capability. Tests of the simple photonic switch further illustrate the modulator’s potential for carrying information on a terahertz transmission wave. The modulation mechanism is explained through energy band theory and photoconductivity data. This work also presents a novel method for probing heterostructure formation using THz-TDS with laser irradiation.

Anion Exchange and Lateral Heterostructure Formation in Ferromagnetic PEA2Cr(Cl,Br)4 Two-Dimensional Perovskites.

Postsynthetic vapor-phase anion exchange in the ferromagnetic two-dimensional (2D) hybrid metal-halide perovskite, PEA2CrCl4 (PEA+ = phenethylammonium), is reported. Anion exchange using vaporous trimethylsilyl bromide (TMS-Br) is shown to drive complete conversion of solution-processed PEA2CrCl4 polycrystalline thin films to PEA2CrBr4. Low-temperature magnetic circular dichroism spectroscopy indicates ferromagnetic ordering in these PEA2CrCl4 and PEA2CrBr4 films. Via partial anion exchange of exfoliated flakes of PEA2CrCl4 single crystals, we demonstrate that it is possible to generate abrupt lateral PEA2CrCl4/PEA2CrBr4 magneto-heterointerfaces. Kinetic studies reveal that lateral heterostructure formation is dictated by rapid edge-site halide exchange followed by slower intralayer bromide diffusion, and there is negligible interlayer (3D) bromide or TMS-Br diffusion. The importance of the bulky PEA+ interlayer cation in suppressing 3D diffusion is highlighted by parallel anion-exchange experiments on MA2CrCl4 (MA+ = methylammonium), which instead show 3D exchange. Comparison of anion-exchange reactions in PEA2CrCl4, PEA2MnCl4, and PEA2PbCl4 shows that 2D bromide diffusion is slowest in PEA2CrCl4, attributed to the antiferrodistortive ordering found in this composition. In addition to demonstrating both postsynthetic composition control and heterostructure formation in ferromagnetic Cr-based 2D perovskites for the first time, these results also advance our fundamental understanding of ion-exchange processes in this relatively unexplored family of 2D perovskites, broadening opportunities for investigation and control of novel spin effects in low-dimensional metal-halide perovskites.

Electrochemical in-situ probing of heterocatalytic green reduction of 4-nitroaniline by novel non-noble CuO/Co3O4 nanocomposites

Nobel metals are commonly used catalysts in reactions due to their excellent catalytic activities. Transition metals, too, possess good catalytic activity due to the availability of vacant d-orbitals that provide avenues for electron exchange during reactions. In this work, the performance of CuO/Co3O4 (CCO) catalyst is evaluated. The catalyst is prepared by a facile coprecipitation method. X-ray diffraction, Fourier transform infrared spectroscopy, HRTEM, Ultraviolet spectroscopy, Scanning electron microscopy and X-ray photoelectron spectroscopy techniques were used to study the material properties. XRD analysis confirms the formation of CCO heterostructure with supporting evidence from FTIR, HRTEM and XPS. The catalyst shows optical bandgap contributions of CuO and Co3O4 at 1.6 eV and 2.4 eV, respectively. The SEM analysis shows the presence of agglomerates with a mean length of 111 ± 3 nm. The prepared catalyst is employed for the 4-nitroaniline reduction using sodium borohydride. The kinetics of the reduction reaction were studied, and an apparent rate constant of 0.323 min−1 was estimated. The catalyst shows a turnover frequency of 1.44 min−1 and 100% recyclability up to 5 cycles that are competitive with noble metal and rare-earth-based catalysts. The fast reduction of 4-NA is attributed to the novel p-p type isojunction formed by the heterostructure of CCO. Additionally, extensive electrochemical analysis has been used as an in situ probe to monitor the reduction reaction. Accordingly, the study shows the different intermediary reduction species formed in the process of reduction, adding evidence to the proposed mechanism.

Cauliflower-like Pd/MoC||Mo2C/C heterostructure as an efficient trifunctional catalyst for formic acid oxidation, hydrogen evolution, and oxygen reduction reactions

The use of Pd-based catalytic materials as electrocatalysts for formic acid oxidation reaction (FAO), hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) has been well-established for some time. The incorporation of a second phase can markedly enhance the electronic properties of the composites. The combination of different compounds with superior electronic properties is crucial for the design and preparation of catalysts with optimal catalytic activity and stability. In this study, a novel cauliflower-like Pd/MoC||Mo2C/C composite with heterostructure is synthesised, which exhibits excellent catalytic activity and long-term stability against FAO, HER, and ORR. The high-temperature treatment results in the formation of small-sized Mo₂C and MoC nanoparticles on the carbonaceous substrate, thereby exposing a greater number of Mo and Mo-C active sites. The formation of heterostructures between Mo₂C and MoC optimises the electronic structure of the composite, thereby facilitating enhanced reaction processes. In terms of FAO, the mass activity of Pd/MoC||Mo2C/C is 1.87A mgPd-1, which is 2.75 times higher than that of Pd/C (0.68A mgPd-1). As for the HER, a much lower overpotential of 28mV is required to achieve a current density of 10mAcm-2 compared to Pd/C (40mV). Fortunately, Pd/MoC||Mo2C/C also shows excellent ORR activity with a half-wave potential of 0.798V and the maximum current density of approximately 5.73mAcm-2 in alkaline electrolyte. These findings may contribute to the development of other noble metal-based materials loaded on intermetallic compounds with stable and effective electrocatalytic performance.

Construction of Visible light Driven Z-Scheme 1D/1D p-CuBi2O4/n-CdWO4 Heterojunction Nanocomposite for Effective Degradation of Organic Pollutants

The effective separation and harnessing of photoinduced charge carriers in photocatalysis are significant challenges. The present study aims to overcome this obstacle by developing a Z-Scheme heterojunction between a p-type CuBi2O4 (CBO) and a n-type CdWO4 (CWO) through a straightforward heat treatment method. The powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and High-resolution transmission electron microscopy (HRTEM) results revealed the successful formation of heterostructures. The photocatalytic efficiency of the materials was assessed by selecting an anionic methyl orange (MO) and cationic Rhodamine-B (Rh-B) dyes under visible light irradiation. Among all the materials, 85 wt.% CBO+ 15 wt.% CWO (CBO/CWO-15) heterostructure exhibited superior photocatalytic activity (90%) corresponding to 90 and 45 times higher than the pristine CBO and CWO, respectively. The positively charged photocatalyst surface attracts a greater number of MO dye molecules than Rh-B, thereby enhancing the degradation of MO over Rh-B. The scavenger results confirmed the involvement of hydroxy ( and superoxide () radicals in the degradation of MO. The rate constant of CBO/CWO-15 (0.01061 min-1) was 64 and 39 times higher than those of CBO (0.00016 min-1) and CWO (0.00027 min-1), respectively. The photoluminescence (PL) and electrochemical impedance spectroscopy (EIS) analyses substantiated the improved charge separation in the CBO/CWO-15 composite, establishing the Z-scheme mechanism. Cycling experiments over four cycles demonstrated consistent stability of the CBO/CWO-15 composite. The study provides an in-detail plausible mechanism of MO degradation. This type of Z-scheme composite material has potential applications in environmental remediation for the effective removal of organic pollutants and antibiotics from wastewater.

Lateral Heterostructures Fabricated via Artificial Pressure Gradient.

Hydrostatic conditions are generally pursued in high-pressure research, maintained to prevent the intrinsic pressure gradient on the culets of diamond anvil cells (DACs) from introducing heterogeneity to the structure and physical properties of the regulated materials. Here, a pioneering route to fabricate lateral heterostructures is proposed via artificial pressure gradients intentionally designed in DACs. Under the tailored pressure gradients, different structural phases emerge in distinct parts of the material, resulting in the formation of heterostructures. Harnessing the polymorphic transition nature of violet phosphorus under high pressure, violet/blue and violet/black phosphorus lateral heterostructures with different electrical properties have been successfully prepared by the pressure gradient method. This achievement highlights the potential of artificial pressure gradients as a portable and universal strategy for the fabrication of lateral heterostructures, shedding new light on the preparation and regulation of lateral heterostructures across a wider range of materials.

Boosted Electrochemical Hydrogen Evolution Activity via the Core-Shell Heterostructure of Nickel Sulfide Nanoframe-Supported Layered Rhenium Disulfide.

The strategic design of a heterostructure catalyst with a core-shell nanoarchitecture is imperative for enhancing the efficiency of the electrocatalytic hydrogen evolution reaction (HER). Herein, the core-shell catalyst comprising the rhenium disulfide nanosheets was vertically integrated onto a hollow nickel sulfide (NiS@ReS2) via coprecipitation and hydrothermal treatment. The morphology involves the sulfurization of a nickel-based Prussian blue analogue, effectively mitigating the aggregation of ReS2 nanosheets and maximizing the exposed active sites. By the synergistic effect of morphological design and heterostructure formation, the overpotential of NiS@ReS2 is 136 mV at 10 mA cm-2 in an alkaline electrolyte, and the rapid kinetics is confirmed by the small Tafel slope and low charge transfer resistance during the HER process. Moreover, the electrocatalytic durability of NiS@ReS2 is elucidated, and the boosted catalytic activity of NiS@ReS2 is confirmed by density functional theory. This study unveils a promising method for advancing ReS2-based electrocatalysts with potential implications for producing hydrogen.

Hierarchical Superhydrophilic/Superaerophobic Ni3S2/VS2 Nanorod-Based Bifunctional Electrocatalyst Supported on Nickel Foam for Overall Urea Electrolysis.

The design and preparation of effective nonprecious metal-based catalysts for the urea oxidation reaction (UOR) coupled with the hydrogen evolution reaction (HER) are of great significance to solve both energy shortage and environmental pollution problems. In this study, a novel hierarchical superhydrophilic and superaerophobicity three-dimensional nanorod-like bifunctional catalyst with a heterostructure (Ni3S2/VS2) was prepared on nickel foam via a simple one-step hydrothermal method, serving as an excellent electrocatalyst for both UOR and HER. The formed heterostructure significantly alters the electronic structure, optimizing charge transfer and increasing the number of active sites, which enhances the electrocatalytic performance of Ni3S2/VS2. As a result, this catalyst requires an extremely low potential of 1.396 V at the current density of 100 mA cm-2 for UOR and only 164 mV overpotential at -10 mA cm-2 for HER. Notably, a constructed two-electrode electrolyzer system (Ni3S2/VS2∥Ni3S2/VS2) demonstrates extraordinary activity and long-term stability, achieving a current density of 10 mA cm-2 at a low cell voltage of 1.48 V, which is superior to majority of the reported catalysts. This work demonstrates that the formation of heterostructures can effectively enhance the catalytic activity of nanomaterials toward UOR and HER and provides a feasible strategy for fabricating highly efficient nonprecious metal overall urea electrocatalysts.

Interface engineering of AgI/(P, K)-g-C3N4 novel S-scheme heterostructures as a highly efficient photocatalyst for RhB degradation

In this study, we developed an in-situ deposition method to load small-sized AgI nanoparticles as an oxidative photocatalyst (OP) onto phosphorus (P) and potassium (K) co-doped two-dimensional porous g-C3N4 (PK-CN-N) as a reductive photocatalyst (RP), forming an S-scheme heterojunction photocatalyst AgI/PK-CN-N. PK-CN-N achieved morphology control and element doping, leading to surface functionalization and heterostructure formation for the AgI/PK-CN-N photocatalyst. Notably, the 50AgI/PK-CN-N composite demonstrated an approximately 95 % removal efficiency for RhB within 30 minutes, 17.6 times higher than pure g-C3N4, surpassing most reported g-C3N4-based photocatalysts. The enhanced photocatalytic efficiency is attributed to the surface modification strategy and heterostructure formation of g-C3N4, which broadens the visible light response range, increases the number of active sites, improves the separation of photogenerated electron-hole pairs, and enhances REDOX capabilities. The band structure of the composite was elucidated through Mott-Schottky analysis and UV–vis DRS. The formation of the AgI/PK-CN-N S-scheme heterojunction and its charge transfer mechanism was confirmed through XPS, band structure analysis, KPFM, and EPR spectroscopy. Experimental data confirmed the presence of a strong and effective interface electric field between the two semiconductors, leading to band bending and accelerated charge separation. Additionally, the introduction of small-sized AgI semiconductors enhanced the exposure of the coupling interface, further improving catalytic performance. The reusability and lifespan of the catalyst were also analyzed, showing that after four cycles, the photocatalytic activity remained above 92 %.

First-principles study of GeC/Ga2SO heterostructure as a potential direct Z-scheme photocatalyst for water splitting

The rational design of van der Waals heterostructure offers an effective avenue for improving the photocatalytic efficiency of individual two-dimensional materials, garnering extensive interest in recent years. Herein, the feasibility of GeC/Ga2SO heterostructure as a photocatalyst for overall water splitting has been explored based on the first-principles calculations. Our findings reveal that the electronic bandstructure of GeC/Ga2SO heterostructure can be engineered in staggered or straddling band alignment depending on stacking patterns. Particularly, in the GeC/Ga2SO heterostructure with staggered band alignment, an intrinsic built-in electric field is established at the interface with the direction from GeC to Ga2SO, facilitating the formation of a direct Z-scheme heterostructure. Also importantly, the band-edge positions of Z-scheme GeC/Ga2SO heterostructure cross the water redox potentials, providing adequate driving force for both the reduction and oxidation reactions of water. Gibbs free energy calculations demonstrated that the photocatalytic overall water splitting can proceed spontaneously in the neutral environment (pH = 7) under light irradiation. Moreover, GeC/Ga2SO heterostructure exhibits good thermal stability and a strong (magnitude in 105 cm−1) and broad (from visible to ultraviolet light) optical absorption. Finally, through applying the tensile strain, further enhancements in the optical absorption and carrier redox ability are achieved due to the favorable modulation in the bandgap. Therefore, all these features make GeC/Ga2SO heterostructure show great potential in the application of photocatalytic water splitting.

Analysis of Heterostructure Formation of Abnormally Oriented Grains in Sputter-Deposited AlScN Films and Its Impact on Bulk Acoustic Wave Devices.

The presence of abnormally oriented grains (AOGs) in sputter-deposited aluminum scandium nitride (AlScN) films significantly degrades their physical properties, compromising the performance of bulk acoustic wave (BAW) devices. This study utilizes first-principles calculations to reveal that in tetrahedral wurtzite AlScN film-doped Sc atoms tend to aggregate at the second nearest-neighbor positions, forming dense ScN octahedral structures. The rock-salt (RS) ScN continued to grow due to further Sc aggregation. However, due to inadequate scandium flux, embryonic RS structures cannot be sustained, resulting in the nucleation of AOGs at the (111) faces of the octahedral ScN structure. Electron microscopy studies indicated that AOGs possess wurtzite structures and originate at tilted grain boundaries. These boundaries were characterized as RS ScN with more Sc atoms. This corroborated the theoretical predictions. BAW resonators and filters fabricated from sputter-deposited AlScN films demonstrate that AOGs degraded the piezoelectricity of AlScN, reducing the resonator's electromechanical coupling coefficient (Keff2). Measurements showed that AOG density increased from edge to center of the 8 in. wafer, resulting in a 3% decrease in average Keff2 in the resonators and a 137 MHz decrease in the filter bandwidth at 5 dB.

Ionic covalent organic framework-MXene heterojunction constructed by electrostatic interaction for stable electrocatalytic hydrogen generation

Constructing stable electrocatalysts by pyrolysis-free technique is an important topic in hydrogen-evolution reaction (HER) for water splitting reactions. Covalent organic frameworks (COFs), an emerging class of porous materials, offer ideal candidates owing to their abundant active sites and unique structures. Herein, a novel pyrolysis-free heterostructure was constructed using electrostatic interactions between an ionic COF (JUC-628) and Ti3C2Tx (MXene) nanosheets, which exhibits an impressively low overpotential of 137 mV at 10 mA cm−2 and excellent catalytic activity and stability for five days operation under alkaline conditions. Theoretical calculations depict that the formation of a stable heterostructure between MXene nanosheets and JUC-628 is the critical factor underlying the outstanding catalytic performance. Moreover, the optimized catalyst showed superior hydrogen-evolution capability in alkaline seawater electrolysis, highlighting the first successful application of a COF-based catalyst for hydrogen production from seawater electrolysis. As a leading covalent organic porous material–based catalyst for HER, as a proof of concept, this study represents a novel strategy to construct efficient electrocatalysts by COFs directly without the pyrolysis technique.

Significant promotion of interlayer ion diffusion for MoS2 /MoBS heterostructure as high performance Li/Na ion batteries anode material

As a member of the new two-dimensional materials family, functionalized MoB (MBene) attracts great interest as energy storage materials due to their excellent mechanical properties and metallicity. Here, we aim to leverage the superior properties of MBene to develop new promising electron materials for Li/Na-ion batteries by designing the MoS2 /MoBS heterostructure. Our investigation focuses on the structural stability, mechanical and electrochemical properties by first-principles calculation. The high Young's modulus, robust structural stability and metallicity prevent the electrode pulverization and guarantee cycle stability of battery. Impressively, the interlayer diffusion barriers of Li and Na atoms are only 0.26 and 0.16 eV, outperforming other MoS2-based heterostructures. With calculated open circuit voltage of 0.01–1.83 V for Li atoms and 0.02–1.28 V for Na atoms, the heterostructure is suitable for deployment as an anode material. Besides, the reversible specific capacity (376 mAh/g) of Li atoms is improved by the electron transfer caused by the formation of heterostructure compared to that of monolayer MoS2 (335 mAh/g) and MoBS(193 mAh/g). These findings fully underline the potential of MoS2/MoBS heterostructure as anode material of Li/Na-ion batteries.

Graphene-Templated Achiral Hybrid Perovskite for Circularly Polarized Light Sensing.

This study points out the importance of the templating effect in hybrid organic-inorganic perovskite semiconductors grown on graphene. By combining two achiral materials, we report the formation of a chiral composite heterostructure with electronic band splitting. The effect is observed through circularly polarized light emission and detection in a graphene/α-CH(NH2)2PbI3 perovskite composite, at ambient temperature and without a magnetic field. We exploit the spin-charge conversion by introducing an unbalanced spin population through polarized light that gives rise to a spin photoconductive effect rationalized by Rashba-type coupling. The prepared composite heterostructure exhibits a circularly polarized photoluminescence anisotropy gCPL of ∼0.35 at ∼2.54 × 103 W cm-2 confocal power density of 532 nm excitation. A carefully engineered interface between the graphene and the perovskite thin film enhances the Rashba field and generates the built-in electric field responsible for photocurrent, yielding a photoresponsivity of ∼105 A W-1 under ∼0.08 μW cm-2 fluence of visible light photons. The maximum photocurrent anisotropy factor gph is ∼0.51 under ∼0.16 μW cm-2 irradiance. The work sheds light on the photophysical properties of graphene/perovskite composite heterostructures, finding them to be a promising candidate for developing miniaturized spin-photonic devices.