Search

Amorphous molybdenum disulfide has shown potential as a hydrogen evolution catalyst, but the origin of its high activity is unclear, as is its atomic structure. Here, we have developed a classical inter-atomic potential using the charge equilibration neural network method, and we have employed it to generate atomic models of amorphous MoS2 by melting and quenching processes. The amorphous phase contains an abundance of molybdenum and sulfur atoms in low coordination. Besides the 6-coordinated molybdenum typical of the crystalline phases, a substantial fraction displays coordinations 4 and 5. The amorphous phase is also characterized by the appearance of direct S–S bonds. Density functional theory shows that the amorphous phase is metallic, with a considerable contribution of the 4-coordinated molybdenum to the density of states at the Fermi level. S–S bonds are related to the reduction of sulfur, with the excess electrons spread over several molybdenum atoms. Moreover, S–S bond formation is associated with a distinctive broadening of the 3s states, which could be exploited for experimental characterization of the amorphous phases. The large variety of local environments and the high density of electronic states at the Fermi level may play a positive role in increasing the electrocatalytic activity of this compound. [ABSTRACT FROM AUTHOR]

Two-dimensional transition metal dichalcogenides and semiconductor metal oxides have shown great potential in photocatalysis. However, their stability and efficiency need to be further improved. In this paper, porous ZnO nanorods with high specific surface area were prepared from metal-organic framework ZIF-8 by a simple hydrothermal method. A MoS2/ZnO composite was constructed by loading MoS2 onto the surface of porous ZnO nanorods. Compared with ZnO materials prepared by other methods, MoS2/ZnO prepared in this paper exhibits superior photocatalytic performance. The enhanced photocatalytic activity of the MoS2/ZnO composite can be attributed to the formation of heterojunctions and strong interaction between them, which greatly facilitate the separation of electrons and holes at the contact interface. In addition, due to the wide absorption region of the visible spectrum, MoS2 can greatly broaden the light absorption range of the material after the formation of the composite material, increase the utilization rate of visible light, and reduce the combination of electrons and holes. This study provides a new way to prepare cheap and efficient photocatalysts. [ABSTRACT FROM AUTHOR]

Three‐dimensional molybdenum disulfide (MoS2) functionalized MWCNTs hybrid nanoparticles were synthesized using in‐situ hydrothermal reaction. Two types of hybrids, MoS2/MWCNTs‐1 and MoS2/MWCNTs‐2 with MWCNTs to MoS2 precursor weight ratios 1:2 and 1:1 respectively were prepared with varying degrees of hybridization and the effects of their incorporation on tensile strength and fracture toughness properties of epoxies were investigated. Epoxy/MoS2/MWCNTs‐2 nanocomposites showed exceptional mechanical properties due to their improved dispersion, constrained chain mobility and excellent interfacial interactions. MoS2/MWCNTs‐2 nanocomposites showed maximum improvement of tensile strength by 28.52% at 0.5 wt% nanofiller concentration and the highest improvements in fracture toughness by 172% at 0.2 wt% nanofiller concentration. The excellent enhancement of fracture toughness properties was due to the synergic effect of MoS2/MWCNTs hybrid nanoparticles due to the crack pinning and bifurcation properties of MoS2 nanoparticles along with the pull‐out and crack bridging mechanisms of MWCNTs as observed in morphological analysis of fractures nanocomposites. The incorporation of 0.2 wt% of MoS2/MWCNTs‐2 increased the degradation temperatures of epoxy from 591 to 796°C at 95% weight loss due to the improved physical barrier effect. Highlights: MoS2/MWCNTs nanoparticles were synthesized using in‐situ hydrothermal reaction0.5 wt% MoS2/MWCNTs‐2 incorporated epoxies showed highest tensile strength0.2 wt% MoS2/MWCNTs‐2 incorporated epoxy composites show improved K1c valueIncorporation of MoS2/MWCNTs improved the thermal stability of epoxySynergistic effect of nanocomposite due to crack pinning, bifurcation & bridging [ABSTRACT FROM AUTHOR]

ABSTRACT Organophosphorus pesticides are commonly employed in agricultural fields due to their potent insecticidal properties and short environmental persistence. However, organophosphorus pesticides enter the human body through the food chain, surface, and groundwater, leading to irreversible damage to the nervous system. Therefore, monitoring the presence of organophosphorus pesticides in food is necessary to ensure human safety. Herein, an ultra‐sensitive electrochemical biosensor has been prepared by using graphitic carbon nitride decorated molybdenum sulfide (g‐C3N4@MoS2) as a catalyst for the detection of organophosphorus pesticides, trichlorfon. The synergistic effect of g‐C3N4@MoS2 boosts the electron transfer across the electrode surface, further contributing to the immobilization of acetylcholinesterase (AChE) enzyme using glutaraldehyde as a crosslinking agent. At optimum conditions, the developed biosensor (AChE/g‐C3N4@MoS2/ITO) demonstrated a broad linear range (5–100 nM) with a low detection limit (LOD) of 2.1 nM obtained using the equation 3σ/S where σ is the standard deviation and S is the sensitivity of the bioelectrode. In addition, the AChE/g‐C3N4@MoS2/ITO biosensor exhibited good stability and reproducibility, with satisfactory results for real sample analysis of trichlorfon detection. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting offers a promising avenue for producing clean hydrogen fuel, essential for a sustainable energy landscape. A highly efficient catalyst, featuring a one-dimensional structure, has been synthesized by combining zinc iron sulfide with molybdenum disulfide (ZFSMS) on a nickel foam substrate. This synthesis method utilizes a simple yet effective hydrothermal approach tailored for efficient water splitting. By carefully engineering the interface between zinc iron sulfide and molybdenum disulfide, the electronic conductivity of the catalyst is significantly boosted, enhancing its catalytic performance. The resulting hybrid, ZFSMS, exhibits remarkable electrocatalytic efficiency with minimal overpotentials. Specifically, overpotentials of 130 mV and 220 mV are recorded for the oxygen evolution reaction at 20 mA cm−2 and 50 mA cm−2, respectively. Moreover, for the hydrogen evolution reaction, overpotentials of 145 mV and 257 mV are observed at 10 mA cm−2 and 40 mA cm−2, respectively, in a 1.0 M potassium hydroxide solution. Notably, the ZFSMS-based electrolyzer operates at a low voltage of 1.5 V at 10 mA cm−2, underscoring its efficiency in facilitating electrochemical hydrogen generation. This catalyst good candidate for advancing green hydrogen production, contributing to the progress of sustainable and clean hydrogen fuel production methods. [Display omitted] • A highly efficient catalyst, characterized by a one-dimensional morphology and structure, has been developed. • The overpotentials are measured for the oxygen evolution reaction at 20, and 50 mA cm−2. • The hydrogen evolution reaction, the overpotentials are 145 mV and 257 mV at 10, and 40 mA cm−2. • The zinc cobalt sulfide and molybdenum disulfide (ZFSMS), demonstrates remarkable electrocatalytic activity with low overpotentials. [ABSTRACT FROM AUTHOR]

[Display omitted] Phase change materials (PCMs) offer significant advantages in energy conversion and storage by facilitating the storage and release of thermal energy during phase transition processes. However, challenges such as leakage during PCM phase transitions and poor light absorption properties have constrained their application in the field of photothermal energy storage. In this study, Montmorillonite (Mt) and molybdenum disulfide (MoS 2) has been used to design and synthesize hybrid aerogels (MoS 2 /Mt) boasting high mechanical strength and excellent photothermal conversion performance. These aerogels are then used to encapsulate polyethylene glycol (PEG) to prepare composite PCMs with outstanding solar-thermal conversion and storage performances. The results show that the synthesized MoS 2 /Mt-PEG composite PCMs exhibit high enthalpies of melting and solidification of 169.16 J/g and 170.78 J/g, respectively, while the aerogel supporting material has a high compressive modulus of 1.96 MPa. Moreover, the composite material displayed excellent thermal stability and leakage resistance after undergoing 30 melting-cooling cycles. Furthermore, the incorporation of MoS 2 imparted outstanding light absorption properties to the MoS 2 /Mt-PEG composite, resulting in a high light absorption and photothermal conversion-storage efficiency of 93.4 % and 96.47 %, respectively. Synthesized composite PCMs also demonstrate outstanding performance in solar-thermal-electricity conversion, achieving a voltage output of 458 mV under illumination conditions and maintaining a sustainable voltage output even after removing the light source. Thus, the composite PCMs prepared in this work can meet the requirements of high enthalpy, effective leakage prevention, efficient solar-thermal conversion and solar-thermal-electricity conversion performance, thereby presenting potential applications in practical solar energy collection, conversion, and storage. [ABSTRACT FROM AUTHOR]

Passive imaging for mid-wave infrared (MWIR) is resistant to atmospheric pollutants, guaranteeing image clarity and accuracy. Arrayed photodetectors can simultaneously perform radiation sensing to improve efficiency. Room temperature van der Waals (vdWs) photodetectors without lattice matching have evolved rapidly with optimized stacking methods, primarily for single-pixel devices. The urgent need to implement arrayed devices aligns with practical demands. Here, we present an 8 by 1 black phosphorus/molybdenum sulfide (BP/MoS2) vdWs photodetector linear array with a fill-factor of ~77%, fabricated using a temperature-assisted sloping transfer method. The flat interface and uniform thickness facilitate carrier transport and minimize pixel nonuniformities, showing an average peak detectivity (D*) of 2.34 × 109 cm·Hz1/2·W-1 in the mid-wave infrared region. Compared to a single pixel, push-broom scanning passive imaging is eight times more efficient and further enhanced through mean filtering and fast Fourier transform filtering for strip noise correction. Our study offers guidance on vdWs arrayed devices for engineering applications. [ABSTRACT FROM AUTHOR]

We obtained 3D nanoflowers of MoS2 (3D-MoS2) with an average size of 1–3 µm synthesized by a one-step hydrothermal method, the "flower-shape" being composed of several petal-like sheets with a thickness of about 19 nm. The 3D nanoflowers underwent functionalization with diethyl[2-hydroxy-2-(thiophen-3-yl)ethyl]phosphonate and 2-tiophene carboxylic acid. P3HT/MoS2 composites were synthesized by Grignard metathesis using a 2,5-dibromo-3-hexylthiophene/MoS2 weight ratio of 1:0.05. As a reference, the P3HT/MoS2 composites were also synthesized with unfunctionalized 3D-MoS2. The P3HT/MoS2 composites were characterized by FTIR, XRD, TEM, 1H NMR, UV–Vis, TGA, and cyclic voltammetry. We studied the influence of 3D-MoS2 nanoflowers functionalized with phosphonic and carboxyl groups on the properties of the P3HT/MoS2 composites. The addition of functionalized 3D-MoS2 in the P3HT/MoS2 composites improved the percentage of HT dyads and the definition of shoulders in the dyad signal, indicating a better arrangement of the polymeric chains in the P3HT/3D-MoS2 functionalized composites. In addition, the functionalization of the 3D-MoS2 white phosphonic group increased the conjugation length, the percentage of crystallinity, and the conductivity. Likewise, the P3HT/MoS2 functionalized composites showed a decrease in the energy gap compared to P3HT. The functionalization of the 3D-MoS2 was successfully carried out, and a close interaction between the P3HT and 3D-MoS2 was determined. We achieved the in situ synthesis of P3HT/MoS2 composites by Grignard metathesis using functionalized 3D-MoS2 obtained by the hydrothermal method. We compared two functionalization groups with 3D-MoS2 and their subsequent polymerization with P3HT. Our work provides evidence for a better performance in composites functionalized with a phosphonate group because a phosphonic anchor provides strong electronic coupling with the 3D-MoS2. The above makes this material suitable for applications in flexible electronics photosensors, electrochromic devices, photocatalysis, and harvesting energy material in solar cells. [ABSTRACT FROM AUTHOR]

Molybdenum sulfide (MoS2) and modified MoS2 with different percentages of CdS (10%, 30%, and 50% CdS@MoS2) were successfully synthesized and characterized. The photocatalytic performance of the MoS2 and CdS@MoS2 was evaluated by degrading brilliant green (BG), methylene blue (MB), and rhodamine B (RhB) dyes under visible light irradiation. Amongst the synthesized photocatalysts, 50% CdS@MoS2 exhibited the highest photocatalytic activity, degrading 97.6%, 90.3%, and 75.5% of BG, MB, and RhB dyes, respectively within 5 h. The active species involved in the degradation processes were investigated. All trapping agents inhibited BG and MB degradation to a similar extent, indicating that all of the probed active species play an important role in the degradation of BG and MB. In contrast, h+ and O2•− were found to be the main reactive species in the photocatalytic RhB degradation. A potential mechanism for the photocatalytic degradation of dyes using CdS@MoS2 has been proposed. This work highlights the potential of CdS@MoS2 as a photocatalyst for more efficient water remediation applications. [ABSTRACT FROM AUTHOR]

Cathodic electrochemical intercalation/exfoliation of transition metal dichalcogenides (TMDs) with bulky tetraalkylammonium‐based cations is gaining popularity as it avoids the semiconducting (2H) to metallic (1T) phase transformation in TMDs like molybdenum disulfide (MoS2) and, generally, produces sheets with a larger aspect ratio – important for achieving conformal sheet‐to‐sheet contact in optoelectronic devices. Large single crystals are typically used as the precursor, but these are expensive, often inaccessible, and result in limited quantities of material. In this paper, a 3D‐printable electrochemical cell capable of intercalating gram‐scale quantities of commercially available TMD powders is presented. By incorporating a reference electrode in the cell and physically restraining the powder with a spring‐loaded mechanism, the system can probe the intercalation electrochemistry, for example, determining the onset of intercalation to be near −2.5 V versus the ferrocene redox couple. While the extent of intercalation depends on precursor quantity and reaction time, a high yield of exfoliated product can be obtained exhibiting average aspect ratios as high as 49 ± 44 similar to values obtained by crystal intercalation. The intercalation and exfoliation of a wide variety of pelletized commercial powders including molybdenum diselenide (MoSe2), tungsten diselenide (WSe2), tungsten disulfide (WS2), and graphitic carbon nitride (gCN) are also demonstrated. [ABSTRACT FROM AUTHOR]

Large‐scale production of high‐quality ultrathin layers (1–3 nm) of molybdenum disulfide (MoS2) with absolute (≈100%) 1T‐phase is still in its infancy. Therefore, it is extremely crucial to have a technique for the mass production of ultrathin 1T‐MoS2 layers. Here, a direct, single‐step, and ultra‐fast technique that produces high‐quality ultrathin layers of 1T‐MoS2 with a production rate as high as 58 g h−1 without the usage of any intercalates or solvents is demonstrated. The exfoliated ultrathin 1T‐MoS2 layers exhibited ≈100% 1T‐phase with a large specific surface area (67 m2 g−1), higher electrical conductivity (140 S m−1), high thermal stability (up to 500 °C) and hydrophilicity (water contact angle (WCA): ≈23.4⁰). The ultrathin 1T‐MoS2 layers showed a higher specific capacitance of 420 F g−1; perhaps an ideal candidate for the electrodes of supercapacitors. Moreover, the ultrathin 1T‐MoS2 layer exhibited better mechanical flexibility and retained its original performance on bending between 0 and 180⁰ angles. Further, to assess the adeptness of the protocol, An initial trial is done on other transition metal dichalcogenides (TMDs) i.e., tungsten disulfide (WS2), and observe similar results. The work sheds light on the simultaneous exfoliation and phase transformation of TMDs in large quantities, and detailed proofs‐of‐concept demonstrate its application in next‐generation energy storage devices. [ABSTRACT FROM AUTHOR]

Large‐scale production of high‐quality ultrathin layers (1–3 nm) of molybdenum disulfide (MoS2) with absolute (≈100%) 1T‐phase is still in its infancy. Therefore, it is extremely crucial to have a technique for the mass production of ultrathin 1T‐MoS2 layers. Here, a direct, single‐step, and ultra‐fast technique that produces high‐quality ultrathin layers of 1T‐MoS2 with a production rate as high as 58 g h−1 without the usage of any intercalates or solvents is demonstrated. The exfoliated ultrathin 1T‐MoS2 layers exhibited ≈100% 1T‐phase with a large specific surface area (67 m2 g−1), higher electrical conductivity (140 S m−1), high thermal stability (up to 500 °C) and hydrophilicity (water contact angle (WCA): ≈23.4⁰). The ultrathin 1T‐MoS2 layers showed a higher specific capacitance of 420 F g−1; perhaps an ideal candidate for the electrodes of supercapacitors. Moreover, the ultrathin 1T‐MoS2 layer exhibited better mechanical flexibility and retained its original performance on bending between 0 and 180⁰ angles. Further, to assess the adeptness of the protocol, An initial trial is done on other transition metal dichalcogenides (TMDs) i.e., tungsten disulfide (WS2), and observe similar results. The work sheds light on the simultaneous exfoliation and phase transformation of TMDs in large quantities, and detailed proofs‐of‐concept demonstrate its application in next‐generation energy storage devices. [ABSTRACT FROM AUTHOR]

Hybrid supercapacitors (HSCs) bridge the unique advantages of batteries and capacitors and are considered promising energy storage devices for hybrid vehicles and other electronic gadgets. Lithium‐ion capacitors (LICs) have attained particular interest due to their higher energy and power density than traditional supercapacitor devices. The limited voltage window and the deterioration of anode materials upsurged the demand for efficient and stable electrode materials. Two‐dimensional (2D) molybdenum sulfide (MoS2) is a promising candidate for developing efficient and durable LICs due to its wide lithiation potential and unique layer structure, enhancing charge storage efficiency. Modifying the extrinsic features, such as the dimensions and shape at the nanoscale, serves as a potential path to overcome the sluggish kinetics observed in the LICs. Herein, the MoS2 nanoflowers have been synthesized through a hydrothermal route. The developed LIC exhibited a specific capacitance of 202.4 F g−1 at 0.25 A g−1 and capacitance retention of >90 % over 5,000 cycles. Using an ether electrolyte improved the voltage window (2.0 V) and enhanced the stability performance. The ex‐situ material characterization after the stability test reveals that the storage mechanism in MoS2‐LICs is not diffusion‐controlled. Instead, the fast surface redox reactions, especially intercalation/deintercalation of ions, are more prominent for charge storage. [ABSTRACT FROM AUTHOR]

Research on two-dimensional material-based phototransistors has recently become a topic of great interest. However, the high number of design features, which impact the performance of these devices, and the multi-physical nature of the device operation make the accurate analysis of these devices a challenge. Here, we present a simple yet effective numerical framework to overcome this challenge. The one-dimensional framework is constructed on the drift-diffusion equations, Poisson's equation, and wave propagation in multi-layered medium formalism. We apply this framework to study phototransistors made from monolayer molybdenum disulfide ( MoS 2 ) placed on top of a back-gated silicon-oxide-coated silicon substrate. Numerical results, which show good agreement with the experimental results found in the literature, emphasize the necessity of including the inhomogeneous background for accurately calculating device metrics such as quantum efficiency and bandwidth. For the first time in literature, we calculate the phase noise of these phototransistors, which is a crucial performance metric for many applications where precise timing and synchronization are critical. We determine that applying a low drain-to-source voltage is the key requirement for low phase noise. [ABSTRACT FROM AUTHOR]

Purpose: The primary focus of this study is to tackle a critical industry issue concerning energy inefficiency. This is achieved through an investigation into enhancing heat transfer in solar radiation phenomena on a curved surface. The problem formulation of governing equations includes the combined effects of thermal relaxation, Newtonian heating, radiation mechanism, and Darcy-Forchheimer to enhance the uniqueness of the model. This research employs the Cattaneo–Christov heat theory model to investigate the thermal flux via utilizing the above-mentioned phenomenon with a purpose of advancing thermal technology. A mixture of silicon dioxide (SiO_2)\ and Molybdenum disulfide (MoS_2) is considered for the nanoparticle's thermal propagation in base solvent propylene glycol. The simulation of the modeled equations is solved using the Shifted Legendre collocation scheme (SLCS). The findings show that, the solar radiation effects boosted the heating performance of the hybrid nanofluid. Furthermore, the heat transmission progress increases against the curvature and thermal relaxation parameter. Design/methodology/approach: Shifted Legendre collocation scheme (SLCS) is utilized to solve the simulation of the modeled equations. Findings: The findings show that, the solar radiation effects boosted the heating performance of the hybrid nanofluid. The heat transmission progress increase against the curvature and thermal relaxation parameter. Originality/value: This research employs the Cattaneo–Christov heat theory model to investigate the thermal flux via utilizing the above-mentioned phenomenon with a purpose of advancing thermal technology. [ABSTRACT FROM AUTHOR]

A simple, quick and environmentally friendly microwave-assisted synthesis method was developed to produce MoS2 nanoparticles (MoS2NP) for the preconcentration of thallium. The characteristics of the synthesized MoS2NP were validated by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The determination of thallium was achieved with MoS2NP based preconcentration and a flame atomic absorption spectrophotometer (MoS2NP-PM-FAAS). A detection limit of 14.6 µg/kg was achieved for thallium using the optimum conditions by the MoS2-PM-FAAS method. The developed method provided an improvement in the detection power of the FAAS system by approximately 20-fold. The applicability of the method was validated with tea samples through spike recovery experiments. [ABSTRACT FROM AUTHOR]

Electrocatalytic hydrogen evolution and (S2−) recycling present promising strategies for cost‐effective hydrogen production and simultaneous removal of environmental pollutants. However, the advancement of this technology is hindered by the limited availability of affordable, efficient, and stable catalysts. Herein, the study synthesizes ultrafine ruthenium (Ru) nanoclusters on a substrate of iron molybdenum sulfide (FeMo‐S) nanosheets, creating a new heterointerface catalyst (FeMo‐S/Ru) for the hydrogen evolution reaction (HER) and sulfion oxidation reaction (SOR). Experimental and theoretical calculations suggest that strong electron interactions between Ru nanoclusters and FeMo‐S substrate, optimizing *H adsorption and promoting HER activity on one side while facilitating the production and adsorption of sulfur intermediates on the other side, effectively catalyzing SOR. Additionally, the assembled electrocatalytic coupling system with FeMo‐S/Ru displays an ultralow cell voltage of 0.57 V at 100 mA cm−2, achieving high Faradaic efficiencies (>96%) for H2 production, while also exhibiting remarkable durability over 1 month (838 h). This work paves the way for the development of highly efficient and durable supported catalysts, enabling energy‐saving hydrogen production and environmentally friendly sulfion recycling. [ABSTRACT FROM AUTHOR]

[Display omitted] Incorporating piezo-response into photocatalysis holds great promise for eco-friendly strategies in environmental remediation and sustainable energy conversion. Herein, flexible N -defect nanoporous g-C 3 N 4 nanosheets (NPCNs) was prepared via one-step method, then whose surface was protonated. And existed dense 1T/2H phase and vertical interfaces in non-layer-dependent-piezo-response sailboat-like-MoS 2 (Sv-MS) formed by in-situ stresses during nucleation and growth by experiments and MD-simulations. Noble-metal-free Z-scheme PC/VM heterojunction with broad-spectrum absorption, enhanced piezo-response and intimate triple-interface was established by electrostatic self-assembly, performing efficient hybrid-driven piezo-photocatalysis. With a systematic modification of morphology, grain size, phase composition, and surface condition of the components, the optimal PC(3.6H)/VM(u2) exhibited high piezo-photocatalytic rates for degradation of organic dyes and antibiotic (RhB (0.565 min-1), MO (0.052 min-1), MB (1.557 min-1), TC (0.062 min-1)) and hydrogen evolution (3528 μmolg-1h-1) under visible-light and ultrasonic-wave, with maintenance under NIR-light (λ max = 1000 nm) attributed to up-conversion effect (RhB: 0.212 min-1, H 2 : 2355 μmolg-1h-1). Furthermore, the piezo-photocatalytic mechanism was proposed by experiments and DFT-calculations for effective triple-interface Z-Scheme charge migration. This work provides a rational protocol for constructing diverse-energy-triggered, multiple-interfaces and broad-solar-spectrum (UV–Vis-NIR) piezo-photocatalysts in degradation and hydrogen evolution. [ABSTRACT FROM AUTHOR]

[Display omitted] Molybdenum sulfide materials have long been considered as attractive non-precious-metal electrocatalysts for the hydrogen evolution reaction (HER). However, comparing with the crystalline counterpart, amorphous MoS x has been less investigated previously. We here propose to increase the catalytical activity of a-MoS x by raising the reactant concentration at the catalytic interface via a chemical doping approach. The reconstruction of coordination structure of a-MoS x via Pd doping induces the formation of abundant unsaturated S atoms. Moreover, the reactant friendly catalytic interface is constructed through introducing hydrophilic groups to a-MoS x. The doped a-MoS x catalyst exhibits significantly enhanced HER activity in both acid and alkaline media. [ABSTRACT FROM AUTHOR]

A S-scheme heterojunction of CuPc/DR-MoS 2 with abundant sulfur vacancies is proposed, enabling extended visible-light absorption, enhanced charge carrier separation/transfer, and improved efficiency of semiconductors. Additionally, sulfur vacancies play a significant role in enhancing CO 2 adsorption/activation on the photocatalyst surface during photocatalysis. [Display omitted] Constructing a heterojunction by combining two semiconductors with similar band structures is a successful approach to obtaining photocatalysts with high efficiency. Herein, a CuPc/DR-MoS 2 heterojunction involving copper phthalocyanine (CuPc) and molybdenum disulfide with S-rich vacancies (13.66%) is successfully prepared by the facile hydrothermal method. Experimental results and theoretical calculations firmly demonstrated that photoelectrons exhibit an S-scheme charge transfer mechanism in the CuPc/DR-MoS 2 heterojunction. The S-scheme heterojunction system has proven significant advantages in promoting the charge separation and transfer of photogenerated carriers, enhancing visible-light responsiveness, and achieving robust photoredox capability. As a result, the optimized 3CuPc/DR-MoS 2 S-scheme heterojunction exhibits photocatalytic yields of CO and CH 4 at 200 and 111.6 μmol g-1h−1, respectively. These values are four times and 4.5 times greater than the photocatalytic yields of pure DR-MoS 2. This study offers novel perspectives on the advancement of innovative and highly effective heterojunction photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Core–shell CdS/ZnS nanorod co-doped with MoS 2 were fabricated by three step process. • The 7 mol% MoS 2 co-doped CdS/ZnS heterostructure showed maximum H 2 evaluation of 13,589 μmol h-1g−1. • The optimal sample showed 19 and 158 times higher H 2 evolution than individual metal sulfides. • CdS/ZnS co-doped with MoS 2 nanorods demonstrated good chemical stability. Hydrogen generation via semiconductor photocatalysts has gained significant attention as a sustainable fuel generation process. To demonstrate the performance of nanoscale core–shell heterostructure in photocatalytic hydrogen production, we have fabricated CdS nanorods coated with ZnS photocatalyst via wet-chemical reaction followed by deposition of ultrathin MoS 2 nanosheets by photo reduction process. The effect of ZnS content and suitable amount of MoS 2 loading over the visible-light induced photocatalytic hydrogen evolution was examined in Na 2 S and Na 2 SO 3 aqueous solutions. Interestingly, it is apparent that a close connection (or heterojunction) between CdS and ZnS is believed to easily tunnel the charge carriers to the surplus surface states, making its electrons and holes energetically favourable to transfer from ZnS to MoS 2 for photocatalytic reactions and subsequently, enhances the H 2 evolution activity in CdS/ZnS type I core–shell heterostructures. The optimal MoS 2 concentration is resolved to be 7 mol% and the subsequent visible-light induced H 2 generation rate was 13589 μmol h−1g−1, which is 19 and 158 fold higher than pristine CdS and ZnS respectively. The probable photocatalytic mechanism of CdS/ZnS type I core–shell heterostructure with MoS 2 cocatalyst is proposed. Our inexpensive and convenient preparation strategy may offer novel prospects in the engineering of desirable nanoheterostructures with better performance. [ABSTRACT FROM AUTHOR]

Vanadium doping can effectively modify the physical properties of transition metal dichalcogenides (TMDCs), broadening their application prospect in electronic, spintronic, and valleytronic devices. However, vanadium dopants always suppress the growth of TMDCs and lower the growth controllability. Here, we report the morphology-controlled growth of vanadium-doped MoS2 (V-MoS2). Both the layer-controlled growth and fractal growth of monolayer V-MoS2 were realized, and the mechanism was analyzed, including contributions from the localized concentration of Mo atoms, the etching effect, and formation energies of different terminations. It will shed light on the morphology-controlled growth of other vanadium-doped TMDCs, promoting the construction of novel devices. Controll vanadium dopants enables layer-controlled and fractal growth of V-MoS2 in this work with contributions from the localized concentration of Mo atoms, the etching effect, and formation energies of different terminations. It will help to realize the morphology-controlled growth of other vanadium-doped TMDCs and thus promotes the construction of novel devices. [ABSTRACT FROM AUTHOR]

Recently, two-dimensional (2D) transition metal dichalcogenides (2D TMDs), such as molybdenum sulfide (MoS2) and molybdenum selenide (MoSe2), have been presented as effective materials for extracting the generated holes from perovskite layers. Thus, the work function of MoS2 can be tuned in a wide range from 3.5 to 4.8 eV by adjusting the number of layers, chemical composition, elemental doping, surface functionalization, and surface states, depending on the synthetic approach. In this proposed work, we attempt to synthesize MoS2 nanoparticles (NPs) from bulk MoS2 using two steps: (1) initial exfoliation of bulk MoS2 into few-layer MoS2 by using curcumin-cholesteryl-derived organogels (BCC-ED) and curcumin solution in ethylene diamine (C-ED) under sonication; (2) ultrasonication of the subsequently obtained few-layer MoS2 at 60–80 °C, followed by washing of the above chemicals. The initial treatment with the BCC-ED/C-ED undergoes exfoliation of bulk MoS2 resulted in few-layer MoS2, as evidenced by the morphological analysis using SEM. Further thinning or reduction of the size of the few-layer MoS2 by prolonged ultrasonication at 60–80 °C, followed by repeated washing with DMF, resulted in uniform nanoparticles (MoS2 NPs) with a size of ~10 nm, as evidenced by morphological analysis. Since BCC-ED and C-ED produced similar results, C-ED was utilized for further production of NPs over BCC-ED owing to the ease of removal of curcumin from the MoS2 NPs. Utilization of the above synthesized MoS2 NPs as an ETL layer in the cell structure FTO/ETL/perovskite absorber/spiro-OMeTAD/Ag enhanced the efficiency significantly. The results showed that MoS2 NPs as an ETL exhibited a power conversion efficiency (PEC) of 11.46%, a short-circuit current density of 18.65 mA/cm2, an open-circuit voltage of 1.05 V, and a fill factor of 58.66%, at the relative humidity of 70 ± 10% (open-air conditions) than that of the ED-treated MoS2 devices without curcumin. These results suggest that the synergistic effect of both curcumin and ED plays a critical role in obtaining high-quality MoS2 NPs, beneficial for efficient charge transport, lowering the crystal defect density/trap sites and reducing the charge recombination rate, thus, significantly enhancing the efficiency. [ABSTRACT FROM AUTHOR]

Crystalline molybdenum disulfide has become a central actor in the 2D-materials community due to its promising optoelectronic and thermoelectric properties. Despite the extensive work made in investigating these properties, a vast area of knowledge remains unknown on the structure and dynamics of its disordered phases such as liquid and amorphous. Thus, the goal of this work is to investigate the melting of bulk molybdenum disulfide using ab initio molecular dynamics based on density functional theory. We employ the two-phase and Z-methods to evaluate the melting in a number of conditions. Our results at 1 bar reveal that the two-phase procedure is preferred since it predicts a melting point of 2266.92 K that is directly computed using simulations at constant pressure and energy. In contrast, this temperature is indirectly estimated at 2154.01 K with the Z-method using an interpolation of simulations at constant volume and energy. Nevertheless, we find that both methods are complementary as they allow computing different thermodynamic and structural properties. For instance, we estimate a melting heat of 0.67 eV/atom with the two-phase coexistence route, which shows very good agreement with the value of 0.75 eV/atom obtained from the difference of the internal energies of separate crystalline and liquid ensembles at the same conditions of 1 bar and 2266.92 K. In contrast, the Z-method allows us to determine the influence of pressure on the melting temperature, density, and coordination number with a lower computational cost. [ABSTRACT FROM AUTHOR]

Crystalline calcium fluoride (CaF2) is drawing significant attention due to its great potential of being the gate dielectric of two-dimensional (2D) material MOSFETs. It is deemed to be superior to boron nitride and traditional silicon dioxide (SiO2) because of its larger dielectric constant, wider band gap, and lower defect density. Nevertheless, the CaF2-based MOSFETs fabricated in the experiment still present notable reliability issues, and the underlying reason remains unclear. Here, we studied the various intrinsic defects and adsorbates in CaF2/molybdenum disulfide (MoS2) and CaF2/molybdenum disilicon tetranitride (MoSi2N4) interface systems to reveal the most active charge-trapping centers in CaF2-based 2D material MOSFETs. An elaborate Table comparing the importance of different defects in both n-type and p-type devices is provided. Most impressively, the oxygen molecules (O2) adsorbed at the interface or surface, which are inevitable in experiments, are as active as the intrinsic defects in channel materials, and they can even change the MoSi2N4 to p-type spontaneously. These results mean that it is necessary to develop a high-vacuum packaging process, as well as prepare high-quality 2D materials for better device performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • 2D GnP/MoS 2 and 3D (GnP/MoS 2)/MWNT composites are prepared by a facile, robust and ecofriendly method. • Effects of N-doping of GnPs and mass fraction of MWNTs on ORR activity are explored and rationalized. • Best synergistic ORR activity is obtained for N-doped catalyst with 3:1 2D-to-1D ratio. • Catalysts exhibit excellent stability and methanol resistance in alkaline medium. • Promising route to develop bifunctional ORR/OER catalysts. Nanocomposites have garnered attention for their potential as catalysts in electrochemical reactions vital for technologies like fuel cells, water splitting, and metal-air batteries. This work focuses on developing three-dimensional (3D) nanocomposites through aqueous phase exfoliation, non-covalent functionalization of building blocks with surfactants and polymers, and electrostatic interactions in solution leading to the nanocomposites assembly and organization. By combining molybdenum disulfide (MoS 2) layers with graphene nanoplatelets (GnPs) to form a binary 2D composite (MoS 2 /GnP), and subsequently incorporating multiwalled carbon nanotubes (MWNTs) to create ternary 3D composites, we explore their potential as catalysts for the oxygen reduction reaction (ORR) critical in fuel cells. Characterization techniques such as X-ray photoelectron spectroscopy, scanning electron microscopy, and X-ray diffraction elucidate material composition and structure. Our electrochemical studies reveal insights into the kinetics of the reactions and structure–activity relationships. Both the (MoS 2 /GnP)-to-MWNT mass ratio and nitrogen-doping of GnPs (N -GnPs) play a key role on the electrocatalytic ORR performance. Notably, the (MoS 2 / N -GnP)/MWNT material, with a 3:1 mass ratio, exhibits the most effective ORR activity. All catalysts demonstrate good long-term stability and methanol crossover tolerance. This facile fabrication method and observed trends offer avenues for optimizing composite electrocatalysts further. [ABSTRACT FROM AUTHOR]

A robust "on–off" fluorescent aptasensor was developed using nanohybrids of molybdenum sulfide (MoS2) quantum dot (QD)–doped zinc metal–organic frameworks (Zn-MOF) for selective and sensitive detection of cadmium ions (Cd2+) in water. This nanohybrid (MoS2@Zn-MOF), synthesized via "bottle around the ship" methodology, exhibited a high-intensity fluorescence emission centered at 430 nm (λEm) (blue) on excitation at 320 nm (λEx). Further, the conjugation of this fluorophore to phosphate-modified cadmium aptamer (Cd-2–2) was achieved through carbodiimide reaction. The hybridization of prepared sensing probe (MoS2@Zn-MOF/Cd-2–2 aptamer) was done with dabcyl-conjugated complementary DNA (cDNA), acting as energy donor–acceptor pair in the fluorescence resonance energy transfer (FRET) system. This hybridization causes the fluorescence quenching of the nanohybrid. In the presence of Cd2+, the aptamer from the fabricated nano-biosensing probe binds to these ions, resulting in release of dabcyl-cDNA oligomer. This release of dabcyl-cDNA oligomer from the sensing probes restores the fluorescence of the nanohybrid. Under optimized conditions (sensing probe/dabcyl-cDNA ratio 1/7, pH 7.4, and temp 28 °C), the sensing probe showed a fast response time of 1 min. The fluorescence intensity of the nanohybrid can be utilized to determine the concentration of Cd2+. The proposed aptasensor achieved highly sensitive detection of Cd2+ with a limit of detection (LOD) of 0.24 ppb over the range of 1 × 10−9 to 1 × 10−4 M along with minimal effects of interferences (e.g., Hg2+, Pb2+, and Zn2+) and good reproducibility. The designed aptasensor based on MoS2@Zn-MOF nanofluorophore offers a highly sensitive and selective approach for rapid screening of metal ions in aqueous environments. [ABSTRACT FROM AUTHOR]

Chitosan (CS) and two-dimensional nanomaterial (2D nanomaterials)-based scaffolds have received widespread attention in recent times in biomedical applications due to their excellent synergistic potential. CS has garnered much attention as a biomedical scaffold material either alone or in combination with some other material due to its favorable physiochemical properties. The emerging 2D nanomaterials, such as black phosphorus (BP), molybdenum disulfide (MoS2), etc., have taken huge steps towards varying biomedical applications. However, the implementation of a CS-2D nanomaterial-based scaffold for clinical applications remains challenging for different reasons such as toxicity, stability, etc. Here, we reviewed different types of CS scaffold materials and discussed their advantages in biomedical applications. In addition, a different CS nanostructure, instead of a scaffold, has been described. After that, the importance of 2D nanomaterials has been elaborated on in terms of physiochemical properties. In the next section, the biomedical applications of CS with different 2D nanomaterial scaffolds have been highlighted. Finally, we highlighted the existing challenges and future perspectives of using CS-2D nanomaterial scaffolds for biomedical applications. We hope that this review will encourage a more synergistic biomedical application of the CS-2D nanomaterial scaffolds and their utilization clinical applications. [ABSTRACT FROM AUTHOR]

The photocatalytic production of fuels and chemicals utilizing highly effective catalysts has garnered a lot of interest as a sustainable and clean strategy. Herein, we have reported the effective fabrication of an imine-linked covalent organic framework, FP-BTA COF, supported 2D–2D MoS2/FP-BTA heterojunction with molybdenum sulfide (MoS2) utilizing an easy hydrothermal technique. The development of a 2D–2D heterojunction between a covalent organic framework (COF) and molybdenum sulfide (MoS2) with well-matched band positions can efficiently restrict the recombination of the charge carriers and boost the light absorption capacity along with the surface area, which is mainly responsible for the greatly improved catalytic efficiency. This as-prepared MoS2/FP-BTA hybrid photocatalyst demonstrated exceptional dual catalytic efficiency for the oxidative coupling of benzylamine derivatives to generate higher yields (92%) of N-benzylidene benzylamines along with selective reduction of carbon dioxide (CO2) to formic acid (highest generation rate = 43.3 mol gcat−1 h−1) at atmospheric carbon dioxide (CO2) pressure as compared to molybdenum sulfide (MoS2) and the FP-BTA COF without the requirement of any extra sacrificial electron donors under sunlight. The present research also focuses on economically viable, straightforward and sustainable methods for visible-light induced oxidation of a sequence of benzylamines under atmospheric oxygen (O2) utilizing the MoS2/FP-BTA hybrid material and the highest 98% isolated yield of the product containing a mixture of the corresponding imine and carbonyl compounds was achieved under ambient reaction conditions. The photocatalyst produced a good amount of the intended products and was easily recoverable and recyclable up to the fifth run for both reactions. The creation of a single hybrid with a 2D–2D interface by fusing organic and inorganic materials as well as the twin strategy of producing valuable chemicals in a single process may open up new prospects for sustainable development and enhance the atom economy. [ABSTRACT FROM AUTHOR]

The fast, accurate, and affordable determination of the anti-epileptic drug levetiracetam (LEV) is the need of time for human health. In this study, a novel electrochemical sensor platform was proposed for the cost-effective and sensitive determination of the levetiracetam based on molybdenum sulfide nano-flower-adorned pencil graphite electrode (MoS2/PGE). The nano-flowers of MoS2 were prepared by a cost-effective one-step facile hydrothermal method and the morphology of synthesized MoS2 micro-flowers was characterized via FESEM, XRD, and EDS techniques. The various electro-kinetics parameters like diffusion coefficient (Do =1.41 × 10−5 cm2 s−1), heterogeneous rate constant (Kh= 9.04 × 10−4 cm s−1), electron transfer coefficient (α = 0.66), the effective surface area of the fabricated electrode (A = 0.0767 cm2), and surface coverage (Γo = 2.98 × 10−11 mol cm−2) were evaluated for the oxidation of LEV at MoS2/PGE employing voltammetric techniques. The oxidative peak current in the optimized square wave stripping voltammetry varies linearly with LEV concentration within the range of 72.0 to 130.0 µM with detection limit (LOD) value of 14.20 µM. The proposed MoS2/PGE platform provides a sensitive, low cost and eco-friendly tool for the rapid detection of LEV in clinical samples. [ABSTRACT FROM AUTHOR]

In this study, we simulated the performance of solar cells using appropriate optical and electrical parameters for MoX2 compounds. We used the solar cell capacitance simulator software to simulate MoS2-based solar cells with two structures (ZnO/WS2/MoS2 or ZnO/WSe2/MoS2). We investigated the impact of varying the thickness of the MoS2 absorbing layer, doping, temperature elevation, and exploring the effect of the buffer layer on the electrical characteristics of the solar cell, including parameters like open-circuit voltage (Voc), short-circuit current (Jsc), and solar cell efficiency (η). This analysis aimed to provide valuable insights into optimizing the design and performance of MoS2-based solar cells, contributing to advancements in thin-film solar cell technology. [ABSTRACT FROM AUTHOR]

In this study, a new electrochemical sensor based on molybdenum disulfide (MoS2) nanoflowers/glassy carbon electrode (GCE was created for the sensitive detection of gluten. The prepared nanocatalysts were characterized using scanning electron microscopy with energy dispersive spectroscopy, x‐ray diffraction, and x‐ray photoelectron spectroscopy. The effects of the prepared nanocatalysts, pH value, and dropping amounts on the results were examined in detail. The electrochemical performance of the developed sensor (MoS2 nanoflowers/GCE) was then evaluated using differential pulse voltammetry, and the sensor was found to have significant electrochemical activity against gluten. A substantial linear connection was observed in the range of 0.5–100 ppm of gluten concentration under optimum experimental circumstances, and the detection limit between peak current and gluten concentration was determined as 1.16 ppm. The findings showed that the MoS2 nanoflowers/GCE gluten sensor has exceptional selectivity and stability. Finally, the generated electrochemical sensor was effectively utilized for gluten detection in commercial gluten‐containing materials with a detection limit of 0.1652 ppm. Thus, the developed MoS2 nanoflowers/GCE sensor offers a potential method for the detection of other molecules and is a promising candidate for gluten detection in commercial samples. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) layered MoS2 membrane has a unique pore structure, adjustable interlayer spacing and excellent transmission performance, which has wide-ranging and excellent application prospects for water treatment. However, the MoS2 membrane exhibits a narrow interlayer height, which can only accommodate one layer of water molecules, causing low water permeation and flux. In this work, a MoS2/SiO2 composite membrane with regular transport channels was prepared by the vacuum-assisted self-assembly (VASA) process using the intercalation of nano-silica (SiO2) nanoparticles. The resulting membrane showed an increase in interlayer widths from 0.61 nm to 0.69 nm. The MoS2/SiO2 composite membrane featured a high-efficiency dye separation performance and aqueous stability as the mass ratio of MoS2/SiO2 was 2.5, and the water permeance flux could reach 979 L m−2 h−1 bar−1, with a rejection of 100% for Evans blue (EB), methyl blue (MB) and neutral red (NR) and a rejection of over 98% for rhodamine B (RhB). MoS2 membranes decorated by SiO2 nanosheet nanoparticles could effectively achieve precision regulation of interlayer spacings and hold the channel order of MoS2 laminates. In addition, the rejection rate of the composite membrane remained 100% after remaining immersed in strong oxidizing acid for up to 60 days, which showed their stability toward strong acid and oxidative environments. This work suggests that an interlayer manipulation strategy in 2D laminar membranes could improve membrane performance for wastewater treatment and other separations. [ABSTRACT FROM AUTHOR]

Two-dimensional transition metal sulfides possess high intrinsic catalytic activity for the oxygen evolution reaction (OER) during water splitting but are restricted by their low conductivity and unattractive stability in alkaline electrolytes. Herein, newly designed CoS2/MoS2 nanosheets with enriched heterointerfaces synthesized by the combination of hydrothermal and vulcanization methods showed great promise as a highly efficient OER electrocatalyst. Owing to the fast vulcanization process, some heterometallic sulfide nanoparticles get distributed on the nanosheets, thus forming a nanoparticle-nanosheet bridging structure. The rich heterogeneous interface between CoS2 and MoS2 regulates the electronic structure and provides sufficient electrochemical active sites, thus forming a fast channel conducive to electron transport and ensuring high OER activity. Besides, the rough heterostructured surface enhances hydrophilicity, which promotes the decomposition of H2O and decreases the energy barrier of intermediate reactions, leading to fast electrochemical kinetics. Benefiting from the structural merits, the optimized CoS2/MoS2-1 : 1 nanosheets exhibit a low overpotential of 283 mV at 10 mA cm−2, a small Tafel slope of 105.32 mV dec−1 and long-term durability for the OER. [ABSTRACT FROM AUTHOR]

A CoMoS composite is synthesized to combine the benefits of cobalt and molybdenum sulfides as an anodic material for advanced lithium‐ion batteries (LIBs). The synthesis is accomplished using a simple two‐step hydrothermal method and the resulting CoMoS nanocomposites are subsequently encapsulated in a carbonized polydopamine shell. The synthesis procedure exploited the self‐polymerization ability of dopamine to create nitrogen‐doped carbon‐coated cobalt molybdenum sulfide, denoted as CoMoS@NC. Notably, the de‐lithiation capacity of CoMoS and CoMoS@NC is 420 and 709 mAh g⁻1, respectively, even after 100 lithiation/de‐lithiation cycles at a current density of 200 mA g⁻1. Furthermore, excellent capacity retention ability is observed for CoMoS@NC as it withstood 600 consecutive lithiation/de‐lithiation cycles with 94% capacity retention. Moreover, a LIB full‐cell assembly incorporating the CoMoS@NC anode and an NMC‐532 cathode is subjected to comprehensive electrochemical and practical tests to evaluate the performance of the anode. In addition, the density functional theory showcases the increased lithium adsorption for CoMoS@NC, supporting the experimental findings. Hence, the use of dopamine as a nitrogen‐doped carbon shell enhanced the performance of the CoMoS nanocomposites in experimental and theoretical tests, positioning the material as a strong candidate for LIB anode. [ABSTRACT FROM AUTHOR]

Chemical doping-induced magnetism in semiconducting transition metal dichalcogenides (TMDC) can have significant implications in electrically controlled spintronics. In addition, strain engineering of the layered structures of TMDCs can further allow for tuning the interlayer van der Waals (vdW) bonds and controlling their electronic properties. Of particular interest are the effects of Fe doping coupled with strain tuning on the vdW bonds and associated electronic properties of Fe:MoS2. Here, we have investigated compressive strain tuning effects on the structural and vibrational properties of Fe:MoS2 using in situ angle-dispersive x-ray diffraction and Raman scattering spectroscopy at quasi-hydrostatic pressures up to 25.0(1) GPa. Our results indicate that Fe:MoS2 undergoes isostructural electronic transitions similar to those in pristine MoS2, but at significantly lower pressures. Sudden changes in the microscopic strain, Raman peak splitting, and phonon softening are observed at the transition pressures, suggesting that the structural instability introduced by the Fe dopants is responsible for the early onset of the transitions. The significant effects of Fe dopants on the interlayer vdW bonding, as well as the structural and phononic properties under compressive strain indicate a strategy for modulating the electronic and ferromagnetic properties of TMDCs. [ABSTRACT FROM AUTHOR]

Edge structures, thiophene adsorption and hydrodesulfurization (HDS) mechanisms are investigated on the S-edge of triangular MoS2 nanoclusters using density functional theory. The calculated formation energies for different S coverages on the S-edge suggest that the formation of coordinative unsaturated site at the vertex and edge-I (close to the vertex) sites is preferred over the edge-II (away from the vertex) sites. The adsorption of thiophene on the top site of Mo atom mainly occurs at the edge-I, whereas bridge adsorption occurs at the edge-II. The 92% and 50% S-edge coverages involve relatively larger adsorption energies (− 0.68 and − 0.79 eV) among all the possible adsorption configurations. On the S edge with 92% S coverage, the hydrogenation route is more favorable, producing 1-butene. On the S edge with 50% S coverage, the direct desulfurization route is preferred, yielding butadiene. These findings deepen the understanding of edge structures of MoS2 nanoclusters and the corresponding HDS mechanisms for MoS2-based HDS catalysts. [ABSTRACT FROM AUTHOR]

2D/2D semimetal 1T′ phase MoS 2 /ZnIn 2 S 4 (1T′-MoS 2 /ZnIn 2 S 4) S-Scheme heterojunction has been prepared by a simple hydrothermal method. The 1T′-MoS 2 /ZnIn 2 S 4 2D/2D S-Scheme heterojunction presents excellent photocatalytic activity for hydrogen production without the addition of noble metal co-catalysts. [Display omitted] Heterojunction engineering is an effective strategy to improve photocatalytic performance. Two-dimensional (2D)/2D semimetal 1T′ phase molybdenum sulfide/zinc indium sulfide (1T′-MoS 2 /ZnIn 2 S 4) S-scheme heterojunctions with tight and stable interfaces were synthesized by a simple hydrothermal synthesis method. Under the optimal 1T′-MoS 2 loading ratio (5 wt%), the hydrogen production rate of 1T′-MoS 2 /ZnIn 2 S 4 composites reaches 11.42 mmol h−1 g−1, which is 3.1 and 1.4 times higher than that of pure ZnIn 2 S 4 (2.9 mmol h−1 g−1) and ZnIn 2 S 4 /Pt (8.01 mmol h−1 g−1), and the apparent quantum efficiency (AQE) reaches 53.17 % (λ = 370 nm). Semimetal 1T′ phase MoS 2 on ZnIn 2 S 4 broadens the light absorption range, enhances the light absorption ability, promotes electron transfer, and offers abundant active sites. The establishment of S-scheme heterojunctions achieves the spatial separation of photogenerated charges and increases the reduction potential. This work provides insights for the design of novel photocatalysts. [ABSTRACT FROM AUTHOR]

Until now, Surface Plasmon Resonance (SPR) biosensors still rely on gold as their transducer element, and this makes cheap analytical devices difficult to achieve. On the other hand, lossy mode resonance (LMR) sensors offer transducers with more alternative materials due to their flexibility, which can be excited in p‐ and s‐polarized light. In this research it is carried out a numerical investigation using the transfer matrix method on LMR sensor composed of molybdenum disulfide (MoS2) as lossy layer and Cytop as matching layer. The reflectance curves for different thicknesses of MoS2 and Cytop are numerically investigated. The results obtained show that the chip consisting of 250 nm Cytop and 4 layers of MoS2 has a penetration depth 3 times higher than conventional SPR chips. If sensors with two types of polarization are compared, sensors with s‐polarized light have shown higher sensitivity reaching 72.13°/RIU with a wider dynamic range starting from a refractive index of 1.331 to 1.401. In this refractive index range, this sensor has displayed good signal stability where the reduction in resonance dip depth is only ≈6%. These computational results make the proposed structure very promising to be applied in the quantification of biological materials. [ABSTRACT FROM AUTHOR]

The title compound, [Mo3(C9H18NS2)3(S2)3S]2S, crystallizes on a general position in the monoclinic space group P21/n (No. 14). The cationic [Mo3S7(S2CN NiBu²)3]+ fragments are joined by a monosulfide dianion that forms close S...S contacts to each of the disulfide ligands on the side of the Mo3 plane opposite the μ32- ligand. The two Mo3 planes are inclined at an angle of 40.637 (15)°, which gives the assembly an open clamshell-like appearance. One μ6-S2- ...S22- contact, at 2.4849 (14) Å, is appreciably shorter than the remaining five, which are in the range 2.7252 (13)-2.8077 (14) Å. [ABSTRACT FROM AUTHOR]

This paper delves into the synthesis strategies of molybdenum disulfide (MoS2) nanomaterials and their prospective applications in the fields of energy conversion and storage. Through a comprehensive analysis of various synthesis methods, including solvothermal and sol-gel processes, the specific impacts of these methods on the morphology and properties of MoS2 nanostructures are revealed. The study indicates that MoS2 nanomaterials with optimized electronic properties and surface activity can be fabricated by precisely controlling the synthesis conditions. These materials demonstrate exceptional performance in applications such as lithium-ion batteries and photodetectors, especially in enhancing battery charge-discharge cycle stability and improving photoelectric conversion efficiency. The paper further discusses the challenges faced in the development of MoS2 applications, particularly in terms of the scalability of material synthesis and consistency of performance. Lastly, the article presents a vision for future research directions, emphasizing the potential to broaden the application of MoS2 in high-performance energy devices through innovative synthesis strategies and material structure optimization. [ABSTRACT FROM AUTHOR]

Molybdenum sulfide–oxide (MoS2, MS) emerges as the prime electrocatalyst candidate demonstrating hydrogen evolution reaction (HER) activity comparable to platinum (Pt). This study presents a facile electrochemical approach for fabricating a hybrid copper (Cu)/MoS2 (CMS) nanostructure thin-film electrocatalyst directly onto nickel foam (NF) without a binder or template. The synthesized CMS nanostructures were characterized utilizing energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and electrochemical methods. The XRD result revealed that the Cu metal coating on MS results in the creation of an extremely crystalline CMS nanostructure with a well-defined interface. The hybrid nanostructures demonstrated higher hydrogen production, attributed to the synergistic interplay of morphology and electron distribution at the interface. The nanostructures displayed a significantly low overpotential of −149 mV at 10 mA cm−2 and a Tafel slope of 117 mV dec−1, indicating enhanced catalytic activity compared to pristine MoS2.This research underscores the significant enhancement of the HER performance and conductivity achieved by CMS, showcasing its potential applications in renewable energy. [ABSTRACT FROM AUTHOR]

We deposited high-quality molybdenum disulfide (MoS2) monolayer and multilayer crystals on SiO2/Si substrates, by means of a chemical vapor deposition (CVD) process at atmospheric pressure. Notably, NaCl salt was used as component of the precursors to assist the growth of MoS2 crystals, which were intended for use as the active channel layer in the fabrication of field-effect transistors (FETs). The resulting MoS2 crystals from this CVD process were analyzed by optical, scanning electron, and atomic force microscopies, and by Raman and photoluminescence spectroscopies. The optical images and the micrographs obtained by SEM revealed the formation of dispersed MoS2 crystals with a triangular shape all over the SiO2 surface. The thickness of the MoS2 crystals, analyzed by atomic force microscopy, showed minimum values of around 0.7 nm, confirming the formation of monolayers. Additionally, multilayers with larger thickness were also identified. The Raman and photoluminescence spectra of the MoS2 crystals corroborated the formation of single and multiple layers. The fabrication of the FET back-SiO2 -gate configuration was made by depositing patterned source and drain Ti contacts on the dispersed MoS2 crystals to achieve the Ti/MoS2/SiO2/Si layer stacks. MoS2-based FETs with one and three layers were assembled and their electrical response analyzed by I–V output and transfer curves showing the typical characteristics of an n-type semiconductor channel operating in depletion mode. The electrical performance parameters of the devices, such as mobility and threshold voltage, were also determined from this analysis. Finally, to enhance their electrical response, the MoS2-based devices were thermally annealed at 200 °C for 30 min in Ar atmosphere. The increase in the mobility of the device was 176% compared to the device before the treatment. [ABSTRACT FROM AUTHOR]

Understanding and improving the contact resistance of two-dimensional materials for the fabrication of next-generation devices is of vital importance to be able to fully utilize the new physics available in these materials. In this work, eight different contact metals (Ag, Au, Cr, Cu, In, Mo, Ni, and Ti) have been investigated using the same sample of monolayer MoS2. Through the fabrication and testing of multiple, identically sized field-effect transistor devices per contact metal, we compensate for large variability in electrical properties of as-grown chemical vapor deposition MoS2 and deduce the relative performance of each metal. The general trend of lower work function metals having lower contact resistance holds with In, Ag, and Ti performing the best of the metals tested. Our results are compatible with recent research suggesting that the contact resistance in undoped, monolayer MoS2 is dominated by a lateral junction resistance, and we provide context for how this manifests in device-to-device variation. Multiple orders of magnitude differences in contact resistance are observed between metals and can be explained by this lateral barrier operating in the thermionic-field emission regime. [ABSTRACT FROM AUTHOR]

Our successfully prepared an efficient photo-Fenton composite catalyst, denoted as 1T-2H MoS 2 @TP/PPy (MTP), by copolymerizing tea polyphenol (TP) and polypyrrole (PPy) onto the surface of 1T-2H MoS 2. The inclusion of tea polyphenol and the iron coupling structure (TP-Fe2+/Fe3+) not only resolved the iron source issue but also significantly broadened the pH range within which MTP operates effectively. The introduction of PPy brought about remarkable improvements in the catalyst's stability, and it played a pivotal role in modifying the energy band structure of 1T-2H MoS 2 , thus facilitating the separation of photogenerated electron-hole pairs. Additionally, elevating the solution temperature promotes the photo-Fenton process. [Display omitted] In this study, we present the successful development of a unique photo-Fenton catalyst, 1T-2H MoS 2 @TP/PPy (MTP), achieved through the coating of a copolymer of tea polyphenol (TP) and polypyrrole (PPy) onto the surface of heterophase molybdenum disulfide (1T-2H MoS 2). This innovative approach involves the integration of hydrothermal synthesis with copolymerization techniques. Our strategy utilizes nanoflower-like 1T-2H MoS 2 as the foundational framework, which is then enveloped in TP and PPy copolymer. This innovative approach involves the integration of hydrothermal synthesis with copolymerization techniques. Our strategy utilizes nanoflower-like 1T-2H MoS 2 as the foundational framework, which is then enveloped in TP and PPy copolymer. This distinctive architecture demonstrates exceptional catalytic performance owing to the hetero-phase entanglement of 1T-2H MoS 2 , which provides a diverse array of active sites. The coupled structure of TP and iron (TP-Fe2+/Fe3+) effectively overcome the limitation associated with the iron source. The incorporation of PPy not only reduces the recombination of photogenerated electron-hole pairs but also enhances the stability of 1T-2H MoS 2. Remarkably, our experiments on the degradation of methylene blue (MB) and tetracycline (TC) degradation demonstrate that TP-Fe2+/Fe3+ significantly expands the pH applicability range of the MTP composite catalyst. Additionally, we examine several factors, including different catalysts, H 2 O 2 addition, variations in light intensity, solution pH, temperature fluctuations, and the role of active species, to comprehensively understand their impact on the photo-Fenton degradation process. In conclusion, MTP composite exhibits robust catalytic stability and demonstrates a broad pH utilization range in the photo-Fenton oxidation process, highlighting its promising potential for a wide range of applications. [ABSTRACT FROM AUTHOR]

Two-dimensional transition sulfides (TMDs) are ideal materials for room-temperature gas sensing due to their high carrier mobility at room temperature. Nevertheless, the inferior response and incomplete recovery of TMDs at room temperature hinder their development in the field of the most advanced gas sensors. Herein, we propose two-dimensional surface p-p heterojunctions constructed via organic conjugated molecules assisted stripping of molybdenum disulfide (MoS 2) for high-performance room-temperature nitrogen dioxide (NO 2) gas sensing. The aniline tetramer (TANI) was employed as an exfoliation-assistant reagent, adhering evenly to the surface of the exfoliated MoS 2 nanosheets, and forming a good MoS 2 /TANI heterostructure. The sensor built with this heterostructure has a 28.5% response to 1 ppm NO 2 at room temperature, outperforming a standalone MoS 2 sensor by more than fourfold. The device still has a significant response even at NO 2 concentrations as low as 30 ppb. Furthermore, the MoS 2 /TANI-3 heterostructure gas sensor also exhibits excellent repeatability, long-term stability, superior linearity, and good selectivity at room temperature. Above all, the proposed design technique, as well as the developed structures, can pave the way for the development of high-performance TMDs-based gas sensors. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS 2) contains inactive basal and edge planes, which hinders its effectiveness in facilitating environmentally clean Hydrogen Evolution Reaction (HER) in electrocatalytic water splitting. Herein, we report a single-step synthesis strategy for developing ZnS–ZnO–MoS 2 /Ti 3 C 2 T x MXene (ZZM/MX) nanostructures through a hydrothermal approach. The SEM micrographs clearly demonstrate edge plane modification in MoS 2 , making them sharper and more exposed outward. XRD analysis exhibited the formation of ZnS and ZnO phases over MoS2 surface which was further supported by XPS analysis. The molar percentage of Zn precursor was increased from 1 % to 6 % and the resultant samples were designated as ZZM/MX-1, ZZM/MX-2, ZZM/MX-4, and ZZM/MX-6, respectively. Among the prepared samples, ZZM/MX-4 electrocatalyst exhibited the least overpotential of 327.6 mV @ 10 mA cm−2; and a low Tafel slope of 79.5 mVdec−1 in 0.5 M H 2 SO 4 electrolyte for HER. Also, it demonstrated excellent stability, withstanding 50 h of operation under acidic conditions. The higher electrocatalytic performance in this material can be attributed to the robust interaction between hetero-phase interfaces along ZnS–ZnO–MoS 2 and MXene (Ti 3 C 2 T x) support, which activates MoS 2 basal planes and enhances the charge transfer properties. Further, the activation of MoS 2 edges by introduction of ZnS/ZnO phases led to enhanced number of active sites for HER electrocatalysis. This work showcases an opportunity to apply dual modification of edge and basal planes in various other chalcogenide materials to enhance environmentally friendly clean HER performance and stability. [Display omitted] • Development of HF-Free environmentally safe method of Mxene etching. • Successful formation of MoS2/Mxene composite through mild hydrothermal approach. • Physicochemical Characterization evidenced the formation of Zn doped MoS2/Mxene. • Doping of MoS2/Mxene with Zinc improved electrochemical HER performance. [ABSTRACT FROM AUTHOR]