MoS2 Composites Research Articles

Dual-function efficient hydrogen evolution reaction electrocatalyst and electrode material for supercapacitors based on ternary composite FeS2/Fe2O3/MoS2 nanostructures

Hydrogen is a promising and environment-friendly energy source that can be produced in a highly efficient manner through water electrolysis. This process requires the use of effective electrocatalysts to facilitate the hydrogen evolution reaction (HER). In this study, the synthesis, characterization, and electrochemical performance of FeS2, Fe2O3, a binary composite of FeS2 and Fe2O3 (FeS2/Fe2O3), and a ternary composite of FeS2, Fe2O3, and MoS2 (FeS2/Fe2O3/MoS2) are investigated. The materials were prepared using a hydrothermal technique and analyzed using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–Vis) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and electrochemical assessments. The ternary composite demonstrated improved HER performance, with the FeS2/Fe2O3/MoS2 hybrid exhibiting the highest electrochemically active surface area ECSA (27.79 μF/cm2), and lowest charge transfer resistance Rct (288 Ω), overpotential (96 mV vs. SHE at 10 mA/cm2) and Tafel slope (72 mV/decade), indicating the superior performance of the ternary composite in facilitating the HER. These results indicate that the combination of MoS2 with FeS2 and Fe2O3 greatly enhances the catalytic activity, making the ternary composite a highly attractive option for effective water-splitting applications. In addition, the hybrid composite exhibited outstanding supercapacitor performance, with a specific capacitance of 171.42 F/g at a current density of 1 A/g. These results indicate that FeS2/Fe2O3/MoS2 can function as a highly effective electrocatalyst for the HER and is a superior material for supercapacitors.

Synthesis, Characterization, and Hydrogen Evolution Reaction Activity of MoS2 Nanostructures Prepared Using Nonionic Surfactant

Molybdenum disulfide (MoS2) has garnered significant interest as an auspicious catalytic material for the hydrogen evolution reaction (HER). Here, MoS2 nanostructures are synthesized using the hydrothermal method with ammonium molybdate tetrahydrate ((NH4)6Mo7O24∙4H2O) as the Mo source; thioacetamide (CH3CSNH2) as the reducing agent and S source; and nonylphenols 9, nonylphenols 40, and polysorbate 80 as the surfactants. The impact of the different nonionic surfactants on the materials is comprehensively investigated. Moreover, the MoS2 fine structure was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, scanning electron microscopy (SEM), and transmission scanning microscopy (TEM). The HER characteristics of the MoS2 composites are assessed through electrochemical experiments, including linear sweep voltammetry and chronoamperometry measurements. Among the prepared specimens, MoS2/NP 9 exhibits the best electrocatalytic performance in a neutral medium. Furthermore, 240 mV is required to reach the current density of 10 mAcm−2.

Synthesis, characterisations and applications of boron nitride based hybrid metal matrix composites

ABSTRACT This study focuses on how reinforcements impact the base material (specifically AA 6082) regarding its microstructure, mechanical behaviour& corrosion behaviour. Boron nitride (BN) & molybdenum disulphide (MoS2) employed as reinforcing materials ranged from 1% to 3% of BN & 1% to Constant MoS2. The composite materials were produced utilising the stir casting technique. X-ray diffraction (XRD), scanning electron microscope (SEM) with Energy Dispersive spectroscopy (EDAX) & an optical microscope (OM) were used to examine microstructural phase identification analysis. Tensile, compressive, impact, density& porosity fracture mechanisms were investigated by mechanical testing. BN & MoS2 reinforced particles’ presence in the samples is confirmed by XRD and microstructural pictures showing consistent matrix reinforcement distribution. According to the findings, incorporating BN & MoS2 reinforcements improved the mechanical & corrosion properties but slightly reduced the impact strength. The fractured samples revealed micro cuts, micro ploughing, cracks, trans-granular cleavage facets, dimples in the tensile & impact tests. Reduction in Corrosion rate was achieved gradually by adding reinforcement particles for the composites.AA6082, 3 wt: % BN, & 1 wt.% MoS2 composites have shown a decrease in corrosion current density by 1.901 mA/cm2 & an increase in charge transfer resistance by 99.934 Ω cm-2, attributed to passivation.

Dry sliding wear behaviour of AA6082/BN/Mos2 hybrid metal matrix composites synthesized using stir casting process

This study examines the wear behaviour of AA6082/x Boron Nitride (BN) (x = 1, 2, 3 wt.%)/1 wt.% of Molybdenum Disulphide (MoS2), a novel hybrid metal matrix composite (MMC), under dry sliding conditions. The composite was fabricated through liquid-state processing, i.e., stir casting. A pin-on-disk tribometer was used to estimate the coefficient of friction (COF) and wear rate by varying tribological process parameters under dry sliding conditions. The results show that at the maximum load of 40 N, the wear rate of the unreinforced alloy is observed 4.077 × 10−2 mm3/m, while at the AA6082/3 wt. of %, BN/1 wt. % of the MoS2 composite's wear rate is reduced to 2.162 × 10−2 mm3/m. Further, the wear rate increases as the sliding distance increases from 500 m to 2000 m. Moreover, the friction coefficient of the unreinforced alloy is observed 0.37, whereas the AA6082/3 wt.% of BN/1 wt.% of MoS2 composites is observed 0.31 under reduced loads. It might be due to the presence of hard ceramic BN and MoS2 reinforcements enhancing the developed composite's resistance to wear by forming a mechanically mixed layer (Fe2O3) on the sliding contact surface. Moreover, the novel hybrid composite materials exhibit a lower coefficient of friction at higher sliding velocities, sliding distances, and applied loads. However, minimal fine grooves with limited abrasion are observed on the worn surface, which was examined through a scanning electron microscope.

Tailoring SrFe12O19 – MoS2 composites for enhanced microwave absorption performance in X-band

The electromagnetic wave-absorbing composites, incorporating strontium hexaferrite and molybdenum disulfide (SrFe12O19-MoS2), are synthesized by mixing in different weight ratios. In the present work, strontium hexaferrite (SrFe12O19) is developed through a low-temperature auto-combustion method while two-dimensional molybdenum disulfide (MoS2) is synthesized by a facile hydrothermal process. The materials and their composites undergo analysis using characterization techniques such as X-ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), and vibrating sample magnetometer (VSM) to assess their structural, morphological, and magnetic properties, respectively. The minimal reflection loss (RLmin) of – 47.35 dB is observed at 8.66 GHz for the SrFe12O19-MoS2 (50 %-50 %) composite cast into pellets for microwave absorption analysis in the X-band frequency range. This RLmin is obtained with a sample thickness of 1.7 mm. An adequate bandwidth of 3.1 GHz, representing 77.5 % of the entire X band, is observed for a loss below −10 dB. The synergistic interaction between magnetism and dielectricity makes it an efficient electromagnetic absorber for modern technologies.

1 T/2 H mixed phase MoS2 nanosheets decorated with Ag nanoparticles for effective photocatalysis of organic dyes for wastewater treatment

The rapid industrialization and urbanization have led to the proliferation of organic dyes in wastewater, necessitating the development of efficient and sustainable treatment technologies. We report here a novel photocatalyst based on 1 T/2 H mixed-phase molybdenum disulfide nanosheets (1 T/2 H-MoS2 NSs) decorated with silver (Ag) nanoparticles for the enhanced photodegradation of both cataionic and anionic organic dyes under natural sunlight. Hydrothermally synthesized silver nanoparticles decorated 1 T/2 H MoS2 nanosheets (Ag-1 T/2 H MoS2 NSs) are characterized through X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM), Raman spectroscopy, UV–vis spectroscopy, and Photoluminescence (PL) spectroscopy. FESEM results reveal that MoS2 NSs of thickness 17 nm clustered into nanoflowers where Ag nanoparticles are embedded in them. XRD results show the characteristic diffraction peaks at 2ϴ value 9.80 and 32.380 for (002) and (100) planes respectively. Photocatalytic performance has been evaluated by the degradation of Crystal Violet (CV) and Methyl Orange (MO) under direct sunlight irradiation. Nanocomposites exhibit a significant improvement in degradation efficiency i.e. 97 % for both (CV) and (MO) in 15 minutes and 25 minutes respectively compared to pure MoS2. The superior activity of the Ag-1 T/2 H MoS2 composite is attributed to the synergistic effects of the mixed-phase MoS2 structure and the charge transfer phenomenon provided by Ag nanoparticles. This work highlights the potential of Ag-1 T/2 H MoS2 NSs as an effective photocatalyst for the treatment of dye-contaminated wastewater.

Novel MoS2-In2O3-WS2 (2D/3D/2D) ternary heterostructure nanocomposite material: Efficient photocatalytic degradation of antimicrobial agents under visible-light

Fabrication of ternary composited photocatalytic nanomaterials with strong interaction is vital to deriving the fast charge separation for efficient photodegradation of organic contaminants in wastewater under visible light. In this work, novel ternary 2D/3D/2D MoS2-In2O3-WS2 multi-nanostructures were synthesized using facile hydrothermal processes. XRD, FTIR, and XPS results confirmed the phase, functional groups, and element composition of pure MoS2, MoS2-In2O3, and MoS2-In2O3-WS2 hybrids. UV-DRS spectra of the MoS2-In2O3-WS2 ternary hybrid indicate maximum absorption in the visible light range with a band-gap energy value of 2.4 eV. The surface of the 2D WS2 nanosheet structure tightly blends and densely disperses 2D MoS2 nanosheets and 3D In2O3 nanocubes. This confirmed the formation of the MoS2-In2O3-WS2 ternary hybrid in the form of 2D/3D/2D multi-nanostructures, which is also indicated from SEM and HR-TEM images. The synthesized MoS2-In2O3-WS2 ternary hybrid showed maximum photocatalytic activity under visible-light for antimicrobial agents such as triclosan (TCS) and trichlorocarban (TCC). The photocatalytic activity of TCS was revealed to be 95% at 90 min, while that of TCC was 93% at 100 min. The reusability and stability tests of the prepared MoS2-In2O3-WS2 ternary hybrid after four consecutive photocatalytic cycles were analyzed by FTIR and SEM, which indicated that the prepared ternary hybrid was very stable. Overall results suggested that the developed MoS2-In2O3-WS2 (2D/3D/2D) multi-nanostructures are environmentally friendly and low-cost nanocomposites as a potential photocatalyst for the removal of antimicrobial agents from wastewater.

Construction of high-performance g-C3N4/MoS2 heterojunction humidity sensor and investigation of its application

In the paper, a g-C3N4/MoS2 humidity sensor with high response, low hysteresis and fast response/recovery for skin health status detection was prepared. The synthesis of g-C3N4/MoS2 heterojunction materials increases the interfacial barrier and improves the sensitivity of sensor. The edge unsaturated bonds and S defects of g-C3N4/MoS2 composites together enhance the adsorption of H2O, which in turn improves the sensitivity of sensor. The consequent acceleration of electron transfer between the material surface and water molecules led to an improvement in the response/recovery speed and humidity hysteresis. The N-H on the composite surface promotes the formation of physically adsorbed water layer and enhances the sensor recovery capability. The g-C3N4/MoS2 sensor shows high sensitivity (204875 Ω/%RH), fast response/recovery speed (11/9 s), and low hysteresis (2.0 %) at the 11 %-95 % RH range. In this study, the sensors were successfully used for the detection of skin health conditions, providing a viable solution for skin detection.

Tailoring Heterojunctions in CsPbBrxCl3−x−MoS2 Composites for Efficient Photocatalysis and Hydrogen Evolution

AbstractWe demonstrate appropriate tuning of heterojunctions in CsPbBrxCl3−x−MoS2 composites (where x=0,1,2,3) by controlled regulation of the halide stoichiometry in the perovskite. A thorough optimization procedure determined the most effective photocatalyst, considering the pristine MoS2, perovskites with varying halide ratios, various physical mixing ratios of the two, and in‐situ synthesized composite ratios of CsPbBrxCl3−x and MoS2 (2 : 1, 1.5 : 1, 1 : 1, 1 : 1.5, 1 : 2). Under two hours of exposure to visible light, a remarkable photocatalytic performance of CsPbBrCl2 : MoS2 with a 1 : 2 ratio was observed, removing 98 % of the methylene blue (MB) dye. Notably, only the CsPbBrCl2 and MoS2 composite demonstrated higher efficiencies since it resulted in a n‐n type II heterojunction. Additionally, the CsPbBrCl2 : MoS2 composite exhibits the highest reaction rate constant, fifteen times higher than the pristine perovskite. Reusability assessment of this combination revealed sustained activity of 87 % for up to 5 cycles. The hydrogen evolution reaction investigations were carried out using the optimized CsPbBrCl2 : MoS2 composite, which yielded 265 times more hydrogen than pristine CsPbBrCl2. The Faradaic efficiency for 1 : 2 CsPbBrCl2 : MoS2 was found to be 96.61 %. Our results offer crucial perspectives on optimizing perovskite‐MoS2 composites and demonstrate their utility in sustainable applications, including water treatment, renewable energy harvesting, and environmental remediation.

Enhanced tribological performance of MoS2 and hBN-based composite friction materials: Design of tribo-pair for automotive brake pad-disc systems

This research comprehensively analyzes the friction and wear behavior of composite friction materials when dry sliding against grey cast iron and laser-clad nickel-based (LC1) and iron-based (LC2) alloy discs. The composite friction materials (P1, P2, P3, P4, P5, and P6) under investigation contain graphite, MoS2, and hBN-based solid lubricant synthesized through the powder metallurgy technique. Tribological tests were conducted using a pin-on-disc configuration to simulate the dynamic interaction between the composite materials and the laser-clad grey cast iron discs. The tests were performed at a 60 N load, 6283.19 m sliding distance, and 2.094 m/s sliding velocity under dry sliding conditions. The results provide valuable insights into the effectiveness of MoS2 and hBN-based solid lubricant composites in reducing friction and wear when in contact with iron and nickel alloy-based laser-clad grey cast iron surfaces. The study elucidates the mechanisms governing tribological behavior, including the formation of friction plateaus and the role of laser-clad counter-discs in reducing wear. The specific wear rate of the nickel-based laser-clad counter disc (LC1) and iron-based laser-clad (LC2) system improved by 63.76 % and 48.32 %, respectively, compared to the conventional grey cast iron disc system when using the hBN-based pin (P6). Additionally, the specific wear rate of the hBN-based pin was 38.49 % lower than the conventional graphite-based pin when sliding against the grey cast iron counter-disc. Artificial Neural Network (ANN) was used to validate the wear rate of the best-performing tribological pair, namely the hBN-based pin (P6) and LC2 counter discs, through supervised learning.

Tenfold Enhancement of Wear Resistance by Electrosynthesis of a Nanostructured Self‐Lubricating Al2O3/Sn(S)MoS2 Composite Film on AlSiCu Casting Alloys

Enhancing tribological performance through nanostructure control is crucial for saving energy and improving wear resistance for diverse applications. We introduce a new electrochemical approach that integrates aluminum (Al) anodization, tin alternating current (AC) electrodeposition, and anodic MoS2 electrosynthesis for fabricating nanostructured Al2O3/Sn(S)MoS2 composite films on AlSiCu casting alloys. Our unique process uses Sn‐modified MoS2 deposition to form robust solid lubricant MoS2–SnS electrodeposits within the nanochannels and microsized voids/defects of anodic alumina matrix films on the base materials, resulting in a bilayered Al2O3/SnSMoS2 and MoS2–SnS–Sn composite film. The AC‐deposited Sn enhances conductivity in the anodic alumina matrix film, acts as catalytic nuclei for Sn@SnS@MoS2 core‐shell nanoparticles and a dense top layer, and serves as a reductant for the direct synthesis of hybrid solid lubricant MoS2–SnS from MoS3 by anodic electrolysis of MoS42− ions. The resulting nanocomposite film provides a two‐fold increase in lubricity (friction coefficient (COF) μ = 0.14 ⇒ 0.07) and a ten‐fold improvement in wear resistance (COF μ < 0.2) compared to conventional Al2O3/MoS2 film formed by anodizing and reanodizing. The effectiveness of the Al2O3/Sn(S)MoS2 composite is further validated through real automotive engine piston tests.

Lamellar Ti3C2 MXene composite decorated with platinum-doped MoS2 nanosheets as electrochemical sensing functional platform for highly sensitive analysis of organophosphorus pesticides

Precisely detecting organophosphorus pesticides (OPs) is paramount in upholding human safety and environmental preservation, especially in food safety. Herein, an electrochemical acetylcholinesterase (AChE) sensing platform entrapped in chitosan (Chit) on the glassy carbon electrodes (GCEs) decorated with Pt/MoS2/Ti3C2 MXene (Pt/MoS2/TM) was constructed for the detection of chlorpyrifos. It is worth noting that Pt/MoS2/TM possesses good biocompatibility, remarkable electrical conductivity, environmental stability and large specific surface area. Besides, the heterostructure formed by the composite of TM and MoS2 improves the conductivity and maintains the original structure, which is conducive to improving the electrochemical property. The coordination effect between the individual components enables the even distribution of functional components and enhances the electrochemical performance of the biosensor (AChE-Chit/Pt/MoS2/TM). Under optimal efficiency and sensitivity, the AChE-Chit/Pt/MoS2/TM/GCE sensing platform exerts comparable analytical performance and a wide concentration range of chlorpyrifos from 10−12 to 10−6 M as well as a low limit of detection (4.71 × 10−13 M). Furthermore, the biosensor is utilized to detect OPs concerning three kinds of fruits and vegetables with good feasibility and recoveries (94.81% to 104.0%). This work would provide a new scheme to develop high-sensitivity sensors based on the two-dimensional nanosheet/laminar hybrid structure for practical applications in environmental monitoring and agricultural product detection.

Microstructures and properties of Cu/50 vol% MoS2 composites prepared with Cu-coated MoS2 powders and sintered at different temperatures

Constitution and distribution of phases and interphase reactions are crucial for properties of composites. So far, the problem of MoS2 agglomeration remains unsolved in Cu/MoS2 composites, and interfacial structures and reaction products between MoS2 and Cu have not been fully considered. Herein, Cu-coated MoS2 powders prepared via electroless plating were sintered at different temperatures into Cu/MoS2 composites. Cu does not react with MoS2 in the composites sintered at 600 ℃ and 650 ℃, leading to their desirable tribological properties under dry sliding. Reactions between Cu and MoS2 occur in the composites sintered at 700 ℃ and 800 ℃, and the resultant products include Cu2S, Cu1.8Mo6S8 and Cu1.83Mo3S4 phases, resulting in a better wear resistance under oil lubrication and mechanical properties.

Preparation of SnS2/MoS2 with p–n heterojunction for NO2 sensing

Conventional metal sulfide (SnS2) gas-sensitive sensing materials still have insufficient surface area and slow response/recovery times. To increase its gas-sensing performance, MoS2 nanoflower was produced hydrothermally and mechanically combined with SnS2 nanoplate. Extensive characterization results show that MoS2 was effectively integrated into SnS2. Four different concentrations of SnS2–MoS2 composites were evaluated for their NO2 gas sensitization capabilities. Among them, SnS2–15% MoS2 at 170 °C demonstrated the greatest response values to NO2, 7.3 for 1 ppm NO2, which is about three times greater than the SnS2 sensor at 170 °C (2.58). The creation of pn junctions following compositing with SnS2 was determined to be the primary reason for the composite’s faster recovery time, while the heterojunction allowed for the rapid separation of hole–electron pairs. Because the MoS2 surface has multiple vacancy defects, the adsorption energy of these vacancies is significantly higher than that of other places, resulting in increased NO2 adsorption. Furthermore, MoS2 can serve as active adsorption sites for SnS2 micrometer sheets during gas sensing. This study may help to build new NO2 gas sensors.

Ratio design of bimetallic Pd‐Rh nanoparticles on MoS2 nanosheets: Excellent electrocatalysts for hydrogen evolution reaction

The decrease in noble metal content presents an efficient approach to attain commercial, effective, and durable electrocatalysts for the hydrogen evolution reaction (HER) at a low fabrication cost. Nonetheless, achieving a proper balance between bimetallic loading ratios and HER performance remains challenging. In this study, a simple and environmentally friendly sonochemical method is employed to successfully synthesize bimetallic palladium–rhodium nanoparticles (Pd‐Rh) with varying ratios, confined within molybdenum disulfide (MoS2) nanosheets. Bimetallic Pd‐Rh/MoS2 composite with different ratios of Pd:Rh is synthesized by adjusting the feed ratio of Pd and Rh precursors (1:4, 1:1, and 4:1). The HER electrocatalytic activity of the bimetallic Pd1‐Rh1/MoS2 composite exhibits the lowest overpotential and a superior Tafel slope, closely rivaling the electrocatalytic activity of the commercial 20 wt% Pt/C. Furthermore, the bimetallic Pd1‐Rh1/MoS2 composite exhibits remarkable stability and durability, with almost negligible performance decay after 2000 cycles. These outstanding HER electrocatalytic properties of the bimetallic composite result from a higher number of active sites, a significantly larger electrochemically active surface area, reduced charge‐transfer resistance, and a larger double‐layer capacitance. These factors collectively facilitate faster adsorption and desorption of hydron on the surface of electrocatalyst.

A competitive strategy toward 1 T/2H MoS2 to balance impedance for optimizing electromagnetic wave absorption

Interface engineering and phase engineering play crucial roles in enhancing the design and development of advanced electromagnetic wave (EMW) absorbers. However, there is a lack of focus on designing phase structures and interfaces from a microscopic perspective to adjust impedance matching and EMW absorption. This study introduced a competitive strategy involving 1 T/2H MoS2. The phase structure and composition of MoS2 were controlled using a microwave hydrothermal method. By creating a diverse phase interface within the material in the form of 1 T/2H, a balance between conduction loss and polarization loss was achieved, leading to improved EMW absorption through enhanced impedance matching. The results indicated that the incorporation of the 1 T phase boosted the electron transfer capability of MoS2, increasing conduction loss. The 1 T/2H phase interface enhanced interface polarization, thereby amplifying polarization loss. At a thickness of 2.8 mm, the absorber demonstrated a minimum reflection loss of −64.9 dB and an effective absorption bandwidth of 4.6 GHz. In far-field conditions, the maximum radar cross-section (RCS) of the 1 T/2H phase MoS2 nanoflowers was −27.5 dBm2. This study elucidates the relationship between 1 T/2H phase MoS2 content and phase interfaces with impedance matching, offering a novel approach for developing high-performance MoS2-based EMW absorbing materials.

Molybdenum disulfide modified silicon carbide ceramic nanofiber: Phase engineering for tuning microwave absorption properties of absorbers

Molybdenum disulfide (MoS2) is an important two-dimension multifunction material, which is widely used in semiconductor devices due to its special electrical properties. However, the electromagnetic wave absorption performance of MoS2 is severely limited as a result of the impedance mismatch between the material and free space. To address this issue, effective strategies of phase engineering and in situ growth techniques are employed to synthesize 2 H MoS2, 1 T/2 H MoS2, SiC@2 H MoS2, and SiC@1 T/2 H MoS2 composites. The electromagnetic absorbing property data reveal that the minimum reflection loss can reach 58.04 dB at 11.16 GHz in a 2.5 mm thick SiC@1 T/2 H MoS2 nanofiber coating; the effective absorbing bandwidth is up to 5.04 GHz (9.16–14.2 GHz). From the detailed analysis, it can be seen that the dielectric loss strength and the degree of impedance matching are the critical factors impacting the microwave absorption properties. The attenuation mechanisms underlying the excellent microwave absorption performance and related phenomena are explored, opening new directions for synthesizing MoS2-based electromagnetic wave absorbing materials with efficient and broadband.

Hierarchical flower bud-like P, W co-doped NiCo2S4@MoS2 composites as high-performance electrodes for asymmetric supercapacitor

Engineering binary transitional metal sulfides (BTMSs)-based electrode materials with a rationally designed constituent architecture is a viable strategy for improving their rate capability and electrochemical durability, which provides a possibility for their application in supercapacitors (SCs). Herein, a novel three-dimensional (3D) flower bud-like phosphorus and tungsten co-doped NiCo2S4 and MoS2 composites (P, W-NCS@MS) is prepared on conductive carbon cloth using the hydrothermal method. The effects of P, W-doping, or MoS2-combination on the morphology, structure and electrochemical properties of NiCo2S4-based electrode materials are systematically studied. The designed P, W-NCS@MS achieves a high specific capacity of 1250C g−1 at 1 A g−1 and a satisfactory capacity retention of 80 % after 10,000 cycles. In addition, the asymmetric supercapacitor (ASC) constructed through P, W-NCS@MS and activated carbon electrodes delivers a high energy density of 65.0 Wh kg−1 at the power density of 400 W kg−1 and shows satisfactory cycling stability of 85 % capacitance retention after 20,000 cycles. Notably, the assembled ASC device successfully powered electronic devices in a serial circuit, highlighting its prospective applications in energy storage. This work offers a viable design approach for heteroatom doping and hierarchical interface structures in composite electrode materials toward high-performance SCs.

TiO2 nanorod decorated with MoS2 nanospheres: An efficient dual-functional photocatalyst for antibiotic degradation and hydrogen production

The design and preparation of dual-functional photocatalysts for simultaneously realizing photocatalytic wastewater purification and hydrogen energy generation pose significant challenges. This article presents the engineering of a binary heterostructured photocatalyst by combining TiO2 (nanorods) and MoS2 nanosphere using a straightforward solvothermal method and the assessment of the phase structures, morphologies, and optical properties of the resulting nanocomposites using diverse analytical techniques. The TiO2(Rod)/MoS2 composite exhibits remarkable efficacy in degrading ciprofloxacin, achieving 93% removal rate within 1 h, which is four times higher than that of bare TiO2. Moreover, the optimized TiO2(Rod)/MoS2 presents an outstanding hydrogen production rate of 7415 μmol g−1, which is ∼24 times higher than that of pristine TiO2. Under UV–visible light irradiation, the TiO2(Rod)/MoS2 heterojunction displays an exceptional photocatalytic performance in terms of both photodegradation and hydrogen production, surpassing the performance of TiO2 particle/MoS2. The study findings demonstrate that TiO2(Rod)/MoS2 nanocomposites exhibit considerably improved photocatalytic degradation and hydrogen generation activities. Based on the experimental results, a possible mechanism is proposed for the transfer and separation of charge carriers in Z-scheme heterojunctions.

Simultaneous removal of methylene blue and Cr(VI) in a dual-chamber photocatalytic microbial fuel cell with WO3/MoS2/FTO photocathode

Carbon felt was used as the anode and WO3/MoS2/FTO (fluorine-doped tin oxide) was used as the photocathode in a photocatalytic microbial fuel cell (PMFC). The photoelectric performance of the WO3/MoS2/FTO photocathode and the removal efficiency of methylene blue (MB) and Cr(VI) mixed pollutants were systematically investigated in the cathode chamber. The results showed that after 12 h of light irradiation in the PMFC with WO3/MoS2/FTO as the photocathode, the removal rates of MB and Cr(VI) were 84.56 and 68.11 %, respectively, which were much higher than those using WO3/FTO as a photocathode (55.57 % and 45.26 %, respectively). The corresponding maximum output power was 33.14 mW/m2, which was 1.85 times that of the WO3/FTO photocathode PMFC. These results can be attributed to the fact that WO3 is an n-type semiconductor and MoS2 is a p-type semiconductor. Analysis of trapping experiments showed that the composite of WO3 and MoS2 formed a Z-scheme heterojunction, which improved the separation efficiency of the photoelectric carriers and enhanced the pollutant removal efficiency of the photocathode. PMFCs are a new and environment-friendly technology for removing pollutants thereby providing an experimental basis for future engineering applications.