Few-Layer MoS2 Nanosheets Encapsulated in N-Doped Carbon Hollow Spheres as Long-Life Anode Materials for Lithium-Ion Batteries

Two-dimensional molybdenum disulfide (MoS₂) has been recognized as a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity, but its rapid capacity decay owing to poor conductivity, structure pulverization, and polysulfide dissolution presents significant challenges in practical applications. Herein, triple-layered hollow spheres in which MoS₂ nanosheets are fully encapsulated between inner carbon and outer nitrogen-doped carbon (NC) were fabricated. Such an architecture provides high conductivity and efficient lithium-ion transfer. Moreover, the NC shell prevents aggregation and exfoliation of MoS₂ nanosheets and thus maintains the integrity of the nanostructure during the charge/discharge process. As anode materials for LIBs, the C@MoS₂@NC hollow spheres deliver a high reversible capacity (747 mA h g⁻¹ after 100 cycles at 100 mA g⁻¹) and excellent long-cycle performance (650 mA h g⁻¹ after 1000 cycles at 1.0 A g⁻¹), which confirm its potential for high-performance LIBs.     

Enhancement of tensile,electrical and thermal properties of epoxy nanocomposites through chemical hybridization of polypyrrole and graphene oxide

This paper presents the properties of epoxy nanocomposites, prepared using a synthesized hybrid Polypyrrole-Graphene Oxide (PPy-GO) filler, via in-situ chemical polymerization, at various filler loadings (i.e., 0.5–2 w. t %). The microstructures and properties of the PPy-GO hybrids and epoxy nanocomposites were studied via Fourier transform infrared (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), mechanical (Tensile Properties), electrical, Dynamic mechanical thermal analysis (DMTA) and thermogravimetric analyses (TGA). Morphological study demonstrated that varying the nanofiller nature (PPy-GOs, PPy or GO) lead to different states of dispersion. Mechanical, electrical and thermal analysis demonstrated that the hybrid concentration and its architecture (PPy:GO ratio) are interesting factors significantly affected the properties of the epoxy based nanocomposites. On the other hand, the mechanical performance of the cured nanocomposites outperformed the PPy-GO, with enhancements of 78% and 51% of Young's modulus and strength, respectively. Here it has been established that the embedding of PPy-GO hybrids into pristine epoxy endows optimum dispersion of PPy and GO as well as better interfacial adhesion between the fillers and matrix, which results in a significant improvement in load transfer effectiveness. Electrical conductivity measurements showed that conductivity of epoxy filled nanocomposites increased up 10⁻⁴ S/cm for Epoxy/PPy-GO nanocomposites. DMTA test indicated that incorporation of PPy-GO resulted in a significantly increase in Tg of the resultant nanocomposites, which is attributed to the highly exfoliation structure and the stronger interfacial interaction. The PPy-GO particles enhanced electrical, thermal and mechanical properties of nanocomposites, confirming the synergistic effect of PPy-GO as multifunctional filler.     

Physio-chemical influence of high electron-phonon coupling induced by 120 MeV Ag9+ SHI irradiation on exfoliated MoS2 - PVA nanocomposite films for achieving remarkable electrical conductivity for potential application in organic electronics

Swift heavy ion (SHI) irradiation technology is known to enhance the optical, electronic, mechanical, and electrical properties in polymer nanocomposites by the virtue of electron-phonon coupling. In the present work, Molybdenum disulphide (MoS₂), a two-dimensional metal dichalcogenide, has been exfoliated via liquid-phase exfoliation using N-methyl-2- pyrrolidone (NMP) as the solvent that yielded nanosheets of around 2–4 layers as depicted by HR-TEM images. MoS₂ - PVA free-standing films were prepared by wet chemical technique i.e. solution casting method and irradiated by focussed high-energy Ag⁹⁺ ion beam at fluence range of 1E10 - 3E11 ions/cm². As a consequence, the structural modification was observed by X-Ray diffraction studies that showed the shift of (002) plane of MoS₂ while Raman studies indicated the decrease of degree of disorderness at fluence 1E10 ions/cm². SHI irradiation has found to induce a two-order increase in the electrical conductivity yielding a 9.7 E-3 S/cm against that of the pristine films at 2.6E-5 S/cm. The enhanced conductivity is attributed to the induced dispersion and annealing of MoS₂ nanosheets in the PVA matrix due to the interaction of 120 MeV Ag⁹⁺ ion beam irradiation as explained by Thermal spike model.     

Highly Dispersible Hexagonal Carbon–MoS2–Carbon Nanoplates with Hollow Sandwich Structures for Supercapacitors

MoS₂, a typical layered transition-metal dichalcogenide, is promising as an electrode material in supercapacitors. However, its low electrical conductivity could lead to limited capacitance if applied in electrochemical devices. Herein, a new nanostructure composed of hollow carbon–MoS₂–carbon was successfully synthesized through an l -cysteine-assisted hydrothermal method by using gibbsite as a template and polydopamine as a carbon precursor. After calcination and etching of the gibbsite template, uniform hollow platelets, which were made of a sandwich-like assembly of partial graphitic carbon and two-dimensional layered MoS₂ flakes, were obtained. The platelets showed excellent dispersibility and stability in water, and good electrical conductivity due to carbon provided by the calcination of polydopamine coatings. The hollow nanoplate morphology of the material provided a high specific surface area of 543 m² g⁻¹, a total pore volume of 0.677 cm³ g⁻¹, and fairly small mesopores (≈5.3 nm). The material was applied in a symmetric supercapacitor and exhibited a specific capacitance of 248 F g⁻¹ (0.12 F cm⁻²) at a constant current density of 0.1 A g⁻¹; thus suggesting that hollow carbon–MoS₂–carbon nanoplates are promising candidate materials for supercapacitors.     

Hydrothermal exfoliated molybdenum disulfide nanosheets as anode material for lithium ion batteries

Ultrathin MoS2nanosheets were prepared in high yield using a facile and effective hydrothermal intercalation and exfoliation route. The products were characterized in detail using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that the high yield of MoS2nanosheets with good quality was successfully achieved and the dimensions of the immense nanosheets reached 1 μm–2 μm. As anode material for Li-ion batteries, the as-prepared MoS2nanosheets electrodes exhibited a good initial capacity of 1190 mAh g-1and excellent cyclic stability at constant current density of 50 mA g-1. After 50 cycles, it still delivered reversibly sustained high capacities of 750 mAh g-1.     

Controlled Synthesis of Ni-Doped MoS2 Hybrid Electrode for Synergistically Enhanced Water-Splitting Process

The development of high-efficiency, low-cost, and earth-abundant electrocatalysts for overall water splitting remains a challenge. In this work, Ni-modified MoS₂ hybrid catalysts are grown on carbon cloth (Ni-Mo-S@CC) through a one-step hydrothermal treatment. The optimized Ni-Mo-S@CC catalyst shows excellent hydrogen evolution reaction (HER) activity with a low overpotential of 168 mV at a current density of 10 mA cm⁻² in 1.0 m KOH, which is lower than those of Ni-Mo-S@CC (1:1), Ni-Mo-S@CC (3:1), and pure MoS₂. Significantly, the Ni-Mo-S@CC hybrid catalyst also displays outstanding oxygen evolution reaction (OER) activity with a low overpotential of 320 mV at a current density of 10 mA cm⁻², and remarkable long-term stability for 30 h at a constant current density of 10 mA cm⁻². Experimental results and theoretical analysis based on density functional theory demonstrate that the excellent electrocatalytic performance can be attributed mainly to the remarkable conductivity, abundant active sites, and synergistic effect of the Ni-doped MoS₂. This work sheds light on a unique strategy for the design of high-performance and stable electrocatalysts for water-splitting electrolyzers.     

Fabrication of thermoplastic polyurethane composites with a high dielectric constant and thermal conductivity using a hybrid filler of CNT@BaTiO3

Thermoplastic polyurethane composites with an excellent dielectric constant and high thermal conductivity were obtained using CNT@BaTiO₃ as a filler through a low-speed melt extrusion method. Before preparing the hybrid filler for the composite, the filler particles were surface modified to ensure that the outer surfaces could facilitate the reaction among particles to form the hybrid and ensure complete dispersion in the thermoplastic polyurethane matrix. After confirming the proper surface treatment of the filler particles using infrared spectroscopy, thermal degradation analysis and field emission scanning electron microscopy, they were used to prepare the composite materials at a processing temperature of 200 °C. The thermal stability, thermomechanical properties, mechanical properties, thermal conductivity, and dielectric properties of the composites were investigated. Compared to the neat thermoplastic polyurethane matrix, the prepared composite exhibited a higher thermal stability, approximately 300% higher storage modulus, higher tensile strength and elongation at break values, approximately three times higher thermal conductivity (improved from 0.19 W/(m.K) to 0.38 W/(m.K), and approximately five times larger dielectric constant at high frequencies (at 1 MHz a dielectric constant of 19.2 was obtained).     

Custom-made sulfonated poly (vinylidene fluoride-co-hexafluoropropylene) nanocomposite membranes for vanadium redox flow battery applications

Sulfonated poly (vinylidene fluoride-co-hexafluoropropylene) (SPVDF-co-HFP) based nanocomposite proton exchange membranes (PEM) are fabricated by simple solution casting method using polydopamine coated exfoliated molybdenum disulfide (PDA-MoS₂) nanosheets as an alternative for Nafion® in vanadium redox flow batteries (VRFBs). PDA-MoS₂ is synthesized by the etching of exfoliated MoS₂ nanosheets with dopamine molecule by self-polymerization method. Various characteristic results clearly demonstrated that the incorporated PDA-MoS₂ nanosheets homogeneously distributed into the SPVDF-co-HFP matrix and the presence of NH/NH₂ group electrostatically interacts with SPVDF-co-HFP to form a strong acid-base pair and thus enhances the proton transport via Grotthuss type mechanism. Besides, the improvement in surface hydrophilicity provides the vehicle type conduction also. As a result, SPVDF-co-HFP/PM nanocomposite membranes showed higher proton conductivity in comparison with the pristine membrane. Especially SPVDF-co-HFP/PM-1 membrane demonstrated the excellent proton conductivity of 5.24 × 10⁻³ Scm⁻¹ at 25 °C, lower vanadium-ion permeability of 1.05 × 10⁻⁸ cm²min⁻¹ and highest membrane selectivity of 49.9 × 10⁴ Scm⁻³min. On the other hand, vanadium-ion stability of the membrane increased by adding the PD-MoS₂ content is attributed to their strong electrostatic attraction towards the polymer matrix. Overall results suggested that the SPVDF-co-HFP/PM-1 nanocomposite membrane is found to be a better alternative for commercially costly Nafion in VRFB applications.     

Nanohybridization of CoS2/MoS2 Heterostructure with Polyoxometalate on Functionalized Reduced Graphene Oxide for High-Performance LIBs

To address the poor cycling stability and low rate capability of MoS₂ as electrode materials for lithium-ion batteries (LIBs), herein, the CoS₂/MoS₂/PDDA-rGO/PMo₁₂ nanocomposites are constructed via a simple hydrothermal process, combining the advantages of all three, namely, CoS₂/MoS₂ heterojunction and polyoxometalates (POMs) provide abundant catalytically active sites and increase the multi-electron transfer ability, and the positively charged poly(diallyldimethylammonium chloride) modified reduced graphene oxide (PDDA-rGO) improve electronic conductivity and effectively prevent the aggregation of MoS₂, meanwhile stabilize the negatively charged [PMo₁₂O₄₀]³⁻. After the electrochemical testing, the resulting CoS₂/MoS₂/PDDA-rGO/PMo₁₂ nanocomposite achieved 1055 mA h g⁻¹ initial specific capacities and stabilized at 740 mA h g⁻¹ after 150 cycles at 100 mA g⁻¹ current density. And the specific capacities of MoS₂, MoS₂/PDDA-rGO, CoS₂/MoS₂, and CoS₂/MoS₂/PDDA-rGO were 201, 421, 518, and 589 at 100 mA g⁻¹ after 150 cycles, respectively. The fact of the greatly improving capacity of MoS₂-based nanocomposites suggests its potential for high performance electrode materials of LIBs. Moreover, the lithium storage mechanism of CoS₂/MoS₂/PDDA-rGO/PMo₁₂ has been discussed on the basis of cyclic voltammetry with different scan rates.     

Nanomechanical and nanotribological characterization of multilayer self-lubricating Ti/MoS2/Si/MoS2 nanocoating on aluminium-silicon substrate

Ti/MoS₂/Si/MoS₂ multilayer coating was fabricated by a pulse laser deposition method from a titanium, molybdenum disulphide, and silicon targets, and the coating was deposited in layers on aluminium-silicon substrates, at room temperature. The structural analysis and surface morphology of multilayer Ti/MoS₂/Si/MoS₂ coating were analysed using X-ray diffraction, Raman spectroscopy, and scanning electron microscopy integrated with energy dispersive X-ray spectroscopy. Nanomechanical tests were performed on Ti/MoS₂/Si/MoS₂ coating at small loads of 2000 to 6000 μN to study the effect of load on hardness and Young's modulus. Nanoscratch and nanowear tests were conducted on Ti/MoS₂/Si/MoS₂ coating at a low load of 1000 to 5000 μN and 100 to 500 μN, respectively, to study deformation and failure behaviours of coating/substrate system and also their nanotribological properties. The results show that hardness and Young's modulus of Ti/MoS₂/Si/MoS₂ coating decrease with increase in load. A low friction coefficient of 0.09 to 0.16 was observed, which proves that the Ti/MoS₂/Si/MoS₂ coating possesses self-lubricating property. The wear rate of Ti/MoS₂/Si/MoS₂ coating increases 3.3 × 10⁻¹⁰ to 7.8 × 10⁻¹⁰ mm³/Nm with increase in load. Ti/MoS₂/Si/MoS₂ multilayer coating shows a smooth wear track with no cracks and debris on the surface, which attributed plastic flow of softer coating material around the wear track.     

Polylactide/montmorillonite nanocomposites: Structure, dielectric, viscoelastic and thermal properties

Polylactide-based systems composed of an organoclay (Cloisite^® 30B) and/or a compatibilizer (Exxelor VA1803) prepared by melt blending were investigated. Two types of not compatibilized nanocomposites containing 3 wt% or 10 wt% of the organoclay were studied to reveal the effect of the filler concentration on the nanostructure and physical properties of such systems. The 3 wt%-nanocomposite was also additionally compatibilized in order to improve the nanoclay dispersion. Neat polylactide and polylactide with the compatibilizer processed in similar conditions were used as reference samples. The X-ray investigations showed the presence of exfoliated nanostructure in 3 wt%-nanocomposite. Compatibilization of such system noticeably enhanced the degree of exfoliation of the organoclay. Viscoelastic spectra (DMTA) showed an increase of the storage and loss moduli with the increase of the organoclay content and dispersion. Dielectric properties of the nanocomposites show a weak influence of the nanoclay on segmental (α_S) and local (β)-relaxations in PLA, except for the highest nanoclay content. Above T_g a strong increase of dc conductivity related to ionic species in the clay is observed. It gives rise also to the Maxwell-Wagner-Sillars interfacial polarization and both real and imaginary parts of ε strongly increase. In the temperature dependence of low frequency dielectric constant and mechanical moduli (at 1 Hz) an additional maximum around 80-90 °C is observed due to cold crystallization of PLA.     

Dielectric,pyroelectric and piezoelectric properties in the (1 − x)(0.1BaTiO3–0.9NaNbO3)–xLiNbO3 system

New lead free piezoceramics with the given compositions (1 − x)(0.1BaTiO₃–0.9NaNbO₃)–xLiNbO₃(0.01 ≤ x ≤ 0.125) were prepared by solid–state reaction technique. XRD patterns revealed a single perovskite-structured phase only for 0.01 ≤ x < 0.05. The dielectric, pyroelectric and piezoelectric responses were investigated for compositions with x = 0.01 and 0.02. For both compositions, ɛ’_r exhibited a sharp peak with no frequency dependence (classical ferroelectrics). Losses displayed a strong dispersion at low frequencies in the paraelectric phase which was attributed to Li ionic conductivity in these compositions. The spontaneous polarization was found to be 35 and ≈22 μC cm⁻² for x = 0.01 and 0.02 respectively. The transverse piezoelectric coefficient d₃₁ measured for x = 0.01 reached value of 37 pC/N at room temperature while the planar coupling factor was about 0.23.     

Nano lithium aluminate filler incorporating gel lithium triflate polymer composite: Preparation,characterization and application as an electrolyte in lithium ion batteries

Gel polymer composites electrolytes containing nano LiAlO₂ as filler were prepared using a solution cast technique and characterized using different techniques such as X-ray diffraction (XRD), thermal analysis (TG, DSC), Fourier transform infra – red spectroscopy (FT-IR) and scanning electron microscope (SEM). X-ray diffraction analysis showed the effect of lithium tri fluoro methane sulphonate (LiCF₃SO₃), poly vinyl acetate (PVAc) and nano lithium aluminate (LiAlO₂) on the crystalline structure of the poly vinylidene fluoride –co– hexa fluoro propylene (PVDF-co-HFP) matrix containing ethylene carbonate (EC) and diethyl carbonate (DEC) as plasticizers. FT-IR analysis confirmed both the good dissolution of the LiCF₃SO₃ salt and the good interaction of the nano LiAlO₂ filler with the polymer matrix. TG analysis showed the good thermal stability of the LiAlO₂ samples compared to the free one. Also, addition of nano LiAlO₂ filler enhanced the conductivity value of the polymer composites electrolytes. The sample containing 2 wt% of LiAlO₂ showed the highest conductivity value, 4.98 × 10⁻³ Ω ⁻¹ cm⁻¹ at room temperature, with good thermal stability behavior (T_d = 362 °C). This good conductive and thermally stable polymer nano composite electrolyte was evaluated as a promising membrane for lithium ion batteries application.     

Influence of composition and processing parameters on the properties of solution-processed aluminum phosphate oxide (AlPO) thin films

The effects of precursor solution concentration, composition, and spin-processing parameters on the thickness and electrical properties of ultra-smooth aluminum oxide phosphate (Al₂O_3−3x(PO₄)_2x or “AlPO”) thin films prepared using aqueous solutions are reported. Compositions were verified by electron probe micro-analysis and range from Al₂O_1.5(PO₄) to AlPO₄ (x = P:Al from 0.5 to 1.0). Film thicknesses were determined using X-ray reflectivity measurements and were found to depend systematically on solution concentration, P:Al ratio, and spin-speed. Metal-insulator-semiconductor devices were fabricated to determine electrical properties as a function of composition. As the P:Al ratio increased from 0.5 to 1.0, the dielectric constant decreased from 6.0 to 4.6, leakage currents increased from 0.45 to 65 nA cm⁻² at 1 MV cm⁻¹ and dielectric breakdown (defined as leakage currents >10 μA cm⁻²) decreased from 9.74 to 2.84 MV cm⁻¹. These results establish composition, concentration, and spin-speed for the production of AlPO films with targeted thicknesses and electrical properties.     

Electrical conductivity and ion-exchange kinetic studies of polythiophene Sn(VI)phosphate nano composite cation-exchanger

A polymeric hybrid nanocomposite, namely polythiophene tin(IV)phosphate (PTh–SnP), was expediently synthesized by incorporating polythiophene (PTh) in tin phosphate (SnP) to enhance the conducting behavior and sorption of heavy metal ions by porous polymeric cation exchanger. Composite was characterized by Fourier Transform-Infra Red and Transmission Electron Microscopy. The dc electrical conductivity studies carried out on the composite, showed conductivity within the range of 4.0 × 10⁻²–1.0 × 10⁻³ S/cm⁻¹; measured by a 4-in line-probe dc electrical conductivity measuring technique. Ion-exchange kinetics for few divalent metal ions was evaluated by particle diffusion-controlled ion-exchange phenomenon at four different temperatures. The particle diffusion mechanism is confirmed by the linear τ (dimensionless time parameter) vs t (time) plots. The exchange processes thus controlled by the diffusion within the exchanger particle for the systems studies herein. Some physical parameters like self-diffusion coefficient (D₀)_, energy of activation (E_a) and entropy (ΔS°) have been evaluated under conditions favoring a particle diffusion-controlled mechanism.     

Dielectric,thermal, and mechanical properties of CeO2‐filled HDPE composites for microwave substrate applications

Cerium oxide‐filled high density polyethylene (HDPE) composites for microwave substrate applications were prepared by sigma‐blend technique. The HDPE was used as the matrix and the dispersion of CeO₂ in the composite was varied up to 0.5 by volume fraction, and the dielectric properties were studied at 1 MHz and microwave frequencies. The variations of thermal conductivity (k_eff), coefficient of thermal expansion (α_c) and Vicker's microhardness with the volume fraction of the filler were also measured. The relative permittivity (ε_eff) and dielectric loss (tan δ) were found to increase with increase in CeO₂ content. For 0.4 volume fraction loading of the ceramic, the composite had ε_eff = 5.7, tan δ = 0.0068 (at 7 GHz), k_eff = 2.6 W/m °C, α_c = 98.5 ppm/°C, Vicker's microhardness of 18 kg/mm² and tensile strength of 14.6 MPa. Different theoretical approaches have been used to predict the effective permittivity, thermal conductivity, and coefficient of thermal expansion of composite systems and the results were compared with the experimental data. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 998–1008, 2010     

Tune the photoresponse of monolayer MoS2 by decorating CsPbBr3 perovskite nanoparticles

Tuning the photoresponse of monolayer MoS₂ could extend its potential application in many fields, however, it is still a challenge. In this study, CsPbBr₃ nanoparticles were prepared and spin-coated on the surface of monolayer MoS₂ to fabricate hybrid CsPbBr₃/MoS₂ photodetectors. By combing the photoelectrical property of the CsPbBr₃, the synergistic effect has been systematically studied from its carrier mobility, photoresponse and detectivity. It was found that nanofilm-coating of CsPbBr₃ would impede the photoelectric performance due to the electron-hole recombination facilitated by the defects at the interface of CsPbBr₃ and MoS₂ films. While the nanoparticles decorating was observed to significantly improve the conductivity of the monolayer MoS₂, which also increased the on/off ratio of the MoS₂ transistor from 8.2 × 10³ to 4.4 × 10⁴, and enhanced the carrier mobility from 0.090 cm² V⁻¹ s⁻¹ to 0.202 cm² V⁻¹ s⁻¹, ascribing to a mixed electron recombination-injection process. Furthermore, the CsPbBr₃ nanofilm would decrease the responsivity to 136 and 178 A/W under the light wavelength of 400 and 500 nm, respectively, while decorating CsPbBr₃ nanoparticles improve the photoresponse to 948 and 883 A/W with the detectivity at the level of 10¹¹ Jones. This work may provide an easy and cost-efficient way to tune the photoresponse of MoS₂ photodetectors.     

Characterization and physical properties of Li2O-CaF2-P2O5 glass ceramics with Cr2O3 as a nucleating agent—Physical properties

In this paper, studies on various physical properties, viz., dielectric properties (dielectric constant, loss tan δ, a.c. conductivity σ) over a wide range of frequency and temperature, optical absorption, ESR at liquid nitrogen temperature and magnetic susceptibility at room temperature of Li₂O-CaF₂-P₂O₅: Cr₂O₃ glass ceramics, have been reported. The optical absorption, ESR and magnetic susceptibility studies indicate that the chromium ions exist in Cr⁵⁺, Cr⁴⁺ and Cr⁶⁺ states in addition to Cr³⁺ state in these samples. The dielectric constant and loss variation with the concentration of Cr₂O₃ have been explained on the basis of space charge polarization mechanism. The dielectric relaxation effects exhibited by these samples have been analysed by a graphical method and the spreading of dielectric relaxation has been established. The a.c. conductivity in the high-temperature region seems to be connected both with electronic and ionic movements.     

Mg2MTaO6 (M=Nd or La): a group of new pyrochlore oxides

Preparation of two novel mixed metal oxide ceramic materials, namely magnesium neodymium tantalum oxide (Mg₂NdTaO₆) and magnesium lanthanum tantalum oxide (Mg₂LaTaO₆) by conventional solid-state reaction method is reported in this paper. The crystal structure of these new compounds, were studied by indexing the X-ray diffraction patterns, powder pattern calculation and profile fitting. They were found to have a defective cubic pyrochlore structure, with the A site being randomly occupied by Mg and La/Nd, while, Ta and Mg are randomly distributed at the B site. The formula assigned were (MgNd)(MgTa)O₆ and (MgLa)(MgTa)O₆. The variation of dielectric constant, dielectric loss and conductivity of sintered pellets of these materials with applied frequencies in the range of 30 Hz-1 MHz were studied at room temperature. These room temperature studies at 1 MHz gave dielectric constant values of 24.8 and 25.35; conductivity values of 7.75×10⁻⁶ and 8.27×10⁻⁶ S/m as well as dielectric loss values of 0.0055 and 0.006 for Mg₂NdTaO₆ and Mg₂LaTaO₆, respectively. These new pyrochlore compounds were found to have dielectric constant, dielectric loss and conductivity values in the range suitable for possible electronic ceramic applications.     

Boron doped 1T phase MoS2 as a cocatalyst for promoting photocatalytic H2 evolution of g-C3N4 nanosheets

As one of the 2D transition metal sulfides,1T phase MoS₂ nanosheets (NSs) have been studied because of their distinguished conductivity and suitable electronic structure.Nevertheless,the active sites are limited to a small number of edge sites only,while the basal plane is catalytically inert.Herein,we report that boron (B) doped 1T phase Mo S₂NSs can replace precious metals as a co-catalyst to assist in photocatalytic H₂production of 2D layered g-C₃N<...