12058-18-3Relevant articles and documents
Synthesis of MoSe2 nanocrystallites by a solvothermal conversion from MoO3
Zhan,Zhang,Qian,Wang,Xie,Qian
, p. 497 - 501 (1999)
Nanocrystalline 2H-MoSe2 was prepared from MoO3, N2H4·H2O, and Se in pyridine at 300°C for 12 h by a solvothermal method. A gray-black product was collected and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. The XRD pattern showed that a phase-pure product was prepared. TEM analysis showed that the product was polycrystalline and had plate-shaped particles with a diameter of about 40 nm. The conversion process from MoO3 to MoSe2 is discussed.
Controllable synthesis of flower-like MoSe2 3D microspheres for highly efficient visible-light photocatalytic degradation of nitro-aromatic explosives
Huang, Jingwen,Jin, Bo,Liu, Huiqiang,Li, Xiaojuan,Zhang, Qingchun,Chu, Shijin,Peng, Rufang,Chu, Sheng
, p. 11424 - 11434 (2018)
Nitro-aromatic explosives existing on the surface of the Earth are difficult to degrade, and they greatly harm the ecological environment and human security. Herein, we successfully conducted the large-scale synthesis of novel flower-like MoSe2 3D microspheres and nanospheres by a simple hydrothermal method. The two types of MoSe2 3D spheres had a high crystal quality with abundant nanosheets, and their diameters were approximately 1.5 μm and 300-400 nm, respectively. The Brunauer-Emmett-Teller (BET) and UV-vis diffuse reflectance spectra (UV-vis DRS) analyses revealed that the specific surface area and the band gap of MoSe2 microspheres and nanospheres were 33.3 m2 g-1 and 1.68 eV and those of the nanostructures were 13.6 m2 g-1 and 1.52 eV, respectively. Moreover, two different morphologies of MoSe2 were used for the degradation of nitrobenzene (NB), p-nitrophenol (PNP) and 2,4-dinitrophenol (2,4-DNP) through a photocatalytic process. The results demonstrated that the three nitro-aromatic explosive solutions NB, PNP and 2,4-DNP (40 mg L-1) could be completely degraded by MoSe2 3D microspheres under visible-light irradiation in 3.5 h, 1.5 h and 2.5 h, and the degradation time for MoSe2 nanospheres was 4.5 h, 2.5 h and 4 h, respectively. The mechanism of the photocatalytic reaction was also investigated in detail, and the photocatalytic degradation process was found to follow the pseudo-first-order kinetics. Our study demonstrated the potential application of MoSe2 microspheres as a photocatalyst for the degradation of nitro-aromatic explosives and other organic contaminants.
Cr1.45Tl1.87Mo15Se19, a monoclinic variant of the hexa-gonal In3Mo15Se 19 type
Gougeon,Salloum,Potel
, p. i87-i90 (2009)
The monoclinic compound Cr1.45Tl1.87Mo 15Se19 (chromium thallium penta-deca-molybdenum nona-deca-selenide) represents a variant of the hexa-gonal In3Mo 15Se19 structure type. Its
Modulating in-plane electron density of molybdenum diselenide via spontaneously atomic-scale palladium doping enables high performance lithium oxygen batteries
He, Miao,Hu, Anjun,Li, Jiabao,Li, Minglu,Long, Jianping,Shu, Chaozhu,Yan, Yu
, (2021)
Lithium-oxygen batteries (LOBs) are considered to be one of the most competitive energy storage devices due to their high theoretical energy density. However, challenges including poor catalytic activity and durability of the oxygen electrode seriously hinder the in-depth development of LOBs. Adjusting the surface electronic structure of the oxygen electrode provides a new prospect for realizing highly efficient electrocatalysts. In this contribution, we report that atomic-scale palladium (Pd) involving in MoSe2 (Pd–MoSe2) is capable of adjusting the in-plane electron density of MoSe2 via spontaneous interface chemical reactions, thereby accelerating the electron migration along the in-plane direction. The synergy between the created Se vacancies and Pd atoms can further increase the electroactive sites on the Pd–MoSe2 surface, which is conducive to improving the catalytic activity of the electrode and thereby accelerating the kinetics of oxygen electrode reactions. The results show that Pd–MoSe2 based LOBs exhibit excellent electrochemical performance such as high Coulombic efficiency (97.81%) as well as extended cycle life (1952 h). This work shows that the adjustment of in-plane electron density by exotic metal atom is a viable strategy to improve the catalytic activity of layered transition metal selenide, which provides the possibility of developing highly efficient electrocatalysts for LOBs.
Synthesis and characterization of indium intercalation compounds of molybdenum sulphoselenide
Mandal,Srivastava
, p. 3191 - 3196 (1996)
The synthesis, structure and properties of indium-intercalated compounds of molybdenum sulphoselenide, In1/3MoSxSe2-x (0 ≤ x ≤ 2) compounds were investigated. X-ray analysis shows that all these compounds possess layer-typ
Dual surfactants applied in synthesis of MoSe2 for high-efficiency hydrogen evolution reaction
Li, Changdian,Zhu, Lili,Li, Han,Li, Hui,Wu, Ziqiang,Liang, Changhao,Zhu, Xuebin,Sun, Yuping
, (2021)
Molybdenum diselenide (MoSe2) has been considered as a promising electrocatalyst for the hydrogen evolution reaction (HER), having great significance in the exploration of catalysts for green energy production. To obtain excellent electrocatalytic properties of MoSe2, the structural design of materials has become a commonly-used strategy. Hence, the combination of hexadecyl trimethyl ammonium bromide (CTAB) and polyethylene-polypropylene glycol (F68) was employed during hydrothermal process to modify the structure of MoSe2. Compared with using only one surfactant (CTAB or F68), MoSe2 catalyst represents better surface activity, more active sites and enhanced catalytic activity in the presence of dual surfactants. The as-prepared MoSe2-CTAB@F68 catalyst achieves an excellent HER activity with an overpotential of 189 mV versus the reversible hydrogen electrode (RHE) at a current density of 10 mA cm?2 and a low Tafel slope of 62 mV dec?1. Therefore, this work paves a way to prepare electrocatalysts with dual surfactants existence, which is greatly attractive for an optimizing electrocatalyst performance in a more efficient way.
Hierarchical Co0.85Se-CdSe/MoSe2/CdSe Sandwich-Like Heterostructured Cages for Efficient Photocatalytic CO2 Reduction
Du, Lizhi,Chen, Yajie,Wang, Qi,Zhao, Yumeng,Li, Longge,Liu, Xiu,Tian, Guohui
, (2021)
Fabricating efficient photocatalysts with rapid charge carrier separation and high visible light harvesting is an advisable strategy to improve CO2 reduction performance. Herein, hierarchical Co0.85Se-CdSe/MoSe2/CdSe cages with sandwich-like heterostructure are prepared to act as efficient photocatalysts for CO2 reduction. In this study, the structure and composition of the final products can be regulated through the cation-exchange reaction in the presence of ascorbic acid. In the Co0.85Se-CdSe/MoSe2/CdSe cages, MoSe2 nanosheets function as a bridge to integrate Co0.85Se-CdSe and CdSe on both sides of the MoSe2 nanosheet shell into a sandwich-like heterostructured catalyst system, which possesses multiple positive merits for photocatalysis, including accelerated transport and separation of photogenerated carriers, improved visible light utilization, and increased catalytic active sites. Thus, the optimized Co0.85Se-CdSe/MoSe2/CdSe cages exhibit remarkable visible-light photocatalytic performance and outstanding stability for CO2 reduction with a high CO average yield of 15.04?μmol g?1 h?1 and 90.14% selectivity, which are much higher than those of other control samples including single-component catalysts and binary hybrid catalysts. This study provides a promising way for the design and fabrication of high-efficiency photocatalysts.
Superconducting properties of solid solutions (Mo6Se8)Pbx and PbxMo6Se8 in the ternary system Pb-Mo-Se
Corrignan, Anita,Hamard, Christelle,Pena, Octavio
, p. 260 - 264 (1999)
The homogeneity regions of the superconducting phases (Mo6Se8)Pbx and PbxMo6Se8 were explored along the section [Mo3Se4-Pb1Mo6Se8] in the Pb-Mo-Se ternary system. It is shown, through X-ray diffraction and a.c. susceptibility methods, that a `doped binary' region (i.e., (Mo6Se8)Pbx) exists for x≤0.1, while the ternary Chevrel phase PbxMo6Se8 exists between x>0.7 and x≤1.05. In the first region, the superconducting temperature Tc increases from 6.45 K (x = 0) up to 7.15 K; in the latter, the highest superconducting temperature (Tc = 7.2 K) corresponds to lead-deficient samples (x = 0.75) decreasing linearly with x down to 4.35 K (x = 1.05). Our previous belief that the doped regime depends only on steric effects (i.e., ionic size of the dopant) is reinforced with the present data.
Synergetic effect of TiO2 as co-catalyst for enhanced visible light photocatalytic reduction of Cr(VI) on MoSe2
Chu, Haipeng,Lei, Wenyan,Liu, Xinjuan,Li, Jinliang,Zheng, Wei,Zhu, Guang,Li, Can,Pan, Likun,Sun, Changqing
, p. 19 - 25 (2016)
MoSe2-TiO2 composites were successfully synthesized via a facile solvothermal method. Their morphology, structure and photocatalytic activity in the reduction of Cr(VI) were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV-vis absorption spectroscopy, X-ray photoelectron spectroscopy and electrochemical impedance spectra, respectively. The results show that the introduction of TiO2 into MoSe2 boosts the light harvesting efficiency and charge separation and transfer due to their synergistic effect, thus enhancing the visible light photocatalytic activity of MoSe2 with a maximum Cr(VI) reduction rate of 91% at 120 min compared with pure MoSe2 (61%) and TiO2 (5%).
Graphene-like 2H/1T-MoSe2 with superior full spectrum absorption: Morphology and phase engineering
Wu, Jinzhu,Liu, Yue,Yao, Yuan,Shao, Yanbin,Wu, Xiaohong
, (2021)
Superabsorbers can find application in the fields of solar cells, blackbody radiation, thermal control systems, and stray light elimination devices. Herein, graphene-like 2H/1T-molybdenum diselenide (MoSe2) was synthesized via a hydrothermal method and shows superhigh solar absorption (~99%) within a range of 200–2500 nm. In the synthesis, selenium dioxide (SeO2) was used as a Se source instead of Se powder, which plays an important role in manipulating the graphene-like morphology and the multiphasic composition of the MoSe2. Consequently, the as-prepared MoSe2 nanoflowers possess desired band structure and abundant pores and pore channels for strong optical absorption. DFT calculations clarify that the 1T-MoSe2 primarily contributes to the superior optical absorption over the 2H-MoSe2. This work provides a facile strategy for enhancing the optical absorption of two-dimensional transition metal dichalcogenides (2D TMDCs) by engineering morphology and phase.
Non-stoichiometry and structure of molybdenum diselenide
Naruke,Wakatsuki,Hoshi,Sasaki
, p. 647 - 655 (1996)
Molybdenum diselenides were synthesized at 1273 K for 24 h. The X-ray diffraction (XRD) analysis showed the compound to be non-stoichiometric in the approximate range of 1.85 ≤ Se/Mo ≤ 2.0. Density measurements suggested a co-existence of interstitial Mo and Se vacancies in the lattice over the non-stoichiometric range. Well-grown crystals of hexagonal 2Hb-type were formed in the range of 1.9 ≤ Se/Mo ≤ 2.0, whereas fine powders were given for Se/Mo a mixed-stacking of 2Hb- and 3R-type layers was suggested to take place, and the ratio of 2Hb:3R in the compounds of Se/Mo = 1.85 was estimated to be about 85:15 by means of a simulation of the XRD patterns. Compressed samples of 1.85 ≤ Se/Mo 1.9 were higher in the electrical conductivity and were smaller in its temperature dependence, compared with those of 1.9 ≤ Se/Mo ≤ 2.0.
Chevrel-phase solid solution Mo6Se8-xTex. Study of its superconducting, magnetic and NMR properties
Hamard,Auffret,Pena,Le Floch,Nowak,Wojakowski
, p. 339 - 349 (2000)
The Chevrel-phase solid solution Mo6Se8-Mo6Te8 was studied by X-ray diffraction, AC and DC magnetic susceptibility and 77Se and 125Te NMR spectroscopy. From the smooth evolution of the lattice parameters and superconducting critical temperatures, a progressive substitution of selenium atoms by tellurium is shown, on the whole range of composition 0≤x≤8, in the formulation Mo6Se8-xTex: the unit-cell volume increases linearly because of the larger ionic size of tellurium, while Tc decreases rapidly (from 6.45 down to 0 K) because of the different formal oxidation states of the anions and a probable evolution of the Fermi level in the density of states. Results of magnetic susceptibility support this model and suggest the inhibition of the intrinsic metallic behavior with increasing x. The NMR spectra of the binaries Mo6Se8 and Mo6Te8 reveal two significant features, attributed to two different chalcogen positions in the R3 symmetry. At low Se contents in Mo6Se8-xTex (x = 7.5, 7 and 6), selenium first fills the two X(2) sites along the three-fold axis (2c positions), and then it becomes statistically distributed over the general 6f positions, leading to broad 77Se NMR lines. On the other hand, substitution of Te atoms in Mo6Se8 seems to occur in a random way, creating large perturbations on the 125Te NMR spectra, over the whole range of x. Theoretical analysis based on the presence of two anisotropic lines (of axial and non-axial symmetries, respectively) allowed us to estimate their anisotropy factors and to perfectly simulate the frequency response of both Mo6Se8 and Mo6Te8 binaries. Analysis of the Knight shift anisotropy leads us to conclude about the importance of the molybdenum z2 molecular orbital contribution which controls the Mo-X dipolar interactions.
Single-Crystal Studies of the Chevrel-Phase Superconductor LaxMo6Se8: I: Correlation betweenTcand the Interatomic Distances
Le Berre,Pena,Perrin,Sergent,Horyn,Wojakowski
, p. 151 - 159 (1998)
We report, for the first time in the literature, crystal structure studies of rare-earth-based Chevrel-phase selenides of formulae LaxMo6Se8with variable contents (x) of lanthanum. Single crystals were grown from off-stoichiometric mixtures that had been melted and slowly cooled from about 1675°C. The origin site of the rhombohedral lattice may present a considerable deficiency in the lanthanum occupancy, whereas no vacancies were found in the Mo6Se8sublattice. The superconducting temperature of this phase depends strongly on the lanthanum concentration, as we previously reported for powder samples. From the crystal structure data obtained for three crystals with different lanthanum contents, a clear correlation was established betweenTcand the lanthanum occupancy at the origin site. The critical temperature varied from 9.4 to 11.0 K forx=0.839(2) tox=0.9412(2), respectively, the lanthanum contents being derived from structural data taken on the same single crystals. Lattice constants, positional parameters, and interatomic distances are presented, and their respective variations are discussed in terms of geometrical effects and charge transfer phenomena. A full comparison is made with the corresponding rare-earth molybdenum sulfidesREMo6S8. Basic physical properties, i.e., electrical resistivity, ac susceptibility, and dc magnetization, are presented in an accompanying paper; they confirm that LaMo6Se8is an extremely high-field superconductor.
A novel route to obtain molybdenum dichalcogenides by hydrothermal reaction
Fan, Rong,Chen, Xianhui,Chen, Zuyao
, p. 920 - 921 (2000)
Hydrothermal reactions between aqueous Na2MoO4, Na2ESO3 (E=S, Se) and hydrazine monohydrate at 135 °C for 12 h produce phase-pure MoS2 and MoSe2 with good yield of about 90%. X-ray powder diffraction, chemical analysis and X-ray photoelectron spectroscopy were used to characterize the structure and composition of the products annealed at 350 °C. Transmission electron microscopy images show that the samples of MoS2 and MoSe2 consist of nano-crystallites with average particle size of 4 nm and 7 nm, respectively.
Crystal data for mixed-anion molybdenum dichalcogenides
Schneemeyer, Lynn F.,Sienko
, p. 789 - 791 (1980)
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Optimization of MoSe2 nanostructure by surface modification using conducting polymer for degradation of cationic and anionic dye: Photocatalysis mechanism, reaction kinetics and intermediate product study
Mittal, Honey,Khanuja, Manika
, (2020)
In the present work, optimum nanocomposites of MoSe2-PANI (polyaniline) were successfully synthesized by modifying the surface of MoSe2 with PANI to enhance the photocatalytic efficiency. A series of MoSe2-PANI nanocomposites with different MoSe2 to PANI weight percent ratios (1:1, 1:2, 1:3 and 2:1) were prepared by in-situ oxidative polymerization method to study the effect of variation of surface charge on photocatalytic efficiency. Samples were characterized using X-Ray Diffractometer (XRD), Field-Emission Scanning Electron Microscopy (FESEM), Fourier-transform infrared (FTIR) spectroscopy, Diffuse Reflectance spectroscopy (DRS), zeta potential measurements, Photoluminescence (PL) spectroscopy and time-correlated single photon counting (TCSPC). Comparative photocatalytic degradation of cationic dye (Rhodamine B) and anionic dye (Congo red) were performed. The mechanism of degradation was explained using active species trapping experiments. Intermediate products formed during the degradation process were determined using Liquid chromatography-mass spectroscopy (LC-MS). Reaction kinetics for the adsorption of dyes were also studied. MoSe2-PANI nanocomposite having MoSe2:PANI in 2:1 ratio showed the most significant charge separation and optimized surface charge for photocatalytic degradation of cationic and anionic dye.
Synthesis and characterization of indium intercalation compounds of molybdenum diselenide, InxMoSe2 (0 ≤ x ≤ 1)
Srivastava,Avasthi
, p. 1919 - 1924 (1989)
The synthesis, structure and properties of indium intercalated compounds of molybdenum diselenide, inxMoSe2 (0 ≤ × ≤ 1). X-ray analysis shows that the intercalated compounds, In1/3MoSe2 like the host. 2H-MoSe2 also possess a hexagonal symmetry with a small increase in c lattice parameter. However, a new phase appeared in In2/3MoSe2 and InMoSe2 diffractogram due to In7Se6, In2Se3, InxMo6Se8 or In3.33Mo15Se19. Room temperature magnetic susceptibility, thermoelectric power experiments and two probe conductivity measurements in the temperature range 25 to 300°C indicated that intercalated compounds also exhibit p-type diamagnetic semiconducting behaviour similar to the host MoSe2 and results are explained on the basis of existing band models. Thermal stability behaviour of these compounds has also been studied and X-ray analysis of the oxidized product has also been made.
Kam, Kam-Keung,Chang, Chi-Lan,Lynch, D. W.
, (1984)
X-ray characterization, electronic band structure, and thermoelectric properties of the cluster compound Ag2Tl2Mo9Se11
Al Rahal Al Orabi, Rabih,Gougeon, Patrick,Gall, Philippe,Fontaine, Bruno,Gautier, Rgis,Colin, Malika,Candolfi, Christophe,Dauscher, Anne,Hejtmanek, Jiri,Malaman, Bernard,Lenoir, Bertrand
, p. 11699 - 11709 (2014)
We report on a detailed investigation of the crystal and electronic band structures and of the transport and thermodynamic properties of the Mo-based cluster compound Ag2Tl2Mo9Se11. This novel structure type crystallizes in the trigonal space group R3'c and is built of a three-dimensional network of interconnected Mo9Se11 units. Single-crystal X-ray diffraction indicates that the Ag and Tl atoms are distributed in the voids of the cluster framework, both of which show unusually large anisotropic thermal ellipsoids indicative of strong local disorder. First-principles calculations show a weakly dispersive band structure around the Fermi level as well as a semiconducting ground state. The former feature naturally explains the presence of both hole-like and electron-like signals observed in Hall effect. Of particular interest is the very low thermal conductivity that remains quasi-constant between 150 and 800 K at a value of approximately 0.6 W·m-1·K-1. The lattice thermal conductivity is close to its minimum possible value, that is, in a regime where the phonon mean free path nears the mean interatomic distance. Such extremely low values likely originate from the disorder induced by the Ag and Tl atoms giving rise to strong anharmonicity of the lattice vibrations. The strongly limited ability of this compound to transport heat is the key feature that leads to a dimensionless thermoelectric figure of merit ZT of 0.6 at 800 K.
1T-2H MoSe2 modified MAPbI3 for effective photocatalytic hydrogen evolution
Cai, Yifei,Chen, Jinxi,Lou, Yongbing,Zhang, Tiantian
, (2021/10/25)
Organic-inorganic perovskites such as iodine methylamine lead (MAPbI3) shows superb photocatalytic prospect in the field of solar energy driven photocatalysis. However, its catalytic performance is insufficient due to serious charge recombination. In this article, 1T-2H MoSe2/MAPbI3 composites were obtained by simple electrostatic adsorption method. The results of photocatalytic hydrogen production showed that 10 wt% 1T-2H MoSe2/MAPbI3 performed the best hydrogen evolution rate of 552.93 μmol·h?1·g?1, which was 23 times than that of pure MAPbI3 (23.13 μmol·h?1·g?1). The long-term cyclic stability test also indicated that 1T-2H MoSe2/MAPbI3 composites have good stability. The excellent hydrogen evolution rate activity is thoroughly investigated by optical/optoelectrochemical measurements, showing that 1T-2H MoSe2 as a co-catalyst can effectively transfer electrons and promote the separation of photogenerated charge. This study provided a reference for further exploration of MAPbI3-based catalysts with excellent catalytic activity.
