Synergetic Effect Of MoS2 Research Articles

Construction of UiO-66@MoS2 flower-like hybrids through electrostatically induced self-assembly with enhanced photodegradation activity towards lomefloxacin

Although metal organic frameworks (MOFs) presented excellent photocatalytic activities, the rapid recombination of light-induced charges and low visible light utilization efficiency hindered their practical applications. In this work, a novel heterojunction photocatalytic materials of MOFs-based semiconductor, the flower-like hybrids (UiO-66@MoS2) (UMS), were fabricated via a facile electrostatic induction self-assembly method. A series of characterizations, such as SEM, TEM, EDS, EDX, XRD, XPS, BET, FT-IR and TGA, indicated the successful synthesis of hybrid materials and revealed that MoS2 nanosheets grew on the surfaces of the UiO-66 with an intimate interaction, and then formed a flower-like structure through self-assembly, which effectively prevented recombination of photogenerated charge carriers. Comparing with pure UiO-66 and MoS2, the flower-like hybrids (UMS) exhibited remarkable performance for the degradation of lomefloxacin hydrochloride (LOM) under visible-light irradiation. Furthermore, its photoelectrochemical properties were characterized by photoluminescence spectra (PL), UV–vis diffuse reflectance spectra (DRS), and electrochemical impedance spectra (EIS). Moreover, the possible photocatalytic mechanism of UiO-66@MoS2 was investigated. It indicated that its photocatalytic activity was enhanced by the synergetic effect of MoS2 and UiO-66. In summary, a novel heterojunction photocatalysts, being fabricated via a facile method, could be applied to effectively photocatalytic treatment of medical wastewater.

Layer-by-layer MoS2:GO composite thin films for optoelectronics device applications

With reference of our previous report (Appl. Surf. Sci. 474(2019)227), the molybdenum disulphide (MoS2) thin film were prepared by the dip-coating technique at different temperatures (400 °C–450 °C) using methanolic solution of ammonium molybdate and ammonium thiocyanate that are used as bare-substrate for the deposition of graphene oxide (GO) thin films. For the deposition of graphene oxide (GO), commercially purchased GO (0.5 mg in 10 mL aqueous solution) was deposited by dip-coating technique on dip-deposited MoS2 thin film to make layer-by-layer MoS2:GO composite thin films and hence studied their electronic and electrical behaviours. The micro-structural and surface morphology were studied using Raman spectroscopy, X-ray diffraction (XRD) and field emission scanning electron microscopy, whereas optical band estimated from the optical absorption spectra. The electronic structure and their bonding properties were studied using X-ray photoelectron spectroscopy and the electrical behaviours were observed from the current-voltage (I-V) characteristic curve. The formation of different phases of MoS:GO thin films show an enhanced electronic and electrical performance due to their unique-structure and the synergetic effect of MoS2:GO nanosheets when compared to those of bare MoS2.

Synergetic effect of MoS2 and MXene on the enhanced H2 evolution performance of CdS under visible light irradiation

Water splitting under visible light irradiation over earth-abundant, inexpensive and high active catalysts is an effective and direct way to obtain renewable H2 energy. Here, a kind of novel noble-metal-free composite photocatalyst with high hydrogen evolution performance was synthesized by a simple hydrothermal method. In the composite, MXene slice with excellent conductivity was used to promote the activity of CdS-MoS2 catalyst. A prominent H2 generation rate of 9679 μmol⋅g−1⋅h−1 for the ternary composite was obtained under the irradiation of visible light (λ ≥ 420 nm). It exhibited a great enhancement by a factor of 251.3% in comparison with CdS-MoS2. The exceptional performance of CdS-MoS2-MXene was mainly arised from the high carrier mobility of MXene, which facilitates the separation of photoinduced electron-hole pairs. The present findings would provide a new direction towards exploring MXene-based composite photocatalysts with high photocatalytic performance in water splitting.

Synergetic effect of MoS2 and graphene as cocatalysts for enhanced photocatalytic activity of BiPO4 nanoparticles

The photodegradation of organic pollutants is an attractive green chemistry technology for water pollution control. Here we prepared a new composite material consisting of BiPO4 nanocrystals grown on layered graphene and MoS2 as a high-performance photocatalyst for the photodegradation of organic pollutants. This composite material was synthesized by a facile one-pot microwave-assisted hydrothermal technique in the presence of layered graphene and MoS2. Through optimizing the loading content of each component, the BiPO4-MoS2/graphene nanocomposite exhibited the highest photocatalytic activity for the degradation of Rhodamine (RhB) when the content of MoS2 and graphene was 2wt% and 7wt%, respectively. The enhanced photocatalytic activity of the new composite photocatalyst was attributed to the positive synergetic effect of the layered graphene and MoS2 as cocatalyst, which acted as electron collector and transporter for the interfacial electron transfer from BiPO4 to electron acceptor in the aqueous solution and thus suppressed the charge recombination and made the photogenerated holes more available to participated in the oxidation process. Moreover, the presence of layered MoS2/graphene hybrid could offer more reactive sites and activated the O2 molecular in water to form superoxide radical, thereby resulting in the enhanced photocatalytic activity.

One-pot synthesis of molybdenum disulfide–reduced graphene oxide (MoS2-RGO) composites and their high electrochemical performance as an anode in lithium ion batteries

A simple, effective, and ultra-fast one-pot route is developed to synthesize molybdenum disulfide (MoS2)-reduced graphene oxide (RGO) composites. The method to tightly anchor MoS2 particles on the surface of RGO includes simultaneous reduction of graphene oxide (GO) and heterogeneous nucleation and growth of MoS2 on the RGO surface in supercritical ethanol (scEtOH) medium. The synthesized MoS2-RGO composites have a mesoporous structure with high porosity. The MoS2-RGO composites show an enhanced electrochemical performance due to their unique nanostructure and the synergetic effect of MoS2 and RGO nanosheets when compared to those of compared with bare MoS2 and bare RGO. The MoS2-RGO composite with a MoS2 loading of 74.0wt% can deliver a high reversible discharge capacity up to 1102mAhg−1 at a rate of 0.05Ag−1 after 80 cycles and an excellent cycling stability of 951mAhg−1 at 0.05Ag−1 after 140 cycles.

One-step synthesis of CdS nanoparticles/MoS2 nanosheets heterostructure on porous molybdenum sheet for enhanced photocatalytic H2 evolution

Co-catalysts for H2 production are often made from expensive noble metals, such as the most efficient Pt. The alternative non-noble metal co-catalysts with low cost and high efficiency are therefore highly desirable for economically viable H2 production. Herein, we demonstrated that a CdS/MoS2/Mo sheets system simultaneously containing photocatalysts, co-catalysts, and conductive supports, was prepared via the one-step hydrothermal process by Mo sheets as template and Mo sources. The obtained CdS/MoS2/Mo sheets possess the superior photocatalytic H2 production via water splitting under visible light irradiation, which achieved an extraordinary H2 production of 4540μmolh−1g−1, up to 28.6 and 3.6 times greater than that of CdS alone and Pt/CdS. The synergetic effect of MoS2 as co-catalysts and Mo sheets as conductive supports contribute to the dramatically improved photocatalytic H2 evolution activity of CdS photocatalysts, by means of facilitating charge carriers separation and providing active sites for proton reduction. These findings provide a straightforward and practical route to produce cheap and efficient co-catalysts for large-scale water splitting.

Construction of MoS2/CdS/TiO2 ternary composites with enhanced photocatalytic activity and stability

MoS2/CdS/TiO2 nanocomposites were synthesized via one-step in situ solvothermal method and characterized by X-ray diffraction, scanning electron microscopy, transmission electron micrograph, X-ray photoelectron spectroscopy, photoluminescence spectra, Ultraviolet–Visible diffuse reflectance spectroscopy, and photocatalytic measurement. Enhanced visible light photoresponse, higher efficiency of charge carriers separation, and improved photocatalytic degradation of methylene blue were confirmed for MoS2/CdS/TiO2 nanocomposites. It was observed that the highest degradation ratio was achieved for MoS2/CdS/TiO2 nanoparticles (72%) prepared at 180 °C when exposed to visible light illumination for 160 min relative to CdS/TiO2 (59%) and TiO2 (29%). Furthermore, the improved photocatalytic performance of MoS2/CdS/TiO2 nanoparticles was also demonstrated by the degradation of colorless resorcinol under UV–vis light irradiation. This work demonstrates that synergetic effect of MoS2 and CdS in which it proves to be a good choice for improving the utilization of visible light of TiO2-based materials.

Synergetic effect of MoS2 and g-C3N4 as cocatalysts for enhanced photocatalytic H2 production activity of TiO2

In this paper, we report a new g-C3N4/MoS2/TiO2 composite material as a high-performance photocatalyst for H2 evolution. Without a noble-metal cocatalyst, the g-C3N4/MoS2/TiO2 composite reaches a high H2 production rate of 125μmolh−1 when the content of the g-C3N4/MoS2 cocatalyst is 1.0wt.% and the content of g-C3N4 in this cocatalyst is 10wt.%. This unusual photocatalytic activity is attributed to the positive synergetic effect between the MoS2 and g-C3N4 components in this cocatalyst, which serve as an electron collector and a source of active adsorption sites, respectively.

Well-constructed single-layer molybdenum disulfide nanorose cross-linked by three dimensional-reduced graphene oxide network for superior water splitting and lithium storage property.

A facile one-step solution reaction route for growth of novel MoS2 nanorose cross-linked by 3D rGO network, in which the MoS2 nanorose is constructed by single-layered or few-layered MoS2 nanosheets, is presented. Due to the 3D assembled hierarchical architecture of the ultrathin MoS2 nanosheets and the interconnection of 3D rGO network, as well as the synergetic effects of MoS2 and rGO, the as-prepared MoS2-NR/rGO nanohybrids delivered high specific capacity, excellent cycling and good rate performance when evaluated as an anode material for lithium-ion batteries. Moreover, the nanohybrids also show excellent hydrogen-evolution catalytic activity and durability in an acidic medium, which is superior to MoS2 nanorose and their nanoparticles counterparts.

The synergetic effect of MoS₂ and graphene on Ag₃PO₄ for its ultra-enhanced photocatalytic activity in phenol degradation under visible light.

The photo-degradation of organic pollutants using solar light is an attractive chemical process for water pollution control. In this study, we synthesized a new composite material consisting of silver phosphate (Ag₃PO₄) sub-microcrystals grown on a layered molybdenum disulfide (MoS₂) and graphene (GR) hybrid as a high-performance photocatalyst for the degradation of toxic organic pollutants. This composite photocatalyst was prepared via a simple two-step hydrothermal process that used sodium molybdate, thiourea and graphene oxide as precursors for the MoS₂/GR hybrid and silver nitrate for the Ag₃PO₄ sub-microcrystals. The composite Ag₃PO₄-0.02(MoS₂/0.005GR) was found to be the most effective catalyst for the photo-decomposition of 2,4-dichlorophenol under simulated solar light and visible light (λ ≥ 420 nm). The photocatalyst was also highly active for the degradation of nitrophenol and chlorophenol. The ultra photocatalytic activity of the novel catalyst arose from the synergetic effects of MoS₂ and GR as cocatalysts in the composite. MoS₂/GR nanosheets served as electron collectors for the interfacial electron transfer from Ag₃PO₄ to electron acceptors in the aqueous solution and thus enhanced the separation of the photo-generated electron-hole pairs and made the holes more available for organic oxidation. In addition, the presence of MoS₂ and GR provided more active adsorption sites and allowed for the activation of dissolved O₂ for organic degradation in water.