Enhanced Specific Capacitance of Few-Layer MoS2 Nanosheets via SDBS-Assisted Hydrothermal Method.

Few-layer MoS2 nanosheets have been successfully synthesized by a facile anionic surfactantassisted hydrothermal approach. The as-prepared samples are characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It is found that the anionic surfactant sodium dodecylbenzene sulfonate (SDBS) plays a crucial role in the formation of MoS2 nanosheets with few layers and rich exposed edges. The electrochemical performances of the as-prepared samples are evaluated by cyclic voltammogram, galvanostatic charge-discharge and electrochemical impedance spectroscopy. Compared with the pristine MoS2 without SDBS, the MoS2 nanosheets show a high specific capacitance of 223 F g-1 and its capacitance can still maintained a stable specific capacitance of 147 F g-1 after 500 cycles at 1 A g-1. The enhancement in supercapacitors is attributed to few-layer structure and exposed active edges, which enables fast electron transportation between the electrode and electrolytes. Therefore, the MoS2 nanosheets will be a suitable candidate for electrochemical supercapacitor applications.

Synthesis and Electrochemical Performance of Molybdenum Disulfide-Reduced Graphene Oxide-Polyaniline Ternary Composites for Supercapacitors.

Molybdenum disulfide/reduced graphene oxide/polyaniline ternary composites (MoS2/rGO/PANI) were designed and synthesized by a facile two-step approach including hydrothermal and in situ polymerization process. The MoS2/rGO/PANI composites presented an interconnected 3D network architecture, in which PANI uniformly coated the outer surface of the MoS2/rGO binary composite. The MoS2/rGO/PANI composites with a weight percent of 80% (MGP-80) exhibits the best specific capacitance (570 F g-1 at 1 A g-1) and cycling stabilities (78.6% retained capacitance after 500 cycles at 1 A g-1). The excellent electrochemical capacitive performance is attributed to its 3D network structure and the synergistic effects among the three components that make the composites obtain both pseudocapacitance and double-layer capacitance.

Facile synthesis and electrochemical performances of hollow graphene spheres as anode material for lithium-ion batteries.

The hollow graphene oxide spheres have been successfully fabricated from graphene oxide nanosheets utilizing a water-in-oil emulsion technique, which were prepared from natural flake graphite by oxidation and ultrasonic treatment. The hollow graphene oxide spheres were reduced to hollow graphene spheres at 500°C for 3 h under an atmosphere of Ar(95%)/H2(5%). The first reversible specific capacity of the hollow graphene spheres was as high as 903 mAh g(-1) at a current density of 50 mAh g(-1). Even at a high current density of 500 mAh g(-1), the reversible specific capacity remained at 502 mAh g(-1). After 60 cycles, the reversible capacity was still kept at 652 mAh g(-1) at the current density of 50 mAh g(-1). These results indicate that the prepared hollow graphene spheres possess excellent electrochemical performances for lithium storage. The high rate performance of hollow graphene spheres thanks to the hollow structure, thin and porous shells consisting of graphene sheets. PACS: 81.05.ue; 61.48.Gh; 72.80.Vp.