No abstract

No abstract

A sheet-on-sheet reduced graphene oxide-β-In(2)S(3) (RGO-In(2)S(3)) composite, was successfully synthesized via a one-step mild method. This fresh composite used as an anode material exhibits enhanced cyclability and specific capacity for lithium storage. These results are linked with the intrinsic layered structure of β-In(2)S(3) sheets and the effective combination of β-In(2)S(3) and RGO sheets. This results in a high specific surface area and good conductivity of RGO-In(2)S(3) composites, with higher transport rates of electrolyte ions and electrons, and a more effective electrochemical reaction of the active material. This facile and rapid synthesis method is a promising route for a large-scale production of graphene-based metal sulfides, which could be used as electrode materials for Li-ion batteries.

Emissive PbS/CdS core/shell nanosheets are synthesized using a cation-exchange method. A significant blue-shift of the photoluminescence is observed, indicating a stronger quantum confinement in the PbS core as its thickness is reduced. High resolution transmission-electron-microscopy images of the cross sections of the core/shell nanosheets show atomically sharp interfaces between PbS and CdS. Accurate analysis of the thickness of each layer reveals the relationship between the energy gap and the thickness in the extremely one-dimensionally confined nanostructure. Photoluminescence lifetime of the core/shell nanosheets is significantly longer than the core-only nanosheets, indicating better surface passivation.

Colloidal lead sulfide (PbS) nanoribbons are synthesized using organometallic precursors with chloroalkane cosolvents. The few-atom-thick nanoribbons have a typical width 20 nm and a length more than 50 nm. Different from a nanosheet where the quantum confinement energy is mainly determined by the thickness, the narrow width of the nanoribbon has an additional contribution to the increase of energy gap. In contrast to nanosheets, the nanoribbons are much brighter. At room temperatures, well-passivated nanoribbons have achieved more than 30% photoluminescence quantum yield in the infrared spectrum, competing with the well-developed colloidal lead chalcogenide quantum dots of the similar energy gap.