WS2 and Reduced Graphene Oxide Nanocomposite

WS₂ and reduced graphene oxide (WS₂/rGO) nanocomposite is prepared by in situ reduction of graphene oxide. This kind of material has good catalytic activity for hydrogen evolution as well as high sodium storage capacity. It can be widely used in many fields such as supercapacitor, Na-ion battery and so on.

As the synthesis of WS₂ nanosheet is problematic in hydrothermal process, many researches have tried to make a hybrid nanocomposite of WS₂ nanosheet with reduced graphene oxide by in situ reduction of graphene oxide for numerous applications.

WS₂ and reduced graphene oxide nanocomposite show good catalytic activity for hydrogen evolution. Therefore, it is used for energy storage and conversion such as supercapacitor, Na-ion battery and solar photovoltaic applications. In terms of impedance spectroscopic measurements, it is concluded that modified catalytic activity of WS₂/rGO nanocomposite appears mainly due to charge transfer phenomenon. Efficient charge transfer occurs mainly due to an intimate contact between tungsten disulfide and the reduced graphene oxide components.

Image (a) and (b) depicts the SEM images of WS₂ and WS₂/rGO hybrid nanocomposite respectively. The surface of tungsten disulfide is quite ruff with a large number of micro voids and pores. The prepared WS₂/rGO nanocomposite shrinks immediately after freeze-drying which perhaps due to the removal of water adsorbed on reduced graphene oxide.

The high-resolution transmission electron microscopic image of WS₂/rGO hybrid nanocomposite is shown in Image 1 which displays the overlapping nanosheet morphology with bilayer WS₂ nanosheet in some areas.

WS₂ and reduced graphene oxide nanocomposite imparts promising catalytic properties. This kind of material exhibits a potential window ranging from 150-200 mV versus reversible hydrogen electrode. It also shows the high sodium storage capacity of 590 mA·h/g with excellent performance and cyclability.

• < Prev
• Next >