Preparation Of Graphene Derivatives And Their Application In Dye-Sensitized Solar Cells

Fossil fuel is the most widely used energy in our daily life and production, but at the same time environmental problems and energy crisis it brings to us are getting worse. Solar energy is clean and renewable which is an option for us to solve our current problems. Dye-sensitized soar cell ?DSSC? is the new member of the solar cells family; it brings great interests due to its easy fabrication, low-cost and high efficiency among its counterparts. The traditional material of counter electrode is Pt metal, which indeed has high electrical conductivity and electro-catalytic activity on I3- reduction. However, metal Pt, as a noble metal, is very expensive, which thus obstructs the commercial application of DSSCs. On the other hand, Pt is unstable in the electrolyte, which would short the lifetime of the cell. Accordingly, it's of great importance to explore alternative materials to fabricate low-cost and high-performance CEs for DSSCs. And it's the point of this study.?1? MoS₂/RGO composite was synthesized via a facile one-step annealing method. MoS₂, which exposes a large number of interlaced nanosheets loaded on the flexible sheet-like RGO and display a 3D multi-edge architecture. The catalytic activity of MoS₂ could be improved due to the fast electron-transport network provided by the RGO sheets. These especial morphology containing 3D multi-edge architecture and two dimensional sheet-like structures will benefit to the catalytic process on triiodide reduction. Cyclic voltammetry and Electrochemical impedance tests proved the catalytic activity of the composite is comparable to Pt. And photoelectrical test demonstrated a power conversion efficiency of 6.70%, which is up to 98% of that of Pt ?6.86%?.?2? At the same time, CoS/NiS/RGO composite was prepared by a simple one-step hydrothermal method. This method simplifies the preparation process by avoiding transferring of material as well as enhances the adhesion between the material and the FTO. The CV and EIS tests proved that it has the similar catalytic activity with Pt. The DSSC which applied the composite as CE material obtained a power conversion efficiency of 6.73%, which is up to 96% of Pt CE.?3? On the other hand, the MoS₂/RGO composite was applied as electromagnetic wave absorbing material and its performance was tested. The result showed that it exhibited superior electromagnetic wave absorption performance with high efficiency and broad bandwidth at thin thickness and low filler loadings. So MoS₂/RGO composite is promising electromagnetic wave absorber and deserved further detailed investigations.