Synthesis Of MoS₂/C Composites And Its Catalytic Performance For Triiodide Reduction In Dye-sensitized Solar Cells

MoS2/CNT and MoS2/GN nanocomposites were successfully synthesized by the hydrothermal methods. The morphology, component and structure of the nanocomposites were investigated by field-emission field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and nitrogen adsorption-desorption technique. The electrochemical performances of the nanocomposites as the counter electrode (CE) catalysts in dye-sensitized solar cells (DSSCs) for the regeneration of I3-/I-redox couple were investigated via the cyclic voltammetry (CV), tafel-polarization, electrochemical impendence spectroscopy (EIS). The results show that both the nanocomposites exhibit excellent catalytic reactivity for triiodide reduction.The MoS2/CNT nanocomposites constructed with MoS2nanosheets and CNTs have been successfully synthesized by in situ glucose-assisted hydrothermal method, in which the CNTs can be completely encapsulated by the MoS2nanosheets and no CNTs is bare. The nanocomposites with rodlike structure are relatively uniform in size and the diameters are in a range of100～150nm. The synergetic effect of the CNTs with high conductivity and MoS2flakes with good catalytic activity endow it to be an excellent catalytic reactivity for triiodide reduction, demonstrating great potentials for triiodide reduction as counter electrode catalyst in the dye-sensitized solar cells.Similar results are also found in the MoS2/GN composite system, in which the diameters of the flower type samples are in a range of400～500nm and the thickness of MoS2nanosheets varies in a range of10～15nm. Of the as-obtained MoS2/GN composites, the MoS2/GN with mass ratio of1to1has higher redox reactivity towards I3-to I-than the other electrodes, even higher than Pt, which may be due to the synergistic effects between the conductivity of GN and the catalytic activity of MoS2flakes.