Triiodide reduction activity of hydrangea molybdenum sulfide/reduced graphene oxide composite for dye-sensitized solar cells

The molybdenum sulfide/reduced graphene oxide (MoS2/rGO) composite is prepared by a hydrothermal method. The hydrangea MoS2 powder is composited with rGO to serve as a low-cost and non-platinum counter electrode (CE) to improve photovoltaic performance for dye-sensitized solar cells (DSSCs). The Tafel polarization and electrochemical impedance spectroscopy (EIS) indicate that the MoS2/rGO counter electrode has exceptional electrocatalytic ability and reduction reaction kinetics for the I-/I-3(-) couples on the counter electrode, which is due to hydrangea structure MoS2 formed on rGO surface and matrix as well as the MoS2/rGO composite strongly attached on FTO substrate. The DSSC with novel MoS2/rGO CE achieves a higher power conversion efficiency of 6.72% than that with Pt CE (5.74%) under standard sunlight illumination.