Immobilization of poly(N-vinyl-2-pyrrolidone)-capped platinum nanoclusters on indium-tin oxide glass and its application in dye-sensitized solar cells

Poly(N-vinyl-2-pyrrolidone) (PVP)-capped Pt nanoclusters were deposited on indium-tin oxide glass via a simple two-step dip-coating process. This new type of electrode was examined by atomic force microscopy, inductively coupled plasma-atomic emission spectroscopy, electrochemical impedance spectroscopy, and cyclic voltammetry. The results reveal that the Pt nanoclusters sized about 10-20 nm show a noticeable catalytic effect on tri-iodide reduction although they are surrounded by PVP entanglements. The new electrolyte can serve as a counter electrode in dye-sensitized solar cells (DSSCs). In addition, we have found a counter action between the nanosized effect and the hindrance effect by PVP entanglement on both catalytic kinetics and ion diffusivity. Finally, at certain PVP levels, the so-prepared electrode's performance is similar to a smooth Pt metal sheet electrode. So this process could potentially reduce manufacturing costs for DSSCs, which further enhances the feature of DSSCs in furnishing low cost solar electricity.