Pt Nanoparticles Supported on Polypyrrole Nanospheres as a Catalytic Counter Electrode for Dye-Sensitized Solar Cells

Polypyrrole (PPy) nanospheres (∼80 nm) were synthesized chemically within micelles composed of tetradecyl trimethyl ammonium bromide (TTAB) and decyl alcohol. Highly dispersed Pt nanoparticles (∼3.2 nm) supported on PPy nanospheres (PPy–Pt) were fabricated using a modified microwave-assisted polyol process in the presence of ethylene glycol, a Pt precursor, and PPy nanospheres as supporting materials in an aqueous medium. PPy–Pt was used as a highly efficient catalytic counter electrode for dye-sensitized solar cells (DSSCs). The charge-transfer resistance ( R ct ) (14.9 Ω) of the PPy–Pt counter electrode was lower than that (19.1 Ω) of the conventional Pt counter electrode, indicating higher electrocatalytic activity. The DSSC using a PPy–Pt counter electrode with higher surface area and mesoporosity showed enhanced overall power conversion efficiency (8.6%) compared with that of the conventional Pt-based DSSC (8.1%), under 100 mW·cm –2, AM 1.5 G sunlight illumination.