Catalytic platinum layers for dye solar cells: A comparative study

Comparative investigations concerning the preparation and characterization of zerovalent platinum nanoparticles to be used as precursors for dye-sensitized solar cells (DSSCs) have been carried out. Pt nanopowders were prepared via triorganohydroborate reduction, polyol method, hydrogen reduction, and thermal decomposition of complex compounds. The powders resulting from the various sources were then immobilized on support. Subsequently, the size and crystalline structure of the particles were examined using Transmission Electron Microscopy (TEM), X-Ray diffraction (XRD). The metallic state of the platinum surface- and core-atoms were studied by X-Ray Photoelectron Spectroscopy (XPS) and X-Ray Absorption Near Edge Structure (XANES) analysis. The platinum nanoparticles resulting from the various preparation pathways were each incorporated in a printable platinum paste and then printed on transparent conductive (TCO) glass. After thermal treatment (at 630 °C) the electrochemical performance of the different platinum layers obtained in this study was compared applying impedance spectroscopy. The charge transfer resistance was best observed for the catalyst prepared by the hydrogen reduction method.