A novel method for preparation of a platinum catalyst at low temperatures

Abstract

Uniformly distributed Pt nano-particles with excellent adhesion were deposited on conductive substrates by coating the substrate with a Pt complex precursor and its subsequent reduction with a gaseous reducing agent at temperatures as low as 100 °C. This novel two-step method enables excellent control over the particle size and distribution since it is dependent only upon the deposition of the precursor solution, and there is little to no agglomeration or movement of Pt nano-particles during the reduction process. The good adhesion was the result of the reaction at the solid–gas interface, where the solid precursor was chemically converted to metallic Pt. XPS confirmed that 100% of Pt was in the metallic state. The electrochemical catalytic properties of the Pt nano-particles were tested using cyclic voltammetry in an iodide electrolyte. The prepared samples were also used to assemble dye-sensitised solar cells that achieved a light to electricity conversion efficiency of 5.1% under AM 1.5 illumination.