Finely dispersed Pt nanoparticles in conducting poly(o-anisidine) nanofibrillar matrix as electrocatalytic material

A new approach based on stepwise oxidation of o-anisidine is explored for generating nanoporous films of poly(o-anisidine), POA and loading of Pt nanoparticles that are subsequently used for electrocatalysis of methanol oxidation are presented and compared with bulk Pt. POA film can easily be prepared by stepwise electro-oxidation procedure with very high porosity consisting of nanofibrillar structure using without templates. Controlled sizes of Pt nanoparticles were entrapped into POA matrix by a two-step process in which first PtCl₆²⁻ ions are sorbed into the pores of polymer matrix followed by electroreduction at −0.55 V in a 0.5 M H₂SO₄ solution. Loading of Pt nanoparticles (10-200 μg/cm²) onto POA matrix were accomplished by varying the concentration (2-10 mM) of the sorbate, i.e., H₂PtCl₆. The sizes of the Pt nanoparticles were determined from TEM analysis and Pt particles were found to be in the range of 10-20 nm. The crystallite phase of Pt particles in POA was examined from XRD pattern. AFM image further supports Pt particles embedded in POA matrix.