In situ PEI and formic acid directed formation of Pt NPs/MWNTs hybrid material with excellent electrocatalytic activity

A hybrid material based on Pt nanoparticles (Pt NPs) and multi-walled carbon nanotubes (MWNTs) was fabricated with the assistance of PEI and formic acid. The cationic polyelectrolyte PEI not only favored the homogenous dispersion of carbon nanotubes (CNTs) in water, but also provided sites for the adsorption of anionic ions PtCl42− on the MWNTs' sidewalls. Deposition of Pt NPs on the MWNTs' sidewalls was realized by in situ chemical reduction of anionic ions PtCl42− with formic acid. The hybrid material was characterized with TEM, XRD and XPS. Its excellent electrocatalytic activity towards both oxygen reduction in acid media and dopamine redox was also discussed.