▎ 摘　　要

Graphite oxide (GO) was chemically altered using polyethylene glycol (PEG) to produce functionalized GO (f-GO). An ensemble of reduced f-GO sheets and multiwalled carbon nanotubes (MWNTs), referred to as few-layer graphene-MWNT sandwiches (GCSs), were synthesized by a catalysis-assisted chemical vapor deposition (CCVD) method and explored as the electrocatalyst support material for oxygen reduction reaction (ORR) in a proton exchange membrane fuel cell (PEMFC). Platinum nanoparticles were decorated on the carbon supports by a modified glycol reduction technique. As-prepared electrocatalysts were characterized by Raman spectroscopy, X-ray diffraction and transmission electron microscopy. Electrocatalytic performance was evaluated by cyclic voltammetry and PEMFC fuel cell measurements and compared with a commercially available Pt/C electrocatalyst. The Pt/GCS electrocatalyst gave a maximum PEMFC performance of 495 mW cm(-2) at 60 degrees C temperature. The improvement in the ORR activity was ascribed to the uniform dispersion of Pt nanoparticles with an optimal particle size (similar to 3.5 nm) over a well-organized conducting catalyst support.