Graphene nanosheet-CNT hybrid nanostructure electrode for a proton exchange membrane fuel cell

This work demonstrates two-step growth of graphene nanosheets (GNS), in which carbon nanotubes (CNTs) are grown directly on a carbon cloth. GNS are subsequently constructed on the CNT surface, revealing the stand-up structure of the GNS-CNT hybrid nanostructure. The GNS-CNT hybrid nanostructure shows Nernstian and fast electron-transfer kinetics for electrochemical reactions of Fe(CN)(6)(3-/4-). A 0.1 mg cm(-2) Pt/GNS-CNT is used in the cathode of a proton membrane exchange fuel cell, in which the maximum power density is 1072 mW cm(-2) at 80 degrees C under H-2/O-2. In addition to a low-resistance electron-transfer pathway, the GNS-CNT hybrid nanostructure also provides numerous edge planes with strong electrochemical activity, ultimately enhancing electrochemical activity and fuel cell performance. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.