Synthesis of 3D graphite oxide-exfoliated carbon nanotube carbon composite and its application as catalyst support for fuel cells

•e-CNT was firstly applied as effective carbon spacer to prevent graphene from restacking.•Thermally reduced GO + e-CNT shows enhanced surface area and interlayer distance compared to thermally reduced GO.•The unique 3D morphology was confirmed by TEM and cross-section HR-TEM.•GO + e-CNT supported PtPd shows homogenous particle distribution with enlarged ECSA value and mass activity toward MOR.

The restacking of graphene or reduced graphite oxide (r-GO) is commonly regarded as a severe obstacle for potential applications. We propose the application of exfoliated carbon nanotube (e-CNT) as an effective carbon spacer for fabricating a sandwich-like three-dimensional (3D) carbon composite with GO. The 3D carbon combination of GO + e-CNT is successfully prepared via homogenously mixing of GO and e-CNT in an aqueous dispersion in which carbon spacers are homogenously intercalated with graphene layers. With the addition of a carbon spacer, the BET surface area of 3D carbon (51.6 m2 g−1) is enhanced by a factor of three compared with r-GO (17.2 m2 g−1) after thermal reduction. In addition, the 3D GO + e-CNT supported PtPd catalyst (PtPd-GO + e-CNT) shows homogenous distribution of PtPd nanoparticles of 3.9 ± 0.6 nm in size, with an enlarged electrochemical active surface area (ECSA) value of 164 m2 g−1 and a mass activity of 690 mA mg−1 toward the methanol oxidation reaction (MOR), which is the typical anode reaction for direct methanol fuel cells (DMFC).

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