Oxygen deficiency assisted synthesis of network-like tungsten carbide-carbon nanotubes composites for methanol oxidation

Abstract 3D network-like tungsten carbide-carbon nanotubes composites were in-situ synthesized by using W18O49 as the precursor. The sea urchin like W18O49 with abundant oxygen defects was designed and fabricated to act as not only the source of tungsten, but also the catalyst to initiate the growth of carbon nanotubes. Distinct from carbon nanotubes-supported tungsten carbide, the obtained tungsten carbide-carbon nanotubes display an electroconductive network. In the effective system, tungsten carbide particles cracks due to mechanical stress during the growth of carbon nanotubes but the fragments still connect to the carbon nanotubes. It provides both conductive network and numerous active sites for the ideal electrocatalysts. Finally the tungsten carbide-carbon nanotubes are evaluated as an alternative catalyst for methanol oxidation reaction after being platinized. The peak current density of optimized sample reaches 1350 mA mg-1 Pt which is more than twice that of commercial Platinum Carbon.