Biotemplated synthesis of bark-structured TiC nanowires as Pt catalyst supports with enhanced electrocatalytic activity and durability for methanol oxidation

摘要

Developing Pt eletrocatalysts with high activity and long-term durability remains a great challenge in commercializing fuel cells. Herein, we report a new kind of bark-structured TiC nanowire (NW) as an efficient support for Pt electrocatalysts, which exhibits a higher electrochemically active surface area (ECSA), much improved electrocatalytic activity and long-term durability toward a methanol oxidation reaction (MOR) when compared with commercial Pt/C (Vulcan XC-72) catalysts. The TiC NWs were synthesized via a simple biotemplating method using natural nanoporous cotton fibers as both the carbon source and the template. Their typical size is in the range of 50-150 nm in width and up to several micrometers in length. The Pt nanoparticles deposited onto the TiC NWs by a urea-assisted ethylene glycol reduction method are small [ca. 3 nm), narrowly distributed and well crystallized. The unique one-dimensional (1D) nanostructure of the TiC NWs provides fast transport and a short diffusion path for electroactive species, and a high utilization of catalysts. Moreover, the merits of TiC NWs, such as high electrical conductivity and excellent chemical/electrochemical stability also contribute to enhancing their electrocatalytic properties. The carbide support reported here will promote broader interest in the further development of Pt electrocatalysts in the fields of fuel cells and related electrocatalytic applications.