Direct synthesis of pure single-crystalline Magnéli phase Ti8O15 nanowires as conductive carbon-free materials for electrocatalysis

Abstract

The Magnéli phase Ti₈O₁₅ nanowires (NWs) have been grown directly on a Ti substrate by a facile one-step evaporation–deposition synthesis method under a hydrogen atmosphere. The Ti₈O₁₅ NWs exhibit an outstanding electrical conductivity at room temperature. The electrical conductivity of a single Ti₈O₁₅ nanowire is 20.6 S cm⁻¹ at 300 K. Theoretical calculations manifest that the existence of a large number of oxygen vacancies changes the band structure, resulting in the reduction of the electronic resistance. The Magnéli phase Ti₈O₁₅ nanowires have been used as conductive carbon-free supports to load Pt nanoparticles for direct methanol oxidation reaction (MOR). The Pt/Ti₈O₁₅ NWs show an enhanced activity and extremely high durability compared with commercial Pt/C catalysts.