Monodisperse Pt nanoparticles anchored on N-doped black TiO2 as high performance bifunctional electrocatalyst

Nitrogen-doped black TiO2 (Nx:TiO2-x) recently attracted attention as a novel photocatalyst. It has higher electrical conductivity and more suitable energy level for oxygen reduction and hydrogen evolution than pure TiO2 due to the presence of Ti3+ species. The unique electronic structure and strong metal-support interaction make it a candidate support for Pt-based electrocatalyst. Carbon is universal as support of Pt based electrocatalyst. However, it is restricted to the poor durability and bad methanol tolerance. On the contrary, the chemical stability of nitrogen-doped TiO2 contributes to the higher durability and methanol tolerance of Pt/Nx:TiO2, than Pt/C catalyst. Monodisperse Pt nanoparticles are loaded on Nx:TiO2-x by a facile borohydride reduction method. The Pt/Nx:TiO2-x hybrid shows better oxygen reduction reaction (ORR) activity with the half wave potential of 0.78 V (vs. reversible hydrogen electrode) than Pt and good hydrogen evolution reaction (HER) performance with 19 mV onset overpotential, similar to Pt/C catalyst. More importantly, Pt/Nx:TiO2-x catalyst has robust durability and higher methanol tolerance than Pt/C catalyst. All these electrostatic performances stem from the suitable energy level for ORR and HER and the strong interaction between Pt and Nx:TiO2-x support. This hybrid material is a promising candidate for the fuel cell in the future. (C) 2017 Elsevier B.V. All rights reserved.