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

Abstract Nitrogen-doped black TiO 2 (N x :TiO 2−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 TiO 2 due to the presence of Ti 3+ 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 TiO 2 contributes to the higher durability and methanol tolerance of Pt/N x :TiO 2−x than Pt/C catalyst. Monodisperse Pt nanoparticles are loaded on N x :TiO 2−x by a facile borohydride reduction method. The Pt/N x :TiO 2−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/N x :TiO 2−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 N x :TiO 2−x support. This hybrid material is a promising candidate for the fuel cell in the future.