Nitrogen-doped carbon-embedded TiO₂ nanofibers as promising oxygen reduction reaction electrocatalysts

The development of inexpensive and effective electrocatalysts for oxygen reduction reaction (ORR) as a substitute for commercial Pt/C catalyst is an important issue in fuel cells. In this paper, we report on novel fabrication of self-supported nitrogen-doped carbon-supported titanium nanofibers (N[sbnd]TiO₂@C) and carbon-supported titanium (TiO₂@C) electrocatalysts via a facile electrospinning route. The nitrogen atom integrates physically and homogenously into the entire carbon–titanium structure. We demonstrate the catalytic performance of N[sbnd]TiO₂@C and TiO₂@C for ORR under alkaline conditions in comparison with Pt/C catalyst. The N[sbnd]TiO₂@C catalyst shows excellent ORR reactivity and durability. Interestingly, among all the catalysts used in this ORR, N[sbnd]TiO₂@C-0.75 exhibits remarkable competitive oxygen reduction activity in terms of current density and onset potential, as well as superior methanol tolerance. Such tolerance attributes to maximizing the diffusion of trigger pulse electrons during catalytic reactions because of enhanced electronic features. Results indicate that our fabrication strategy can provide an opportunity to produce a simple, efficient, cost-effective, and promising ORR electrocatalyst for practical applications in energy conversion and storage technologies.