TiN nanoparticles hybridized with Fe, N co-doped carbon nanosheets composites as highly efficient electrocatalyst for oxygen reduction reaction

Titanium nitride (TiN) nanoparticles hybridized with Fe and N co-doped carbon nanosheets (Fe-N-CNS) composite is constructed by a facile in-situ self-template strategy. During the low-temperature pyrolysis process, uniformly TiO₂ nanoparticles were formed and anchored into Fe-doped carbon nitride nanosheets. After further high-temperature pyrolysis, Fe-doped carbon nitride nanosheets as self-template could decompose to form Fe-N co-doped carbon nanosheets and TiO₂ nanoparticles were transferred into TiN nanoparticles during the high-temperature nitriding treatment. As a result, TiN nanoparticles hybridized with Fe-N-CNS composites (TiN/Fe-N-CNS) exhibit excellent ORR activity with more positive half-wave potential (0.87 V) and large limiting current density (4.43 mA cm⁻²) as well as high selectivity (electron transfer number around 4) for ORR in alkaline media. Moreover, it also shows higher stability and better methanol tolerance than those of commercial Pt/C catalyst in both alkaline and acidic media. This excellent ORR performance is attributed to the enhanced specific surface area and synergistically promotion effect of uniformly dispersed TiN on Fe-N-CNS.