Heterogeneous Co–CN nanofibers with controlled active terminal N sites for hydrogen evolution reaction

Abstract

In this work, a series of Co–CN nanofibers with controlled terminal N, Co–N_x, and metal Co site contents were prepared by electrospinning and high-temperature pyrolysis, which served as model catalysts for identifying the active sites for the hydrogen evolution reaction (HER). The results indicate that the thermal treatment would induce Co–N_x moieties to more terminal N sites with higher loading of the Co precursor, and this terminal N site exhibits excellent HER performance. Meanwhile, the activities were linear in accord with the content of terminal N sites, suggesting that terminal N sites would be the primary sites for hydrogen evolution reaction.