Self-supporting multi-channel Janus carbon fibers: A new strategy to achieve an efficient bifunctional electrocatalyst for overall water splitting

Abstract

A new type of self-supporting multi-channel Janus carbon fibers with efficient water splitting has been successfully manufactured using a specially designed parallel spinneret through electrospinning technology and subsequent carbonization technique. Every single Janus fiber composes of a half side of Mo2C and the other half side of Ni components as Mo2C, Ni embedded in N-doped multi-channel Janus carbon fibers ([Mo2C/C]//[Ni/C]-NMCFs) for overall water splitting. Under optimized condition, the hydrogen evolution reaction overpotential of [Mo2C/C]//[Ni/C]-NMCFs (62 mV) is just 24 mV higher than 20 wt% Pt/C (38 mV) at a current density of 10 mA cm−2. Furthermore, it achieves current density of 10 mA cm−2 to require an overpotential of 324 mV for oxygen evolution reaction. Additionally, the cell assembled by the identical [Mo2C/C]//[Ni/C]-NMCFs catalyst as both the cathode and anode needs only 1.607 V at a current density of 10 mA cm−2, which is only 0.022 V higher than that of Pt/C-IrO2 electrodes. Moreover, [Mo2C/C]//[Ni/C]-NMCFs catalyst also exhibits a long-term stability. The synergistic effect and unique heterostructure of Mo2C and Ni enhance the catalytic activity.