Direct synthesis of bifunctional nanorods from Co-Adenine-MoO3 hybrid for overall water splitting
Transition-metal carbides have been proven to be efficient catalysts for hydrogen evolution reaction (HER), however, their application as bifunctional electrocatalyst towards HER and oxygen evolution reaction (OER) altogether remains a significant challenge. Herein, we report a unique heterostructures comprising cobalt-doped molybdenum-carbide (Co-Mo2C) nanorods encapsulated in nitrogen-doped graphitic carbon shell (NGCS) through one-step pyrolysis of a Co-Adenine-MoO3 hybrid. The as-synthesized Co-Mo2C@NGCS heterostructures could be directly used as catalyst for overall water splitting. Low overpotentials of 161 and 360 mV are needed for HER and OER to reach 10 mA·cm-2, and the corresponding Tafel slopes are just 60 and 54 mV dec-1, respectively. Theoretical simulations implied that the synergistic effects between the cobalt heteroatoms, NGCS and Mo2C resulted in the enhanced catalytic performance. Our work not only provides a facile method to construct hybrid electrocatalyst with inexpensive metals, but also gives new insights into the mechanism of HER and OER in alkaline media.