Abstract
Exploring
highly active and stable electrocatalyst for oxygen evolution reaction
is important for the development of water splitting and rechargeable
metal-air batteries. Herein, a hybrid electrocatalyst of CoFe alloy and
CoxN heterojunction encapsulated and embedded in N-doped
carbon support (CoFe-CoxN@NC) was in situ coupling via a
pyrolysis process of a novel coordination polymer from lignin
biomacromolecule. CoFe-CoxN@NC exhibited an excellent
OER activity with a low overpotential of 270 mV at 10
mA·cm−2 and stability with increment of 20 mV,
comparable to commercial Ir/C. DFT calculations revealed that
CoxN and N-doped grapheme encapsulation can reduce the
binding strength between *O and CoFe alloy, prevent metals leaching and
agglomeration, and improve electron transfer efficiency, thereby,
remarkably enhancing the OER activity and stability. In situ coupling
strategy of alloy and nitride heterojunction on N-doped lignin-derived
carbon provided a promising and universal catalyst design for the
development of renewable energy conversion technologies.
Keywords : Lignin-derived carbon; CoFe alloy; Heterojunction;
Oxygen evolution reaction;
Electrocatalysis.