In situ coupling of N-doped lignin-derived carbon-encapsulated CoFe-CoxN
heterojunction for oxygen evolution reaction
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.