MOF-derived nitrogen-doped cobalt-nickel oxide carbon nanotubes for highly efficient oxygen evolution reaction

Highly active electrocatalysts are crucial for hydrogen production through overall water splitting. However, the sluggish kinetics of the oxygen evolution reaction (OER) on electrocatalysts severely reduces the efficiency of water electrolysis. In this work, novel nitrogen-doped double-metal oxide-encapsulated carbon nanotubes derived from metal-organic frameworks (cobalt-nickel oxide@nitrogen-doped carbon nanotubes, CoNiO@NCNT) were successfully synthesized. CoNiO@NCNT shows a lower overpotential (315 mV at 10 mA cm- 2) and Tafer slope (63.6 mV dec-1), which highlights CoNiO@NCNT has excellent OER performance and fast dynamics. Carbon nanotubes provide good mass transfer, and the synergistic effect of bimetallic Co and Ni provides additional active sites. Specifically, the introduction of oxygen mainly provides vacancy for oxygen species, which is the main reason for improving catalyst performance. After 2000 cycles, the catalytic property was maintained, indicating good stability. This work demonstrates that CoNiO@NCNT is an efficient anode oxygen evolution reaction catalyst with good development potential.

Automated summary

In this work, nitrogen-doped double-metal oxide-encapsulated carbon nanotubes (CoNiO@NCNT) derived from metal-organic frameworks were successfully synthesized. CoNiO@NCNT shows excellent oxygen evolution reaction (OER) performance with lower overpotential and faster dynamics. The presence of carbon nanotubes and bimetallic Co and Ni synergistically contribute to the improved catalytic activity.