Highly stable metal-organic framework templated N-doped bimetallic electrocatalysts for bifunctional water splitting reaction

Abstract

Bifunctional water-splitting electrocatalysts were synthesized by the pyrolysis of bimetallic metal-organic frameworks. The as-synthesized catalyst exhibited very low overpotentials of 261 mV for the oxygen evolution reaction (OER) and 101 mV for the hydrogen evolution reaction (HER) at 10 mA cm−2 in the 1.0 M KOH. The well-developed porous structure and conductive sp2 networks during pyrolysis might enhance the electrocatalytic activity. The computational simulation also showed that the formation of ZnN3 and NiN3 complexes by N-doping during the pyrolysis lowered the adsorption energies and accelerated the water-splitting kinetics. The as-prepared catalysts exhibited no current drops even after 3000 cycles of both OER and HER. Instrumental analysis also confirmed the excellent long-term stability after 3000 cycles.