Nickel-Rich Ni3N Particles Stimulated by Defective Graphitic Carbon Nitrides for the Effective Oxygen Evolution Reaction

The development of an effective and inexpensive electrocatalyst for the oxygen evolution reaction (OER) is the key to achieve high hydrogen production since water splitting has sluggish OER kinetics. Herein, a composite of nickel-rich nickel nitride (NR-Ni3N) with graphitic carbon nitrides (GCNs) was prepared for the electrocatalytic OER, showing a low overpotential of similar to 290 mV, a small Tafel slope of similar to 70 mV dec(-1) at 10 mA cm(-2) current density, and low loss of activity after 36 h of test in an alkaline electrolyte, outperforming the pure Ni3N and even the noble catalyst RuO2. The characterization results revealed that the defective GCNs can promote the generation of a Ni-rich region in Ni3N in the nitridation process, and the high conductivity of the formed robust Ni-Ni3N heterojunction and its strong synergistic effect with GCNs explain the excellent OER electrocatalytic performances of NR-Ni3N/GCNs. This work provides a novel feasible strategy for the development of highly active OER electrocatalysts.

Automated summary

In this study, an electrocatalyst composed of nickel-rich nickel nitride (NR-Ni3N) and graphitic carbon nitrides (GCNs) was developed for efficient oxygen evolution reaction (OER). The composite exhibited a low overpotential, small Tafel slope, and minimal activity loss after long-term testing, outperforming pure Ni3N and even the noble catalyst RuO2. The excellent OER performance of NR-Ni3N/GCNs can be attributed to the generation of a Ni-rich region and the strong synergistic effect between Ni-Ni3N heterojunction and GCNs.