In-situ growth of nitrogen-doped mesoporous carbon nanostructure supported nickel metal nanoparticles for oxygen evolution reaction in an alkaline electrolyte

Highlights: • N-doped mesoporous NCNP electrocatalyst prepared by a simple cost-effective approach. • NCNP delivers comparable overpotential value with the benchmark electrocatalyst. • NCNP exhibits excellent accelerated degradation test for 24 h at a 10 mA cm⁻². -- Abstract: Rational three-dimensional nitrogen doped mesoporous carbon nanostructured surfaced Nickel metal (Ni) nanoparticles (nps), NCNP composites have been developed using nickel organic complex and utilized as an electrocatalyst for oxygen evolution reaction. The NCNP composites of tunable physio-chemical characteristics, such as Ni nps size (∼18–∼42 nm), surface area (∼18–∼43 m² g⁻¹), pore size (3.23–3.84 nm) and nitrogen doping amount (1.20–3.87 wt%) have been achieved via controlled carbonization temperature. An optimized NCNP composite of favorable physio-chemical properties has delivered good oxygen evolution kinetics such as a lower overpotential value (370 mV) at 10 mA cm⁻², a minimum Tafel slope value (55 mV dec⁻¹), and relatively a higher electrochemical surface area (0.6325 cm⁻²) than the other NCNP composites. Moreover, the best NCNP electrocatalyst has shown a comparable overpotential value with the benchmarking catalyst at 10 mA cm⁻², equivalent to ∼10% solar photoelectrical conversion efficiency. In addition, the best NCNP electrocatalyst has exhibited excellent accelerated degradation test for 24 h at a constant current density of 10 mA cm⁻² with an increase overpotential value of 0.029 V.