Synergistic effect of Nitrogen and Boron co-doped porous actived carbon encapsulated NiCo2O4 nanosphere composite for enhanced Oxygen Eevolution Reaction

Abstract

There is a growing interest in developing highly efficient, cost-effective, and noble metal-free electrocatalysts. In this study, we synthesized porous activated carbon (AC) derived from waste Agathis dammar cone biomass, co-doped with nitrogen (N) and boron (B), and encapsulated with NiCo₂O₄ nanosphere composites using simple hydrothermal and pyrolysis methods. Characterization results reveal that the incorporation of N and B atoms into the AC lattice significantly enhances the material's surface and electronic structure, improving electron conductivity and increasing the number of active sites. The porous nature of the AC, combined with the synergistic effect of the NiCo₂O₄ binary metal oxide, results in exceptional oxygen evolution reaction (OER) performance, achieving a low overpotential of 289 mV and a small Tafel slope of 84.5 mV dec^-1 at 10 mA cm^-2 in 1 M KOH alkaline medium. Additionally, the N, B-AC/NiCo₂O₄ electrode exhibits excellent stability, maintaining performance for over 50 h. This work demonstrates a promising strategy for synthesizing efficient, noble metal-free electrocatalysts from waste biomass, offering significant potential for future energy production technologies.