Functionalized Lignin for Fabrication of FeCoNi Nanoparticles-Enriched 3D Carbon Hybrid: From Waste to a High-Performance Oxygen Evolution Reaction Catalyst

The application of lignin-derived carbon materials in energy conversion is hindered by the complex molecular structure and few metal coordination sites of lignin. In this work, a simple oxidation-coordination method was developed for scalable synthesis of a FeCoNi nanoparticles-modified nitrogen-doped carbon hybrid (designated as O-FeCo40Ni10-C) with lignin as carbon precursor for oxygen evolution reaction (OER). Specifically, a Fenton reaction-driven pre-oxidation process changed the molecular structure of alkali lignin and increased functional groups, which contributes to the efficient incorporation of metal active sites into lignin-derived carbon materials. Benefiting from abundant active sites, the synergistic effect of CoFe/NiFe compositions and interconnected porous structure, the obtained O-FeCo40Ni10-C exhibited a high OER activity. It only required an overpotential of 280 mV to drive current densities of 10 mA cm(-2) in 1 M KOH solution. Moreover, the turnover frequency of O-FeCo40Ni10-C was 0.030 and 0.185 s(-1) at the overpotential of 300 and 400 mV, respectively. This work provided an environmentally-friendly strategy to synthesize lignin-derived catalyst for OER and expanded the application of lignin in energy conversion filed.