Fabrication of carbon-coated Na/Fe@C nanorods using soybean straw for efficient oxygen evolution reaction catalysts

The oxygen evolution reaction (OER) process in water electrolysis requires high energy consumption. Reducing the interface limitations between metal and carbon precursors can significantly enhance the catalytic performance during the OER process. Because biomass exists in solid form, in this work, a carbon-coated Na/Fe@C nanorod OER electrocatalyst using soybean straw was prepared by coupling polyethylene glycol green liquefaction, in-situ doping, and carbonization route. The carbon coating increased the surface area and active site of the catalyst and prevented catalyst oxidation, thus extending the lifespan of the catalyst. The Na/Fe@C catalysts exhibited excellent OER catalytic activity. The overpotential at a current density of 10 mA cm−2 and 100 mA cm−2 were 275 and 320 mV, respectively. Therefore, this study provides a promising strategy for preparing stable electrocatalysts and reducing OER energy consumption.