Lignin-derived dual-doped carbon nanocomposites as low-cost electrocatalysts

Converting waste biomass into functional materials is promising to achieve the high-value utilization of low-cost and sustainable resources. Here we demonstrate a facile surface/interfacial approach to transforming biomass waste lignin to heteroatom-doped carbon-based catalysts for oxygen reduction and oxygen evolution reactions in alkaline media. The formation of dual-heteroatom incorporated carbon nanocomposites is attributed to the strong interfacial complexation in the lignin-based precursor. Compared to commercial catalyst standards, the dual-doped carbon nanocomposites show promising catalytic activities and superior long-term durability, especially for oxygen evolution reactions. The catalytic mechanisms for oxygen reduction reaction and oxygen evolution reactions are attributed to nitrogen-coordinated phosphorous and pyridinic nitrogen, respectively. The developed method is believed to facilitate the massive production of non-metal electrocatalysts from the abundant, inexpensive, and environmentally benign lignin, offering attractive renewable energy solutions.