Nitrogen-doped nanoporous carbon nanosheets derived from plant biomass: an efficient catalyst for oxygen reduction reaction

Catalysts for oxygen reduction reaction (ORR) are crucial in fuel cells. Developing metal-free catalyst with high activity at low-cost and high-volume production remains a great challenge. Here, we report a novel type of nitrogen-doped nanoporous carbon nanosheets derived from a conveniently available and accessible plant, Typha orientalis. The nanosheets have high surface area (the highest surface area can be 898 m(2) g(-1)), abundant micropores and high content of nitrogen (highest content of 9.1 at.%). The typical product exhibits an unexpected, surprisingly high ORR activity. In alkaline media, it exhibits similar catalytic activity but superior tolerance to methanol as compared to commercial 20% Pt/C. In acidic media as well, it shows excellent catalytic ability, stability and tolerance to methanol. This low-cost, simple and readily scalable approach provides a straightforward route to synthesize excellent electrocatalysts directly from biomass, which may find broad applications in the fields of supercapacitors, sensors, and gas uptake.