Few-layer N-doped porous carbon nanosheets derived from corn stalks as a bifunctional electrocatalyst for overall water splitting

The environmental crisis of the earth's living has led to in-depth research on energy generation and conversion, and electrocatalytic water splitting appeared suitable for sustainable energy cycles and conversion. Here, a N-doped few-layer porous carbon nanosheets catalyst (labeled as NPCSS) with high specific surface area, enormous active sites and high atom ratio of pyridinic/pyrrolic N was obtained by pyrolysis of mixture of corn stalks soot and melamine. Compared with corn stalks soot during pyrolysis without melamine, the NPCSS is featured with more electrochemically active sites and smaller mass transfer resistance, leading to a superior water splitting activity in 1 M KOH solution. NPCSS shows outstanding water splitting performance with small overpotentials of 195 mV and 358 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at the current density (j) of 10 mA cm−2, respectively. Our method realizes the high value-added utilization of biomass carbon.