Hierarchically interconnected nitrogen-doped carbon nanosheets for an efficient hydrogen evolution reaction

Exploring low-cost and efficient electrocatalysts based on earth-abundant elements for the hydrogen evolution reaction (HER) is of great importance for the development of clean and renewable energy. In this work, we report a facile self-foaming strategy for synthesis of hierarchically interconnected nitrogendoped carbon nanosheets (NCNS). The doping N species within the 3D interconnected carbon network affords rich active sites for the HER and facilitates fast charge transfer. As a result, the NCNS exhibit excellent catalytic activity with an onset potential of -65 mV, and a Tafel slope of 81 mV dec(-1) with robust stability over 10 h in acidic media. Further analyses suggest that the graphitic N species in the NCNS contribute to their catalytic activity. Such a high catalytic performance makes the NCNS a promising metalfree HER electrocatalyst for practical hydrogen production.