Fullerene-Derived Porous and Defective N-Doped Carbon Nanosheets as Advanced Trifunctional Metal-Free Electrocatalysts

Dopants and defects are crucial for multifunctional carbon-based metal-free electrocatalysts, but the rational design and facile production remain as a big challenge. Herein, we report a novel strategy using salt-assisted pyrolysis of derivatized fullerenes to fabricate defect-rich and N-doped carbon nanosheets. Molecular level modification of C₆₀ via amination and hydroxylation gives rise to well-defined fullerol molecules bearing N-containing groups (FNG). Subsequent calcination of FNG and NaCl at 750 °C generates porous carbon nanosheets (FNCNs-750) and turns the N-containing groups into high-level N dopants (12.43 at.%). Further pyrolysis of FNCNs-750 at 900 °C (FNCNs-900) leads to a reduced N content populated by graphitic-N. Meanwhile, abundant intrinsic defects (e. g., topological defects and edges) are created due to the breakdown of fullerene cages and partial removal of edged N atoms. These structural features endow FNCNs-900 with outstanding trifunctional catalytic performance, better than or close to the noble metal-based benchmark catalysts.