Kinetically Controlled Assembly of Nitrogen-Doped Invaginated Carbon Nanospheres with Tunable Mesopores

Mesoporous hollow carbon nanospheres (MHCS) have been extensively studied owning to their unique structural features and diverse potential applications. A surfactant-free self-assembly approach between resorcinol/formaldehyde and silicon alkoxide has emerged as an important strategy to prepare MHCS. Extending such a strategy to other substituted phenols to produce heterogeneous-atom-doped MHCS remains a challenge due to the very different polymerization kinetics of various resins. Herein, we report an ethylenediamine-assisted strategy to control the cooperative self-assembly between a 3-aminophenol/formaldehyde resin and silica templates. Nitrogen-doped mesoporous invaginated carbon nanospheres (N-MICS) with an N content of 6.18 at %, high specific surface areas (up to 1118 m²g⁻¹), large pore volumes (2.47 cm³g⁻¹), and tunable mesopores (3.7–11.1 nm) have been prepared. When used as electrical double-layer supercapacitors, N-MICS show a high capacitance of 261 F g⁻¹, an outstanding cycling stability (≈94 % capacitance retention after 10 000 cycles), and a good rate performance.