O–N–S Self-Doped Hierarchical Porous Carbon Synthesized from Lotus Leaves with High Performance for Dye Adsorption

[Image: see text] Three-dimensional porous carbon was fabricated using lotus leaves as a renewable precursor. The as-synthesized carbon had a high surface area (3601 m(2)/g), suitable O–N–S self-doping, and three-dimensional (3D) architecture with interconnected micro/meso/macropores, together with proper pore size distribution. Consequently, these admirable features endowed porous carbon as a superadsorbent for dye removal with ultrahigh adsorption capacity for rhodamine B (9444.39 mg/g) and reliable cyclability (>97% capacitance retention after 10 cycles). The adsorption of dye onto the as-prepared carbon was a spontaneous endothermic process and followed the pseudo-second-order kinetic model and the Langmuir isotherm model. The π–π stacking, hydrogen bond, and acid–base interactions were proposed to mainly account for the combination of the adsorbate and the adsorbent. Overall, these values indicated the high-performance biomass-derived carbon as a dye adsorbent and may boost the large-scale production and application of 3D hierarchical porous carbon with heteroatom doping in the field of wastewater treatment.