Bamboo-like Carbon Nanotubes with the Theoretical Upper-Limit N-Doping Concentration for Advanced Nonradical Oxidation

Increasing the N-doping concentration has been recognized as one of the most effective strategies to improve the potential properties of carbonaceous materials in energy, the environment, and other fields. However, the instability of N dopants at high temperatures makes the N-doping concentration far from the theoretical upper limit. Herein, we prepared bamboo-like carbon nanotubes (BCNTs) with a theoretically upper-limited N-doping concentration via one-step pyrolysis of zinc cyanamide in the presence of Ni ions. The N-doping concentration of optimized BCNT-5 reached 12.45 atom %, approximate to the theoretical upper limit of 12.50 atom % at a carbonization temperature of 1000 °C. By using peroxymonosulfate-based advanced oxidation processes as an example, BCNT-5 exhibited excellent catalytic performance for nonradical tetracycline degradation with good versatility and adaptability. Graphitic N was demonstrated to be the active site for nonradical peroxymonosulfate activation. Our work provided a facile and effective strategy for ultrahigh N-doping and morphology regulation in carbonaceous materials toward different applications.