Design of electronic conduction structure based on graphite structure: mechanism and peroxymonosulfate activation enhancement

Metal free carbon materials such as graphene, diamond, and carbon nanotubes are becoming alternative catalysts for peroxymonosulfate（(PMS）activation to avoid drawbacks of traditional transition metal-containing catalysts, such as leaching of metal ions and harshing usage environments. However, these new catalysts have drawbacks such as complex processes and high synthesis costs. Herein, in this study, graphite with a unique "multilayer cake" structure was prepared as an efficient peroxymonosulfate (PMS) activator to degrade the antibiotic in the wastewater. Specifically, Specifically, by optimizing the spacing between graphite layers, the expanded graphite (EG) exhibited exceptional performance, achieving over 80% removal of tetracycline (TC) molecules within 15   mins. The enhancement of PMS activation ability is attributed to the enhanced electronic conductivity and adsorption capacity of EG. Notably, the electron-donating capability of EG facilitates a degradation mechanism dominated by singlet oxygen ( 1 O 2 ) rather than conventional free radicals (SO 4 •− , •OH), imparting the system with enhanced environmental adaptability. Furthermore, the facilitated electron transfer between pollutants and EG accelerates degradation. Compared with reported，The inherent hydrophobicity and excellent stability of graphite enable self-separation and reusability, ensuring cost-effectiveness and practicality. Collectively, this study highlights the promising application of the highly self-separating "multilayer cake" structured EG catalyst as a low-cost, high-efficiency PMS activator, offering valuable insights into the practical deployment of carbon-based materials in Fenton-like catalytic systems.