A novel CNTs-Fe3O4 synthetized via a ball-milling strategy as efficient fenton-like catalyst for degradation of sulfonamides

A novel composite (CNTs-Fe3O4) was synthesized by a ball-milling strategy and characterized by BET, SEM, FTIR, XRD and VSM. The as-fabricated CNTs-Fe3O4 was used to remove six sulfonamides by a Fenton degradation process, including sulfanilamide (SAM), sulfamerazine (SMR), sulfadimethoxine (SMX), sulfadiazine (SDZ), sulfamethazine (SMT) and sulfametoxydiazine (SMD). The degradation behaviors of six sulfonamides in CNTs-Fe3O4/H2O2 system and the relationship between molecular structure of sulfonamides and their degradation behaviors were investigated systematically. Batch experimental results showed that the as-fabricated CNTs-Fe3O4 had excellent Fenton catalytic activity for the degradation of sulfonamides due to its unique porous structure and the good combination mode of CNTs with Fe3O4 particles. The first-order kinetic mode could better describe the degradation behaviors of six sulfonamides in CNTs-Fe3O4/H2O2 system, and the degradation rate constant could be ordered as: SAM < SMT < SDZ < SMR < SMD < SMX. The quantitative relationship between the Mulliken charge of sulfonamides (x) and their degradation rate constant (y) in CNTs-Fe3O4/H2O2 system could be described as: y = - 28.719x + 15.67 (R-2 = 0.957). Finally, the possible synthesis mechanisms of CNTs-Fe3O4 and the degradation mechanisms of sulfonamides in CNTs-Fe3O4/H2O2 system was proposed. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

A novel composite (CNTs-Fe3O4) was synthesized and characterized for the removal of six sulfonamides through Fenton degradation. The study systematically investigated the degradation behaviors and molecular structures of the sulfonamides. The results showed that the as-fabricated CNTs-Fe3O4 had excellent Fenton catalytic activity and a quantitative relationship between the Mulliken charge of sulfonamides and their degradation rate constant was established.