Enhanced catalytic decoloration of Rhodamine B based on 4-aminopyridine iron coupled with cellulose fibers

BACKGROUNDA novel heterogeneous Fenton-like catalyst (FePy-CFs) was prepared by supporting 4-aminopyridine iron (FePy) onto cellulose fibers (CFs) by covalent bonds for the rapid decoloration of Rhodamine B (RhB). RESULTSCompared with the use of homogeneous FePy alone, the introduction of CFs to FePy significantly enhanced the catalytic decoloration of RhB. In addition, repetitive tests revealed that FePy-CFs could maintain high catalytic activity in 15 successive runs, suggesting FePy-CFs has excellent sustaining catalytic ability. More importantly, compared with the traditional homogeneous Fenton reagent, the catalytic reaction could proceed over a wider range of pH values from acidic to alkaline. Various scavengers and probe compounds combined with electron paramagnetic resonance (EPR) technology had been used to identify the active species involved in the catalytic system. The results indicated that hydroxyl radicals (center dot OH), peroxy radicals (center dot HO2) and high-valent iron (Fe(IV)) may be responsible for the decoloration of RhB. Furthermore, the effects of operational parameters and thermodynamic parameters have also been investigated. CONCLUSIONThis study not only opens a new perspective for the development of highly efficient catalytic systems, but also extends the potential applications of cellulose fibers in wastewater treatment. (c) 2014 Society of Chemical Industry