Activation of hydrogen peroxide by graphite supported H2SO4-CeO2 for isoniazid degradation under neutral pH

Graphite felt (GF) supported cerium oxide (CeO 2 ) composite with sulfation pretreatment (H 2 SO 4 -CeO 2 /GF) was prepared by the impregnation method and employed as the catalyst to activate H 2 O 2 for degradation of isoniazid (INH). The obtained samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectrum (XPS). The results showed that H 2 SO 4 -CeO 2 /GF had good properties in activating H 2 O 2 for the degradation of INH. The INH removal was about 89.4% in 120 min under the following conditions: H 2 O 2 2.94 mM, H 2 SO 4 -CeO 2 /GF 2.6 g/L, INH 10 mg/L, initial pH at 6.8 and temperature at 25 °C. The effects of some reaction parameters, including initial H 2 O 2 concentration, initial INH concentration, initial pH value, the catalyst dosage and reaction temperature, on INH degradation were investigated. On the basis of mechanism study and intermediate analysis, the possible degradation pathway of INH was proposed. Besides, effective degradation of methyl orange (MO) and norfloxacin (NOF) also confirmed the high activity of H 2 SO 4 -CeO 2 /GF in activation of H 2 O 2 . The H 2 SO 4 -CeO 2 /GF was relatively stable, showing good application prospects. Acidified cerium oxide/GF composite (H 2 SO 4 -CeO 2 /GF) was prepared by impregnation. The activity of H 2 SO 4 -CeO 2 /GF for activation of H 2 O 2 is high even at pH 7.0. The catalyst of H 2 SO 4 -CeO 2 /GF is stable and has great potential for application. The role of acidification of sulfuric acid in the catalyst is explained.