Enhanced removal of dye from wastewater by Fenton process activated by core-shell NiCo2O4@FePc catalyst

Abstract To achieve efficient degradation of dye in wastewater, the core-shell nickel cobalt spinel coated with iron phthalocyanine (NiCo2O4@FePc) catalyst was prepared via a facile template method and investigated as heterogenous catalyst for degradation of dye in Fenton process. The catalysts were systematically characterized by transmission electron microscopy (TEM), N2 adsorption/desorption isotherms, X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis. The results indicated that the NiCo2O4@FePc catalyst exhibits core-shell structure with abundant oxygen vacancies and high specific surface area (261.9 m2/g). NiCo2O4@FePc showed much higher catalytic activity for the mineralization of (TOC removal rate > 90%) RhB than nickel cobalt spinel (NiCo2O4), iron phthalocyanine (FePc) and the physical mixture of NiCo2O4 and FePc (NiCo2O4-FePc-M). The radical scavenging experiments and reaction kinetics experiments revealed that the excellent catalytic perormance of NiCo2O4@FePc benefits from the efficient production of •O2− and •OH radical. Moreover, the catalytic performance of NiCo2O4@FePc can be well maintained in the presence of inorganic anions (HCO3− and Cl−), natural organic matter or tap water. Besides, the liquid stability and resubility of NiCo2O4@FePc were demonstrated by filtration and recyling experiment. This work can provide new insight for construction of Fe-based heterogenous catalysts which are promising for the efficient elimination of organic pollutants.