Magnetic LDH-based CoO–NiFe2O4 catalyst with enhanced performance and recyclability for efficient decolorization of azo dye via Fenton-like reactions

Abstract

Abstract Magnetic CoO–NiFe2O4 catalyst was successfully fabricated from layered double hydroxide through a simple co-precipitation and calcination method, and for the first time applied as a novel Fenton-like catalyst for the decolorization of Eriochrome black T dye (EB). The characteristics results demonstrated that CoO–NiFe2O4 exhibits a broad pore size distribution in the range of 5–40 nm, large specific surface area (363.6 m2 g–1) with the high structural stability and saturation magnetization (83.2 emu g–1), hence, can be easily recycled for five subsequent runs without significant activity loss. The catalytic activity of CoO–NiFe2O4 was systematically evaluated under varying reaction conditions including initial pH, catalyst dosage, initial dye and H2O2 concentrations. Under the optimal conditions, the CoO–NiFe2O4 accomplished ∼87–97% decolorization of EB within 120 min. Here, the possible catalytic mechanism for EB decolorization is proposed and concluded to be multi-process induced by OH, O2− or h+ in the Fenton-like system.