Preparation of Ni and Fe doped molybdate-based catalyst from Ni-Fe layered double hydroxide for the catalytic wet air oxidation of dyes

We report a novel hybrid Ni and Fe doped molybdate-based catalyst as highly efficient catalytic wet air oxidation (CWAO) catalyst for dye degradation. The hybrid catalyst was synthesized from (NH4)6Mo7O24 in the presence of NiFe-NO3 layered double hydroxides (LDHs). The synthesized materials were carefully characterized using XRD, SEM and EDX analysis. It showed extremely high activity even at room temperature and atmosphere pressure for the degradation of cationic red GTL. With only 0.05 g catalyst, and 300 mL, 200 mg/L dye wastewater, 100% degradation efficiency could be achieved within 40 min at 30 °C and 1 bar. In view of practical applications, the influence of some key parameters including operation temperature and the volume of dye wastewater had been optimized. We also demonstrated that the hybrid material Na2Mo4O13/α-MoO3 plays a crucial role for the enhanced activity. Considering the facile preparation and its superior activity, this novel catalyst is promising for practical dye wastewater treatment.