Efficient degradation of p-nitrophenol by electro-oxidation on Fe doped Ti/TiO2 nanotube/PbO2 anode

• A novel Fe doped PbO2 electrode was prepared based on Ti/TiO2 nanotube arrays.
• It has high OEP and excellent performance for p-nitrophenol degradation.
• The effect of Fe doping on activity was investigated, and 0.02 M Fe was the optimal.
• After Fe doping, the p-NP degradation rate increased 4.3 times.
• It is promising for treating wastewater containing biorefractory organic pollutants.

A novel Fe doped PbO2 electrode with a high oxygen evolution potential (OEP) and excellent electrochemical oxidation performance was prepared based on Ti/TiO2 nanotube arrays (TNTs) for p-nitrophenol (p-NP) degradation. Characterized by scanning electron microscope (SEM), linear sweep voltammetry (LSV) and chronoamporometric experiments, the effect of Fe doping amount on the electrode activity was investigated. Fe doping on PbO2 electrode improved the electrode morphology, OEP, step current and thus the degradation of p-NP. The optimal Fe doped concentration was 0.02 M, and the electrode prepared under this condition possessed the highest OEP of 2.7 V and p-NP degradation performance. After 90 min treatment, the p-NP degradation efficiency reached 100% with similar energy consumption, and the reaction rate constant increased about 4.3 times compared with that of the unmodified one. This Fe doped Ti/TNTs/PbO2 anode has a more promising application potential in treatment of wastewater containing biorefractory organic pollutants.