Effect of matrix on the electrochemical characteristics of TiO2 nanotube array-based PbO 2 electrode for pollutant degradation

Hu, Zhongxin; Zhou, Minghua; Zhou, Lei; Li, Yunlin; Zhang, Chao

Effect of matrix on the electrochemical characteristics of TiO2 nanotube array-based PbO 2 electrode for pollutant degradation

2014

Hu, Zhongxin | Zhou, Minghua | Zhou, Lei | Li, Yunlin | Zhang, Chao

A series of lead dioxide electrodes developed on titania nanotube arrays with different matrix were fabricated by electrodeposition. Before the deposition of PbO₂, the matrix of this anode was electrochemically reduced in (NH₄)₂SO₄solution and/or pre-deposited with certain amounts of copper. To gain insight into these pretreatments, the PbO₂electrodes were characterized by SEM, LSV, and XRD, and their electrocatalytic activities for pollutant degradation were compared using p-nitrophenol (p-NP) as a model. It was confirmed that the electrochemical reduction with (NH₄)₂SO₄resulted in the partial conversion of TiO₂into Ti₄O₇and Ti₅O₉, which increased the conductivity of PbO₂anode, but decreased its electrochemical activity, while the Ti/TNTs*-Cu/PbO₂electrode with both pretreatments possessed the highest oxygen evolution overpotential of 2.5 V (vs. SCE) and low substrate resistance. After a 180-min treatment on this electrode, the removal efficiency of p-NP reached 82.5 % and the COD removal achieved 42.5 % with the energy consumption of 9.45 kWh m⁻³, demonstrating the best performance among these electrodes with different matrices. Therefore, this titania nanotube array-based PbO₂electrode has a promising application in the industrial wastewater treatment.

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