# Applications of Ti/TiO2 nanotube arrays/CeO2@PbO2 and Ti/β-PbO2-CuOx electrodes for efficient electrocatalytic degradation of paraquat: cell design and comprehensive mechanistic studies

## TL;DR

Researchers developed and tested new electrode materials for efficiently breaking down the toxic herbicide paraquat through electrocatalytic processes.

## Contribution

The study introduces novel Ti/TiO2 nanotube arrays/CeO2@PbO2 and Ti/β-PbO2-CuOx electrodes for enhanced electrocatalytic degradation of paraquat.

## Key findings

- Ti/TiO2 nanotube arrays/CeO2@PbO2 electrodes showed better degradation efficiency than Ti/β-PbO2-CuOx electrodes.
- A degradation efficiency of 75% was achieved under specific conditions (pH = 7, current density = 7.8 mA cm−2, 50 ppm initial concentration).
- The study proposed a degradation mechanism based on intermediate species analysis using various spectroscopic techniques.

## Abstract

Ti/TiO2 nanotube arrays (NTA)/CeO2@PbO2 and Ti/β-PbO2-CuOx electrodes were used for the electrocatalytic degradation of paraquat (PQ2+), a highly toxic and widely used herbicide. The fabricated electrodes were characterized by XPS, SEM, EDS, mapping, XRD and EIS methods. The results show that the performance of the Ti/TiO2 nanotube in the electrocatalytic degradation of PQ2+ is better than that of the Ti/β-PbO2-CuOx electrode. This electrode increases the production of hydroxyl radicals and degradation efficiency. The results show that the highest degradation efficiency of 75% was achieved at pH = 7, a current density of 7.8 mA cm−2 and an initial concentration of 50 ppm. The intermediate species formed during the electrolysis of PQ2+ were analyzed based on cyclic voltammetry, UV-vis spectroscopy and LC-MS techniques, and a possible mechanism for the degradation of PQ2+ was proposed. In the second part of this study, the electrochemical behavior of PQ2+ was studied, gaining a deeper insight and understanding of the redox properties and adsorption activity of this molecule.

Ti/TiO2 nanotube arrays (NTA)/CeO2@PbO2 and Ti/β-PbO2-CuOx electrodes were used for the electrocatalytic degradation of paraquat (PQ2+), a highly toxic and widely used herbicide.