A comparison study of TiO2 @ATO@MOx (TAM, M = Mn, Fe, Co, Ni, Cu, and Zn) electrodes on the electrochemical activity and stability

Antimony doped tin(IV) oxide (ATO) based materials are promising alternatives used in electrochemistry for water purification. However, their practical application remains a major bottleneck due to the drawback of poor stability. Therefore, we design a simple and viable strategy for preparing a series of TiO2 @ATO@MOx (TAM, M = Mn, Fe, Co, Ni, Cu, and Zn) electrodes. The oxygen evolution potential, electrode stability, and electrochemical activity toward methylene blue (MB) were studied and compared. When evaluated as electrode material toward methylene blue (MB) oxidation, TiO2 @ATO@NiO (TANi) exerts an excellent degradation efficiency and service lifetime; these are the highest values among these TAM electrodes. Cyclic voltammetry (CV) measurements demonstrated that NiO can effectively enhance roughness factor and voltammetric charge, indicating a large electrochemically active surface area and abundant electroactive sites. The addition of NiO effectively lowers the charge transfer resistance and enhances the electrode stability. Moreover, theoretical calculations based on the first-principle density functional theory (DFT) indicate that the conductive property of TAM is manipulated by MOx adding and thus an excellent electrochemical activity is achieved. Based on the experimental data and computational simulations, our work brings new important insights that will contribute to the development of high-performance and stable ATO-based electrode materials.