Influence of Current Density on the Photocatalytic Activity of Nd:TiO₂ Coatings

Abstract

The Nd:TiO₂ PEO coatings were formed in a phosphate-based electrolyte with the addition of Nd₂O₃ under the current density of 150, 200, 250 and 300 mA/cm². SEM results showed that the micropores decreased on quantity and increased on scale with the increasing current density. AFM results revealed that the roughness of the coatings increased with the increasing current density. Phase and composition analysis showed that the Nd:TiO₂ coatings were mainly composed of anatase and rutile phase. And the anatase phase content has reached the maximum value at the current density of 250 mA/cm². XPS results indicated that Ti2p spin-orbit components of the Nd:TiO₂ coatings are shifted towards higher binding energy, compared with the pure TiO₂ coating, suggesting that some of the Nd³⁺ ions are combined with TiO₂ lattice and led to dislocation. Photocatalytic test showed that the photocatalytic activity of Nd:TiO₂ coatings varied in the same pattern with the anatase content variation in Nd:TiO₂ coatings. The photocatalytic experiment results show that the photocatalytic activity of Nd:TiO₂ coatings can be greatly enhanced with moderate amount of Nd³⁺. However, excessive amount of Nd³⁺ does not have an effective impact on the photoctalytic activity improvement.

Keywords

PEO / current density / AFM / XPS / Nd:TiO₂ / photocatalytic

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