Photodecomposition of methylene blue over Dy³⁺ impregnated MAO TiO₂ films

ABSTRACT

TiO₂ films were formed in phosphate-based electrolyte on pure titanium by micro-arc oxidation (MAO) technology. After that, they were impregnated with Dy³⁺-containing electrolyte to produce TiO₂:Dy³⁺ composite films. Effects of the duty cycle, impregnation time and concentration on physical and chemical properties of TiO₂ and TiO₂:Dy³⁺ composite films were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). A UV-VIS spectrophotometer was used to study photocatalytic properties of both films. XPS results revealed that Ti 2p spin-orbit components of the TiO₂:Dy³⁺ composite film are shifted towards higher binding energy, with respect to the TiO₂ film, suggesting that some of the Dy³⁺ ions are incorporated into TiO₂ lattice. The TiO₂:Dy³⁺ composite films showed an obvious enhanced photocatalytic activity than that of the TiO₂ film under UV-irradiation.

KEYWORDS:

• Micro-arc oxidation
• TiO₂
• TiO₂:Dy³⁺
• impregnation
• photocatalytic activity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The financial aids of Research on Public Welfare Technology Application Projects of Zhejiang Province under grant number 2017C31039 and the National Natural Science Foundation of China under grant number 51275477 and number 61572438 are gratefully acknowledged.