EFFECT OF ANNEALING TEMPERATURES ON THE CRYSTALLIZATION AND PHOTOCATALYTIC ACTIVITY OF MICRO-NANOPOROUS TiO2 FILMS PRODUCED BY ELECTROCHEMICAL ANODIZATION

Authors : Melis Yurddaskal, Metin Yurddaskal, Tuncay Dikici, Hülya Durmuş

Pages : 85-92

Doi:10.18596/jotcsa.370781

View : 162 | Download : 11

Publication Date : 2017-12-15

Article Type : Research Paper

Abstract :Normal 0 21 false false false TR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:`Table Normal`; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:``; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:`Calibri`,sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:`Times New Roman`; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;} In this study, micro-nanoporous TiO 2 films were prepared by electrochemical anodization of titanium insert ignore into journalissuearticles values(Gr-2); in an aqueous solution containing 0.5 wt. % HF solution at a constant potential of 30 V and then annealed in ambient air at 500, 600, 700 and 800 ° C for 2 h to obtain crystalline structures. The crystalline phase and surface morphology of the samples were characterized by X-ray diffraction insert ignore into journalissuearticles values(XRD); and scanning electron microscope insert ignore into journalissuearticles values(SEM);. The photocatalytic performances of the samples were evaluated by the photocatalytic degradation of aqueous methylene blue insert ignore into journalissuearticles values(MB); solutions under UV light illumination for different periods. XRD results indicated that at annealing temperatures higher than 600°C, anatase started to transform into rutile. Increasing annealing temperatures resulted in reduced micro-nanopores diameter and increased wall thickness. At 800 ° C, the structure completely disappeared. The results demonstrated that changes in both the crystalline structure and surface morphology have a strong influence on the photoactivity of the nanostructured TiO 2 films.
Keywords : Nanostructured TiO2, anatase, surface morphology, photocatalytic, methylene blue