Nanoporous TiO2 films grown in ethylene glycol-based media containing fluoride. Understanding the effect of early anodization stages on the morphology

MARTIN I. BROENS; WILKENDRY RAMOS CERVANTES; ANDRÉS M. ASENJO COLLAO ; RODRIGO A. IGLESIAS; MANUEL LÓPEZ TEIJELO; OMAR E. LINAREZ PÉREZ

JOURNAL OF ELECTROANALYTICAL CHEMISTRY

ELSEVIER

Lugar: Amsterdam; Año: 2023

0022-0728

n this work, we develop a phenomenological model describing the nanoporous TiO2film growth by titanium anodization in ethylene glycol-based electrolytes containingfluoride. The model considers ionic film growth in terms of the High-Field mechanism(HFM), electronic current contribution according to the Oxygen Bubble Mold (OBM)model and the film thinning by chemical dissolution. For the first time, the inclusion ofthe nucleation of oxygen bubbles as the rate determining step at early anodizationtimes is considered. By simultaneous fitting of the potentiostatic [[EQUATION]]profiles and the time evolution of morphological features such as pore radius, filmthickness and pores density, the behavior observed for several experimental conditionsis accurately described, in contrast to previously reported Field Assisted Dissolution(FAD) and OBM models. Additionally, the proposed model allows obtaining physicaland phenomenological information concerning the formation and growth of nanoporousoxide