Colored Anodic Titania Thin Layers Involving Various Deep Eutectic Solvent Formulations-Evaluation of Corrosion...

Area of Science:

• Materials Science
• Electrochemistry
• Surface Engineering

Background:

• Titania (TiO2) thin films are crucial for various applications.
• Anodization is a common method for TiO2 film preparation.
• Deep eutectic solvents (DES) offer tunable properties for electrochemical applications.

Purpose of the Study:

• To investigate the preparation of colored anodic titania thin films using novel DES-based electrolytes.
• To analyze the influence of DES composition and anodization voltage on film color and morphology.
• To evaluate the corrosion performance of the prepared titania films in different aggressive media.

Main Methods:

• Anodization of titanium in various DES electrolytes (choline dihydrogen citrate-oxalic acid-ethylene glycol, choline chloride-oxalic acid, choline chloride-lactic acid) at voltages from 10-100 V.
• Characterization of film appearance, morphology, and color using the CIELAB system.
• Corrosion performance assessment via immersion tests in NaCl and Hank's solution, electrochemical impedance spectroscopy, and potentiodynamic polarization.

Main Results:

• Successful preparation of colored titania films with a chromatic scale ranging from golden to violet, dependent on applied voltage and DES.
• Films exhibited high brightness and color saturation.
• A nearly linear relationship was observed between oxide growth and anodization voltage.
• Corrosion performance varied significantly based on the electrolyte and the corrosive environment.

Conclusions:

• DES-based electrolytes are effective for producing colored anodic titania films with tunable optical properties.
• The anodization voltage is a key parameter controlling film color and growth.
• The corrosion resistance of titania films is influenced by the DES formulation and the nature of the corrosive medium.