Electrochemical synthesis, structural features and photoelectrocatalytic activity of TiO2–SiO2 ceramic coatings on dye degradation

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Solid-state materials for advanced technology, 2015-08, Vol.198, p.62-73
• Main Authors: Mumjitha, M., Raj, V.
• Format: Article
• Language: English
• Subjects: Anodization; Anodizing; Ceramics; Coatings; Degradation; Dye degradation; Dyes; Electric potential; Nanostructure; PEC activity; Titanium dioxide; Voltage
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2015.03.020

•Titania–silica ceramic coatings were fabricated by anodization in a single step.•Fabrication conditions are optimized based on their photoelectrochemical activity.•The SiO2 incorporated TiO2 coating shows good photoelectrochemical activity.•Titania–silica coating can degrade methyl orange dye effectively within 70min. In this work, dome like TiO2–SiO2 ceramic nanostructures comprises of nanoflakes were successfully formed by anodization method on Ti surface using sodium hexafluoro silicate (SFS) electrolyte. The effects of electrolyte concentration and anodization voltages on the silica incorporation, microstructure and photoelectrocatalytic (PEC) performance of fabricated coatings were investigated and compared in details. The coating formed at 3% SFS concentration and 50V shows good morphology, better thickness with maximum PEC activity and higher oxygen evolution potential than titania and bare electrodes owing to the enhanced photogenerated electron–hole pairs separation. The PEC activity of the samples was evaluated by the degradation of methyl orange (MO) solutions for different periods of time. The removal efficiency was studied as a function of several operation variables, such as various coatings, dye degradation methods, applied voltages, initial dye concentration, initial pH values and chloride ions.