Electrochemical synthesis of titanium dioxide nanostructures and its application in the in dye photocatalytic removal

Abstract

By electrochemical anodization to titanium sheets, titanium dioxide nanostructures were sintered for 10 V and 20 V and times of 3 hours and 5 hours. For the electrolytic solution, 0.3 g of ammonium fluoride, 97 mL of ethylene glycol and 3 mL of distilled water were used. The sheets (51 mm × 21 mm × 0.4 mm) were treated using abrasive paper and cleaned with a 1:1 solution of ethanol water by means of ultrasound and dried using hot air. A stirring frequency of 300 rpm was used during anodizing. For the sintering of the titanium dioxide anatase phase, heat treatment was applied at 550 °C for 3 hours by means of an electric muffle, with heating speed of 10 °C/min. The crystallinity index, and the quantification of the sintered phases was carried out by means of X-ray diffraction, while the nanoporosities and their distribution were carried out using imageJ software to the images taken by means of scanning electron microscopy. For the photocatalytic treatment of the methylene blue dye in water, the titanium dioxide nanostructures that reported the highest anatase phase were used, where ultraviolet C radiation from a led lamp was applied for 4 direct hours. The efficiency in the removal of the dye was studied by UV-Vis spectrophotometry, finding the highest degradation of the dye for the wavelength of 644 nm.